°C
°F
2oo3
3LPP
A&C
A8
AA
AA
AAH CO
AAV
AB3™ Valve
Abandon[ment]
ABCB
ABD
ABOI
ABS
Absolute Pressure
Absorbed Dose
Absorption
Absorption Plant
ABT
ac
AC/H
ACB
ACC
Accept Button
Accident Frequency
Account
Accountable Person
Accumulator
Degrees Celsius
1°C = 5/9[°F-32]
Degrees Fahrenheit 1°F = 0.556 °C
Two out of three [voting]
3 Layer Polypropylene
Atlantic and Cromarty
Exposure over an 8 hour period
Area Authority
Asset Authority
Analyzer alarm high for carbon monoxide
Annulus Access Valve
Alpha Thames’ compact, quarter-turn rotary, parallel full-bore, double block and bleed, expanding plug valve
To cease efforts to produce oil or gas from a well, and to plug the wells of a depleted formation and salvage all material and
equipment OR final plugging of wells, and/or permanent dismantling, etc. of a production platform or other installation
Association of British Certification Bodies
As-Built Design
Association of British Offshore Industries
American Bureau of Shipping OR Acrylonitrile Butadiene Styrene [a hard, tough thermoplastic] [C8H8· C4H6·C3H3N]n
Gauge pressure plus atmospheric pressure, e.g. PSIA.
Quantity of energy imparted by Ionising Radiations to unit mass of matter such as tissue. The unit is the Gray [Gy] 1 Gy = 1
Joule per Kilogram [1 J/Kg]
To soak up as a sponge takes water. It is the ability of a gas, liquid or solid to attract and retain another substance without
chemical combination.
A quantity of such a substance that has absorbed as much of another as is physically possible is said to be saturated with it.
Some refinery processes use this ability, for instance to separate different hydrocarbons.
ALSO The penetration or apparent disappearance of molecules or ions of one or more substances into the interior of a solid or
liquid.
For example, in hydrated bentonite, the planar water that is held between the mica-like layers, is the result of absorption. In a
contacting tower, glycol absorbs water vapour present in natural gas. [See also adsorption].
An oil field facility that, applying the absorption principle, removes water and liquid hydrocarbons from natural gas.
Annulus Bore Test
Alternating current
Air changes per hour
Air Circuit Breaker
Annulus Choke – Closed
Provided where the user is required to make a decision to accept a conclusion for instance a Level 2 Task Risk Assessment
A calculation which gives the predicted number of accidents per 1,000,000 man hours worked.
An environment on a computer system which defines the functionality a user has on that system.
The person in the organization who has ultimate responsibility.
A pressure vessel charged with nitrogen gas and used to store hydraulic fluid under pressure for the operation of hydraulic
valve actuators.
Page 1 of 310
Accumulator
Acetone
ACFM
Acid
Acid Gas
Acidizing
ACO
ACoP
Acoustic Log
Acoustic Re-entry
Acoustic Well Sounder
ACQ
Acre-foot
ACRON
Active Monitoring
Activities
ACTS
Acts [various]
Actuator
Acute
Condensed overhead vapours from distillation columns collect in vessels called accumulators. These keep the tower
functioning smoothly and prevent tower fluctuation from downstream equipment. Hence surge residence time is the basic
design factor in designing vessels for this type of service.
Acetone CH3COCH3 is made by dehydrogenation of isopropyl alcohol. It is a colourless stable liquid with a high rate of
evaporation and a boiling point of 56.50C.
Alternating Current Field Measurement
Any chemical compound containing hydrogen capable of being replaced by positive elements or radicals to form salts. Acids
lower the pH. Examples of acids or acidic substances are: hydrochloric acid, tannic acid, sodium acid pyrophosphate.
Acid gas is natural gas or any other gas mixture which contains significant amounts of hydrogen sulphide [H2S], carbon
dioxide [CO2], or similar contaminants. Although the terms acid gas and sour gas are used interchangeably, strictly speaking,
a sour gas is any gas that contains hydrogen sulphide in significant amounts. Whereas an acid gas is any gas that contains
significant amounts of acidic gases such as carbon dioxide [CO2] or hydrogen sulfide. Thus, carbon dioxide by itself is an acid
gas but it is not a sour gas.
The treatment of formations with hydrochloric or other acids in order to increase production or injection.
Annulus Choke - Open
Approved Code of Practice
A type of porosity log, which records the time taken by an acoustic wave to travel over a certain distance through the
geological formations, Also called Sonic log.
A method used in deep-water operations offshore to reposition a drill ship over a borehole previously drilled and cased. The
technique employs acoustic signals to locate the pipe and guide the ship into position.
An instrument for the determination of the fluid level in the casing of a pumping well. Fluid level is determined by discharging a
blank cartridge in a special fitting connected to the casing, converting the resulting sound echoes into electric pulses which are
recorded, after amplification, on a Strip chart.
Annual contract quantity [UK gas sales]
Unit used to measure the rock volume of an oil or gas reservoir structure.
Atlantic and Cromarty Reservoir Operation Notice
Active Monitoring is the process of critically reviewing a task being undertaken to ensure that the personnel undertaking the
task have recognised the hazards inherent in the task and have taken appropriate actions to prevent, control or mitigate these
hazards.
Specific actions or pursuits.
Advisory Committee on Toxic Substances
The Health and Safety at Work etc. Act, 1974.
The Wireless Telegraphy Act 1949 to 1967.
Offshore Installations & Pipeline Works (Management & Administration) Regs 1995 (MAR) SI 738
Offshore Installations (Prevention of Fire & Explosion, and Emergency Response) Regs SI 743
Lifting Operations and Lifting Equipment Regulations 1998 SI 2307
Manual Handling Operations Regulations 1992 SI 2793
Provision and Use of Work Equipment Regulations 1998 SI 2306
North of Scotland Water Authority Sewerage (Scotland) Act 1968
A [hydraulic or electrical] device for the remote and/or automatic operation of a valve or choke.
Of short duration.
Page 2 of 310
AD
ADELT
Adiabatic Process
Administrator
ADS
Adsorption 1
Adsorption 2
ADT
AEGC
AEP
Aeration
ÆSOP™
AFC
AFCP
AFD
AFE
AFFF
AFGO
AFM
AFP
AFP
AGA
AGAS
Agglomerator
Aggregate
Automatic Drain
Automatic Deployable Emergency Locator Transmitter [helicopter] - normally found on the tail section, starboard side.
A process without heat entering or leaving the system - no heat exchange with the surroundings.
Work Activity Management System [WAMS] Administrator able to input / edit and assign password to Users and perform
some system configuration.
Atmospheric Diving System.
The attraction exhibited by the surface of a solid for a liquid or a gas when they are in contact, without absorbing the liquid or
gas.
A process that occurs when a gas or liquid solute accumulates on the surface of a solid or, more rarely, a liquid [adsorbent],
forming a molecular or atomic film [the adsorbate].
It is different from absorption, in which a substance diffuses into a liquid or solid to form a solution.
The term 'sorption' encompasses both processes, while desorption is the reverse process. Adsorption is operative in most
natural physical, biological, and chemical systems, and is widely used in industrial applications such as activated charcoal,
synthetic resins and water purification.
Adsorption, ion exchange and chromatography are sorption processes in which certain adsorptives are selectively transferred
from the fluid phase to the surface of insoluble, rigid particles suspended in a vessel or packed in a column.
Similar to surface tension, adsorption is a consequence of surface energy.
In a bulk material, all the bonding requirements [be they ionic, covalent or metallic] of the constituent atoms of the material are
filled. But atoms on the (clean) surface experience a bond deficiency, because they are not wholly surrounded by other atoms.
Thus it is energetically favourable for them to bond with whatever happens to be available.
The exact nature of the bonding depends on the details of the species involved, but the adsorbed material is generally
classified as exhibiting physisorption or chemisorption.
Advanced Drilling Techniques
Assured Equipment Grounding Conductor
Authorised Electrical Person
Blower process of forcing air bubbles into a pool of liquid
All-Electric Seabed Oil/Gas Processing. Alpha Thames’ prototype System-Module™ for use in an AlphaCPU™
Approved for Construction [or fabrication]
Auxiliary Fire Control Panel
Approved for Design
Approved for Enquiry [or Expenditure]
Aqueous Film-Forming Foam see AR-AFFF
Auxiliary Fire and Gas Annunciator Panel
Approved For Manufacture
Active Fire Protection
Approved For Purchase OR Active Fire Protection
American Gas Association
Associated Gas [Compressor]
Entrained small liquid droplets in gas are coalesced by an Agglomerator, which is comprised of a knitted wire mesh or vane
pack, and forms larger droplets.
A group of two or more individual particles held together by strong forces. Aggregates are stable to normal stirring, shaking, or
handling as powder or a suspension. They may be broken by drastic treatment such as ball milling a powder or by shearing a
suspension.
Page 3 of 310
AGSO
AGT
AH
AHTS
AHV
AI
AIC
AIDS
AIM
AIP
AISC
AISI
AIT
ALARP
Aliphatic hydrocarbons
Aliphatic hydrocarbons
Alkalinity
Alkanes
Alkylation
Alluvial fan
AlphaCPU™
AlphaPRIME™
ALQ
Australian Geological Survey Organisation
Authorised Gas Tester
Along Hole
Anchor Handler Tug Supply [Vessel]
Anchor Handling Vessel.
Analogue Input
Anti-surge Indicating Controller
Auto Immune Deficiency Syndrome
Analogue Input Module
Australian Institute of Petroleum
American Institute of Steel Construction
American Iron and Steel Institute
Auto Ignition Temperature
As Low [risk] As Reasonably Practicable
A group of hydrocarbon substances, including the alkanes and most of the other fractions found naturally in crude oil.
Annual Limit of Intake. For oral intake and inhalation, the ALI is the lowest activity of the specific radionuclide taken into the
body that would give rise to an effective dose of 20 mSv/y to a particular organ or tissue.
The combining power of a base measured by the maximum number of equivalents of an acid with which it can react to form a
salt. In water analysis, it represents the carbonates, bicarbonates, hydroxides, and occasionally the borates, silicates and
phosphates in the water. It is determined by titration with standard acid to certain datum points.
Naturally occurring paraffin fractions of which the molecules are based on a “straight chain” of hydrogen; saturated carbon
atoms. Alkanes are chemical compounds that consist only of the elements carbon [C] and hydrogen [H] [i.e. hydrocarbons],
where each of these atoms are linked together exclusively by single bonds [i.e. they are saturated compounds] without any
cyclic structure [i.e. loops]. Alkanes belong to a homologous series of organic compounds in which the members differ by a
constant relative atomic mass of 14.
A refining process used to produce improved gasoline components with, for instance, lower pollutant effects. The process is
also used in the manufacture of plastics.
A pattern of sedimentary deposit frequently laid down by streams or rivers where they spread out into plains. Alluvial fans from
past geological eras are potential reservoir structures.
The AlphaCPU™ [Central Processing Unit] is a diverless, seabed, modular, processing system for the production of
hydrocarbons, which forms the heart of an AlphaPRIME™ developed field. It comprises a foundation system, KeyMAN™ and
a minimum of two System-Modules™. It utilises all-electric power and control for maximum efficiency and reliability. This
ensures its suitability for all field developments including deepwater applications and those requiring long tie-backs.
Alpha Thames’ incremental field development solution for the production and processing of subsea hydrocarbons. It provides
field control from reservoir to host, and can evolve to meet all future requirements.
Additional Living Quarters
Page 4 of 310
Aluminium
AM
Am3/hr
Amines
AMV
Anchor Seal Assembly
Angular accuracy
Anhydrous
Anion
Annealing
Annular space
Annulus
Anode
Anomaly
Anoxia
ANP
A silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13. It is
not soluble in water under normal circumstances. Aluminium is the most abundant metal in the Earth's crust, and the third
most abundant element therein, after oxygen and silicon. It makes up about 8% by weight of the Earth’s solid surface.
Aluminium is too reactive chemically to occur in nature as the free metal. Instead, it is found combined in over 270 different
minerals. The chief source of aluminium is bauxite ore.
Aluminium is remarkable for its ability to resist corrosion [due to the phenomenon of passivation] and its low density. Structural
components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of
transportation and building. Its reactive nature makes it useful as a catalyst or additive in chemical mixtures, including being
used in ammonium nitrate explosives to enhance blast power.
Amplitude Modulation
Actual Cubic Meters per Hour
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are
derivatives of ammonia, wherein one or more hydrogen atoms are replaced by organic substituents such as alkyl and aryl
groups.
Compounds with the nitrogen atom next to a carbonyl of the structure R-C[=O]NR2 are called amides and have different
chemical properties. Important amines include amino acids, biogenic amines, trimethylamine [fish smell], and aniline.
Aqueous monoethanolamine [MEA], diglycolamine [DGA], diethanolamine [DEA], diisopropanolamine [DIPA] and
methyldiethanolamine [MDEA] are widely used industrially for removing carbon dioxide [CO2] and hydrogen sulphide [H2S]
from natural gas streams and refinery process streams.
They may also be used to remove CO2 from combustion gases / flue gases and may have potential for abatement of
greenhouse gases.
Annulus Master Valve
A packer seal assembly with a threaded latch sleeve which matches the left hand square top thread of a permanent packer.
By latching onto the packer, the tubing is anchored to the packer. The anchor seal assembly can be released from the packer
by right-hand rotation of the tubing.
The measure of shaft positioning accuracy on a servo or stepping motor.
Without water.
A negatively charged ion; an ion that is attracted to the anode during electrolysis. Compare cation.
A heat treatment of steel. The steel -f-s heated above a critical temperature and cooled very slowly (usually in a furnace). The
treatment is done mainly for the following purposes: to remove stresses; to induce softness; to alter ductility, toughness,
electric, magnetic or other physical and mechanical properties; to change the crystalline structure; to remove gases.
The ring-shaped cavity between two concentric tubes OR the space around a pipe in a wellbore, the outer wall of which may
be the wall of either the borehole or the casing; sometimes termed the annulus.
Also called the annular space [see above]. The ring-shaped cavity between two concentric tubes, e.g. inner and outer strings
of casing, or between casing, or drill pipe, and the well borehole.
A block of non-ferrous metal connected to or buried near a pipeline, storage tank, or other facility and connected to the
structure to be protected. The anode sets up a weak electric current that flows to the structure thus reversing the flow of
current that is associated with the corrosion of iron and steel. Also An electrically positive electrode, see sacrificial anode.
A deviation from the norm. In geology, the term indicates an abnormality such as a fault or a dome in a sedimentary bed.
A total decrease in the level of oxygen in the tissues - an extreme form of Hypoxia.
National Petroleum Agency [Brazil]
Page 5 of 310
ANSI
Anticlinal trap
Anticline
Anticline
Antifoam
AO
AO
AOC
AOCC
AODC
AOF
AP
APAU
API
API gravity
APIA
Apparent Viscosity
Application
Appraisal well
Approved Key Control System
Apron ring
Apron spreader
APSD
APT
Aquagel
Aquifer
AR-AFFF
Archive
Archive State
American National Standards Institute
A hydrocarbon trap in which petroleum accumulates in the top of an anticline. See anticline.
A fold in layered rocks in which the strata are sloping down and away from the axis, like the roof of a house. Opposite:
Syncline.
An arched, inverted-trough configuration of folded and stratified rock layers. [Compare with syncline.]
An antifoam is a substance which prevents [suppresses] the formation of foam by acting to reduce the surface tension at the
interface between gas bubbles and the surrounding liquid. They will cause irritation of the eyes and skin on contact.
Analogue Output
Asset Owner
Air Operators Certificate
Aberdeen Operations Co-ordination Centre [defunct]
Association of Offshore Diving Contractors [became International AODC [IAODC] now part of IMCA]
Absolute Open Flow potential
Annulus Pressure
Accident Prevention Advisory Unit [of HSE]
American Petroleum Institute
The standard adopted by API for measuring the density of a liquid, [especially hydrocarbons] expressed in degrees. It can be
converted from specific gravity by the following equation: Degrees API gravity = [141.5/specific gravity @ 60°F] - 131.5
Australian Pipeline Industry Association
The viscosity a fluid appears to have on a given instrument at a stated rate of shear. It is a function of the plastic viscosity and
the yield point. The apparent viscosity in centipoises, as determined by the direct – indicating viscometer is equal to 1/2 the
600-rpm reading. See also Viscosity, Plastic Viscosity, and Yield Point . In a Newtonian fluid, the apparent viscosity is
numerically equal to the plastic viscosity.
A computer program or suite of programs
A well drilled to further confirm and evaluate the presence of hydrocarbons in a reservoir that has been found by a wildcat well.
Also The first wells to be drilled after oil and/or gas has been discovered by a discovery or wildcat well, in order to establish
the limits of the oil or gas - reservoir, the productivity of wells in it, and oil or gas properties. Also A well drilled to confirm the
size or quality (commercial potential) of a hydrocarbon discovery. Before development, a discovery is likely to need at least two
or three such wells.
A system which is clearly defined for the safe‑keeping of all keys for locking off electrical equipment subject to the permit
system. The preferred system is a Lockout Box into which all keys used for locking off equipment subject to the permit system
are placed. The key(s) for the Lockout Box is/are then kept by the person to whom the permit is issued.
The first or lowest ring of plates in a tank.
A flat plate in the bottom of a tank that causes fluid coming into-the tank to spread out.
Abandon Platform Shut Down
Annulus Pressure Transducer
A specially prepared bentonite [clay] widely used as a conditioning material in drilling mud.
A water-bearing rock strata. In a water-drive field, the aquifer is the water zone of the reservoir underlying the oil zone.
Alcohol Resistant Aqueous Film-Forming Foam
A record of all completed permits and associated Certificates to be retained on the Installation for a period of six months.
A WCC where the task has been completed, all the controls have been removed and no further actions are required is moved
into the Archive State by the Area Authority.
Page 6 of 310
Area Authority
Area Display Board
Area Filter
Areometer
ARL
Aromatic hydrocarbons
Aromatics
ARPA
ARRC
Articulated platform
Artificial drive
Artificial lift
ARV
AS
ASA
ASL
ASME
ASNT
ASP
Asphalt
Asphalt based crude
ASRP
Assess
The person responsible for the supervision of designated Installation areas and who is appointed to Authorise Work Permits.
A board located prominently at specified locations used to display active Work Control Certificates and associated certificates
related to a specific area.
This defines the Area on the installation that is concerned with the work. A list of all available areas is defined within the
system
An instrument for measuring the specific gravity of liquids, a hydrometer.
Atlantic Resourcing Limited
The group of hydrocarbon products which include benzene, toluene, etc. and provide feedstocks for many of the main
petrochemical processes, as well as high octane rating gasoline blends. So-called from their “sweet” smell.
A group of hydrocarbons characterised by their having at least one ring structure of six carbon atoms, each of the latter having
one valency outside the ring. If these valencies are occupied by hydrogen atoms, hydrocarbon radicals, or anorganic groups
one speaks of mono-aromatics.
If part, or all of the valencies form other carbon atom rings one speaks of condensed aromatics. These hydrocarbons are
called aromatics because many of their derivatives have an aromatic odour.
They are of relatively high specific gravity and possess good solvent properties.
Certain aromatics have valuable anti-knock characteristics.
Typical aromatics are: benzene, toluene, xylene, phenol (all mono-aromatics) and naphthalene [a di-aromatic].
Automatic Radar Plotting Aid
Australian Resources Research Centre [Perth, Australia]
A semi-buoyant structure anchored to the seabed by means of a “Universal” joint coupling which allows it to “sway” with the
Methods of producing oil when natural reservoir pressures are insufficient or have declined, such as injection of gas or water
Any method used to raise oil to the surface through a well after reservoir pressure has declined to the point at which the well
no longer produces by means of natural energy. Sucker rod pumps, gas lift, hydraulic pumps, and submersible electric pumps
are the most common forms of artificial lift.
Annular Reverse Valve
Air Supply
American Standards Association OR Advanced Safety Audit
Approved Supplier List
American Society of Mechanical Engineers. ASME International.
American Society of Non-destructive Testing
Alkaline Surfactant Polymer. In the Alkaline Surfactant Polymer [ASP] process, a very low concentration of the surfactant is
used to achieve ultra low interfacial tension between the trapped oil and the injection fluid/formation water. The ultra low
interfacial tension also allows the alkali present in the injection fluid to penetrate deeply into the formation and contact the
trapped oil globules. The alkali then reacts with the acidic components in the crude oil to form additional surfactant in-situ,
thus, continuously providing ultra low interfacial tension and freeing the trapped oil. In the ASP Process, polymer is used to
increase the viscosity of the injection fluid, to minimize channeling, and provide mobility control.
A solid petroleum residue, similar to bitumen, tar and pitch.
Crude oil containing very little paraffin wax and a residue primarily asphaltic. Sulphur, oxygen and nitrogen are often relatively
high. This type of crude is particularly suitable for making high-quality gasoline, lubricating oil, and asphalt. See Paraffin-base
crude .
Activity Safety Review Panel
To consider and make a judgment upon.
Page 7 of 310
ATW
The buildings, plant, machinery and other permanent items required by the user to produce and supply the product..
Assistant
Natural gas which is in contact with crude oil in the reservoir or which is dissolved in the oil.
A guarantee, giving certainty.
Annulus Subsurface Safety Valve
American Society for Testing and Materials
Automatic Synchronising Unit
Annulus Swab Valve
Annular Safety Valve
Air Traffic Control
Atmopheres Explosif [French]
Smallest particle of matter which can enter into chemical combinations. In basic terms, consists of a nucleus formed from
The Atomic Number [Z] of an atom indicates the number of protons in the nucleus and identifies the element uniquely.
The relative weight of an atom of an element as compared with the weight of I atom of oxygen, using 16 as the weight of 1
atom of oxygen.
Auxiliary Temporary Safe Refuge
All Terrain Vehicle. A single-seat vehicle with three or more wheels, a seat that has to be straddled, and has handlebars for
steering.
Authorisation to Work
Audit
Structured review of areas of the business to verify whether activities and relate results comply with planned arrangements.
Asset
ASSIS
Associated gas
Assurance
ASSV
ASTM
ASU
ASV
ASV
ATC
Atex
Atom
Atomic Number
Atomic Weight
ATSR
ATV
Audit
Audit
Auditee
Auditing
Auditor
Authorised Electrical Person
Authorised Gas Tester
Authorised Permits
Authorised Person
Authorised State
Authority
Authority Delegations
AUV
A documented investigation conducted by the company to verify that the procedures applicable to the success of our business
are being complied with.
Systematic assessment of the adequacy of the Petrofac Production Service Management System to achieve it’s defined
purpose, carried out by persons who are sufficiently independent of the system [but who may be employed by Petrofac
Production Services to ensure that such assessment is objective.
Project, Department, Organisation or individual to be audited
A formal or official examination and verification. The audit process should include monitoring, review, and reporting of the
outcome of the audit to those people who can implement any changes needed.
A person who is familiar with and knowledgeable about the Work Activity Management System who reviews WCC’s, ICC’s and
Workpacks in the system and there associated tasks to verify that they are being carried out in accordance with the company
procedures. The findings of Auditors will be formally recorded and retained in the WAMS system.
The person authorised by the RPE to ensure that all electrical work is undertaken safely and professionally.
A person who has been trained and is competent to an authorised level to test for all types of gases.
A Work Permit which has been Authorised for work, but which has not yet started.
The person who is stated in the Authority Delegations as having financial authority to approve the commitment of expenditure
at a particular level.
A WCC that has been checked and authorised to move from the Pending State to the Authorised State by the appropriate
authority. In this state it can be issued and go Live. Depending on the type of WCC some will require two levels of
authorisation.
a. Official permission. b. A position that has the power to make a judgement; an individual cited or appealed to as an expert.
States the individual levels of authority for making commitments.
Autonomous underwater vehicle
Page 8 of 310
AVB
AVr
AVR
AW
AWG
AWS
AWV
Azimuth
A report that is generated from the personnel system which details availability of current and/or ex and/or potential employees
by trade discipline, geographic area or certification requirements as necessary.
Atmospheric Vacuum Breaker. A backflow prevention device used in plumbing to prevent backflow of non-potable liquids into
Amps Volts reactive
Automatic Voltage Regulator (regulation)
Application Workstation Processor
American Wire Gauge
American Welding Society
Annulus Wing Valve
Geology: The angle between the vertical projection of a line of interest onto a horizontal surface and true north or magnetic
Azimuthing thrusters
Rotatable ducted propeller used in conjunction with a DPS to enable ships to maintain position without the use of anchors.
B/D
BA
Blow Down
Breathing Apparatus
A soft, silver-coloured metal alloy of relatively low melting point used for engine and pump bearings, an alloy containing tin,
copper and antimony.
Moves from the present location back to a previous stage [the opposite to Next button].
The voltage generated when a permanent magnet motor is rotated. This voltage is proportional to motor speed and is present
regardless of whether the motor winding[s] are energised or de-energised.
In drilling, to pull the drill-string out of, or partly out of, the borehole to unscrew a joint of drillpipe or to slacken off a line or
block.
Limited ventilation can lead to a fire in a compartment producing fire gases containing significant proportions of partial
combustion products and unburnt pyrolysis products. If these accumulate then the admission of air when an opening is made
to the compartment can lead to a sudden deflagration. This deflagration moving through the compartment and out of the
opening is a Backdraught.
A copy of data from computer systems which can be used to restore any loss in the integrity of that data.
Breathing apparatus controller
Banks Automated Clearing System
A special casing collar with a reduced bore which serves as a stop for the bottom-cementing plug. Usually installed 30 or 60
feet above the casing shoe.
Plates or obstructions built into a tank or other vessel that change the direction of the flow of fluids.
A long cylindrical container, fitted with a valve at its lower end, run on wire-line, used to remove water, sand, mud and oil from
a well.
A beam-type balance used in determining mud density. It consists primarily of a base, graduated beam with constant- volume
cup, lid, rider, knife-edge and counterweight.
A connector in-a subsea, marine riser assembly whose ball and socket design permits an angular deflection of the riser pipe
caused by horizontal movement of the drillship or floating platform of 10* or so in-all directions.
For ships: water taken onboard specific tanks in ships to permit proper angle of response of the vessel in the water, and to
assure structural stability. For mobile offshore drilling rigs: weight added to make the rig more seaworthy, increase draft, or
sink it to the seabed. Seawater is used for ballast, but sometimes concrete or iron is used additionally to lower the rig’s centre
of gravity permanently.
The fouling of a rotary drilling bit in, sticky, gumbo-like shale which causes a serious drag on the bit and sometimes loss of
circulation.
Availability Listing
Babbitt
Back Button
Back EMF
Back off
Backdraught
Backup
BACO
BACS
Baffle collar
Baffles
Bailer
Balance, mud
Ball joint
Ballast
Balling of the bit
Page 9 of 310
Bandwheel
Banksman
bar
bar[a]
bar[g]
bara
Barefoot completion
barg
Barite
Barite, Barytes or heavy spar
Barityse
BarOmega
Barrel
Barrel equivalent
Barrelage
Base
Base sedimant
BASEEFA
Basement rock
Basicity
Basin
Basket
BAT
Bathymetry
Batter
In a cable tool rig, the large vertical wheel that transmits power from the drilling engine to the crank and pitman assembly that
actuates the walking beam. Used in former years in drilling with cable tools. Old pumping wells still use a bandwheel.
Person with a responsibility for safely directing the crane by hand or radio signals. Only one person should signal the crane –
unless in an emergency.
Unit of Pressure = 100 000 Pascal
Bar Absolute
Bar Gauge
bar, absolute pressure
A completion method in which the casing is cemented down to a point immediately above the producing formation and the
productive layer is left unsupported. Also called Open-hole completion.
bar, gauge pressure
A very heavy substance used as a main component of drilling mud, to increase its density [mud weight] and counter-balance
downhole pressures.
Natural barium sulphate used for increasing the density of drilling fluids. If required, it is usually upgraded to a specific gravity
range of 3.8 - 4.2.
Heavy rock used for rock-dumping
Baroid’s [osmotic membrane efficiency generating aqueous] “green mud” drilling fluid
A quantity of 42 US Gallons [34.97 UK Gallons]. The traditional unit of measure of oil volume. 1m³ oil = 6.29 barrels of oil.
A laboratory unit used for evaluating or testing drilling fluids. One gram of material, when added to 350 ml of fluid is equivalent
to 1lb of material when added to one 42-gal barrel of fluid.
A term for oil flow quantity measured by volume.
A compound of a metal, or a metal-like group, with hydrogen and oxygen in the proportion to form an OH radical, which
ionises in aqueous solution to yield excess hydroxyl ions. Bases are formed when metallic oxides react with water. Bases
increase the pH. Examples are caustic soda and lime.
Impurities and foreign matter contained in oil produced from a well.
British Approvals Service for Electrical Equipment in Flammable Atmospheres
Igneous or metamorphic rock lying below the sedimentary formations in the earth’s crust. Basement rock does not usually
contain petroleum deposits. (Hydrocarbons have been found in fractured basement rocks in Venezuela).
pH value above 7. Ability to neutralise, or accept protons from acids.
A synclinal structure in the subsurface, once the bed of a prehistoric sea. Basins, composed of sedimentary rock, are
regarded as good prospects for oil exploration.
A hollow tool used to retrieve junk from the well when fishing. The name is also sometimes given to the birdcage. OR Open
framed “Basket” used for lowering/raising small components to the seabed.
Best Available Techniques.
The measurement of ocean depth and the study of floor topography.
The inward slope of the legs of a steel platform for stability so that the base of the jacket covers a larger area than at deck
level.
Page 10 of 310
Baume Scale
bbl
bbl
bbl/d
bbl/d
bbls
bboe
BC
BCD
BCF
bcf
bcpmm
BD
bdo
bdpd
BE
Bead
Bean
Becquerel
Bell nipple
Benching
Benthic
The Baumé scale is a pair of hydrometer scales developed by French pharmacist Antoine Baumé in 1768 to measure density
of various liquids.
One scale measures the density of liquids heavier than water and the other, liquids lighter than water. At 20°C, the relationship
between specific gravity (relative density) and degrees Baumé is: For liquids heavier than water: s.g. = 145 ÷ (145 - degrees
Baumé).
For liquids lighter than water: s.g. = 140 ÷ (degrees Baumé + 130). An older version of the scale for liquids heavier than water,
at a reference temperature of 15.5 °C, uses 144.32 rather than 145.
Baumé degrees (heavy) originally represented the percent by mass of sodium chloride in water at 60 degrees Fahrenheit (15.5
°C).
Baumé degrees (light) was calibrated with 0°Bé (light) being the density of 10% NaCl in water by mass and 10°Bé (light) set to
the density of water.
Because of vague instructions or errors in translation a large margin of error was introduced when the scale was adopted.
The API gravity scale is a result of adapting to the subsequent errors from the Baumé scale.
The Baumé scale is related to the Balling, Brix, Plato and 'specific gravity times 1000' scales. The Baumé scale is sometimes
used by US brewers.
barrel [of oil]
barrel[s]
barrels per day
barrel[s] of oil per day [see also Mbbl/d and MMbbl/d]
Barrels
Billion barrels of oil equivalent
Barrels of Condensate OR Bottom Choke
Bolt Circle Diameter
Bromochlorodifluoromethane [Halon 1211 - extinguishant hand held appliances]
billion cubic feet [109]
Barrels of condensate per million [cubic feet]
Business Development or Basis of Design
Barrels of diesel oil
Barrels of distillate per day
Bevel End
The fused metal resulting from a welding operation or “pass” in a major weld, as in a pipeline. There are normally three, the
root or stringer bead, the filler bead and the cap bead.
The orifice in a flow control or choke valve. To “bean up” or “bean down” means to install a larger or smaller orifice, or to open
or close a variable valve. See choke.
SI unit of radioactivity. Defined as the occurrence of one atomic disintegration per second within the isotope [Bq].
Receptacle attached to the top of a BOP or marine drilling riser which directs the drilling mud returns to the shale shaker or
mud pits. A large swage nipple for attaching casing head fittings to the well's casing above the ground or at the surface. Also
The ball nipple is threaded on the casing end and has a plain or weld-end to take the casing head valves. The flow conduit
above the BOP stack, which has a belled out top section to allow easy passage of the bit. A flared out nipple screwed on the
bottom of the tubing string to facilitate re-entry of wire-line tools into the tubing.
A method of protecting employees from cave-ins by shaping the sides of an excavation to form one or a series of horizontal
levels or steps, usually with near-vertical surfaces between levels
Relating to organisms that are attached to, or resting on, the bottom sediments.
Page 11 of 310
Bentonite
BEP
BES
BFC
BFS
BGU
BH
BHA
BHA
BHAB
Bhp
BHP
Bid
Bid Analysis
Bid Analysis Summary
Bid Clarification Meeting
Bid Opening Form
Billion
Bioaccumulate
Biocide
Biogenic
Biomagnify
Bipolar chopper driver
Bit [drill]
Bit nozzle
A colloidal clay that swells when wet. Bentonite (silicate of Ca, Mg and Al with H20) is the basis of most drilling mud and
imparts gel-forming properties. See Mud.
Best Efficiency Point.
Bid Evaluation Strategy
Bulk Foam Carrier
Ball Float Shutoff. Liquid separator device that cuts off vacuum and airflow if liquid level exceeds collector capacity
Break Glass Unit
Bottom Hole
Bottom-hole assembly. This includes the drilling bit, drill collars, stabilizers and other drilling components run into the well on
the end of the drillpipe. See Drill String.
Bottom Hole Assembly
British Helicoptor Advisory Board
Brake horse power - The power output of a driver as measured against a calibrated load, such as a friction brake or
dynamometer. This is an actual measure of the available power of a driver of any type, engine or turbine or motor as all
internal losses before the coupling don't have to be estimated. In American terminology also refers to the power input at the
shaft of a driven machine, not strictly correct.
Bottom Hole Pressure
A Bid is a Supplier's presentation of their offer in response to the Enquiry
A Bid Analysis is a detailed technical and commercial assessment of the various Bids received
A Bid Analysis Summary [BAS] is a document which records the results and recommendations on the Bids received
Meeting held with prospective Supplier[s] to discuss their Bid prior to making any recommendation to Client. At this stage of
the negotiations, Supplier selection has not been made and therefore, the discussions are confidential
A Bid Opening form is a form used to record the initial data gleaned from bids at the time of Bid opening. It is usually only used
as a part of a Sealed Bid procedure.
In oil and gas usage, a billion means 109 not 1012. One billion cubic feet [bcf] = one thousand million cubic feet.
The increasing concentration of compounds within fauna such as limpets, oysters and other shellfish.
A chemical toxic or lethal to living organisms.
Produced by the action of living organisms.
Increase in toxicity within a species.
A class of step motor driver which uses a switch mode [chopper] technique to control motor current and polarity. Bipolar
indicates the capability of providing motor phase current of either polarity [+ or -].
The cutting or boring element used in drilling oil and gas wells. The bit consists of a cutting element and a circulating element.
The circulating element permits the passage of drilling fluid and utilises the hydraulic force of the fluid stream to improve
drilling rates. In rotary drilling, several drill collars are joined to the bottom end of the drill pipe column, and the bit is attached to
the end of the string of drill collars. Most bits are used in rotary drilling are roller cone bits, but diamond bits are also used
extensively.
The part of the bit that includes a hole or opening for drilling fluid to exit. The hole is usually small [around 0.25 in. in diameter]
and the pressure of the fluid inside the bit is usually high, leading to a high exit velocity through the nozzles that creates a highvelocity jet below the nozzles. This high-velocity jet of fluid cleans both the bit teeth and the bottom of the hole. The sizes of
the nozzles are usually measured in 1/32-in. increments [although some are recorded in millimeters], are always reported in
"thirty-seconds" of size [i.e., fractional denominators are not reduced], and usually range from 6/32 to 32/32.
Page 12 of 310
Blast Gate
BLEVE
A form of heavy, solid petroleum. A non-crystalline solid or semi-solid cementitious material derived from petroleum, consisting
essentially of compounds composed predominantly of hydrogen and carbon with some oxygen and sulphur; it gradually
softens when heated. Bitumens are black or brown in colour. They may occur naturally or may be made as end products from
the distillation of, or as extracts from, selected petroleum oils. See Asphalt.
Tar sand, a mixture of asphalt and 100SEt sand which, when processed, may yield as much as 12- percent asphalt.
A term denoting residual oil, oil used in ships' boilers or in large heating or generating plants, bunkers. Black-coloured oil used
for lubricating heavy, slow--moving machinery where the use of higher-grade lubricants would be impractical. Also Crude oil,
or distilled crude containing the fractions heavier than middle distillates.
Butterfly valve that limits air passing through a blower or vacuum producer to prevent overload
Boiling Liquid Expanding Vapour Explosion
Blind rams
Steel rams with rubber inserts, which are fitted to a blowout preventer and which in the closed position, shut in the wellhead.
Bitumen
Bituminous sand
Black Oil/Black Cargo
Block
Block valve
Bloom
Blow down
Blowout
Blowout preventer
blpd
BMGV
BMS
BMSL
bo
BOD
BOE
BOELV
BOG
boi
Boll weevil
The subdivided areas of the sea for the purposes of licensing to a company for exploration or production rights. In the UK, a
block is one thirtieth of a quadrant [one degree by one degree] and is approximately 200 to 250 km2; OR any assembly of
pulleys on a common framework; in mechanics, one or more pulleys, or sheaves, mounted to rotate on a common axis. The
crown block is an assembly of sheaves mounted on beams at the top of the derrick. The drilling line is reeved over the
sheaves of the crown block alternately with the sheaves of the travelling block, which is raised and lowered in the derrick by
the drilling line. When elevators are attached to a hook on the travelling block and drill pipe latched in the elevators, the pipe
can be raised or lowered. See crown block and travelling block.
A valve which allows isolating a section of pipeline or part of an installation, e.g. on a crude oil. Or products trunk line placed
on each side of a pipeline river crossing to isolate possible leaks at the crossing.
The rainbow-like fluorescence shown by oil for instance when floating on water.
The process of releasing pressure in e.g. a refinery pressure vessel by venting to atmosphere OR primary production of a
crude oil or condensate reservoir using the pressure of the associated gas.
A blowout is the uncontrolled release of a formation fluid, usually gas, from a well being drilled, typically for petroleum
production. A blowout is caused when a combination of well control systems fail—primarily drilling mud hydrostatics and blowout preventers [BOPs] - and formation pore pressure is greater than the wellbore pressure at depth. When such an incident
occurs, formation fluids begin to flow into the wellbore and up the annulus and/or inside the drill pipe, and is commonly called a
kick. If the well is not shut in, a kick can quickly escalate into a blowout when the formation fluids reach the surface, especially
when the fluid is a gas, which rapidly expands as it flows up the wellbore and accelerates to near supersonic speeds. Blowouts
can cause significant damage to drilling rigs, and injuries or fatalities to rig personnel.
See BOP
Barrels of liquid per day
Biological Monitoring Guidance Value
Business Management System
Below Mean Sea Level
Barrels of oil
Basis of Design OR Biological Oxygen Demand
Barrels of Oil Equivalent [10 Mcf is equivalent to 1 bbl of oil. This factor is not based on either energy content or price.]
Binding Occupational Exposure Limits Value
Boil off Gas - as in LNG.
Initial barrels of oil [in place].
A bowl-type tubing hanger. An inexperienced worker or green hand on a drilling crew.
Page 13 of 310
Bolsters
BoM
Bonding
Boomer
Boot
BOP
bopd
Borehole
BOSIET
Bottlenecking
Bottles
Bottom of the barrel
Bottom-hole
Bottom-hole pressure
Bottom-hole pump
Bottoms up
Bow thruster
Box
BP
BP Company
BP Employee
BP Operations
BP Premises
bpd
Break circulation
Breakaway torque
Breakout
Wooden supports used on truck beds.
Bill of Materials
Joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct
safely any current likely to be imposed.
This expression normally refers to a compressed air, or electrical, source of sound used in marine seismic survey work.
A tall section of large diameter pipe inside or outside a, [usually] dehydration tank which acts as a surge vessel and
atmospheric separator for the crude oil before it enters the tank.
Blowout Preventer: An arrangement of valves installed at the wellhead to prevent the sudden escape of reservoir and
hydrocarbon pressure during drilling completion operations. Blowout preventers on land rigs are located beneath the rig at the
land’s surface; on jackup or platform rigs, at the water’s surface; and on floating rigs, on the seabed.
Barrels of oil per day
A well, especially referring to the face of the rock outside or below the casing. Test boreholes are also sunk to examine the
suitability of a site for major foundation work, and to examine geological formations at points where no hydrocarbons are
expected.
Basic Offshore Induction & Emergency Training
The deformation of the ends of the casing or tubing in the hanger resulting from excessive weight of the string of pipe and the
squeezing action of the slips.
Small pressure vessels of various kinds, especially to absorb pressure fluctuations OR cylindrical flotation tanks such as those
temporarily attached to a platform jacket during placement.
See Fuel Oil, Heavy Ends, etc.
The deepest part of a well
The reservoir or formation pressure at the bottom of the hole. If measured under flowing conditions, readings are usually taken
at different rates of flow in order to determine the well's productivity. A decline in pressure indicates the amount of depletion
from the reservoir. In drilling it refers to The pressure executed by The hydrostatic column of fluid in the well bore, which is
usually in excess of the formation pressure. Also Formation pressures measured at reservoir depth.
A pump installed in the lower end of the wellbore, to increase productivity. [Also downhole pump.]
Circulation of drilling fluid in a well, until the bottom hole mud and cuttings reach the surface, indicating that normal circulation
can commence.
A propeller mounted transversely in the bows of a vessel to assist in docking, manoeuvring and station keeping. [See
Thrusters.]
The hollow, or female end in a threaded connection, such as a drillpipe.
British Petroleum / Amoco
A company in the BP Group, or a company or other legal entity where BP has operational control, is responsible for HSSE and
has the right to impose this Standard.
A person employed by a BP Company.
BP Business Units, projects, facilities sites and operations
Any site, location or marine vessel that is owned or operated by or for a BP Company.
Barrels per Day
To start movement of the drilling or workover fluid after it has been quiescent in the hole.
The torque required to start a machine in motion. Almost always greater than the running torque.
Refers to the act of unscrewing one section of pipe from another section, especially in the case of drill pipe or tubing while it is
being withdrawn from the well bore. During this operation, the breakout tongs are used to start the unscrewing operation.
Page 14 of 310
Breakout
Breathing
Bridge plug
Bridge plug
Bridle
BRINDEX
Brine
British Thermal Unit Btu
British Trade International BTI
Brown Book
Brownial Movement
Brushless motor
BS
BS&W
BSI
BT
BTEX
BTM
Btu
BU
Bubble cap trays
Bubble point
Buffer
Oil that has risen to the surface of the mud which previously had been combined in the mud as emulsion.
When a storage tank containing volatile products is heated by solar radiation, some of the liquid content evaporates. The
excess vapour thus formed is blown out to the atmosphere. On cooling, the less volatile components of the vapour contents
condense and a slight vacuum is created, causing air from outside to be sucked into the tank. This double action is referred to
as breathing of the tank.
An obstruction in a well formed by intrusion of subsurface formations, or in tubing by formation sand.
A down hole packer assembly used in a well to seal off or isolate a particular formation for testing, acidizing, cementing, etc.
Also a type of plug used to seal off a well temporarily while the wellhead is removed. Also An expandable plug used in a
well's casing to isolate producing zones or to plug back to produce from a shallower formation, also to isolate a section of the
borehole to be filled with cement when a well is plugged.
The cable sling between horsehead and polished rod on a pumping well.
Association of British Independent Oil Exploration Companies
Water saturated with or containing a high concentration of common salt (sodium chloride); hence any strong saline solution
containing such other salts as calcium chloride, zinc chloride, calcium nitrate, etc.
The quantity of heat required to raise the temperature of 1lb. of water through 1º F. 1000 Btu = 252 kcal.
Part of DTI, [Not to be referred to as BTI], see also IEP
The Department of Trade and Industry’s annual publication which contains facts and figures relevant to oil and gas production
in the UK; it is available from HMSO
Continuous, irregular motion exhibited by microscopic particles suspended in a liquid or gaseous medium, usually as a
colloidal dispersion.
Class of motors that operate using electronic commutation of phase currents, rather than electromechanical [brush-type]
British Standard OR Bottom Sediment
Base Sediment and Water [e.g. crude oil shipment adjustment] Also Base sediment or base sediment and water trapped in
crude oil at the time of its production. The amount of sediment and water present is determined by testing by centrifuge. This
amount is then deducted from the gross volume of oil, so that a transporter or refinery pays for net clean oil, rather than a
mixture of petroleum and contaminants.
British Standards Institution
British Telecom
Benzene, Toluene, Ethylbenzene and Xylene
Bromotrifluoromethane [Halon 1301 - extinguishant fixed systems]
British thermal unit
Business Unit
Fractionating trays consisting of a plate provided with holes and bubble caps. The latter cause the vapour to be distributed
through the liquid. The flow is essentially of the single-phase type. Bubble caps are made in a variety of designs, the more
common type consisting of a circular cap inverted over a vapour riser of smaller diameter than the cap. The periphery of the
cap, which clears the plate by a short distance, is slotted in order to disperse the vapour through the liquid as evenly as
possible In the absorption process of gas dehydration the bubble caps; are used to bring the natural gas in intimate contact
with glycol.
The point at which dissolved gasses begin to vaporise from a liquid. It is dependent upon temperature, pressure, and
gas/liquid composition.
Any substance or combination of substances which, when dissolved in water, produces a solution which resists a change in its
hydrogen ion concentration upon the addition of acid or base. A certain volume of liquid in a tank or vessel to reduce the effect
of fluctuations in throughput.
Page 15 of 310
Bulk
Bull (head) Bullhead
Bumper sub
In a flow station the incoming production is usually split up in two streams: the flow from one well in order to be measured, and
the combined flow of the remainder of the wells. The latter is called the bulk flow or bulk stream. Hence: bulk header, bulk
separator, bulk meter, etc.
See Squeeze kill.
A slip-joint that is part of the string of drill pipe used in drilling from a drill ship to absorb the vertical motion of the ship caused
by wave action. The slip joint is inserted above the heavy drill collars in order to maintain the weight of the collars on the drill bit
as the drill pipe above the slip joint moves up and down with the motion of the ship.
Bunker ‘C’
A heavy residual fuel oil obtained as a result of distillation of crude oil, and used as fuel primarily for marine steam generation.
Bunte Schilling
Bureau Veritas
See Schilling apparatus
Verification authority
C4H10 n-butane. Butane is a very flammable gas. It can catch light at low temperatures, and if released into the air readily
reaches a concentration at which an explosion is possible. Form: colourless gas [or liquid under pressure] Stability: stable, but
very flammable Melting point -138.4C Boiling point 0.5C Vapour density 0.579g cm-3 Flash point -60 C Explosion limits 1.8 8.4% Water solubility - slight.
Bureau Veritas
Butt weld
Barrels of water per day
Circulating and Conditioning [drilling fluid].
Cost and freight only. [See also CIF]
Coat and Wrap [e.g. pipeline protection]
Cased Hole
Completion/Workover [temporary riser for these operations]
Claims Administrator
Certifying Authority
Civil Aviation Authority
Compressed Air Breathing Apparatus
Early method of oil well drilling consisting of making a hole by repeated blows with a bit attached to a drill stem, which is a
heavy length of steel suspended from a wire rope.
Computer Aided Design
Butane
BV
BW
bwpd
C&C
C&F
C&W
C/H
C/WO riser
CA
CA
CAA
CABA
Cable tool drilling
CAD
Caisson
Caisson-type platform rig
Calibration
Caliper Calliper
Length of pipe extending vertically downwards from an installation into the sea as a means of disposing of waste waters, or for
the location of a seawater pump OR one of several columns made of steel or concrete, which serves as the foundation for a
rigid offshore platform rig, such as the concrete gravity platform rig OR a steel or concrete chamber that surrounds equipment
below the waterline of an arctic submersible rig, thereby protecting the equipment from damage by moving ice.
A rigid offshore drilling platform that stands on steel caissons and is used to drill development wells. The caissons are firmly
affixed to the seabed and the drilling and production decks are laid on top of them. The platform is used in certain artic waters
where the caissons are needed to protect equipment from moving ice. See also platform rig.
The determination of fixed reference points on the scale of any instrument by comparison with a known standard and the
subsequent subdivision or graduation of the scale to enable measurements in definite units to be made with it. Also the
process of measuring or calculating the volumetric contents or capacity of a receptacle.
[Calliper in the UK] A tool for checking casing in a well for deformation before e.g. running drilling tools, which might become
stuck, or packers which might leak.
Page 16 of 310
Calliper logging
CALM
Calorie
Calorific value
Cancel Button
Cantilevered jackup
CAP
CAP 437
Cap bead
Cap rock
CAPEX
CAPO
CAPP
Capping
CAR
Carbon dioxide [CO2] injection
Carrier bar
Casing
Casing head
Casing head pressure
Casing shoe
Catenary
Cathead
An operation to determine the diameter of the well bore or the internal diameter of casing, drill pipe, or tubing. In the case of
the well bore, calliper logging can indicate undue enlargement of the bore due to caving or other causes. In the case of tubular
goods, the calliper log can reveal -internal corrosion, wear or damage.
Catenary Anchor Leg Mooring.
The amount of heat required to raise the temperature of I gram of water through 10 C (from 14.50 to 15.50 C). In calculation
the kilocalorie, equal to 1000 calories, is often used. 1000 kilocalories - 3968 Btu.
The quantity of heat produced by complete combustion of unit weight of a material. Expressed as either calories per gram, or
British Thermal Units [btu] per pound, or btu per standard cubic foot of gas.
A button provided in the wizards that will cancel the current wizard without saving the data. This information will be
permanently lost.
A jackup drilling unit in which the drilling rig is mounted on two cantilevers that extend outward from the barge hull of the unit.
The cantilevers are supported only at the barge end.
Civil Aviation Publication
Helicopter Landing Areas [CAP - Civil Aviation Publication].
Welding term, see Bead.
An impermeable layer of rock above a discovered or potential hydrocarbon reservoir, providing a seal to contain the reservoir
fluids.
Capital Expenditure
Computer Assisted Production [or Platform] Operations
Canadian Association of Petroleum Producers
To install and close a shut-in device on top of a well flowing uncontrolled.
Corrective Action Report
A method used in secondary recovery from an oil reservoir, in conjunction with water flooding.
A horizontally placed bar with a slot which fits around the polished rod of a pumping well. It is connected to the cable looped
around the horse head of a pumping unit and positioned below a clamp placed on the polished rod. Via these three parts the
up-and-down movement of the beam is transferred to the rod string.
Steel pipe placed in an oil or gas well as drilling progresses to seal the well and to prevent the wall of the hole caving in during
drilling, to prevent seepage of fluids, and to provide a means of extracting petroleum if the well is productive. A number of
casing strings [lengths] are used in decreasing diameters. Also Steel pipe used in oil wells to seal off fluids from the borehole
and to prevent the walls of the hole from sloughing off or caving. There may be several strings of casing in a well, one inside
the other. The first casing put in a well is called surface pipe or conductor which is cemented into place and serves to shut out
shallow water formations and also as a foundation or anchor for all subsequent drilling activity. See Production string .
A unit, attached to the upper end of a casing string or installed on top of another casing head, which serves to support the next
smaller casing string and to effect a seal of the annular space between the two strings.
Pressure between the casing and the well's tubing or between casings.
A reinforcing collar of steel screwed onto the bottom joint of casing to prevent abrasion or distortion of the casing as it forces
its way past obstruction on the wall of the borehole. Casing shoes are about an inch thick and 10 to 16 inches long and are an
inch or so larger in diameter in order to clear a path for the casing.
The curve assumed by a chain or cable suspended between two points [e.g. an anchor chain].
A spool-shaped attachment on a winch around which rope is wound for hoisting and pulling.
Page 17 of 310
Cathodic protection
Cation
Catline
CATS
Catwalk
Caustic soda
Caution Notice
Cave-in
Cavern storage
Cavernous formations
Cavitation
CB
CBA
CBI
CBT
CC
cc
CCC
CCG
CCM
CCR
CCTV
CCU
CD
CDM
CDR
CDS
CE
CE
CECR
Corrosion protection system which relies on sacrificial anodes or impressed current to protect submerged steel components
from corrosion by electrolytic action. Alsao An anti-corrosion technique for metal installations - pipe-lines, tanks, buildings In
which weak electrical currents are set up to offset the current associated with metal corrosion.
A positively charged ion; an ion that is attracted to the cathode during electrolysis. Compare anion. Also The positively
charged particle in the solution of an electrolyte which, under the influence of an electrical potential, moves toward the cathode
(negative electrode). Examples are: Na+, H+,NH4+, Ca++, Mg++, A1+++
A hoisting or pulling line operated from a cathead.
Central Area Tramsmitting System [Teesside]
A narrow elevated platform or walkway for access to equipment.
The common name for sodium hydroxide [NaOH]. Caustic soda is used in most water-base muds to increase and maintain pH
and alkalinity. It is a hazardous material to handle because it is very caustic and gives off heat when dissolved in water. Proper
training and equipment are needed to handle it safely.
A Caution Notice is a notice attached to Electrical Equipment which is DEAD, conveying warning against interference with
such equipment. Note An Earth Notice is a notice to be displayed at all points or sections of an electrical installation where a
temporary earth has been applied.
Collapse of part of the wall of a borehole usually in a poorly consolidated rock formation. Also See Sloughing . Cave-in is a
severe form of sloughing.
Underground natural or man-made storage chambers in suitable impermeable or artificially-lined rock formations. They may
also be designed for cryogenic storage. See also Jug.
A formation having voluminous voids, usually the result of dissolving by formation waters which may or may not be still
present.
The creation of a partial vacuum or a cavity by a high-speed impeller blade or boat propeller moving in or through a liquid. A
pump drawing in liquid where there is an insufficient suction or hydrostatic head to keep the pump suction supplied also
causes cavitation.
Centre of Buoyancy
Cost Benefit Analysis OR Commercial Bid Analysis
Confederation of British Industry
Computer Based Training
Choke valve – Close
Cubic centimetre [cm3]
Compressor Controls Corporation Series II Controller
Commercial Catering Group
Computer Control Mode
Central Control Room
Closed Circuit Television
Catalytic Cracking Unit OR Cargo Carrying Units
Calendar Day OR cellar deck OR closed drains OR compact disk OR contract depth
Construction [Design and Management] Regulations 1994
Company Designated Representative
Chemical Data Sheet
Contract Engineer
Carbon Equivalent OR Community European
Central Electrical Control Room
Page 18 of 310
CEI
Council for Engineering Institution
Cellar deck
The deck or floor beneath the working floor of a drilling rig OR the deck below the main superstructure of an offshore platform.
Cement
Cement squeeze
Cementing
CEN/TC
Centipoise [cP] Centistoke
Centralisers
Centrifuge
CEO
Certificates
Certification [Classification]
CES
Cetation
CF
C-face mounting
cfb
A powder consisting of alumina, silica, lime and other substances that hardens when mixed with water. Extensively used in the
oil industry to bond casing to the walls of the well bore. [Also Cem.] Also A mixture of calcium aluminates and silicates made
by combining lime and clay while heating. Slaked cement contains about 62.5 percent calcium hydroxide, which is the major
source of trouble when cement contaminates mud.
A method whereby perforations, large cracks, and fissures in the wall of the borehole are forced full of cement and sealed off.
Often used to repair poor casing cementation.
The operation by which cement: slurry is forced down through the casing and out at the lower end in such a way that it fills the
space between the casing and the well bore to a pre-determined height above the bottom of the well. This is for the purpose of
securing the casing in place and excluding water and other fluids from the well bore.
The European Committee for Standardization/ Technical Committee
A unit of measurement of dynamic viscosity. It expresses the force needed to overcome resistance to flow, and to maintain
unit velocity of flow, in a given field. Also A centipoise cP is 1/100th of a poise P, which is the fundamental unit of dynamic
viscosity in the centimetre-gram-second system of units. The viscosity of water at 20ºC is approximately 1 cP. The centistoke
cS is 1/100th of a stoke S which is the fundamental unit of kinematic viscosity in that system. The two are related by the
density, ie number of centistokes = number of centipoises divided by liquid density in g/cm³
Spacing collars attached to the outside of casing when run in a well, to keep it central in the bore and ensure an evenlyshaped annulus in which cement can circulate and set.
A separator operating on the principle of differential acceleration of particles of different mass, an effect produced by
equipment similar to a turbine “spinning” the feedstock in an enclosed chamber.
Chief Executive Officer
Authorised documents which support a Work Permit. The certificate serial number is to be referenced on the Permit and the
corresponding copy to be attached to the Work Permit. Certificates are yellow in colour.
The process of certifying the origin, quality, and fitness for use of operation to given standards of a platform structure, process,
item of equipment etc. Certification originated in ship construction and insurance classification. Hence major Certification
Authorities acceptable to Government agencies etc., are Lloyds Register of Shipping, American Bureau of Shipping, Bureau
Veritas and Det Norske Veritas [DNV]. OR Classification of electrical equipment for hazardous locations to BASEEFA
Standards.
Coast Earth Station
Aquatic mammals comprising porpoises, dolphins and whales.
Connection Function OR cubic feet
A standard NEMA mounting design, where the mounting holes in the face are threaded to receive the mating mount.
Cubic feet per barrel
Page 19 of 310
CFC
CFD
cfg
CFU
Cg
CG [CoG]
CGR
Ch
CH3OH
Chain tongs
Chamber lift
CHAN
Channelling
CHAOS
CHARM
Check valve
Checkerboard Leasing
Checklist
CHI
Chicksan
Chiller
CHIP
Chlorofluorocarbons - a class of chemical compounds that deplete ozone. Chlorofluorocarbons or CFCs (also known as
Freon) are non-toxic, non-flammable and non-carcinogenic. They contain fluorine atoms, carbon atoms and chlorine atoms.
The 5 main CFCs include CFC-11 (trichlorofluoromethane - CFCl3), CFC-12 (dichloro-difluoromethane - CF2Cl2), CFC-113
(trichloro-trifluoroethane - C2F3Cl3), CFC-114 (dichloro-tetrfluoroethane - C2F4Cl2), and CFC-115 (chloropentafluoroethane C2F5Cl).
CFCs are widely used as coolants in refrigeration and air conditioners, as solvents in cleaners, particularly for electronic circuit
boards, as a blowing agents in the production of foam (for example fire extinguishers), and as propellants in aerosols. Indeed,
much of the modern lifestyle of the second half of the 20th century had been made possible by the use of CFCs.
Man-made CFCs however, are the main cause of stratospheric ozone depletion. CFCs have a lifetime in the atmosphere of
about 20 to 100 years, and consequently one free chlorine atom from a CFC molecule can do a lot of damage, destroying
ozone molecules for a long time. Although emissions of CFCs around the developed world have largely ceased due to
international control agreements, the damage to the stratospheric ozone layer will continue well into the 21st century.
Computational Fluid Dynamics
Cubic feet of gas
Compact Flotation Unit.
Coring
Centre of Gravity
Condensate Gas Ratio
Channel
Methanol
A pipe wrench with a flexible chain to hold the toothed wrench-head in contact with the pipe. The jointed chain can be looped
around pipes of different diameters and made fast in dogs on the wrench head.
A special form of gas lift in which gas is injected intermittently to lift the liquid which has filled up a chamber at the bottom of a
well, to the surface.
Chemical Hazard Alert Notice
During production from a reservoir which is being supported by pressure from contiguous water or gas, the water or gas tends
to travel towards the well bore faster through channels or layers of more permeable rock [see Permeability] by-passing and
“holding back” production from the less permeable rocks.
Consequences of Hazards and Accidents on Offshore Structures
Chemical Hazard and Risk Management
A non-return valve, allowing only one-way flow. Also A valve with a free-swinging tongue, flapper or floating piston that permits
fluid in a pipeline to flow in one direction only; also Non-return valve”, sometimes also Back-pressure valve.
A phrase used in exploration to describe granting concessions or leases on alternate blocks. A discovery will tend to increase
the value of contiguous blocks still unlet.
A method for hazard identification by comparison with experience in the form of a list of failure modes and hazardous
Critical Handover Information
Adjustable temporary pipe
A heat -exchanger to cool gas in a gas dehydration installation. The gas to be treated is cooled by contact with cold propane or
freon gas from a separate closed-cycle refrigeration system.
Chemicals [Hazard Information and Packaging for supply] 1994
Page 20 of 310
Choke
Christmas tree
Christmas tree [marine]
Chromate
CHWO
CI
CIF
CIMAH
CIO
CIP
Circulating components
Circulation bottoms-up
Circulation drilling
CISPR
CITHP
CIV
CKS
Cl2
Claim
Class A Fires
Class B Fires
Class B insulation
Class C Fires
Class D Fires
Class F insulation
Class H insulation
Classified Worker
Clastic Rock
A valve [or valve-like device] with a fixed or variable aperture specifically designed to regulate the flow of fluids OR an aperture
restricting flow in a well or flowline. See also Bean. Also A device that is used to control the flow of produced fluids. It may
have either a positive, fixed orifice or a variable, adjustable orifice or opening. They are installed either at the wellhead or at
the end of the flowline at the station manifold. Also called Bean or Flow-bean.
Wellhead. An assembly of valves and fittings installed as a unit on top of the tubinghead of a well, used for product-ion
control. Also An arrangement of isolation valves, pressure gauges and possibly chokes installed at the top of a well to control
the flow of oil and gas after the well has been drilled and completed.
A subsea production system similar to a conventional land tree except it is assembled complete for, remote installation on the
sea floor with or without diver assistance. The marine tree is installed from the drilling platform; it is lowered into posit-ion on
guide cables anchored to foundation legs implanted in the ocean floor. The tree is then latched mechanically or hydraulically to
the well head by remote control.
A compound in which chromium has a valence of 6, e.g. sodium bichromate. Chromate may be added to drilling fluids either
directly or as a constituent of chrom lignites or chrom ligno-sulfonates. In certain areas, chromate is widely used as an anodic
corrosion inhibitor, often in conjunction with lime.
Cased Hole Workover Rig
Chemical Injection OR corrosion inhibitor OR compression-ignition
Cost, Insurance, Freight [included in price]. See also C & F.
Control of Industrial Major Accident Hazards Regulations [1984].
Control, Inputs and Outputs
Chemical Injection Package
The equipment included in the drilling fluid circulating system of a rotary rig. Basically, the components consist of the mud
pump, rotary hose, swivel, drill stem, bit and mud return line.
See Bottoms-up.
The passage of fluids, primarily drilling mud, down the interior of the drill-stem and back to the surface via the annulus.
[Reverse Circulation is in the opposite direction.]
International Special Committee on Radio Interface
Closed in Tubing Head Pressure
Chemical Injection Valve OR Chemical isolation valve
A modified chromium coating [eg on top piston rings].
Liquid Chlorine
Any cost incurred in executing rectification work due to defective workmanship or failure by the Supplier to complete his scope
of work to the Specifications, Standards and Terms and Conditions of the order.
Fires involving cellulosic combustibles, e.g. paper, wood etc.
Fires involving burning liquids [including hydrocarbons].
A NEMA insulation specification. Class B insulation is rated to an operating [internal] temperature of 130°C.
Fires involving burning gases [including hydrocarbons].
Fires involving burning metals.
A NEMA insulation specification. Class F insulation is rated to an operating [internal] temperature of 155°C
A NEMA insulation specification. Class H insulation is rated to an operating [internal] temperature of 180°C.
An employee who has been designated as such and informed by his employer as being likely to receive a dose of ionising
radiation which exceeds 3/10ths of a relevant dose limit.
Rock which has been formed from the sediment and detritus of other rocks e.g. sandstone, shale, conglomerates, etc.
Page 21 of 310
Clathrate
Claus Unit
Clay
Cleared Lines
Client
Client
Closed loop
Closure
Cloud Point
CLSID
CMAS
CMB
CMC
CMI
C-Mn
CMS
A clathrate or clathrate compound or cage compound is a chemical substance consisting of a lattice of one type of molecule
trapping and containing a second type of molecule. The word clathrate is derived from the Latin 'clatratus' meaning with bars
or a lattice. An example of a clathrate is clathrate hydrate, a special type of gas hydrate in which a lattice of water molecules
encloses molecules of a trapped gas. Scientists believe that compounds on the sea bed have trapped large amounts of
methane in similar configurations. A clathrate therefore, is a material which is a weak composite, with molecules of suitable
size captured in spaces which are left by the other compounds. They are also called host-guest complexes, inclusion
compounds, and adducts.
The Claus process is the most significant gas desulfurizing process, recovering elemental sulfur from gaseous hydrogen
sulfide. The Claus technology can be divided into two process steps, thermal and catalytic. In the thermal step, hydrogen
sulfide-laden gas reacts in a substoichiometric combustion at temperatures above 850 °C such that elemental sulfur
precipitates in the downstream process gas cooler.
The H2S-content and the concentration of other combustible components [hydrocarbons or ammonia] determine the location
where the feed gas is burned. Claus gases [acid gas] with no further combustible contents apart from H2S are burned in
lances surrounding a central muffle by the following chemical reaction: 2H2S + 3O2 → 2SO2 + 2H2O.
The Claus reaction continues in the catalytic step with activated alumina or titanium dioxide, and serves to boost the sulfur
yield. The hydrogen sulfide [H2S] reacts with the SO2 formed during combustion in the reaction furnace, and results in
gaseous, elemental sulfur. This is called the Claus reaction: 2H2S + SO2 → 3S + 2H2O.
The catalytic recovery of sulfur consists of three substeps: heating, catalytic reaction and cooling plus condensation. These
three steps are normally repeated a maximum of three times.
A plastic, soft, variously coloured earth, commonly a hydrous silicate of alumina, formed by the decomposition of feldspar and
other aluminium silicates. Clay minerals are essentially insoluble in water but disperse under hydration, shearing forces such
as grinding, velocity effects, etc., into the extremely small particles varying from submicron to 100-micron sizes.
Pipelines or equipment that have been drained, vented, flushed, and verified to be clear of any hazardous residue, pluggage,
or pressure.
Company/organisation to whom main contract lies.
Any existing or potential customer.
A broadly applied term, relating to any system in which the output is measured and compared to the input. The output is then
adjusted to reach the desired condition. In motion control, the term typically describes a system utilizing a velocity and/or
position transducer to generate correction signals in relation to desired parameters.
Four-way [all round] closure or seal is necessary, over the top and down the gradients on the sides of a potential reservoir,
before it can trap or retain hydrocarbons. Closure may be structural as in an anticline, or may be partly due to an impermeable
fault, or stratigraphic trapping or e.g. salt intrusion.
The temperature at which paraffin waxes will solidify and give a cloudy appearance to the oil of which they form part. Also The
temperature at which paraffin wax begins to crystallise or separate from the solution, imparting a cloudy appearance to the oil
as it is chilled under prescribed conditions.
Class Identification
Competence Management Assurance System
Conventional Mooring Buoy OR Choke manifold base
Sodium Carboxymethyl cellulose. A non-fermenting cellulose product used in drilling fluids to combat contamination from
Christian Michelson Institute
Carbon Manganese steel
Commissioning Management System
Page 22 of 310
CMS
CMT
CMTS
CNG
CNS
CO
CO&S
CO2
Coagulation
Coal gas
Coalescence
COAST
Coating [pipeline]
Codes and Standards
Completion Management System
Crisis Management Team
Control module test stand
Compressed natural gas
Central North Sea
Carbon Monoxide OR Choke valve – open OR Cleaned/circulated out. [See also CO & S]
Clean Out and Shoot [well]
Carbon Dioxide
In drilling-fluid terminology, a synonym for flocculation.
A manufactured gas made by destructive distillation Carbonisation of bituminous coal in a gas resort. Its chief components are
methane - 20 to 30 percent, and hydrogen about 50 percent.
The change from a liquid to a thickened curd like state by chemical reaction. The combining of small particles or droplets into
larger ones caused by molecular attraction of the surfaces. The large drops will drop out easier in separation processes - e.g.
in the separation of water droplets from oil.
Computer Assisted Shipping Traffic database.
Cement applied externally, weight-coating OR anti-corrosion compounds applied internally.
The Offshore Installations (Operational Safety, Health and Welfare) Regulations 1976 (SI 1976 No. 1019).
The Electricity at Work Regulations 1989 (SI 1989 No. 635).
The Offshore Installations (Lifesaving Appliances) Regulations 1977 (SI 1977 No. 486).
The Offshore Installations (Emergency Procedures) Regulations 1976 (SI 1976 No. 1542).
HSE Safety Notice 3/84 (revised and re issued January 1992) Safe Isolation of Electrical Equipment.
The Pipeline Act, 1962, and The Safety in Pipelines (DEn).
Guidance Notes in support of the Offshore Installations (Emergency Pipeline Valve) Regulations (DEn).
BS 1710:1984, Identification of Pipelines and Services Offshore Installations, Guidance on design, construction and
certification.
BS 8010, Code of Practice for Pipelines.
ASME/ANSI 816.5 1988, Pipe Flanges and Flange Fittings.
CoG
Cogging [Cogging torque]
COHb
Certificate of Fitness
Calculated Open Flow
In platform construction, the “floatable” wall used to seal a dry construction dock. When the dock is filled with water for
platform float-out, the cofferdam is de-ballasted and floated to one side to allow egress. Cofferdams have various other uses.
Also, a void space in a ship between vertical divisions.
Centre of Gravity
A term used to describe non-uniform angular velocity. Cogging appears as a jerkiness, especially at low speeds.
Carboxyhaemoglobin
Cohesion
The attractive force between the same kind of 'molecules, i.e. the forces which hold the molecules of a substance together.
CoF
COF
Cofferdam
Coiled tubing
Cold Work
Collar
Flexible, high-pressure steel tubing used in production piping [often down hole] to deliver chemicals and equipment to the local
problem site. e.g. Can be used to deliver methanol directly at the site of a hydrate plug.
All work requiring a Work Permit other than Hot Work.
A coupling for two lengths of pipe; a pipe fitting with threads on the inside for joining two pieces of threaded pipe of the same
size.
Page 23 of 310
Colloid
COLMS
COMAH
Combined flow
Combustible liquids
Commingling
Commissioning
Common Carrier
Comms
Commutation 1
Commutation 2
Compact head
Company Man
Competency
A state of subdivision of matter, which consists, either of single large molecules or of aggregations of smaller molecules
dispersed to such a degree that the surface forces become an important factor in determining its properties. The size and
electrical charge of the particles determine the difference phenomena observed with colloids, e.g., Brownian movement. The
sizes of colloids range from I x 10-7 cm. to 5 x 10-5 cm (0.001 to 0.5 microns) in diameter, although the particle size of certain
emulsoids can be in the micron range,
Crude Oil Loading Metering Station
Control of Major Hazards
Tubing flow plus annulus flow.
A liquid having a flash point at or above 100ºF but less than 200ºF.
The intentional mixing of petroleum products having similar specification. In some instances, products of like specification are
commingled in a product pipeline for efficient and convenient handling; Producing two or more zones in the same well bore
through a common tubing and flowline.
Preparatory work, servicing etc. usually on newly-installed equipment, and all testing prior to full production testing [see Start
The legal status of some pipeline companies, primarily in the USA.
Communications [systems]
A term which refers to the action of steering currents or voltages to the proper motor phases so as to produce optimum motor
torque. In brush type motors, commutation is done electromechanically via the brushes and commutator. In brushless motors,
commutation is done by the switching electronics using rotor position information obtained by Hall sensors, a Tachsyn, or a
resolver.
Commutation of step motors is normally done open loop. Feedback from the motor is not required to hold rotor position
precisely.
A combined casing/tubing head that can receive as many as two casing strings plus one tubing string, allowing normal drilling
and completion operation to be completed through one single blowout preventer system.
A representative of an oil-drilling company. Other terms that may be used are Company Representative, Foreman, Drilling
Engineer, Company Consultant, or Rigsite Leader.
Oil-drilling companies typically rent or lease rigs from another company that owns the rig and the majority of the personnel on
the drilling rig.
The company man is the on-site representative of the drilling company and is directly in charge of most operations pertaining
to the actual drilling and integrity of the wellbore.
However, other domains such as rig maintenance and crew upkeep are often attended to instead by the Toolpusher.
Thus, the Company man is not a supervisor in the traditional sense. In matters where safety may be questioned the oil rig
workers, who may not be employed by the same company as the Company Man, may refuse to perform an action requested
by the Company Man. In recent years it has become standard safety policy that anyone can Stop the Job if they feel there is a
hazard that has not been properly addressed.
This can be found in most contractor safety manuals and is generally encouraged by the drilling company also.
The Company man is usually knowledgeable in the area of drilling operations and to some extent completion operations.
While the well is being drilled, the Company man must rely on the wellsite geologist (or mudlogger) to inform him if the well is
dry or if it is going to be a producer.
Though a few Company men are informed as to the producing horizons in the area of the well, the real expert (from an
investor's standpoint) is the mudlog geologist.
Most Company men have favorite mudlog geologist that they rely on religiously.
In the modern era, most Company men are degreed Petroleum Engineers (or some other discipline of engineering) with broad
The ability to fulfil the jobs/tasks to a recognised standard.
Page 24 of 310
Competency
Competency
Competent Electrical Person
Competent Person
Complete a well
Completion
Completion methods
Completion test
Concession
Condensate
Conductivity
Conductor
Conductor casing
Conductor pipe
Confined Space
Confirmation Well
A competent person is a person who can demonstrate that they have sufficient professional or technical training, knowledge,
actual experience, and authority to enable them to:
a] carry out their assigned duties at the level of responsibility allocated to them
b] understand any potential hazards related to the work [or equipment] under consideration; and
c] detect any technical defects or omissions in that work [or equipment], recognise any implications for health and safety
caused by those defects or omissions and be able to specify a remedial action to mitigate those implications.
The ability to perform a task in the correct manner with the correct understanding and reasoning behind the task.
A Competent Electrical Person is one who has sufficient technical knowledge and experience to prevent danger, or is under
such degree of supervision as may be appropriate having regard to the nature of the work.
A person who has demonstrated that they have the knowledge, training and experience required to perform the defined role to
the standard required.
To finish work on a well and bring it to productive status. See well completion.
Installation in a well of production tubing and equipment, wellhead and Christmas Tree OR fulfilment of a contractual
obligation.
Methods of completing a well in such a manner as to permit the production of oil or gas. According to the nature of the
producing formation, different methods are usually applied, depending on conditions. At: the surface, a well may be completed
by either a Christmas tree or a pumping head and pumping unit.
The procedure specified in e.g. a construction contract, or project financing agreement, for determining whether the plant, field
development, etc. in question meets the operating specifications laid down. A completion test may in some cases extend over
several months.
A licence, lease, or other permit for exploration and/or production in an area or block. It usually donates a government lease.
Also An agreement (usually with a government) to permit a company to prospect for and produce hydrocarbons or minerals in
the area covered by the agreement.
Volatile liquid consisting of the heavier hydrocarbon fractions that condense out of the gas as it leaves the well, a mixture of
pentanes and higher hydrocarbons. See also 'gas condensate'. Also A straw-coloured or colourless liquid hydrocarbon
mixture of over approx. 500 API gravity, which may be recovered at the surface from some unassociated gas reservoirs. Also
Light hydrocarbon fractions produced with natural gas which condense into liquid at normal temperatures and pressures
associated with surface production equipment.
A measure of the quantity of electricity transferred across unit area per unit potential gradient. per unit time. It is the reciprocal
of resistivity.
The first casing string of a borehole, also called Surface string. It is secured in the formations by cementing.
Generally the first string of casing in a well. It may be lowered into a hole drilled into the formations near the surface and
cemented in place; or it may be driven into the ground by a special pile driver [in such cases, it is sometimes called drive pipe];
or it may be jetted into place in offshore locations. Its purpose is to prevent the soft formations near the surface from caving in
and to conduct drilling mud from the bottom of the hole back to the surface when drilling starts. It supports the subsequent
drilling strings. See also conductor pipe.
A short string of large diameter casing used to keep the wellbore open and to provide a means of conveying the upflowing
drilling fluid from the well bore to the mud pit. It is the first pipe to be inserted [spudded] into the seabed when drilling a hole
A confined space is one that is large enough for personnel to enter, has limited or restricted means of entry, and is not
designed for normal or continuous occupancy. It can be any enclosed or partially enclosed space where there is a risk of
death or serious injury from hazardous substances or dangerous conditions [e.g. lack of oxygen].
An early appraisal or step-out well.
Page 25 of 310
Conformance
Coning
Connate Water
CONOPS
Consistency
Construction Services Subcontracts
Construction Subcontracts
Contamination
Continental Shelf
Contract Initiator
Contractors
Contracts and Procurement Manager
Contracts Department
Control
Controlled directional drilling
Controls
Conventional sour service
procedures
CoP
CoQ
Core
Core Capabilities
Core Competence
Core sample
Compliance with specified requirements.
If an oil well is produced at excessive rates the reduction in reservoir pressure may tend to draw up underlying water towards
the well in a cone like shape. Likewise gas can be drawn downwards from an overlying gas cap.
The original water content of a reservoir rock. Connate water reduces the pore-space [porosity] available to hydrocarbons.
Sometimes called interstitial water. Also The water present in a petroleum reservoir in the same zone occupied by oil and
gas. Connate water is not to be confused with bottom or edge (migratory) water. Connate water occurs as a film of water
around each grain of sand in granular reservoir rock and is held in place by capillary attraction. It was probably laid down and
entrapped with sedimentary deposits.
Any two or more sets of activities carried out concurrently within the same organisation or unit under the same management
system that, because of their proximity or other factors could still interact adversely with each other.
The viscosity of a non-reversible fluid, in poises, for a certain time interval at a given pressure and temperature.
Provision of construction services where these do not form part of Construction Subcontracts. Examples are Scaffolding,
Craneage, Site Security, Canteen operations etc.
All contracts which involve construction works on site.
Unwanted radioactive material deposited on surfaces such as the outside of packages or on floors or released into the air.
Surface contamination is classed as fixed , i.e. difficult to remove, or non fixed, i.e. can be removed by washing, scraping, etc.
Measured in terms of radioactivity per unit area of surface. eg Becquerels per square centimetre [Bq/cm2]. Airborne
contamination is measured in terms of radioactivity per unit volume eg Bq/m3
The shelving area covered by shallow water around major land masses. It may be 50-100 miles [80-200 km] in width and
merges into the steeper Continental Slope, and yet steeper Continental Rise which descends to the ocean floor.
The authorised representative for the instigation and co-ordination of the contract.
Members of the work force who are not directly employed by an operator..
Person responsible for the management of the Contracts Department, for developing forms of contract, special conditions and
such.
Responsible for discharging the functions described in this procedure.
a. A mechanism used to regulate a physical process or activity. B. An action to mitigate risk. C. The power to direct [usually
through authority].
See directional drilling.
Measures that are put in place, to mitigate hazards and to control work in an area.
Procedures employed on lower risk sour service plants that allow operations and maintenance without the requirement for
continuous wearing of breathing air [BA]. Lower risk facilities/equipment will be classified as yellow zone operations and staff
working in these zones will be equipped with personal H2S monitors and carry escape sets for immediate use in the event of a
H2S gas release. Any yellow zone work that involves breaching into H2S hydrocarbon containing systems or work that carries
a potential risk of a H2S release will be conducted under breathing air.
Code of Practice OR Cessation of Production
Certificate of Quantity [or Quality]. [Also CQ]
A cylindrical sample taken from a formation for geological analysis. Usually a conventional core barrel is substituted for the bit
and procures a sample as it penetrates the formation. To obtain a formation sample for analysis.
The people and systems that describe what and how Petrofac carries out its business activities.
What Petrofac does best. The strength of our business.
A solid column of rock, usually from two to four inches in diameter, taken from the bottom of a well bore as a sample of an
underground formation. Cores are also taken in geological studies of an area to determine its oil and gas prospects.
Page 26 of 310
Coring
The process of cutting a vertical, cylindrical sample of the formations encountered as an oilwell is drilled. The purpose of
coring is to obtain rock samples or cores in such a manner that the rock retains the same properties that it had before it was
removed from the formation.
Coriolis Meter
Configuration consists of one or two U-shaped, horseshoe-shaped, or tennis-racket-shaped [generalised U-shaped] flow tube
with inlet on one side and outlet on the other enclosed in a sensor housing connected to an electronics unit. The flow is guided
into the U-shaped tube.
When an osillating excitation force is applied to the tube causing it to vibrate, the fluid flowing through the tube will induce a
rotation or twist to the tube because of the Coriolis acceleration acting in opposite directions on either side of the applied force.
For example, when the tube is moving upward during the first half of a cycle, the fluid flowing into the meter resists being
forced up by pushing down on the tube.
On the opposite side, the liquid flowing out of the meter resists having its vertical motion decreased by pushing up on the tube.
This action causes the tube to twist. When the tube is moving downward during the second half of the vibration cycle, it twists
in the opposite direction.
This twist results in a phase difference (time lag) between the inlet side and the outlet side and this phase difference is directly
affected by the mass passing through the tube.
Corporate Services
Corrosion
COSHH
COTS
Coupon
COV
CoW
COW
CP
CP
Cp
CPA
CPF
CPI
CPSI
CPU
Cr
CR
CRA
Petrofac Production Services Commercial, Legal, Insurance, Finance and Tax Departments.
The adverse chemical alteration on a metal or the eating away of the metal by air, moisture, or chemicals; usually an oxide is
formed.
Control of Substances Hazardous to Health [Regulations 1999]. Requires that we identify, control, eliminate or handle harmful
substances in a responsible manner. The regulations apply to all substances, with the exception of asbestos, lead, ionising
materials and hazardous substances below ground in mines, all of which are subject to recent legislation. The regulations
apply to any substance which must be packaged in containers with symbolic hazard signs. They also apply to natural
substances, such as fungus spores, and to substances which are normally considered to be harmless, if they are used in large
enough quantities to become a hazard to health.
Commercial Off The Shelf [components]
Small metal strip or ring which is exposed to corrosive systems for the purpose of determining nature and severity of
corrosion.
Crossover Valve
Control of Work
Control of Work
Change Proposal OR Control Processor
Corrosion Protection OR cathodic protection OR casing pressure
Centipoise, a unit of measurement of dynamic viscosity [See Centipoise]
Closest Point of Approach.
Casing Pressure, Flowing. [See also CPSI] OR Central Processing Facility.
Choke Position Indicator
Casing Pressure, Shut In. [See also CPF]
Central Processing Unit [Computer]
[see AlphaCPU™]
Chromium
Compression and Reception.
Corrosion-resistant alloy OR Corrosion Risk Assessment OR Comparative risk assessment.
Page 27 of 310
Cracking
A petroleum refining process in which heavy-molecular weight hydrocarbons are broken up into light hydrocarbon molecules
by the application of heat and pressure, with or without the use of catalysts, to derive a variety of fuel products. Cracking is one
of the principal ways in which crude oil is converted into useful fuels such as motor gasoline, jet fuel, and domestic oil.
Cracking [Catalytic]
Catalytic cracking breaks complex hydrocarbons into simpler molecules in order to increase the quality and quantity of lighter,
more desirable products and decrease the amount of residuals. This process rearranges the molecular structure of
hydrocarbon compounds to convert heavy hydrocarbon feedstock into lighter fractions such as kerosene, gasoline, liquified
petroleum gas [LPG], heating oil, and petrochemical feedstock.
Catalytic cracking is similar to thermal cracking except that catalysts facilitate the conversion of the heavier molecules into
lighter products. Use of a catalyst [a material that assists a chemical reaction but does not take part in it] in the cracking
reaction increases the yield of improved-quality products under much less severe operating conditions than in thermal
cracking. Typical temperatures are from 850°-950° F at much lower pressures of 10-20 psi. The catalysts used in refinery
cracking units are typically solid materials [zeolite, aluminum hydrosilicate, treated bentonite clay, fuller's earth, bauxite, and
silica-alumina] that come in the form of powders, beads, pellets or shaped materials called extrudites.
There are three basic functions in the catalytic cracking process:
Reaction: Feedstock reacts with catalyst and cracks into different hydrocarbons;
Regeneration: Catalyst is reactivated by burning off coke; and
Fractionation: Cracked hydrocarbon stream is separated into various products.
The three types of catalytic cracking processes are fluid catalytic cracking [FCC], moving-bed catalytic cracking, and
Thermofor catalytic cracking [TCC]. The catalytic cracking process is very flexible, and operating parameters can be adjusted
Cracking [Coking Process]
Coking is a severe method of thermal cracking used to upgrade heavy residuals into lighter products or distillates. Coking
produces straight-run gasoline [coker naphtha] and various middle-distillate fractions used as catalytic cracking feedstock. The
process so completely reduces hydrogen that the residue is a form of carbon called coke. The two most common processes
are delayed coking and continuous [contact or fluid] coking. Three typical types of coke are obtained [sponge coke,
honeycomb coke, and needle coke] depending upon the reaction mechanism, time, temperature, and the crude feedstock.
Cracking [Delayed Coking]
Cracking [Steam]
In delayed coking the heated charge [typically residuum from atmospheric distillation towers] is transferred to large coke
drums which provide the long residence time needed to allow the cracking reactions to proceed to completion. Initially the
heavy feedstock is fed to a furnace which heats the residuum to high temperatures [900°-950° F] at low pressures [25-30 psi]
and is designed and controlled to prevent premature coking in the heater tubes . The mixture is passed from the heater to one
or more coker drums where the hot material is held approximately 24 hours [delayed] at pressures of 25-75 psi, until it cracks
into lighter products. Vapors from the drums are returned to a fractionator where gas, naphtha, and gas oils are separated out.
The heavier hydrocarbons produced in the fractionator are recycled through the furnace. After the coke reaches a
predetermined level in one drum, the flow is diverted to another drum to maintain continuous operation. The full drum is
steamed to strip out uncracked hydrocarbons, cooled by water injection, and decoked by mechanical or hydraulic methods.
The coke is mechanically removed by an auger rising from the bottom of the drum. Hydraulic decoking consists of fracturing
Steam cracking is a petrochemical process sometimes used in refineries to produce olefinic raw materials [e.g., ethylene] from
various feedstock for petrochemicals manufacture. The feedstock range from ethane to vacuum gas oil, with heavier feeds
giving higher yields of by-products such as naphtha. The most common feeds are ethane, butane, and naphtha. Steam
cracking is carried out at temperatures of 1,500°-1,600° F, and at pressures slightly above atmospheric. Naphtha produced
from steam cracking contains benzene, which is extracted prior to hydrotreating. Residuals from steam cracking is sometimes
blended into heavy fuels.
Page 28 of 310
Cracking [Thermal]
Thermal cracking is a refining process in which heat [~800°C] and pressure [~700kPa] are used to break down, rearrange, or
combine hydrocarbon molecules. The first thermal cracking process was developed around 1913. Distillate fuels and heavy
oils were heated under pressure in large drums until they cracked into smaller molecules with better antiknock characteristics.
However, this method produced large amounts of solid, unwanted coke. This early process has evolved into the following
applications of thermal cracking: visbreaking, steam cracking, and coking.
Cracking [Visbreaking Process]
Visbreaking, a mild form of thermal cracking, significantly lowers the viscosity of heavy crude-oil residue without affecting the
boiling point range. Residual from the atmospheric distillation tower is heated [800°-950° F] at atmospheric pressure and
mildly cracked in a heater. It is then quenched with cool gas oil to control overcracking, and flashed in a distillation tower.
Visbreaking is used to reduce the pour point of waxy residues and reduce the viscosity of residues used for blending with
lighter fuel oils. Middle distillates may also be produced, depending on product demand. The thermally cracked residue tar,
which accumulates in the bottom of the fractionation tower, is vacuum flashed in a stripper and the distillate recycled.
Cretaceous
CRF
Cricondenbar Line
Cricondontherm Line
CRINE
Critical flow
Critical Path Analysis
Critical velocity
CRM
CRO
Crossover
Crown block
CRT
Crude Oil
Rock formed in the last period of the Mesozoic era, between the Jurassic and the Tertiary periods, during which chalk deposits
were formed.
Concession Request Form
Is a line drawn tangentially to the phase curve at the point of the highest pressure. The Cricondenbar represents the maximum
pressure at which liquid can occur.
Is a vertical line drawn tangentially to the right side of the phase curve. The Criconentherm represents the maximum
temperature at which liquid can occur.
Cost Reduction in the New Era; a joint initiative by the UK government and the oil industry to standardise documentation
thereby reducing cost. CRINE has been absorbed into another initiative: LOGIC Leading Oil & Gas Industry Competitiveness.
Refers to flow condition of fluid streams through orifices. At a flow rate above that required for critical flow, downstream
pressure fluctuations have no effect on upstream pressure. At critical flow, the fluid velocity equals the velocity of sound in that
fluid. Upstream pressure 1,7 x downstream pressure.
A project planning tool normally used I large construction/development projects. It is based on a “network” of necessary
actions of known sequence and duration, and aims at identifying priority points at which actions “critical to” [holding up other
progress on] the project need improvement or elimination.
That velocity at the transitional point between laminar and turbulent types of fluid flow. This point occurs in the transitional
range of Reynolds numbers of approximately 2000 to 3000.
Corrosion resistant material
Control Room Operator
An item used to connect one component to another differing in size, thread type or pressure rating.
An assembly of sheaves, mounted on beams at the top of the derrick, over which the drilling line is reeved. See block.
Cathode ray tube [monitor]
Oil as it comes from the well; unrefined petroleum. Also An unrefined mixture of naturally-occurring hydrocarbons. Because it
is essentially a mixture, the density and properties of Crude Oil vary widely. Light Crude normally has an A.P.I. gravity of 30° or
more. Gravities of 20° to 30° include the medium gravity crudes, while those below 20° are known as Heavy. Heavy oils are
found right down to the residual solid state. Sour crude has a significant sulphur content; Low-sulphur crude is described as
sweet.
Page 29 of 310
CSA
CSCC
CSE
Csg
CSMA/CD
CSON
CSP
CSS
cST
CSTR
CSU
CSWIP
Generally crude oils are classified into three types.
Paraffinic: Paraffinic hydrocarbons with a relatively lower percentage of aromatics &naphthenes.
Naphthenic: Cycloparaffins in a higher ratio and a higher amount of asphalt than in Paraffinic crude's
Asphaltic: Fused aromatic compounds and asphalt in higher amounts
Crude oil consists primarily of a large variety of hydrocarbons and of some heterocompounds, i.e. compounds containing
sulfur, nitrogen and oxygen. Compounds containing metals, primarily nickel (Ni) and vanadium (V) may also be present.
In addition, the produced crude oil may contain water, dissolved gases, salt and sand. These have to be removed before the
actual petroleum is subjected to refinery processes.
Because of the geological age of petroleum, the most reactive compounds that might have been present at some time, have
already reacted away. In the hydrocarbon series, the more stable compounds are alkanes (paraffins) including cycloalkanes,
and the aromatics.
Therefore, the major building blocks of molecules found in petroleum are based on alkane, cycloalkane and aromatic
(especially polyaromatic) structures. Typically, a given molecule might contain structural elements from each of these
compound types. As mentioned above, sulfur, nitrogen and oxygen may also be present in these compounds.
The more reactive hydrocarbons, i.e. alkenes (carbon-carbon double bonds) and alkynes (carbon-carbon triple bonds) are not
present in crude oil compounds. However, they might be formed as the crude is being subjected to chemical reactions during
refinery processes.
Cryogenic gas plants are often referred to as expander plants. Cryogenic refrigeration processes are generally accepted as
processes working below minus 50C.
In oil industry terms this refers to very low temperature handling processing or storage of hydrocarbon substances. See also
Cavern storage.
Continental Shelf Act [1954] OR Cross Sectional Area relative to electrical cables
Chloride Induced Stress Corrosion Cracking
Confined Space Entry [Certificate]
Casing
Carrier Sensing Multiple Access with Collision Detection
Continental Shelf Operating [or Operations] Notice
Collection Separator Platform
Combined Safety System
Centistoke [unit of measurement. See Viscosity]
Constantly Stirred Tank Reactor
Control & Safety Upgrade
Certification Scheme for Weld Inspection Personnel
CT
Connection Tool OR Computer Tomography [used to inspect flexible risers] [See also TomX a/s] OR Coiled Tubing
ct
CTA
Current transformer
Construction & Tie In Agreement
Cumulative Trauma Disorders. Of the musculo-skeletal and nervous systems, which develop over a period of time as a result
of longer term repetitive motion, forceful exertions, vibration, mechanical compression, [hard and sharp objects] and sustained
or awkward postures.
Crack Tip Opening Displacement
Cost / Time / Resource
Control Key [Computer]
Crude Oil
Crude Oil
Cryogenic
Cryogenics
CTD
CTOD
CTR
CTRL
Page 30 of 310
CTRs
CTUBD
cum wt
Curie
Current at peak torque [IPK]
[Amperes]
Current, Rated
CUSP™
Custodian
Cut/Cut Point
Cuttings
Cuttings Pile
Cv
CV
CVI
CW
Cycling of gas, recycling
D
D En [also DEn & D.En]
D&A
DAC
DAC
DAF
DAFWC
Daisy chaining
Dalton’s Law of partial pressure
Danger Notice
Cost, Time and Resource planning sheets
CoileD Tubing Under-Balanced Drilling
cumulative weight
The original unit of radioactivity defined as the quantity of any radioactive isotope in which the number of disintegrations per
second is 3.7 x 1010. One curie [Ci] is equivalent to 3.7 x 1010 Becquerels.
The amount of input current required to develop peak torque. This is often outside the linear torque/current relationship.
The maximum allowable continuous current a motor can handle without exceeding motor temperature limits.
Connection of Underwater Systems and Pipe/flowlines; it is a lightweight, diverless, horizontal connection system developed
by Alpha Thames Ltd, that is suitable for the connection of both rigid and flexible flowlines, pipelines and umbilicals. CUSP™
has been designed to significantly reduce the complexity of subsea tie-in and connection operations.
The owner of the BMS document
A “cut” is a hydrocarbon substance or group of substances extracted from a wider mixture in a refining process. For instance,
primary distillation will usually yield a Naphtha/Gasoline cut, a Middle Distillate cut, and a Residual Fuel Oil cut, with an
“Overhead Cut” of gases The specific gravity at which each cut is separated by the process is the Cut Point. Cuts are made
with progressive fineness and accuracy as the oil proceeds through the refinery.
The small chips or flakes of rock retrieved from a well by the circulation of the mud. They are studied and logged by the wellsite geologist. Also Chips and small fragments of rock as the result of drilling that are brought to the surface by the flow of
the drilling mud as it is circulated. Cuttings are important to the geologist who examines them for information concerning the
type of rock being drilled. By examination under a fluoroscope they may indicate the presence, or otherwise, of hydrocarbons
in a reservoir
Pile of primarily rock chips deposited on the seabed as a result of drilling activities.
Calorific Value
Curriculum Vitae
Close Visual Inspection
Cold Water
The process by which an unassociated gas reservoir is produced only for the recovery of condensate, the gas being reinjected into the formation.
Diesel pump
Department of Energy [UK Government]
Dry and Abandoned
Derived Air Concentration. Airborne activity intake by inhalation is limited by the use of the DAC which is equal to the ALI
divided by the breathing rate for light work activity over a 2,000 hour working year.
Discipline Acceptance Certificate
Dynamic Amplification Factor
Days Away From Work Case
The name given to the series connection of wells by flowlines.
This states that the total pressure of a mixture of ideal gasses is equal to the sum of the partial pressures of the constituent
gases.
A Danger Notice is a notice to be displayed at all access points or sections of Electrical Equipment when LIVE or otherwise
dangerous, calling attention to the danger of approach to or interference with such equipment or section. It may not be
practical for some equipment (e.g. 24 Volt control circuits).
Page 31 of 310
Darcy
Dart
Data
Date Required
db
dB
DBB
DBC
DBERR
DBS
DBSE
dc
DCA
DCC
DCD
DCMS
DCN
DCQ
DCR
DCR
DCS
DDC
DDCV
DDR
DEAD
Dead Crude
Dead Oil
Dead well
Deadman Control
Deadman Switch
The unit of measurement of rock permeability, i.e. the extent to which it will allow a fluid to flow through it. The permeability of
most oil and gas reservoir rocks is measured in millidarcies, [thousandths of a Darcy]. Also A porous medium has a
permeability of I darcy when a pressure gradient of I atm/cm on a rock sample of 1 sqcm cross section will force a liquid of 1
cp viscosity through the sample at the rate of 1 cc per sec.
A device dropped or pumped through a tubing or coiled tubing string to activate downhole equipment and tools.
Although applied to any factual information, this term most commonly refers to seismic “data” – the computer records and
output of a seismic survey.
The date for which the task defined in the WCC is expected to take place. If the task is to be carried out over more than one
day then this is the first day of the task.
Dry bulb temperature
Sound pressure level in decibels and measurement of attenuation in signal/comms lines.
Double Block and Bleed
Station Database Computer
Department for Business Enterprise and Regulatory Reform
Dual Ball Safety Valve [and Sampler]
Distance Between Shaft Ends
Direct current OR Delayed-action Coker
Drilling Contractors' Association
Document Control Centre
Discrete Control Device
Document Control Management System
Design Change Notice
Daily Contract Quantity [UK gas sales]
Discipline Check Record
Design and Construction Regulations [SI 1996/913].
Distributed Control System
Deck Decompression Chamber
Deep Draught Caisson Vessel
Daily Drilling Report
Dead means at or about zero voltage and disconnected from any source of electrical energy.
Dead crude is the term used to describe crude oil that has been subjected to conditions of maximum removal of solution
gases from the liquids. Such a system will produce crude oil that has passed through the final stage of separation at low
pressures and cooled prior to being routed to storage. This type of system will have a relatively low TVP.
Oil containing no natural gas.
A well which will no longer produce without further stimulation.
A device for shutting down an operation should the attendant or operator become incapacitated. The attendant using such a
device must consciously exert pressure on a hold-down handle or lever to work the job. When pressure is relaxed owing to
some emergency, the operation will automatically come to a halt.
Interlock that deactivates or de-energizes equipment when the operator releases their grip on the controls or when the
Page 32 of 310
Demersal
The human ear responds logarithmically and it is convenient to deal in logarithmic units in audio systems. The bel is the
logarithm of the ratio of two powers, and the decibel is one tenth of a bel.
The decibel scale is often used to express the signal to noise ratio, frequency and amplitude response limits in the majority of
instrument specifications. The main application is, however, in the acoustic field to define response limits in audio equipment
and as a means of defining noise levels. In the latter case a sound pressure level is defined in decibels in which case a
reference pressure of 2x10-5Pa is used as a base pressure and the pressure measured by a microphone is related to this
standard base pressure.
The logarithmic nature of the decibel allows us to compare two values of enormously different magnitudes with conveniently
small numbers. e. g. the limits of hearing in terms of absolute pressure level cover the range from 20µPa to 200,000,000 µPa.
The same range expressed in dB SPL is 0 -140 dB SPL. This is much more convenient.
A difference of 20 dB between two sounds means that the more intense one has 10 times the amplitude (100 times the power)
The process of gradually re-acclimatizing deep divers to surface pressure conditions. For relatively shallow dives, this is
achieved by controlling the rate of ascent. For longer, deep, “saturation” dives, the divers are recovered under pressure into a
Decompression Chamber where pressure reduction may take some days.
A drilling rig designed and equipped to withstand the loads and pressures associated with drilling to deep objectives e.g. over
20,000 ft [6,000 m].
See Schilling apparatus .
Stationary circular fabrication with vanes mounted between rotating impellers to direct air from the tip of one blower impeller to
center of the next rotating impeller
Degrees
Duoethylene glycol
A separator which removes from the returned mud flow any entrained gases from formations down the well. Gases can cause
a potentially dangerous reduction in the density of the mud and hence its ability to contain down-hole pressures OR any
process which removes gases of various kinds from an oil flow.
Dehydration of wet gas streams is the means by which water is removed to an acceptable specified level. This is normally
achieved by two methods, namely absorption or adsorption.
Equipment for the removal of water from a gas stream, for instance prior to transfer by pipeline.
An appraisal well, usually one drilled specifically to determine the boundary of a discovered reservoir.
Demulsifier
The current level at which the motor magnets will start to be demagnetised. This is an irreversible effect, which will alter the
motor characteristics and degrade performance. Also known as peak current.
Living at or near the bottom of the sea.
Demethaniser
After a gas has passed through a turbo expander it passes to a Demethaniser vessel where the NGL product is recovered.
DEn
DEP
Depcon
Department of Energy
Design Engineering Practice [may need this as references may use it]
Deposits Consent.
Progressive reduction in reserves as a result of production. Depletion allowance in some countries is a type of tax-allowable
amortization recognising this reduction. Depletion drive is primary production, i.e. as a result of a discovered reservoir gases
with decreasing pressures.
Department
A relief map of a sub-surface geological structure where the contours relate to depths from the surface datum level, [i.e. sea
level]. This is a further interpretation of a seismic time map.
Decibel
Decompression [chamber]
Deep rig
Deffusiometer
Deflector
Deg
DEG
De-gasser
Dehydration
Dehydrator [gas]
Delineation well
DEM
Demag current
Depletion
DEPT
Depth map
Page 33 of 310
Derivatives
Derrick
DES
Desiccant
Design and Construct
Design Consultancy Services
Design Services
Design wave
Detent torque
DEV
Development
Development well
Deviated well/hole
Deviation
Dew point 1
The type most frequently used in the oil and Gas industry are psuedo-sales transactions [rather than physical sales of oil, etc].
The simplest is the forward sale of oil that is not intended to be delivered, but “matched” with a suitable purchase at some
intervening time. Derivatives include “Swaps” and “Options”. Their most common use is to control price risk fluctuations
through the markets rather than in conflict with them.
A large load-bearing structure, usually of bolted construction. In drilling, the standard derrick has four legs standing at the
corners of the sub structure and reaching to the crown block. The substructure is an assembly of heavy beams used to
elevate the derrick and provide space to install blowout preventers, casing heads, and so forth. Because the standard derrick
must be assembled piece by piece, it has largely been replaced by the mast which can be lowered and raised without
dismantling.
Drilling Equipment Set
A substance that adsorbs water and is used to remove moisture.
In certain cases it may be desirable to subcontract the whole or part of the work on a Design and Construct basis. In such
cases a back to back subcontract arrangement would normally be used to protect the Company's interests. This arrangement
must be agreed with the Procurement Manager
Specific subcontracts for consultancy services
In general where design responsibility is in part, sub-let
The maximum size and frequency of wave that an offshore structure must be able to withstand.
The maximum torque that can be applied to an unenergised step motor without causing continuous rotating motion.
Development
Any major construction such as a refinery, or a production project. It has come to mean, or cover, the whole life of a
production project from design to abandonment. Strictly speaking it refers to the planned, and actual production of reserves
from a reservoir.
A well drilled in proven territory in a field to complete a pattern of production OR an exploitation well.
A well whose path has been deliberately diverted from the vertical. They are used particularly offshore to reach distant parts of
a reservoir from a single platform. Deviated, or directional drilling up to 60° to 70° from the vertical is now fairly common.
Greater deviation is possible with special equipment – see horizontal drilling and slant drilling.
The angle at which a wellbore diverges from vertical. Wells can deviate from vertical because of the dips in the beds being
drilled through. Wells can also be deliberately deviated by the use of a whipstock or other steering mechanism. Wells are often
deviated or turned to a horizontal direction to increase exposure to producing zones, intersect a larger number of fractures, or
to follow a complex structure.
The dew point [or dewpoint] is the temperature to which a given parcel of air must be cooled, at constant barometric pressure,
for water vapor to condense into water.
The condensed water is called dew.
The dew point is a saturation point.
The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current
air temperature.
If the relative humidity is 100%, the dew point is equal to the current temperature.
Given a constant dew point, an increase in temperature will lead to a decrease in relative humidity.
At a given barometric pressure, independent of temperature, the dew point indicates the mole fraction of water vapor in the air,
and therefore determines the specific humidity of the air, or, put differently, determines the specific humidity of the air.
Page 34 of 310
Dew point 2
The temperature at which a vapour, contained in a closed vessel under the given pressure, will form a first drop of liquid on the
subtraction of heat. Further cooling of the vapour at its dew point results in condensation of part or all of the vapour as liquid.
The dew point of a pure compound is the same as its boiling point.
Dew point 3
The pressure at which the first condensate liquid comes out of solution in a gas condensate. Many gas condensate reservoirs
are saturated at initial conditions, meaning that the dewpoint is equal to the initial reservoir pressure. Condensate dissolution is
called retrograde condensation because this is counter to the behaviour of pure substances, which vaporise when the
pressure drops below the saturation pressure under isothermal (constant temperature) conditions.
DFCS
DFI
D-flange mounting
DGB
DH
DHDP
DHPT
DHPT
DHSV
DI
DI&M
Diapir
Diesel Effect
Differential pressure
DIN
Dinoflagellates
DIP
Dip
Dipmeter
DIPS
Directional drilling 1
Diverless Flowline Connection System
Design, Fabrication, Installation
This type of mount has clearance holes on the flange, and the mounting bolts stick out through the flange from the motor side.
This mount is common in cases where the motor is integral to the machine.
Drilling Guide Base
Dry Hole
Downhole Pressure and Temperature
Down Hole Production Tubing
Downhole Pressure and Temperature Transducer
Downhole Safety Valve, see also SCSSV.
Discrete Input OR Digital Input
Directed inspection and maintenance [programme].
An up-thrust intrusion of lower-density rocks through overlying formations, e.g. a salt dome.
The diesel effect occurs in a hydraulic cylinder when air is drawn past the rod seals, mixes with the hydraulic fluid and
explodes when pressurised.
The difference between the pressure in a well due to the mud column and the pressure in the surrounding rock at any point.
See also sticking. Also The difference in pressure between the hydrostatic head of the drilling-fluid column and the formation
pressure at any given depth in the hole. It can be positive, zero, or negative with respect to the hydrostatic head. The
difference in pressure between the top and the bottom of a fluid column. The difference in pressure between the upstream and
downstream side of a certain point in a process.
Deutches Institut fur Normung [Germna standards]
Plankton with two flagellae.
Dual In-line Package. Generally, a DIP is broadly defined as any rectangular package with two uniformly spaced parallel rows
of pins pointing downward, whether it contains an IC chip or some other device(s), and whether the pins emerge from the
sides of the package and bend downwards or emerge directly from the bottom of the package and are completely straight. In
more specific usage, the term refers only to an IC package of the former description (with bent leads at the sides). A DIP is
usually referred to as a DIPn, where n is the total number of pins. For example, a microcircuit package with two rows of seven
vertical leads would be a DIP14.
The inclination from the horizontal of the top surface of a geological structure OR measurement of the contents of a tank by
lowering a weight and prepared line into it. See also tank dipping.
An instrument that indicates dip relative to a well bore.
Design & Instrumentation of Process Systems
Intentional deviation of a wellbore from the vertical. Although wellbores are normally drilled vertically, it is sometimes
Page 35 of 310
Directional drilling 2
Director
Disconnecting means
Discovery well
DisC™
DISH
Disposal well
Dissociation
Distillates
Distillation
DIV
Diverter
Diverter System
Diving Certificate
DL
DM
DMS
DNV
DO
DOA
Docking-Manifold
Document Control Management
System
DOL
Dome
Dome plug trap
DOP
DOS
Dose Rate
While the normal well bore under usual conditions is planned to be drilled vertically, controlled directional drilling is sometimes
used to drill a well at an angle from the vertical. Examples are the drilling of wells under the sea from location on dry land and
killing a blowout by means of a well drilled from a point at a safe distance from the one being brought under control. Modern
development of this technique makes close control on both the direction and the degree of deviation of a directional well from
the 'vertical possible,
A member of the Petrofac board.
A device used to isolate the conductors of a circuit from their source of supply
A successful exploration well, or wildcat. The first successful well on a new prospective reservoir structure.
Abrasion resistant spring choke control valve based upon a multiple flow paths formed by a stack of discs for use in severe
service conditions or for increased service life including high pressure drops and the presence of sand.
Deep Installation of Subsea Hardware
A well used for the disposal of (usually) salt water. The water is pumped into a subsurface formation sealed off from other
formations by impervious strata of rock; a service well.
The splitting up of a compound or element: into two or more simple molecules, atoms, or ions. Applied usually to the effect of
The products of distillation.
The process of heating and “flashing” or boiling off successive fractions [component hydrocarbon substances] from a crude oil
feedstock, or a product of earlier distillation.
Diving Interface Permit
A safety device fitted in the early stages of a well, instead of a blowout preventer, to divert and vent off any shallow gas
An assembly of nipples and air-actuated valves welded to a well's surface or conductor casing for venting a gas kick
encountered in relatively shallow offshore wells. In shallow wells there is often insufficient overburden pressure around the
base of the conductor casing to prevent the gas from a substantial kick from blowing out around the casing. When a kick
occurs, the blowout preventer is closed and the valves of the diverter system open to vent the gas harmlessly to the
atmosphere.
To be raised when Diving / ROV operations are required on or around the Installation and sub-sea wells.
Density Log. [Also DENL]
Data Manager
Data Management System
Det Norske Veritas BV [Verification Authority]
Digital Output
Delegation of Authority
See KeyMAN™.
An established means of controlling the issue, use and updating of documents used in the management of a site. A full
document control management system [DCMS] will include reference numbers on documents, means of tracking changes
and updates and regular audits of the system to ensure compliance.
Direct On Line [method of connecting and starting electric motors].
A geological structure resembling an inverted bowl; a short and declined the plunges on all sides.
A reservoir formation in which fluid or plastic masses of rock material originated at unknown depths and pierced or lifted the
overlying sedimentary strata.
Diving Operations Permit
Disc Operating System [Computer]
A measure of the presence of Ionising Radiations. It indicates the rate at which energy is being deposited in an absorbing
medium, e.g. milliGray per hour [mGy/h], microGray per hour [uGy/h].
Page 36 of 310
DoT
Down Dip
Down Hole
Downstream
Downtime
DP
Department of Transport
An area of structure where the top of the formation is lower [e.g. offshore, deeper below sea level] than the point under
Down a well. The expression covers any equipment, measurement, etc., in a well or designed for use in one.
“Downstream” is a relative term [the opposite of “Upstream”] in oil industry operations. For instance, a refinery is “downstream”
of a crude oil production unit, and a petrochemical unit, and a petrochemical plant usually downstream of a refinery. The term
has also come to mean all operations occurring after the delivery or lifting of saleable quality crude or gas from the production
unit or associated delivery terminal.
A period when any equipment is unserviceable or out of operation for maintenance etc.
Dynamic Positioning OR dynamically positioned OR dew point OR design pressure OR drill pipe OR data processing OR
drilling platform
DPBV - Dripproof Blower Ventilated
Type of motor cooled by blowing air through the inside of the motor using an attached blower.
DPS
DPVOA
DRA
Draft
DRAMMS
Differential Pressure Switch
Dynamic Positioning Vessel Owners Association [now part of IMCA]
Drag Reducing Agent - pipeline internal coating.
The vertical distance between the bottom of a vessel floating in water and the waterline.
Deepwater Reliability Availability and Maintenance Management System.
The difference between the static and the flowing bottom hole pressures. The distance between the static level and the
pumping level of the fluid in the annulus of a pumping well. Also The difference between the static formation pressure and the
flowing bottom hole pressure in a well.
The hoisting mechanism in drilling rig. It is essentially a large winch spools off or takes in the drilling line and thus raises or
lowers the drill stem and bit.
A special type of drag bit which has inserted in the body matrix industrial or synthetic diamonds
A drilling bit used for soft formations
A bit with super-hard metal lugs or cutting points inserted in the bit's cutting cones; a rock hit with cutting elements added that
are harder and more durable than the teeth of a mill-tooth bit.
A bit with cutting teeth integral to the metal of the cones of the bit.
A heavy, tubular connector between drill pipe and bit. Originally, the drill collar was a means of attaching the drill bit to the drill
pipe and to strengthen the lower end of the drill column which is subject to extreme compression, torsion, and bending
stresses. Now the drill collar is used to concentrate a heavy mass of metal near the lower end of the drill column. Drill collars
were once a few feet long and weighed 400 or 500 pounds. Today, because of increased bit pressure and rapid rotation,
collars are made up to 1000 ft from individual lengths of 30 ft. The combined weight may be as much as 100 tons,
A type of drill collar commonly used to prevent differential wall sticking since they have less wall contact area than the
conventional collar.
Drawdown
Drawworks
Drill bit, diamond
Drill bit, drag
Drill bit, insert
Drill bit, mill tooth
Drill collar
Drill collar, spiral length
Drill cpllar, square
Drill pipe
Drill ship
A type of drill collar whose cross-section is square instead of circular as in a more conventional collar. Square drill collars are
used to prevent or minimise the chance of becoming hung up or stuck in a dogleg down hole. The square corners on the
collar, which is located just above the drill bit in the string, act as a reamer and tend to keep the hole passable for the drill pipe.
Heavy, thick-walled steel pipe used in rotary drilling to turn the drill bit and to provide a conduit for the drilling mud. Joints of
drill pipe are about 30-feet long.
A self-propelled vessel, a ship equipped with a derrick amidships for drilling wells in deep water. A drill ship is self-contained,
carrying all of the supplies and equipment needed to drill and complete a well.
Page 37 of 310
Drill ship
Drill stem
Drill stem test
Drill string
Drill string
Driller
Drilling barge submersible
Drilling crew
A self-propelled floating offshore drilling unit that is a ship constructed to permit a well to be drilled from it. While not as stable
as semisubmersibles, drill ships are capable of drilling exploratory wells in deep, remote waters. They may have a ship hull, a
catamaran hull or a trimaran hull. See floating offshore drilling rig.
All members in the assembly used for rotary drilling, from the swivel to the bit, including the kelly, drill pipe and tool joints, drill
collars, stabilisers, and various speciality items.
A test using a string of drillpipe taken by means of special testing equipment to determine whether or not oil or gas in
commercial quantities have been encountered in the well bore. This test is universally used because it yields useful
information. and permits the continuation of drilling after the completion of the drill stem test to explore other possible pay
sections.
The column of drill-pipe made up of single lengths of pipe and drill collars, providing means of rotating the bit. And circulating
the mud.
The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill
collars and bit. Often, especially in the oil patch, this term is loosely applied to both drill pipe and drill collars. Compare drill
stem.
One who operates a drilling rig; the person in charge of drilling operations and who supervises the drilling crew.
A barge equipped with a drilling installation and used for drilling wells in marshy land or offshore wells in very shallow water. It
is floated in place but rests on the bottom during drilling operations.
From the 'spudding in' of a well to its completion the rig operates on a 24-hour-a-day basis. In charge of the rig operation is the
toolpusher who is responsible to the superintendent via the head toolpusher for the day-to-day operations and for ensuring that
all necessary equipment, tools, materials and services are available.
The driller is responsible for his crew and the running of the rig during his eight or twelve hour shift and he is responsible to the
toolpusher. A trainee driller may be included in the crew.
The derrick man is the next most important member of the crew and his duties are mainly concerned with the handling and
racking of drill pipe as it is pulled or run
During a round trip.
Roughnecks work on the derrick floor and handle the make-up and breakout of drill pipe joints when running or pulling a drill
string.
Roustabouts handle the loading and unloading of equipment and assist in general operations around the rig.
Drilling Crew
The crew on a drilling rig is supervised by a senior drilling engineer, known as a “Toolpusher”. Other members of the crew
include the Driller, in charge of a shift, who ensures adherence to the drilling programme and maintenance of the shifts
operating log, or “Tour Sheet”. He controls the lifting mechanism and hence the weight on the bit [See Drill String]. Other
skilled members, or “Roughnecks” may be Motor Men, Derrickmen, Floor Men, Pump Men etc. Partly skilled members are
known as “roustabouts”. In addition a rig crew will incorporate such specialists as Mud Engineers and Well-Site Geologists.
Drilling floor
Derrick floor; the area where the driller and his crew work.
Drilling fluid
Circulating fluid, one function of which is to force cuttings out of the wellbore and to the surface. Other functions are to cool the
bit and counteract downhole formation pressure. While a mixture of barite, clay, water, and chemical additives is the most
common drilling fluid, wells could also be drilled using the air, gas, water, or oil-base mud as the drilling fluid. See mud.
Drilling jars
Drilling line
A jointed section in a drill string made with slack or play between the joints, which can be mechanically or hydraulically
activated. If the bit becomes lodged in the hole the sudden jar or impact developed by taking up of the slack in the jars may aid
in freeing the bit.
A wire rope used to support the drilling tools. Also called the rotary line.
Page 38 of 310
Drilling mast
A type of derrick consisting of two parallel legs, in contrast to the conventional four-legged derrick in the form of a pyramid.
The mast is held upright by guy wires. This type mast is generally used on shallow wells or for reconditioning work. An
advanced type of deep drilling, rig employs a mast-like derrick of two principal members with a base as an integral part of the
mast.
Drilling mud
A special mixture of clay, water, and chemical additives pumped down hole through the drill pipe and drill bit. The mud cools
the rapidly rotating bit, lubricates the drill pipe as it turns in the well bore, carries rock cuttings to the surface and serves as a
plaster to prevent the wall of the borehole from crumbling or collapsing. Drilling mud also provides the weight or hydrostatic
head to prevent extraneous fluids from entering the well bore and to control down hole pressures that may be encountered.
Drilling mud
Drilling out
Drilling out
Drilling platform
Drilling report
Drilling rig
Drilling slot
Drilling spool
Drilling tender
Drilling tools
Drilling vessel, floating
Drive
Driver
DRL
DRLG
Drop point
Dry gas
A specially compounded liquid circulated through the wellbore during rotary drilling operations. See mud.
This refers to drilling out of the residual cement, which normally remains in the lower section of casing, and the well bore after
the casing has been cemented.
When a well must be deviated or side-tracked, either as planned or to avoid a fish it is normally necessary to cut a hole in the
casing wall and drill out on the new path.
Any of several types of drilling units used in marine drilling operations. They fall into the following general categories: fixed
platform with floating drilling tender; self-contained fixed platform (all equipment, pipe :racks etc. on it); self-contained mobile
platform (supported on sea bottom by legs or spuds when in drilling position); tender-assisted mobile derrick platform; floating
platform (either semi-submersible, also called deep floater, or ship-shape); submerged drilling barges.
Every twenty-four hours the Driller’s log and the geological cuttings log, together with the observations of the Toolpusher and
any other significant data are sent, usually by telex, to the Area Drilling Manager and other interested parties. The report will
also include e.g. usage of materials, stock levels and requirements for supplies.
Almost all drilling is now carried out by rotary rigs. The “Rig” comprises a derrick, a draw-works or source power, lifting tackles
and blocks, a Kelly and rotary table to rotate the drill string, a mud pump and mud circulation system, a blow out preventer,
and a system for handling drillpipe casing etc.
See keyway.
A spool with side outlets for kill and choke lines fitted between the BOP stack and the wellhead.
A barge used in marine drilling in conjunction with a fixed platform. It contains the power supply, circulating pumps (connected
to the platform by hoses) and storage tanks, drill pipe racks, casing, cement, living quarters and generally helicopter landing
platform.
A term applied generally to any down-hole accessory including for instance stabilizers, jars, fishing equipment and directional
drilling apparatus.
A vessel anchored in place, from which drilling is carried out
An electronic device that controls torque, speed and/or position of an AC or brushless motor. Typically a feedback device is
mounted on the motor for closed-loop control of current, velocity and position.
Electronics which convert step and direction inputs to high power currents and voltages to drive a step motor. The step motor
driver is analogous to the servomotor amplifier's logic.
Drill
Drilling
The temperature at which, when a grease! is heated, a drop falls from the orifice in the bottom of' the cup holding a sample of
that grease.
Natural gas which has a water vapour content of below sales or transfer specifications and/or which does not contain liquid
hydrocarbons at storage pressure.
Page 39 of 310
Dry Gas
Dry hole
Dry hole
DS
DSAW
DSC
DSCM
DSCS
DSEAR
DSL
DSM
DSMS
DSR
DST
DSU
DSV
DSWP
DT
DTD
DTI
DTp
DTU
Dual Completion
Dual-Fuel Engines
Dubai Storage Tanks
Dump Flooding
Duster
Dutchman
Duty cycle
DV
DWO
DWOP
DWP
DWT
Natural gas, methane and ethane, without any significant content of heavier hydrocarbon fractions.
Somewhat loosely used in oil work, but in general any well that does not produce oil or gas in commercial quantities. A dry
hole may flow water, or gas, or may even yield some oil, but not in commercial quantities.
An unsuccessful well. Sometimes called a “Duster”.
Directional Survey
Double Submerged Arc Welded
Digital Selective Calling
Dummy Subsea Control Module
Duplex Self-Cleaning Strainer
Dangerous Substances and Explosive Atmospheres Regulations 2002
Direct Shuttle Loading
Diving Safety Memorandum
Diving Safety Management System
Direct Screen Reference [number]
Drill Stem Test
Distress Signal Unit
Diving Support Vessel
Deterministic Sea Wave Prediction
Design Temperature
Driller’s Total Depth
Department of Trade and Industry [UK] http//:www.og.dti.gov.uk
Department of Transport
Dry Tree Unit
The completion of a well in two separate producing formations, each at different depths. The two formations may either be
produced through two separate tubing strings (two-string-dual or TSD) or one tubing string (single-string-dual or SSD). In the
latter case the two formations can be produced successively or at the same time (commingled). In both types of completion
packers are used -to seal off between formations .and tubing strings.
Engines equipped to run on liquid as well as gaseous fuel. Stationary engines in the field have modifications made to their
A specially designed, under-water storage tank the shape of an inverted funnel, built by Chicago Bridge & Iron for Dubai
Petroleum Company. The tanks have no bottom and rest on the sea floor supported on their rims. Oil from fields onshore is
pumped into the top of the tanks under pressure forcing the seawater out the bottom. The offshore tanks, which are more than
100 feet tall also, serve as single-point moorings for tankers -taking on crude.
An unusual secondary recovery technique that uses water from a shallow waterbed above the producing zone to flood the oil
A dry well drilled during exploration.
The threaded portion of a length of pipe or nipple twisted or broken off inside a collar or other threaded fitting. Threads thus
lost in a fitting have to be cut out with a chisel or cutting torch.
For a repetitive cycle, the ratio of on time to total cycle time. Duty cycle [%] = [On time / [On time + Off time]] x 100%
Diverter Valve
Drilling With Oil
Deepwater Operations Plan
Design Working Pressure
Dead weight tonnage. The load-carrying capacity of a vessel, the “live” weight being the displacement weight of the unladen
vessel.
Page 40 of 310
DWT
DYNAGRAPH CARD
DYNAMIC
Dynamic braking
Dynamic positioning
DYNAMIC STATIONING
DYNAMOMETER
E&I
E/E/PE
E/E/PES[s]
E/H MUX
EAC
EAH
EALQ
Earthed
EAWR
EBS
EC
ECC
ECD
ECITB
ECN
Economic depletion
Economic limit
Economic zone
ECP
ECSM
EDB
EDC
EDEA
EDF
EDG
EDMS
Dead Weight Tonnage
The graphical recording of the dynamometer.
The state of being active or in motion; opposed to static.
A passive technique for stopping a permanent magnet brush or brushless motor. The motor windings are shorted together
through a resistor which results in motor braking with an exponential decrease in speed.
A satellite monitoring system used to control the action of thruster/propellers to maintain a vessel on location without deploying
anchors.
A method of keeping a drill ship or semi-submersible drilling platform on target, over the hole during drilling operations where
the water is too deep for the use of anchors. This is accomplished by the use of thrusters activated by underwater sensing
devices that signal when the vessel has moved a few degrees off its drilling station.
The surface, or polished rod dynamometer is a tool which records the resultant of all forces acting along the axis of the
polished rod at any particular instant of time during one pumping stroke of a pumping unit. This load curve is recorded with
respect to polished rod position.
Electrical & Instrumentation
Electrical/Electronic/Programmable Electronic
Electrical/Electronic/Programmable Electronic System[s]
Electro-Hydraulic Multiplexed
Ecological Assessment Criteria.
Emergency Anchor Handling
Extra Additional Living Quarters
Earthed means connected to the general mass of the earth in such a manner as will ensure, at all times, an immediate
discharge of electrical energy without danger.
Electricity At Work Regulations 1989
Emergency Breathing System
Commission of the European Communities [European Commission].
Emergency Co-ordination Centre
Equivalent Circulating Density. The increase in bottomhole pressure expressed as an increase in pressure that occurs only
when mud is being circulated. Because of friction in the annulus as the mud is pumped, bottomhole pressure is slightly, but
significantly, higher than when the mud is not being pumped. ECD is calculated by dividing the annular pressure loss by
0.052, dividing that by true vertical depth, and adding the result to the mud weight.
Engineering Construction Industry Training Board
Engineering change notice.
Progressive reduction in the value of a producing asset as a result of production. See also Depletion Allowance.
The minimum rate to which the production of a well may decline and still be profitable.
The area of the seabed over an adjacent state can claim rights of exploitation [currently up to 200 miles].
Emergency Control Point
Electrical Control & Monitoring System
Electrical Distribution Board OR Economic Development Board.
Emergency Disconnect
European Drilling Engineering Association
Early Development Facility
Emergency Diesel Generator
Electronic Data Management System
Page 41 of 310
EDP
EDS
EDT
EDU
EECS
EEM
EEMUA
EEPROM
EER
EER
EERA
EERVA
EFC
Efficiency
Effluent
EFL
EFW
EGC
EH or E/H or E-H
EHDM
EI
EIA
EIA
EIC
EIF
EIS
El
Elastomer
Electric Swivel
Electrical drilling
Electrical Equipment
Electrical Isolation
Electrical survey
Electrical System
Electrical time constant [te]
[Seconds]
Emergency Depressurisation OR Electronic data processing OR Emergency disconnect package OR Early Development
Phase
Element Data Sheet
Eastern Daylight Time [USA & Canada]
Electrical Distribution Unit
Electrical Equipment Certification Service
Electrical Equipment Room
Engineering Equipment and Materials Users Association
Electrical Electronic Erasable Programmable Read Only Memory
Escape, Evacuation and Rescue
Evacuation, Escape and Rescue
Escape, Evacuation and Rescue Analysis
Emergency Response and Rescue Vessel Association
European Federation of Corrosion
The ratio of power output to power input.
The discharge or out-flow from a manufacturing or processing plant; Outfall; Drainage.
Electrical Flying Lead
Electric Fusion Welded
Enhanced Group Calls
Electro-Hydraulic
Electro-Hydraulic Distribution Manifold
Energy Institute, formed in 2003 by the merger of the IP and the InstE
Environmental Impact Assessment.
Energy Information Administration [USA DoE].
Energy Industries Council http//:www.the-eic.com
Environmental Impact Factor
Environmental Impact Statement [or study]
Elevation
An elastic material made of synthetic rubber or plastic; often the main component of the packing material in blowout
preventers and downhole packers.
A powered swivel which rotates the drill stem from above the rig floor, thus replacing the Kelly and rotary table.
A drilling method, used to a certain extent in the USSR, whereby the bit is rotated by a down-the-hole electric motor attached
to the drill pipe or hanging from a cable in the borehole.Electrical equipment includes anything used, intended to be used or installed for use, to generate, provide, transmit, transform,
rectify, convert, conduct, distribute, control, store, measure or use electrical energy.
Electrical Isolation is the disconnection and separation of electrical equipment from every source of electrical energy in such a
way that this disconnection and separation is secure.
Identification of subsurface rocks by measuring their resistance to electric currents.
A system means an electrical system in which all the electrical equipment is, or may be, electrically connected to a common
source of electrical energy, and includes such source and such equipment.
The time required for current to reach 63.2% of its final value for a fixed voltage level. Can be calculated from the relationship
te=L/R where L is inductance [henries] and R is resistance [ohms].
Page 42 of 310
ELI
Eliminate
ELM
ELOCS
ELSBM
ELV
EMA
EMAS
Any activity that requires the installation, repair, removal, replacement, modification, extention or cleaning of any component
part associated with electrical equipment. It does not include electrical isolations [switching] in support of mechanical work,
unless they involve physical disconnection of cables or earthing down of equipment.
The document used to detail the step by step procedure to be followed both for making the equipment safe and the work
process to be undertaken.
A bit powered by an electric down-hole motor which operates without the need to rotate the drill string.
A substance, which dissociates into charged positive and negative ions when in solution or a fused state and which will then
conduct an electric current. Acids, bases and salts are common electrolytes.
A heavy, hinged clamp attached to the hook and travelling block by bail-like arms and used for lifting drill pipe, casing and
tubing and lowering them into the hole. In hoisting a joint of pipe, the elevators are latched on to the pipe just below the tool
joint or coupling which prevents the pipe from slipping through the elevators.
A clamp used in a drilling rig to latch onto the grip drill pipe, casing etc when lifting them.
Alpha Thames’ subsea, wet-mateable, high-voltage, high-power, three-phase, electrical connector. Uniquely, it utilises an
external fluid exchange mechanism [FxM™] to remove the entrained [sea] water and it maintains the electrical connections in
a one-atmosphere inert dry, clean gas environment, thereby eliminating the long-term concerns of electrical breakdown
associated with other subsea electrical connector designs.
Earth Loop Impedance
To remove or get rid of.
Executive Line Monitor
Earthquake Loading, [The Norwegian] Continental Shelf
Exposed Location Single Buoy Mooring
Extra Low Voltage
Electronic Material Administration
Engineering Maintenance Assurance System OR Eco Management and Audit Scheme.
EMBC
Electronic Modulating Bleed Control. Allows a blower to bleed off excess air or a vacuum producer to ingest air to avoid surge
EMC
EMDC
EMI
EMP
EMS
EMTS
Emulsifier
Electromagnetic Compatibility
ExxonMobil Development Company
Electromagnetic Interference
Essential Maintenance Periods
Environmental Management System
ExxonMobil Travel Services
A substance which can produce an emulsion of two liquids which do not mix.
A material that causes water and oil to form an emulsion. Water normally occurs separately from oil; if, however, an
emulsifying agent is present, the water becomes dispersed in the oil as tiny droplets. Or, rarely, the oil may be dispersed in
the water. In either case, the emulsion must be treated to separate the water and the oil.
A heterogeneous system, consisting of at least one immiscible liquid intimately dispersed in another in the form of droplets,
whose diameter, in general, exceed 0.1 micron. Water in crude oil and crude oil in water are two forms of emulsions occurring
in oilfield flow processes.
A mixture in which one liquid, termed the dispersed phase, is uniformly distributed [usually as minute globules] in another
liquid, called the continuous phase or dispersion medium. In an oil-water emulsion, the oil is the dispersed phase and the
water the dispersion medium; in a water-oil emulsion, the reverse holds. Emulsion is a typical product of oilwells. Water-oil
emulsion is also used as a drilling fluid.
Electrical Work
Electrical Work Plan
Electro-Drill
Electrolyte
Elevators
Elevators
ELEx™
Emulsifying Agent
Emulsion
Emulsion
Page 43 of 310
Emulsoid
Emulsoid
EN
Encoder
Energy Systems
EnGarde
Enhanced oil recovery
Enhanced oil recovery
Enquiry
Enquiry
Enquiry Review
Enriched gas injection
Entrained oil
Entrained Oil/Gas
Entry Certificate
Env
ENVID
Environmental aspect
Environmental effect
EOR
EP
EPA
EPAQS
EPC
EPDM
EPIC
EPIRB
EPL
Colloidal particles which take up water.
Colloidal particles that take up water.
Euronorme [standard]
A feedback device which converts mechanical motion into electronic signals. The most commonly used, rotary encoders,
output digital pulses corresponding to incremental angular motion. For example, a 1000-line encoder produces 1000 pulses
every mechanical revolution. The encoder consists of a glass or metal wheel with alternating transparent and opaque stripes,
detected by optical sensors to produce the digital outputs.
Systems, which by their nature contain energy e.g. hydraulic, mechanical, electrical, potential and pneumatic.
A maintenance management system that references particular tasks with a number.
Recovery methods for crude oil which go beyond the primary recovery techniques. Enhanced recovery methods now being
used include mi-cellar-surfactant, steam drive, polymer, miscible hydrocarbon, C02 and steam soak. EOR methods are not
restricted to secondary or even tertiary projects. Some fields require the application of one of the above methods even for
initial recovery of crude oil.
A means used to assist in the extraction of oil either by installing equipment into the production tubing or by injecting water or
gas into the reservoir.
Any contact from a client or potential client with a request to quote for work..
Communication from an existing or potential client which may result in ARL being contracted to supply a service
A documented review prior to contract acceptance to ensure that the client’s requirements are understood, defined and
documented and that the company has the capability in terms of scope, manpower and workload to satisfy the clients
requirements.
An enhanced recovery method involving the injection of gas rich in intermediate hydrocarbons or enriched by addition of
propane, butane, or pentane on the surface or in the well bore as the gas is injected.
Oil occurring as part of a gas stream, but as a relatively small percentage of total flow.
Formation gas that enters the drilling fluid in the annulus. Small amounts of oil which may form part of a gas stream, due to
the difficulties of separation at source. Similarly gas may be entrained in a stream of other fluids.
A document to certify that conditions have been tested and are safe for personnel to enter into a confined space. This may be
cross-referenced to other WCC’s to prevent entry being authorised until other work has been completed first e.g. Isolation.
Environmental OR Environmental Category
ENVironmental issues and hazard IDentification study
An activity that causes an environmental effect.
Any change to the environment or its use.
Enhanced Oil Recovery. See Miscible Gas Injection MGI.
Experimental programme
Environmental Protection Agency [USA]
Expert Panel on Air Quality Standards
Engineering, Procurement and Construction
Ethylene Propylene Diene Monomer
Engineering, procurement, installation and construction. An all-in contract for Engineering Procurement and Construction. In
the many variants such as EPCI, Feed, etc. “I” normally signifies Inspect or Install, and “F” signifies Fabricate.
Emergency Position Indicating Radio Beacon
Emergency Power and Lighting
Page 44 of 310
Epoxide resins
EPR
EPROM
EPRS
EPS
EPU
EQ
EQD
EQDP
Equalising sub
Equip
Equipment Description
Equity crude
Equity Crude
Equivalent circulating density
Equivalent Dose
Equivalent weight
Equivalent weight or Combining
weight
ER
ER
ER
ERA
ERA
ERB
ERC
ERC
ERCR
ERD
ERD
Ergonomic Injury
Ergonomics
ERO
ERP
Resins used as the resin components of surface coatings of various sorts. They are usually made by condensation of
epichlorohydrin with a polyvalent alcohol or phenol. Examples are the EPIKOTE resins (called Epon in the U.S.).
Explosion Protection Review OR Ethylene Propylene Rubber
Erasable Programmable Read Only Memory
Emergency Pipeline Repair System
Emergency Power Supply
Electrical Power Unit
Engineering Query
Emergency Quick Disconnect
Emergency Quick Disconnect Package
The equalising sub provides a means of equalising pressure across sub-surface controls in order to reopen them or to
facilitate releasing the locking mandrel for the removal of the device from the landing nipple.
Equipment
The description of the equipment to be worked on.
In cases where a concession is owned jointly by a host government and an oil company, the crude produced, which belongs to
the oil company, is known as crude is calculated according to the posted price. See also Buy-back .
Crude oil belonging directly to the equity participant in the oil field, as opposed to “Farmers crude”, royalty oil, Government
participation crude, etc.
For a circulating fluid, the equivalent circulating density equals the hydrostatic head plus the total annular pressure drop
divided by the depth to give gradient.
The radiation dose obtained by multiplying the absorbed dose by a radiation weighting factor to account for the varying effects
of different Ionising Radiations when causing damage to tissue. The Sievert [Sv] is the unit of equivalent dose. The radiation
weighting factor for gamma rays and beta particles is 1, hence the absorbed dose in Grays is numerically equal to the
equivalent dose in Sieverts for gamma and beta radiation
Or Cobining Weight. The atomic or formula weight of an element, compound, or ion divided by its valence. Elements entering
into combination always do so in quantities proportional to their equivalent weights.
The atomic or formula weight of an element, compound, or ion divided by its valence. Elements entering into combination
always do so in quantities proportional to their equivalent weights.
Emergency Response
External Reference
Extended Reach
Explosion Risk Analysis
Electrical Research Association
Emergency Response Base/Branch
Emergency Response Centre OR Emergency Response Control.
Evacuee Reception Centre
Emergency Response Control Room
Extended Reach Drilling
Engineering Reference Document [Shell Expro] OR extended reach drilling
Cumulative trauma disorders that result from a work-related activity
The study of the relationship between the worker, the work environment, and the work being performed
Emergency Response Organisations
Emergency Radio Point
Page 45 of 310
ERR
ERRVA
ERT
ERW
Emergency Response Room
Emergency Response and Rescue Vessel Association
Emergency Response Team
Electric Resistance Welded
ES
Engineering Standard [Shell] OR Escape Set OR Emergency Services OR Environmental Statement OR Electrical Supply
ESB
ESC
East Shetland Basin
Engineering Services Contractor
Devices used on offshore drilling or production platforms for emergency escape of personnel in the event of a fire or
explosion. They consist of counter-weighted arms supporting a buoyant head. When the arms are snapped loose from the
platform, they fall outward, the head descending to the water. The workers then slide down a lifeline to the floating head.
An inclined wire-line running from a point above the monkey or fourble board of the derrick down to a ground anchor.
Emergency Shut Down OR electrostatic discharge
Emergency Shut Down panel
Emergency Shutdown Valve – an automatically operated, normally open valve used for isolating a subsea pipeline.
Electric Submersible Jet Pump
Electric Submersible Pump
Elected Safety Representative
Expandable Sand Screen
Emergency Systems Survivability Analysis
Estimated Time of Arrival
Electrical Transient Analysis Programme
Embedded Temperature Detector
Energy Technology Data Exchange
A paraffin hydrocarbon, C2H6; under atmospheric conditions, a gas. One component of natural gas.
A simple hydrocarbon associated with petroleum. Ethane is a gas at ordinary atmospheric conditions.
Extended Tension Leg Platform
Expandable Tubular Technology Forum
European Union
Equipment under test
Enhanced Voidage
Ethylene Vinyl Acetate
An excavation dug to contain oil field salt water or brine which is disposed of by evaporation. Great amounts of salt water are
produced with crude oil in some oil fields, particularly older fields.
A method for illustrating the intermediate and final outcomes which may arise after the occurrence of a selected event. See
Fault Tree.
Enhanced Vertical Shelf Tree
Exploratory Well
Extended Well Test
Symbol which signifies the certified use of electrical equipment in hazardous locations e.g. Ex[d] explosion proof.
Any fabricated cavity or depression in the earth's surface formed by earth removal that produces unsupported earth conditions
due to the work.
Executive Committee.
Page 46 of 310
Escape booms
Escape line
ESD
ESDP
ESDV
ESJP
ESP
ESR
ESS
ESSA
ETA
ETAP
ETD
ETDE
Ethane
Ethane C2 H6
ETLP
ETTF
EU
EUT
EV
EVA
Evaporation pit
Event Tree [Analysis]
EVST
EW
EWT
Ex
Excavation
Excom
Expansion fit
Expansion joint
Expansion loop
Expansion Loop
Expansion roof tank
Expansion Vessel
Exploitation
Exploitation well
Exploration
Exploration
Exploration activities
Exploration well
Exploration well
Explosion proof
Explosive Fracturing
Exposure hours
Extensions
External Cutter
Extra Low Voltage
F&G
Fabrication Contracts
See Shrink fit .
A section of piping constructed in such a way as to allow for expansion and contraction of the pipe connections without
damaging the joints. Specially fabricated, accordion-like fittings are used as expansion joints in certain in-plant hook ups
where there are severe temperature changes.
A circular loop (omega shaped) put in a pipeline to absorb expansion and contraction caused by heating and cooling, without
exerting a strain on pipe or valve connections.
A bend or loop installed in a length of pipeline to absorb longitudinal expansion with changes in outside temperature, the
passage of hot fluids, etc.
A storage or working tank with a roof made like a slip joint, As the vapour above the crude oil or volatile product expands with
the heat of the day, the roof-and-apron section of the tank moves upward permitting the gas to expand without any loss to the
atmosphere. The telescoping roof, as it moves up and down, maintains a gas-tight seal with the inner wall of the tank.
This name applied to the vessel into which gas is expanded for a cold separation application. It also is referred to as a cold
separator or a low temperature separator. The vessel differs considerably from the normal separator since it is designed
primarily to handle and melt gas hydrates that are formed by expansion cooling. In cold separation applications where a
hydrate preventative is used, the design may be very close to that of normal separator. The usual working pressure of this
vessel is in the range of 1000 to 1500 psig.
The development of a reservoir to extract its oil.
A well drilled to permit more effective extraction of oil from a reservoir e.g. an oil or gas producer, or gas or water injector to
support production. Sometimes called a development well [see development well].
The phase in which a possible hydrocarbon region is being investigated, either by geological or geophysical surveys or by
exploratory drilling. Successful exploration is followed by appraisal and development.
The process of identifying a prospective hydrocarbon region and structure, mainly by reference to regional, and specific
geochemical, geological and geophysical [seismic] surveys, including core testing, and the drilling of wildcats.
The search for oil and gas. Exploration activities include aerial surveying, geological studies, geophysical surveying, drilling
and coring of wildcat wells.
A well drilled to discover accumulations of oil and/or gas.
A well drilled to test a potential but unproven hydrocarbon trap or structure where good reservoir rock and a seal or closure
combine with a potential source of hydrocarbons. Also called a wildcat [see wildcat].
Being enclosed in a case, which is capable of withstanding an explosion of a specified gas, or vapour which may occur within
it and of preventing the ignition of the specific gas or vapour surrounding the enclosure by sparks, flashes or explosions of the
gas or vapour within.
When explosives are used to fracture a formation. At the moment of detonation, the explosion furnishes a source of highpressure gas to force fluid into the formation. The rubble prevents fracture healing, making the use of proppants unnecessary.
In Safety: Total number hours of employment including overtime and training but excluding leave, sickness and other
absences.
Tubular components attached to the bottom of a packer to extend it bore.
A fishing tool containing metal-cutting knives that is lowered into the hole and over the outside of a length of pipe to cut it.
The severed part of the pipe can then be brought to the surface.
Normally not exceeding 50 Volt ac or 120 Volt do whether between electrical conductors or to earth.
Fire and Gas
Modular construction works, pipe fabrication, structural fabrication etc. Contracts in which a major part of the work is carried
Page 47 of 310
Facies
FAH
Fail safe
Fail-safe
Failure Modes and Effects Analysis
Fairlead
Fairway
FARSI
Fast line
FAT
Fatality
Fatigue
Fault
Fault trap
Fault Tree [Analysis]
In geology, the “appearance” and hence the composition and characteristics of a rock formation. Cores are taken from a well,
for example, so that the reservoir facies can be studied. A Facies Trap for hydrocarbons is one in which the seal or closure is
provided by a change in rock characteristics, a form of stratigraphic trap.
Federal Agreement Holder
Said of equipment or a System so constructed that, in the event of failure or malfunction of any part of the system, devices are
automatically activated to stabilise or secure the safety of the operation.
Equipment that will leave a system in a safe condition in the event of a power failure.
A process for hazard identification where all known failure modes of components or features of a system are considered in
turn and undesired outcomes are noted.
A guide for ropes or lines on a ship to prevent chaffing; a sheave supported by a bracket protruding from the cellar deck of a
semi-submersible drilling platform over which an anchor cable runs. Some large floating platforms have anchor lines made up
of lengths of chains and cable.
A shipping lane in offshore waters. Permanent structures such as drilling and production platforms are prohibited in a fairway,
which significantly curtails oil activity in some offshore areas.
Functionality, availability, reliability, survivability and interaction.
The end of the hoisting line which is affixed to the drum or reel. It is so called as it apparent-.y travels with greater velocity than
any other portion of the drilling line.
Factory Acceptance Test[s]
In Safety: A death resulting from a Work Injury, regardless of the time intervening between injury and death.
Failure or weakening of a metal under repeated loading.
A break in subsurface strata. Often strata on one side of the fault line have been displaced [upward, downward, or laterally]
relative to their original positions.
A structural trap, favourable for the retention of oil, formed by a body of reservoir rock bounded up-dip by a sealing fault.
A method for representing combinations of various system rates which lead to a justification outcome [“the top event”]. See
Event Tree.
Fault/Fault Block
A discontinuity in a rock formation caused by fracturing of the earth’s crust. There are various causes of fault-fractures such as
the movement of “tectonic plates” relative to each other. In oilfield terms a Fault Block is a compartment of a rock formation
surrounded or partly surrounded by faults, which may have sealed in hydrocarbons separately from the rest of the formation.
FB
FBD
FBE
FBHP
FBM
FBSV
FCCU
FCG
FCM
FCV
FD
FDD
FDM
FDP
Full Bore
Functional Block Diagram
Fusion Bonded Epoxy
Flowing Bottom-Hole Pressure
Field Bus Module
Full Bore Safety Valve
Fluidised Catalytic Cracker Unit or 'Cat Cracker' [as in a refinery]
Free Circulation Goods
Fieldbus Communication Modules
Flow Control Valve
Formation Density
Floppy Disc Drive
Frequency Division Multiplex
Field Development Plan
Page 48 of 310
FDS
FDSI
FE
FEA
FEED
Feedback
Feedstock
FERC
Fermenatation
Ferrite
FeS
FES
FFD
FG1
FG2
FGL
FGMP
FGP
FGTP
FIC
Field
Field
Filter (Dust Scrubber)
Filter cake
Filter Cake/Filtrate
FIM
Find Now Button
Fines
Finger Printing
Fingering
Functional Design Specification
Field Device System Integrator
Flow Element (for example, orifice)
Facilities Engineering Association OR Finite element analysis OR Fire and explosion analysis
Front End Engineering Design [or drawings] - an early phase of oil field development.
A signal which is transferred from the output back to the input for use in a closed loop system.
Stock from which material is taken to be fed (charged) into a processing unit.
Federal Energy Regulatory Commission [US]
Decomposition process of certain organic substance, e.g., starch, in which a chemical change is brought by enzymes,
bacteria, or other microorganisms. Often referred to as souring.
A type of permanent magnet consisting of ceramic compounds made up of oxides of iron, barium and strontium.
Iron Sulphide
Fire and Explosion Strategy
Full Field Development
Fire Grade One Shut Down
Fire Grade Two Shut Down
Fulmar Gas Line
Fire and Gas Mimic Panel
Fire and Gas Panel
Fuel Gas Treatment Plant
Flow indicating controller
The area encompassing a group of producing oil and/or gas wells.
See Oilfield. A field may also be a gas or gas condensate field.
Where liquid is present to a fair degree in a gas stream, the conventional oil and gas separator will remove any solid particles
in the stream. The liquid acts to trap the solids in the mist extractor (or coalescer) and other sections of the separator. It then
serves as a medium to flow solids out of the vessel.
When gas is dry, there are still solid particles present to interfere with some phases of gas transmission and distribution. The
vessel designed to remove these solids is called a filter or dust scrubber.
The filter normally uses a dry filter pack to trap undesirable particles. These filter packs require periodic removal for changing
or cleaning.
A plaster-like coating of the borehole resulting from the solids in the drilling fluid adhering and building up on the wall of the
Build up of mud solids or filtrate on the wall of a well. This helps seal and stabilise the rock face, but too much can cause
sticking of the drill string. See also Differential Pressure.
Fire Input Module
A button that initiates a search based on user defined or default filters.
Small particles of rock or other solid.
Crude oil is a mixture of hydrocarbon components or fractions and other minerals. The composition of each crude is different
in consequence, leading to differences in gravity, etc. Nowadays, the source of a crude – e.g. an oil-spill – can be determined
by analysis known as “finger printing”
A phenomenon that often occurs in an injection project in which the fluid being injected does not contact the entire reservoir
but bypasses sections of the reservoir fluids in a finger-like manner. Fingering is not desirable, because portions of the
reservoir are not contacted by the injection fluid. Also, uneven advance of water and/or gas towards an oil well due to
inconsistent permeability in the reservoir. When the finger reaches the well oil will tend to be excluded.
Page 49 of 310
Finish Button
Fire loop
Fireflooding
First end connection
First line break
Fiscal metering
Fish
Fishing
FIT
Five-Spot Waterflood
Fixed installation
FLAGS
Flame-Jet Drilling
Flammable liquids
Flange Up
Flare
Flare stack
Flash Chamber (Separator, Drum)
Flash drum
Flash Off
Flash Point
Flashover
FLC
FLNG
A button provided on each screen of the wizards allowing the user to terminate and save the document at that step, for
recovery and completion later, by the same or another user. The document will be saved in the Requested State. If
incomplete the document will be represented by an open [transparent].
A pneumatic control line containing temperature sensing elements [fusible plugs, synthetic tubing, etc.] which, when activated,
will initiate a platform shutdown.
A form of Enhanced Oil Recovery in which otherwise unproduceable heavy oils are ignited in the reservoir. The cracking effect
enables resulting lighter fractions to be recovered.
A term used to describe the first end connection of a reeled pipeline or umbilical, as against the second end connection.
The initial opening of lines or equipment after appropriate preparation
The accurate measurement of oil, gas or condensate flow rate for taxation purposes.
An unwanted object down a well, commonly the lower end of a drill string which has broken off.
Fishing is trying to recover the Fish, using various attachments to the drill stem or wireline, known as fishing tools.
Factory Integration Test
A standard method of development where a production well is surrounding by four water injection wells to “sweep” the
maximum amount of oil towards the producer.
A fixed offshore structure involved in the production of oil and gas and which may be constructed of steel or concrete. A term
frequently used in the UK to describe an offshore installation.
Far North Liquids and Associated Gas System
The use of a rocket-fuel flame to penetrate rock by fusing [melting] it. The flame also glazes and seals the walls of the well
with fused rock.
A liquid having a flash point below 100ºF and a vapor pressure exceeding 40 psi absolute at 100ºF
To connect; to complete; to put into operation.
A vent for burning off unwanted gases or to burn off hydrocarbons which due to temporary malfunction or maintenance of
process plant, cannot be safely stored or retained in process vessels.
An elevated tower containing a pipe used for the discharge and burning of waste gases.
This is a two-phase vessel used as a subsequent stage of separation to process the liquid hydrocarbons flashed from a
primary separator. The name is applied to the vessel used as a second stage separator on a cold separation unit. The vessel
is usually of low pressure design-not more than 125 psig working pressure. It rarely differs from the conventional low pressure
separator.
The secondary purpose is degassing liquid before it enters another process. An example is in an electrostatic coalescer or
desalter where no free gas can be tolerated, the fluid is first degassed in a flash separator which is elevated above the
coalescer so that once degassed the fluid will remain gas-free.
A pressure vessel used to lower the pressure of oils and other liquids involved with the production processes in order to
encourage the vaporisation of dissolved gases.
To vaporize or “boil off” a hydrocarbon by heating.
The lowest temperature at which a vapour will burn or explode when ignited.
In a compartment there can come a stage where the total thermal radiation from the fire plume hot gases and hot
compartment boundaries causes the generation of flammable products of pyrolysis from all exposed combustible surfaces
within the compartment. Given a source of ignition this will result in the sudden and sustained transition of a growing fire to a
fully developed fire, this is called a 'Flashover'.
Full Load Current [of an electrical load measured in amperes].
Floating Liquefied Natural Gas [plant].
Page 50 of 310
FLOAct™ Actuator
Float Out
Float/Floating Casing
Floater
Floating offshore drilling rig
Flocculant
Flocculent
Flood
Flotation
Flotation Cans
Flour
Flow Assurance
FlowCap™
Flowing Bottom Hole Pressure
Flowline
Flowline Bundle
Flowmeter
FLP
Fluid
Fluid Flow
Flush Phase
Flyco
FM
FMA
FMC
FMEA
FMECA
FMQ
FO
FOET
FOI
Footage/Footage Rate
Alpha Thames’ pressure-balanced, subsea, electric, linear actuator that is unique in that it is the first subsea electric actuator
available with the performance required for the actuation of choke valves
The launch or leading out of jackets or other structures for installation offshore, on a Flotation barge or other vessel, or in
some cases using their own buoyancy.
A method of inserting heavy lengths of casing into a well without overstressing joints and seals due to the weight of the total
string. The bottom end is sealed, and the hollow string then becomes buoyant in the drilling fluids in the well, which are
gradually displaced. Afterwards the seal is drilled out and the casing cemented into place.
See floating offshore drilling rig.
A type of mobile offshore drilling unit that floats and is not secured to the seabed [except for anchors]. Floating units include
inland barge rigs, drill ships, ship-shaped barges and semisubmersibles. See mobile offshore drilling unit.
A substance added to a suspension to enhance aggregation of the suspended particles.
Aggregated in woolly cloud like masses [e.g. a flocculent precipitate].
To let or pump water into ballast tanks. See also Waterflood and Fireflood.
Flotation barge or other vessel, or in some cases using their own buoyancy.
Are hollow tanks attached to a jacket to assist buoyancy or help control the lowering to the seabed.
Fluorescence
Scale / hydrates / wax / asphaltenes.
A non-processing System-Module within an AlphaCPU™, comprising piping flow-loops to provide for bypass control.
Bottom hole pressure measured at a given flow rate.
The pipe through which produced fluid travels from a well to a manifold, to processing equipment or to storage.
An integrated assembly of production flowlines, and hydraulic and/or electrical control lines, connecting a subsea/satellite well
to its parent installation.
A meter to measure the rate at which a fluid passes a given point.
Flowline Pressure OR Flameproof. [see Ex]
A generic term meaning gas, vapour, liquid, or a combination thereof.
The state in fluid dynamics of a fluid in motion is determined by the type of fluid [e.g., Newtonian, plastic, pseudoplastic,
dilatant]; the properties of the fluid such as viscosity and density; the geometry of the system; and the velocity. Thus, under a
given set of conditions and fluid properties, the fluid flow can be described as plug flow, laminar [called also Newtonian,
streamline, parallel, or viscous] flow, or turbulent flow.
The primary production phase of a reservoir.
Flying Co-ordinator
Frequency Modulation
Fracture Mechanics Assessment
Facility Muster Coordinator
Failure Mode and Effects Analysis
Failure Mode, Effects and Criticality Analysis
Firm Maximum Quantity. [As in delivery into a pipeline system such as Forties].
Flow Orifice (restricting orifice, used in a pump bypass loop to maintain a minimum flow through the pump)
Further Offshore Emergency Training
Fax of Intent
Penetration rate in drilling. Footage Rate may also be a form of remuneration under a drilling contract. Often referred to as a
ROP [Rate of Penetration].
Page 51 of 310
Footprint
FOP
Force/Posture
Form factor
Formal
Formation 1
Formation 2
Formation Damage
Formation Fracturing
Formic Acid
ForPPAS
FoS
Foundation Pile
The limit of radius of action of an underwater vessel or vehicle. OR The impact/impression on the seabed of a jack-up facility
OR the O/A plan dimensions of an item of equipment.
Front of Panel.
Factors that contribute to CTDs Examples: improper lifting, improper turning of valves, poor work station posture.
The ratio of RMS current to average current. This number is a measure of the current ripple in a SCR or other switch-mode
type of drive. Since motor heating is a function of RMS current while motor torque is a function of average current, a form
factor greater than 1.00 means some fraction of motor current is producing heat but not torque.
A formal process or agreement is one that is written, recorded and audited. It may also include tracking to ensure that work is
following the process or agreement.
A rock deposit or structure or homogeneous origin and appearance.
A geologic formation is a formally named rock stratum or geological unit. Formations are Lithostratigraphic units which are
defined by primary lithology. The concept of formally defined layers or strata is central to the geologic discipline of stratigraphy.
Formations allow geologists to correlate geologic strata across wide distances between outcrops and exposures of rock strata.
Formations were initially described to be the essential geologic time markers based on relative ages and the law of
superposition.
The divisions of the geological time scale were the formations described and put in chronological order by the geologists and
stratigraphers of the 17th and 18th centuries.
Modern revision of the geologic sciences has restricted Formations to lithologies, because lithological units are formed by
depositional environments, some of which may persist for hundreds of millions of years and will transgress chronostratigraphic
intervals or fossil-based methods of correlating rocks.
For example, the Hammersley Basin is a Proterozoic sedimentary basin where up to 1200 million years of sedimentation is
preserved within the intact sedimentary stratigraphy, with up to 300 million years represented by a single lithological unit of
banded iron formation and shale.
Geologic formations are usually sedimentary rock layers, but may also be metamorphic rocks and volcanic flows. Igneous
Damage to the reservoir around a well due to e.g. plugging with mud, infiltration by water from the well, crumbling under
pressure or high flow rate, etc.
A method of stimulating production by opening new flow channels in the rock surrounding a production well. Often call a frac
job.
Under extremely high hydraulic pressure, a fluid [such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or
kerosene] is pumped downward through production tubing or drill pipe and forced out below a packer or between two packers.
The pressure causes cracks to open in the formation, and the fluid penetrates the formation through the cracks.
Sand grains, aluminum pellets, walnut shells, or similar materials [propping agents] are carried in suspension by the fluid into
the cracks.
When the pressure is released at the surface, the fracturing fluid returns to the well. The cracks partially close on the pellets,
leaving channels for oil to flow around them to the well.
An organic acid, H2CO2 or HCOOH, used for acidizing oilwells. It is stronger than acetic acid but much less corrosive than
hydrofluoric or hydrochloric acid and is usually used for high-temperature wells.
Forties Pipeline Production Allocation System
Factor of Safety
The first casing or conductor string [generally with a diameter of 30 to 36 inches] set when drilling a well from an offshore
drilling rig. It prevents sloughing of the seabed formations and is a structural support for the permanent guide base and the
blowout preventers.
Page 52 of 310
Four quadrant
FPA
FPAL
FPCC
FPDSO
FPF
FPF
FPO
FPP
FPR
FPS
FPS
FPSO
FPV
FR
FRA
Fracturing
FRAMS
FRC
Free-water knockout
Friable
Friction
FRO
FRS
FS
FSA
FSD
FSEA
FSH
FSIP
FSK
FSM
FSO
Refers to a motion system which can operate in all four quadrants; i.e., velocity in either direction and torque in either direction.
This means that the motor can accelerate, run, and decelerate in either direction.
Fire Precaution Act 1971 [UK]
First Point Assessment Ltd http//:www.fpal.co.uk Industry database which captures information required during
prequalification to eliminate duplication and repetitive activities within the bid process
Forties Pipeline Control Centre.
Floating Production, Drilling, Storage and Offloading [vessel].
Floating Production Facility. [A vessel designed to provide offshore field production control and processing for smaller fields,
more cheaply than a fixed platform. The tension-leg platform is specifically designed to meet this need in deeper waters but
transport barges, semi-submersible drilling rigs, and tankers are all capable of modification for the purpose depending on
water depth and environment].
Floating Production Facility
Field Purchase Order
Floating Production Platform
Field Plateau Rate
Floating Production System
Forties Pipeline System
Floating Production Storage and Off Loading vessel. [A versatile and relatively low-cost Floating Production Facility for small,
difficult isolated or deep water reservoirs].
Floating Production Vessel
Flow Recorder OR final report
Fire Risk Analysis
A well is fraced to stimulate or prolong oil & gas production. Special fluids are pumped into a wellbore with powerful hydraulic
pumps to cause enough pressure to crack or fracture the formation. This process creates a plane of high-permeability sand,
which usually allows the hydrocarbons to flow more freely into the wellbore.
Floating Riser And Mooring System
Fast Rescue Craft
A vertical or horizontal vessel into which oil or emulsion is run in order to allow any water not emulsified with the water oil [free
water] to drop out. See also FWKO.
A material, such as asbestos, that can break into small particles or crumble
A resistance to motion caused by contact with a surface. Friction can be constant with varying speed [Coulomb friction] or
proportional to speed [viscous friction].
Full Range Output
Fisheries Research Station/Service
Feedstock
Formal Safety Assessment
Full Scale Deflection [of measuring instruments]
Fire Structural Endurance Analysis
Flow Switch High (high flow alarm)
Final Shut-In Pressure
Frequency Shift Keying [used in communication signals]
Fiscal Standards Meters
Floating Storage and Off-loading [vessel]
Page 53 of 310
FSU
FSW
FTHP
FTP
FU
Fuel Oil
Fugitive Emissions
Fusible plug
FW
FWD
FWHP
FWHT
FWKO
FWPH
FWV
FxM™
g
GA
GAF
Galv
Gas
Gas Cap/Gas Cap Drive
Gas Chromatography
Gas Column
Gas Condensate
Gas Injection
Gas Kick
Floating Storage Unit
Feet of Sea Water
Flowing Tube Head Pressure
Flowing Tubing Pressure
Field Unit
The “bottom” or “heavy end” of the barrel after removal of middle distillates and lighter fractions. There are various grades of
Light and Heavy Fuel Oil.
Fugitives are defined as the sum of emissions from accidental discharges, equipment leaks, filling losses, flaring, pipeline
leaks, storage losses, venting and all other direct emissions except those from fuel use.
A fail-safe device; a plug in a service line equipped with a seal that will melt at a predetermined temperature releasing
pressure that actuates shut-down devices; a meltable plug.
Fresh Water OR feed water
Forward
Flowing Wellhead Pressure
Flowing Wellhead Temperature
Free Water Knockout. [See Knockout]
Firewater Pumphouse
Flow Wing Valve
The Fluid Exchange Mechanism that expels and replaces seawater, in the ELEx™ Connector enclosure, with a dry clean inert
gaseous atmosphere. The FxM™ is located external to the ELEx™ Connector.
Gauge
General Alarm OR General Arrangement [drawing].
Gross acre-feet
Galvanised
A compressible fluid that fills any container in which it is confined. Technically, a gas will not condense when it is compressed
and cooled, because a gas can exist only above the critical temperature for its particular composition. Below the critical
temperature, this form of matter is known as a vapour, because liquid can exist and condensation can occur. Sometimes the
terms gas and vapour are used interchangeably. The latter, however, should be used for those streams in which condensation
can occur and that originate form, or are in equilibrium with, a liquid phase.
The natural accumulation of associated gas in the top of an oil reservoir. Gas Cap Drive, or primary production utilizes the
pressure and expansion of this gas to drive the oil to the surface. Sometimes called Depletion Drive.
A very accurate laboratory method of separating and analysing the components of a volatile hydrocarbon mixture.
See Oil Column/Gas Column.
Light hydrocarbon fractions entrained in gas production which condense into liquid when brought to the surface. Changes in
reservoir pressures as result of production may cause it to condense in the reservoir, when much of it may become
irrecoverable. See Retrograde Condensation.
A secondary recovery method by which gas is injected into and passed through the reservoir to maintain pressure and/or
entrain heavier hydrocarbons left behind by primary production. The reservoir can in this way also serve as storage for
produced gas until the reservoir pressure can be reduced, and the gas sold.
Increase of down hole pressure above that exerted by the column of drilling fluid in a well, allowing gas to escape to the
surface. If not controlled this could develop into a Blowout.
Page 54 of 310
Gas lift
Gas Oil
Gas Test Certificate
Gas/Oil Ratio
Gasser
Gate
GAUGE TANK
GAUGER
GAUGING NIPPLE
GBL
GBS
GCPD
GCR
GDT
GEC
Gel
Gel strength
Gelled up
Generic Title
Geochemical Survey
Geology
Geology/Geologist
Geophones
Geophysical exploration
Geophysics
Geophysics/ Geophysicist
Geothermal Gradient
GEP
GFCI
The process of lifting fluid from a well by injecting gas down the well through the tubing - casing annulus. Injected gas aerates
the fluid to reduce its SG thereby overcoming the static head of fluid in the wellbore allowing the well fluid to be produced to
the surface. Gas may be injected continuously or intermittently depending on the producing characteristics of the well and the
arrangement of the gas lift equipment.
A middle distillate product fraction.
The document used to detail and authorise the Gas Test requirements associated with a particular task.
A measure of the volume of gas produced with oil, expressed in cubic feet per barrel of cubic meters per tonne.
A gas well.
Used to describe one type of isolation valve.
A tank in which the production from a well or a field is measured.
Production employee charged with measuring activities in production operations (rates, pressures, temperatures, etc.)
A section of pipe in the top of a tank through which a tank may be gauged.
Game Based Learning.
Gravity Base Structure
Gallons of Condensate Per Day
Gas/Condensate Ratio
Gas Down To…
General Electric Company
A state of a colloidal suspension in which shearing stresses below a certain finite value fail to produce permanent deformation.
The minimum shearing stress that will produce permanent deformation is known as the shear or gel strength of the gel. Gels
commonly occur when the dispersed colloidal particles have a great affinity for the dispersing medium, i.e. is lyophilic.
The ability or the measure of the ability of a colloid to form gels. Gel strength is a pressure unit usually reported in lb/100 sq.Oil field jargon usually referring to any fluid with high gel strength and/or highly viscous properties. Often a state of severe
flocculation.
Generic Title - title applied to Class of Requisition to identify materials to be purchased e.g. Pressure Vessels - Carbon Steel
or Atmospheric Storage Tanks.
Analysis of the hydrocarbon-bearing potential of an area by studying shallow cores and subsurface water for evidence of
seepage or kerogens.
The science that deals with the history of the earth and its life as recorded in the rocks.
The study of the history of the earth and its rocks. The geologists in the oil and gas industry tend to specialise of
Sedimentology, Palaeontology and other branches of the science relating directly to prospectivity for hydrocarbon deposits.
Sound wave receivers primarily for onshore seismic surveys. See also Hydrophone.
The search for geological structures favourable to the accumulation of hydrocarbons by means of' geophysical devices, such
as the gravimeter, the magnetometer and the seismometer.
The application of certain familiar physical principles-magnetic attraction, gravitational pull, speed of sound waves, the
behaviour of electric currents - to the science of geology.
Physics applied to the measurement of the earth and study of its composition. A Geophysicist in the oil and gas industry
usually specialises in the interpretation of seismic survey data.
The increase of temperature with depth in the earth’s crust. [About 2 F°. per 100 feet].
Gas Export Pipeline
Ground Fault Circuit Interrupters
Page 55 of 310
GFPTFE
GI
GIIP
GIM
Gin pole
Gin pole truck
GIS
GJ
GKA
GL
GLIS
Globe valve
GLR
Glycol dehydrator
Glycols
GM
Gm/cm3, gm/cc, g/cm3
GMDSS
Goals
GOC
Go-devil
GoM
GOMB
Gone to water
Gooseneck
GOR
GOR
GPA
GPD
GPH
Glass Filled PTFE (or Teflon).
Gas Injection
Gas Initially In Place
Gas Input Module
An A-frame made of sections of pipe mounted on the rear of a truck bed that is used as a support or fixed point for the truck's
winch line when lifting or hoisting. A vertical frame on the top of the derrick, spanning the crown block, providing a support for
hoisting. A mast. A vertical pipe or pole mounted to a christmas tree to lift and support a wireline lubricator.
A truck equipped with a pair of poles, and hoisting equipment for use in lifting heavy machinery around a field. Also used for
lifting the lubricator for wireline work.
Geographic Information System
Gigajoules
Greater Kittiwake Area
Grid Line
Gas Lift Insert String
A valve that does not have seats in its inlet and outlet ports but instead has one seat inside the valve housing through which
the flow is diverted. The valve is opened or closed by turning a handwheel on a Stem which moves a circular plug or flat disc
away from or toward the valve seat. These valves are the most used for regulating.
Gas Liquid Ratio
An absorber tower in which natural gas is brought in intimate contact with glycol to remove water vapour from the gas.
A group of organic compounds with two hydroxyl groups per molecule. The parent of ' this group is monoethylene glycol
(C2H602), often called glycol. Other members are, for example, diethylene glycol (C4H1003) and triethylene glycol
(C6H1404). Glycols are used for the prevention of hydrate formation in natural gas and as absorbents in the dehydration of
natural gas.
General Manager
grams per cubic centimetre
Global Maritime Distress and Safety System
How Petrofac production is trying to achieve specific deliverables.
Gas/Oil Contact OR Guidance on Certification
A round bar of steel used, for instance in formation testing. It is dropped down the drill pipe to open the top valve of the tester
and bring the tester and empty drill pipe into communication. The formation fluid then enters the pipe under the influence of
the pressure in the formation. Also used as a wireline tool to function as a base for a wireline cutter. A device used for cleaning
out a pipeline consisting of a piston type scraper usually pumped through the line. A device used for the separation of two
liquids that are pumped one after the other through the same pipeline. Colloquial: Drift mandrel.
Gulf of Mexico
Gas and Oil Measurement Branch [Department of Energy]
A well in which the production of oil has decreased and the production of water has increased to the point where the well is not
longer--profitable to operate.
A nipple in the shape of an inverted U attached to the top of the swivel and to which the mud hose is attached.
Gas/Oil Ratio. [The proportional amount of gas to oil liquid occurring in production from a reservoir, usually expressed as cubic
Gas-to-Oil Ratio - scf/stb Gas/oil ratio
General Platform Alarm
Gallons Per Day
Gallons Per Hour
Page 56 of 310
GPM
GPS
GPW
Gr. API
Graben
Gradient
Gradient curve
Grains per gallon
Grass-Roots
Gravel Pack
Gravel packing
Gravimeter
Gravitometer
Gravity drive
Gravity Platform/Structure
Gravity survey
Gravity, API
Gravity, specific
GRE
Greenhouse effect
Greenhouse gas
GRN
Gallons Per Minute
Global Positioning System OR Geometrical Product Specification
Gross Product Worth.
Gravity – Degrees API
A structure which has become displaced downward from its original surrounding geological setting.
The rates of increase or decrease of temperature or pressure in relation to depth. Also: flowing gradient, static gradient.
Graphical representation of pressure as a function of depth for flowing reservoir fluids inside a specified tubing and at a
specified G.L.R.
Ppm equals gpg x 17.1.
Description of a refinery or other development project where there is no existing plant or infrastructure – i.e. construction on a
“green field” site.
Where the producing formation in a well is crumbling or caving into the well bore and plugging the perforations, the cavity so
formed is filled with fine gravel, which supports the formation, and keeps the interior of the well clean.
A sand exclusion technique whereby gravel is placed around a metal screen installed opposite the producing formation. Gravel
and screen sizes are selected so that influx of formation sand is stopped. Gravel packs can be set in open hole or inside the
casing.
An instrument which measures minute variations in the earth’s gravitational pull at different surface points due to the density of
the underlying rocks. A gravimetric survey uses this principle in the search for sedimentary rocks which normally have a
relatively low density.
An instrument which measures differences in the specific gravity of liquids, and is used to identify interfaces between batches
of different products in a pipeline.
A reservoir drive mechanism. In highly permeable and steeply dipping formations the effect of gravity may be so pronounced
that liquids should best be withdrawn from wells situated on the flank of the structure.
Offshore platforms etc., which rely on weight alone to keep them stable and in place. They are frequently made of concrete
with steel as a major component. Steel gravity structures are also used. Structures of such size are floated into position, the
buoyancy being provided by hollow chambers in the large base of the platform. Subsequently these are flooded with water,
and can be used for oil storage.
An exploration method in which an instrument that measures the intensity of the earth's gravity is passed over the surface or
through the water. In places where the instrument detects stronger or weaker than normal gravity forces, a geological structure
containing hydrocarbons may exist.
The gravity (weight per unit volume) of crude oil or other related fluids as measured by a system recommended by the
American Petroleum Institute. It is related to specific gravity by the following formula: 141.5 Deg API = ---------------- - 131.5
sp.gr.60 F/60 F
The ratio of weight of equal volume of two substances, one of which is taken as a standard. Water is taken as a standard or
comparison for liquids and solids. For gas, air is usually taken, although hydrogen is sometimes used.
Glassfibre Reinforced Epoxy
The greenhouse effect results in a rise in temperature due to infra-red radiation trapped by carbon dioxide and water vapour in
the earth’s atmosphere.
Gas that contributes to the greenhouse effect. Includes gases such as carbon dioxide and methane.
Goods Received Note
Page 57 of 310
GVC Gross Calorific Value
Ground Disturbance
Grounded, effectively
Grout
GRP
GRV
GSO
GST
GSV
GT
GTF
GTL
Guide Base/Lines/Posts
Guidewords
GUM
Gumbo
Gun perforating
Gunning the pits
Gusher
Guy wire
Guyed-tower platform rig
GVF
GVI
GVP
GW
GWC
GWP
The gross calorific value at constant pressure of a gaseous fuel is the number of heat units produced when unit volume of the
fuel, measured under standard conditions, is burned in excess air in such a way that the materials after combustion consist of
the gases carbon dioxide, sulphur dioxide, oxygen and nitrogen, water vapour equal in quantity to that in the gaseous fuel and
the air before combustion and liquid water equal in quantity to that produced during combustion, and that the pressure and the
temperature of the gaseous fuel, the air and the materials after combustion are one standard atmosphere and 25*C (British
Standard definition).
Work that involves a man-made cut, cavity, trench or depression formed by earth removal, or driving piles into the earth
surface.
Permanently connected to earth through a ground connection that has sufficiently low impedance [less than 25 OHMS] and
sufficient ampacity to ensure that the ground fault current that may occur cannot build up to voltages dangerous to personnel
A mixture of cement and water [no sand] used to secure and seal attachments such as piles into jacket legs.
Glass Reinforced Plastic
Glassfibre Reinforced Vynilester
Goal Setting Objective
GeoSteering Tool
Gross Standard Volume
Gas Turbine
Gas Tight Floor
Gas To Liquid
The seabed framework or template through which a subsea well is drilled. It is fitted with Guide Posts from which Guide Lines
extend to the surface, and enable the wellhead to be located ready for drilling, and for installation and control of eg the Blowout
Preventer.
A list of words applied to system items or functions in a hazard study to identify undesired deviations.
Guide to the expression of Uncertainty in Measurement
A heavy, sticky mud formed down hole by certain shales –when they become wet from the drilling fluid.
A common method of completing a well is to set casing through the oil- or gas bearing formation. The casing is then gun
perforated by a device, which is lowered in the hole and fires projectiles through the casing, and into the productive formation.
Compare: Jet perforating, Shaped-charge perforating.
Mechanical agitation of the drilling fluid in a pit by means of a mud gun, electric mixer, or agitator.
A well that comes in with such great pressure that the oil blows out of the wellhead and up into the derrick, like a geyser. With
improved drilling technology, especially the use of drilling mud to control down hole pressures, gushers are rare today.
A cable or heavy wire used to hold a pole or mast upright. The end of the guy wire is attached to a stake or a deadman.
A compliant offshore drilling platform used to drill development wells. The foundation of the platform is a relatively lightweight
jacket upon which all equipment is placed. A system of guy wires anchored by clump weights helps secure the jacket to the
seabed and allows it to move with wind and wave forces. See platform rig.
Gas Volume Fraction OR gas void fraction.
General Visual Inspection [Structural]
Group Vice President
Gas Well OR Gallons of Water
Gas/Water Contact
Global Warming Potential
Page 58 of 310
GYCC
H&MB
H&SE
H&V
H2S
H2S, H2S
HAA
HACC
HAD
Hall sensor
Halocarbons
Hand-over
Hanger
Hanging in the Slips
Hanging-in the Casing
Hardness
HART
HART [card]
Hastelloy®
HASWA [HASAWA]
HAT
Hatch
HAU
HAVs
Hay pulley
HAZ
HAZAN
Hazard
Great Yarmouth Control Centre
Heat and Mass Balance
Health & Safety Executive
Heating and Ventilation
See Hydrogen Sulphide 1 and 2
Hydrogen Sulphide, [deadly sour gas].
High Level Acoustic Alarm
Hazardous Area Classification Committee
Helideck Attendant
A feedback device which is used in a brushless servo system to provide information for the amplifier to electronically
commutate the motor. The device uses a magnetised wheel and hall effect sensors to generate the commutation signals.
Are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms: fluorine,
chlorine, bromine or iodine. Chlorine halocarbons are the most common and are called organochlorides. There are also
compounds such as methylammonium chloride that include carbon atoms and noncovalent halogen atoms, also called
inorganic halogens. Unlike halocarbon halogens, noncovalent halogen atoms will usually dissociate and ionize in water.
Halocarbons are a class of organic compounds containing covalently bonded fluorine, chlorine, bromine, or iodine.
The detailed review of an operating unit’s status, condition and ongoing work.
See Casing and Tubing.
Suspended drill string or casing from slips or wedges placed in the rotary table.
Tensioning a string of casing which cementing by letting it hang from the wellhead. This helps to offset later expansion due to
The hardness of water is due principall,7 to the calcium and magnesium ions present in the water and is independent of the
accompanying acid ions. The total hardness is measured in terms of parts per million of calcium carbonate or calcium and
sometimes equivalents per million of calcium
Highway Accessible Remote Transducer
Hazard Recognition and Toolbox talk
Highly durable material used to fabricate multistage blowers with properties exceeding stainless steel. Also Hastelloy C-276
for springs in mechanical seals - resists stress corrosion cracking and is standard in most seals of this type.
Health and Safety at Work Act [1974]. [Lays down very clear requirements and obligations on all employers and employees
branded by the words “so far as is reasonably practicable”].
Highest Astronomical Tide level OR Harbour acceptance trials
An opening in the top of a tank or other vessel through which inspections are made or samples taken; a gauge hatch through
which the tank volume is measured.
Hydraulic Accumulator Unit
Hand Arm Vibration syndrome
A grooved sheave chained to the X-mas tree and used to change the direction of the wireline during well entry operations.
Heat Affected Zone [around a weld] where the base metal has not been melted but whose mechanical properties or
microstructure have been affected by the heat generated during the welding process.
Hazard Analysis
A physical situation with the potential to cause harm to an individual or number of individuals, or damage to equipment or the
environment.
Page 59 of 310
Hazard Analysis
Hazard Indices
Hazard Survey
Hazard Zone
Hazardous Area
Hazardous Area [location]
Hazards
HAZID
HAZID
HAZOP
HB
HBV
HC
HC
HCFC
HCLS
HCP
HCR
HCV
HDD
HDPE
Header
Header
Heading
Heat exchanger
Heat Exchanger
Heat treatment
Heater treater
Heave
The identification of undesired events that leads to the modifications of a hazard, the analysis of the mechanisms by which
these undesired events could occur and usually the estimation of the extent, magnitude and likelihood of any harmful effects.
A checklist method of hazard identification which provides a comparative ranking of the degree of hazard posed by particular
design conditions.
The total effort involved in an assessment of the hazards from an installation and their means of control.
An area where special safety precautions apply.
Hazardous area is one in which flammable atmospheres may be present, so that special precautions for the construction, use
and maintenance of electrical equipment are required (see Appendix 3).
An area where volatile gases or substance exist or may exist and only certified electrical equipment can be used and where a
‘permit to work’ situation exists.
Equipment, materials, activities, or conditions that have a significant potential to cause injury.
Hazard Identification
Hazards in Design [analysis]
Hazard and Operability study/analysis. [A study carried out by application of guidewords to identify all deviations from design
intent with undesirable effects for safety or operability].
Brinell Hardness
Hepatitis B Virus
Hydrocarbon
Hand Control (manual control)
Hydrochlorofluorocarbons
Heave compensated lift system [see Heave Compensator]
Health Care Provider
Hydrocarbon Releases (System) reporting via RIDDOR to HSE
Hand Control Valve
Hard Disc Drive
High Density Polyethylene
A large-diameter pipe to which a number of smaller pipes are connected; a collection point for oil or gas gathering lines.
A pipe into which several smaller diameter pipes feed fluid into or feed from fluids.
An intermittent or unsteady flow of oil from a well. This type of flow is often caused by a lack of gas to produce a steady flow
thus allowing the well's tubing to load up with oil until enough gas accumulates to force the oil out.
An apparatus for transferring heat from one fluid to another. Specifically, a piece of equipment having a tubular piping
arrangement that effects the transfer of heat from a hot to a relatively cool material by conduction through the tube walls.
A process vessel which typically uses the passage of one fluid through a set of internal tubes to heat up or cool down another
fluid in which they are immersed. There are many different designs and uses.
An operation or combination of operations involving the heating and cooling of a metal or an alloy in the solid state for the
purpose of obtaining certain desirable conditions or properties.
A pressure vessel for the dehydration of' crude oil. A package unit, very compact, which contains everything necessary for
treating oil: gas/liquid separation section, oil settling section, heating section, wash water section and free water section. The
treated oil is discharged to the storage tanks or pipeline.
The vertical motion of a floating vessel or platform with the waves.
Page 60 of 310
Heave compensator
Heave Compensator
Heaving
Heavy crude
Heavy ends
Heavy Ends
Heavy Oil
HeliC™
Helipad
HEMP
HEPA
Heresite®
Heterogeneous
HF
HFIS
HFO
HGOR
HGT
HIC
HIC
High [Geological]
High pressure gas injection
High Voltage
HIP
HIP
HIP
HIPO
HIPPS
HIRA
HIV
A type of snubber-shock absorber on a floating drilling platform or drill ship chat maintains the desired weight on the drill bit as
the unstable platform heaves on ocean swells. Some compensators are made with massive counterweights others have
hydraulic systems to keep the weight on the bit constant. Without compensators, the bit would be lifted off bottom as the
platform rose on each swell.
A Heave Compensator is installed on a crane on floating drilling rigs to counteract this movement with regards the drillstring
and marine conductor or installation/recovery of other equipment or structures.
The partial or complete collapse of the walls of a hole resulting from internal pressures due primarily to swelling from hydration
or formation gas pressures.
In general terms (not an official classification), crude oil with API gravity below 20 degrees.
In refinery parlance, heavy ends are the heavier fractions of refined oil - fuel oil, lubes, paraffin and asphalt -remaining after the
lighter fractions have been distilled off.
Heavy or residual fractions of a feedstock after distillation, etc. Sometimes referred to as the “bottom” or “heavy end” of the
barrel.
See Crude Oil.
Abrasion resistant spring choke control valve based upon a helically shaped orifice for use in severe service conditions or for
increased service life including high pressure drops and the presence of sand.
A Helicopter landing deck or onshore landing area.
Hazard Effects Management Process
High Efficiency Particulate Air filter that removes dust, pollens, and other air-borne particles from air
Highly durable coating that protects internal blower parts from corrosion
A substance that consists of more than one phase and is not uniform, such as colloids, emulsions, etc. It has different
properties in different parts.
High Frequency
Helicopter Flight Information Service
Heavy Fuel Oil
High Gas/Oil Ratio
High-pressure Grease Tube
Hybrid Integrated Circuit
Hydrogen Induced Cracking
The parts of a geological structure which are nearer to surface datum/sea level. Hydrocarbons tend to accumulate in Highs.
The term is also used on a regional basis, where rocks of one geological era are nearer the surface over a broad area.
Introduction of gas into a reservoir in quantities exceeding the volumes produced in order to maintain reservoir pressure.
Normally exceeding 1000 Volt ac or 1500 Volt do between electrical conductors, or 600 Volt ac or 900 Volt do between
conductor and earth.
High Integrity Power [System]
Hydrate Inhibition Pipeline
Hot Isostatic Processing [moulding technique]
Hazards In Production Operations
High Integrity Pressure [or Pipeline] Protection System . A pressure system with voting logic that activates a fast-acting
isolating valve to protect pipelines which are not designed to withstand the maximum pressure conditions.
Hazard Identification and Risk Assessment
Human Immuno Virus ??
Page 61 of 310
HLA
HLG
HLO
HLSD
HLV
Hmax
HMCG
HMI
HMP
HMPE
HMSO
HO
Hold Up
Holding torque
Hole opener
Hole opener
Hole Temperature
Holiday
Holidays
Homogenous
Hook
Horizon
Horizontal Drilling
Horozon
Horsehead
Horsepower
Horsepower
Horsepower
Horsepower
Horsepower 1
Horst
Hot Tap
Hot tapping
Hot tapping
Hot work
High Level Alarm
High Level Gas
Helicopter Landing Officer
High Level Shut Down
Heavy Lift Vessel
Maximum Wave Height
Her Majesty’s Coastguard
Human Machine Interface
Hazards Management Process
High molecular polyethylene [rope]
Her Majesty’s Stationary Office
Heating Oil OR heavy oil
The quantity of hydrocarbons which is retained, in normal operations, in the process lines and vessels of a plant.
Sometimes called static torque, holding torque specifies the maximum external torque that can be applied to a stopped,
energised motor without causing the rotor to rotate. Generally used as a figure of merit when comparing motors.
A type of reamer used to increase the diameter of the well bore below the casing. The special tool is equipped with cutter arms
that are expanded against the wall of the hole and by rotary action reams a larger diameter hole.
A device used to enlarge the size of an existing borehole, having teeth arranged on its outside circumference to cut the
formation as it rotates.
Formation temperature at a given depth in a well.
A discontinuity in a coating, which exhibits electrical conductivity when exposed to a specific voltage.
Breaks or flaws in the protective coating of a joint of pipe. Holidays are detected by electronic testing devices.
Of uniform or similar nature throughout; or a substance or fluid that has at all points the same property or composition.
The hook attached to the frame of the rig's travelling block and which engages the bail of the swivel., or the bails of the
elevator.
The formation at a given depth in a well, usually identified by geological age, i.e. “Middle Jurassic Horizon”.
A technique for deviating wells through up to 90° from the vertical, but more importantly, “horizontal” to the reservoir strata.
A zone of a particular formation; that part of a formation of sufficient porosity and permeability to form a petroleum reservoir.
See also Pay zone .
The curved guide or head piece on the well-end of a pumping Jack's walking beam. The metal guide holds the short loop of
A unit of power equivalent to 33,000 foot-pounds a minute or 745.7 watts of electricity.
HP = Torque [lb-in.] x Speed [RPM]/63,025 or
HP = Torque [lb-ft.] x Speed [RPM]/5,252 or
HP = Volts x Amps x Efficiency/746
An index of the amount of work a machine or motor can perform. One horsepower is equal to 746 watts. Since power is equal
to torque multiplied by speed, horsepower is a measure of a motor's torque and speed capability. eg 1 HP motor will produce
36 lbin at 1,750 rpm.
A structure such as a fault-block, which has become up-thrust from its original surrounding geological setting.
Inserting a branch line into a pipeline or vessel which is still in operation.
Making repairs or modifications on a tank, pipeline or other installation without shutting down opera-.ions, often under
pressure.
Mechanical method of adding a new tie-in or drain point to existing piping or equipment without interrupting the service
Any work involving the use of flame and/or spark producing equipment, tools, etc.
Page 62 of 310
HP
HPHT or hp/t
HPM
HPR
HPU
HPWC
hr
HR
hr
HR
hrc
HRP
Hs
HS&E
HSC
HSE
HSEQ
HSL
HSMS
HSR
HSS
HSSD
HSSE
HSWA
HT
HTSD
HUC
HUET
HUMS
Work involving the use of open flames, electric welding or any positive or potential sources of ignition
Work which involves either the use or the possible creation of a flame, spark or high energy discharge that could act as the
ignition source for a fire or explosion.
High pressure OR hydrostatic pressure OR horse power
High Pressure, High Temperature
High-level Process Manager
Hydroacoustic Position Reference
Hydraulic Power Unit
High Pressure Water Cleaning
Hour
Hazard Register
Hour
Human Resources
High rupturing capacity [used for electric fuses]
Hazard Recognition Plus [HAZARD +]
Significant Wave Height
Health, Safety and Environment
Health and Safety Commission
Health & Safety Executive [UK] OR Health, safety and environment [in NORSOK Std]
Health, Safety, Environment and Quality
Health & Safety Laboratory
Health & Safety Management System
High Speed Redundancy
Heat Shrink Sleeve
High Sensitivity Smoke Detector
Health, Safety, Security and Environment
Health and Safety at Work Act [1974]
High Tension [electrical voltage]
High Temperature Shut Down
Hook-Up and Commissioning
Helicopter Underwater Escape Training
Health and Usage Monitoring System
Hundred Year Storm
For construction design purposes, the worst weather conditions that can be statistically predicted within a hundred-year period.
HV
HVAC
HVC
HWU
HXT
High Voltage OR Vickers Hardness
Heating Ventilation & Air Conditioning
High Voltage Connector[s]
Hydraulic Workover Unit
Horizontal Christmas tree
A motor designed to move in discrete increments of steps. The motor has a permanent magnet rotor and a wound stator.
Such motors are brushless. Phase currents are commutated as a function of time to produce motion.
A compound formed by the chemical union of water with a molecule of some other substance. Gas hydrates formed from
water and, for example methane, may cause plugging of the tubing and flow lines of gas wells or gas; transmission lines.
Hot Work
Hot Work
Hybrid step motor
Hydrate
Page 63 of 310
Hydrate point
Hydrates
Hydration
Hydraulic fracturing
Hydraulic horsepower
Hydraulic pumping
Hydrazine
Hydril
Hydrocarbons
Hydrocarbons
Hydrocyclone
Hydrogen index
Hydrogen Ion Concentration
The conditions of pressure and temperature of a gas under which hydrates will start to form (in the presence of free water).
Hydrates are chrystaline structures formed from methane gas and water under conditions of low temperatures and high
pressures. If allowed to form, blockage and serious damage may result.
The water content of any export gas stream must be carefully controlled to avoid the formation of hydrates and thus reduce
the risk of corrosion due to the presence of trace quantities of CO2 and H2S.
This is achieved by reducing the water dewpoint of the export gas to a low value [e.g.> –20C] before export. Water is removed
by contacting the gas with lean, Triethylene Glycol.[TEG].
The rich TEG is regenerated by boiling off the water in a reboiler.
The pH of the TEG is kept on the slightly alkaline side [pH 8] and is controlled by the addition of triethanolamine. TEG is noncorrosive and non-volatile and classified as a low hazard substance.
The act of a substance to take up water by means of absorption and/or adsorption.
A met-hod of stimulating production from a formation of low permeability by inducing fractures and fissures in the formation by
applying very high fluid-pressure to the face of the formation, forcing the strata apart. Various patented techniques, using the
same principle, are employed by oil field service companies.
This term means different things to different engineers. To a pump man, it is exactly the same as GHP, but related to liquids.
In hydraulic power, it is the power available from a liquid when dropping from one pressure to another. This applies to oil,
water, etc. It does not include mechanical losses in the system.
A method of pumping oil from wells using a bottom-hole pump without suckerrods. This method uses a bottom-hole production
unit consisting of a hydraulic engine connected to a pump. Hydraulic power to drive the engine is supplied from the surface.
The power oil is returned to Surface either mixed with the produced oil or separated from it.
N2H4 has an ammonia-like odor, and is derived from ammonia, but its physical properties are more similar to those of water.
Hydrazine is usually handled as 60% aqueous solution. Hydrazine is a convenient reductant because the by-products are
typically nitrogen gas and water. Thus, it is used as an antioxidant, an oxygen scavenger, and a corrosion inhibitor in water
boilers and heating systems. In a somewhat related application, sodium azide, the gas-forming agent in air bags, is produced
from hydrazine by reaction with sodium nitrite.[2] Hydrazine is also used in satellites to make adjustments while in orbit. It is
also used as a propellant on board space vehicles.
Trade name of a bag type blow out preventer. The rubber bags can be energised to close around each shape of pipe and
allows stripping in - or out. Trade name of a widely used premium tubing and casing joint
Organic chemical compounds of hydrogen and carbon atoms. There are a vast number of these compounds and they form
the basis o-f all petroleum products. They may exist as gases, liquids or solids. An example of each is methane, hexane and
asphalt.
Organic compounds of hydrogen and carbon, whose densities, boiling points and freezing points increase as their molecular
weights increase. Although composed of only two elements, hydrocarbons exist in a variety of compounds because of the
strong affinity of carbon atoms for other atoms and for itself. The smallest molecules of hydrocarbons are gaseous; the largest
are solids. Petroleum is a mixture of many different hydrocarbons.
A separation device that utilises centrifuging principles to remove oils from water, or as a multicyclone to remove liquids and
solids from a gas stream.
The ratio of the number of hydrogen atoms per unit volume of a material to that number in pure water at 750F.
A measure of the acidity or alkalinity of a solution, normally expressed as pH.
Page 64 of 310
Hydrogen Sulphide 1
Hydrogen Sulphide 2
Hydrolysis
Hydrometer
Occurances - Hydrogen Sulphide can occur naturally in crude oil and gas. During the decomposition of organic materials,
including sewage. In de-oxygenated seawater, which encourages the growth of Sulphate-reducing Bacteria [SBR].
In addition, Hydrogen Sulphide can be produced as a by-product while processing hydrocarbons that contain Sulphur.
From the chemical action of acids on metallic sulphides; for example, during the chemical cleaning of equipment containing
Iron Sulphide deposits.
H2S is generated by bacteria in seawater, which thrives in conditions of oxygen deficiency and, together with organic materials
as a nutrient, reduces the sulphate in seawater to hydrogen sulphide.
Characteristics - Highly toxic, colourless, flammable gas which, in relatively low concentrations, can quickly cause
unconsciousness.
Approximately 20% denser than air and therefore can accumulate inn depressions around an area where the gas is present.
Has an auto-ignition temperature of 260o C, is flammable in the range of 4.3% to 45% volume in air and burns with a blue
flame to produce sulphur dioxide, which is also toxic.
Is highly corrosive to certain metals. In particular, materials containing copper should never be used due to the possibility of an
explosive reaction with H2S.
In air, concentrations are measured in parts per million [ppm] on a volume-to-volume basis. In water, concentrations are
measured in milligrams per litre [mg/I].
Hydrolysis is the reaction of a salt with water to form an acid and base. For example, soda ash (Na2CO3) hydrolyses basically,
and hydrolysis is responsible for the increase in the pH of water when soda ash is added.
An instrument designed to measure the density, API gravity or specific gravity of liquids; a glass tube with a weighted lower tip
that causes the tube to float partially submerged. The density or gravity is read on a graduated stem at the point intersected by
the liquid.
Hydrophile
A substance usually in the colloidal state or an emulsion, which is wetted by water; i.e. it attracts water or water adheres to it.
Hydrophilic
Hydrophobe
Hydrophobic
Hydrophones
Hydrostatic head
Hydrostatic Pressure/Head
A property of a substance having an affinity for water or one that is wetted by water.
A substance, usually in the colloidal state, not wetted by water.
Descriptive of a substance which repels water.
The instruments which detect returning sound waves in offshore seismic surveys/sonar operations.
The pressure exerted by a column of fluid, equalling the height of the column times the fluid density.
The pressure exerted by a column of liquid at a given depth, such as that exerted by drilling fluid in a well.
Testing a pipeline, tank, vessel or other pieces of equipment with water under pressure for tensile strength, its ability to hold a
certain pressure without rupturing or leaking.
Pressure-testing vessels on piping systems by pumping water into them.
Welding under high pressure conditions, i.e. subsea in an air chamber [Hyperbaric Chamber] similar in principle to a diving
bell. Hyperbaric chamber is also the name given to a pressurised surface chamber or habitat in which returning deep divers
are gradually re-acclimatised to surface pressure.
Hypoxia is a reduction of oxygen supply to the tissues. Hypoxia in which there is a complete deprivation of oxygen supply is
called Anoxia.
A proprietary process systems software analysis program
Hertz [unit of frequency 1 Hz = 1 cycle/second]
Invensys Systems Intelligent Automation Series
Input/Output
I/A Series Configuration Component
International Association of Drilling Contractors
Page 65 of 310
Hydrostatic testing
Hydrostatic Testing
Hyperbaric Welding/Chamber
Hypoxia
HYSYS
Hz
I/A
I/O
IACC
IADC
IAODC
IATA
Ibama
IBC
ICC
ICC
ICC
ICC Number
ICES
ICF
ICL
ICP
ICR
ICR
ICRP
ICS
ICS Continuous stall current
[Amperes]
ID
IDC
IDC
IDCN
Idle current reduction
IDMTL
IDS
IDS
IEA
IEC
IEC
IEER
IER
IFA
IFR
IG
IGC
Igneous rock
Igneous rocks
II
International Association of Offshore Diving Contractors [now part of IMCA]
International Air Transport Authority
Brazil’s environmental agency
Industrial Bulk Container
Installation Control Centre
Integrated Control Configurator - Invensys Systems
Isolation Confirmation Certificate – used for controlling the implementation and removal of isolations.
Number given to every system-generated ICC, once the Isolation Planner has been completed, and cannot be changed by the
user.
International Council for the Exploration of the Sea.
Integrated Commissioning Forum
Instrument Check List
Independent Competent Person
Continuous Rated Current [Amperes]. [The maximum allowable continuous current a motor can handle without exceeding the
motor temperature limits].
Incident Control Room
International Commission on Radiological Protection
Intervention Control System
Amount of current applied to a motor [at locked rotor conditions], which results in rated temperature rise. Refer also to
definition of Continuous stall torque
Inside or Internal Diameter OR Identification
Inter Discipline Check
Inter-Disciplinary Check
Integrated Digital OR Data Communications Network
A step motor driver feature that reduce the phase current to the motor when no motor motion is commanded [idle condition]
for a specified period of time. Idle current reduction reduces motor heating and allows high machine throughputs from a given
motor.
Inverse Definite Minimum Time Lag
Integrated Deck Structure
Interface Data Sheet
International Energy Agency
International Electrotechnical Commission
International Electrotechnical Committee / Commission
Instrument and Electrical Equipment Room
Instrument Equipment Room
Issued For Action
Interface Review
Imperial Gallons [also Imp. Gal] [i.e. UK gallons]
International Gas Code
A rock mass formed by the solidification of molten material poured into the earth's crust or onto its surface. Granite is an
igneous rock.
Rocks that have been consolidated from hot liquid material (magma).
Injectivity Index / Indices
Page 66 of 310
IIM
IIWG
IL
ILSU
IM
IMAC
IMCA
IMDG
IMIS
IMN
IMO
Imp. Gal
Impact wrench
Impermeable Rock
Input Interface Module
Installation Integrity Work Group
Integrity Level
Interface/line Switching Unit
Integrity Management
Instrument, Marker, Action, Consequence.
International Marine Contractors Association [formed in 1995 from the IAODC and the DPVOA]
International Maritime Dangerous Goods [Code] was developed as a uniform international code for the transport of dangerous
goods by sea covering such matters as packing, container traffic and stowage, with particular reference to the segregation of
incompatible substances.
Integrated Maintenance Information System
International Mobile Number
International Maritime Organisation
Imperial Gallons [also IG] [i.e. UK gallons]
An air-operated wrench for use on nuts and bolts of large engines, valves, pumps, flanges, etc. Impact wrenches have taken
the place -of heavy end-wrenches and sledgehammers in tightening and loosening large nuts.
A rock with restricted or poorly-communicating pore spaces, such that hydrocarbons will not flow through it.
Impressed Current Protection
The active, or ‘Anodic’ method of preventing corrosion in submarine steel structures. Unlike the cathodic protection system,
the self-potential of the structure is counteracted by passing a large low voltage current through the surface to be protected.
Impression block
A lead-filled cylinder which is often used during wireline fishing operations to ascertain the shape or size of the top of the fish.
IMR
IMS
IMT
IMV
Inspection, Maintenance and Repair
Integrated Management System OR Industrialised Methylated Spirit.
Inspection Management Teams
Injection Master Valve
In line equipment
Pumps, separators, heat exchangers integral to a process or processing chain; in the line, not auxiliary or only supporting.
In Place
In situ combustion
INA
INC/INCL
Incident
Incident Frequency
Inclinometer
Description of the total hydrocarbon content of a reservoir, as distinct from ‘Reserves’ which can be ‘recovered’ or produced.
Oil or gas in placed [OIP, GIP] before the start of production is known as Oil or Gas Originally in Place or Initially in Place. [e.g.
STOOIP = Stock Tank Oil Originally in Place; GIIP = Gas Initially in Place].
An enhanced recovery technique used in some locations to increase and/or accelerate the recovery of low gravity and high
viscosity oil from a field. Essentially, the method involves the heating of the oil in the formation by igniting the oil (burning it in
place) and keeping the combustion alive by pumping air down hole. As the front of burning oil advances, the heat breaks down
the oil into coke and light oil. And as the coke burns, the lighter, less viscous oil is pushed ahead to the well bores of the
producing wells.
Information Not Available
Inclusive
An unplanned, undesired sequence of events, which results in personal injury or property damage or loss of process or
damage to the environment.
A calculation which gives the predicted number of incidents per 1,000,000 man hours worked.
A down-hole instrument for measuring the angle from the vertical or ‘slope’ of a deviated well.
Page 67 of 310
Indexer
Indicated horsepower
Individual Risk
Inductance [L] [mH - millihenries lineto-line]
Inductance [mutual]
Induction log
Industrial gas
Inergen
Inert Gas
Inertial match
Infauna
Infill drilling
Infill Drilling
Inflatable packer
INFO
Inhibited Mud
Electronics which convert high level motion commands from a host computer, PLC or operator panel into step and direction
pulse streams for use by the step motor driver. Indexers can be broadly divided into two classes. A preset indexer typically
accepts distance, velocity and ramp time inputs only. The more sophisticated programmable indexer is capable of complex
motion control and includes program memory.
Calculated horsepower; the power developed within the cylinder(s) of an engine which is greater than the power delivered at
the drive shaft by the amount of mechanical friction that must be overcome and the power to drive accessories. See also
Horsepower, Brake horsepower, Hydraulic horsepower, Gas horsepower .
The frequency with which an individual may be expected to sustain a given level of harm from the realisation of specific
hazards.
The electrical equivalent to mechanical inertia; that is, the property of a circuit, which has a tendency to resist current flow
when no current is flowing, and when current is flowing has a tendency to maintain that current flow. Pacific Scientific
measures inductance [line-to-line] with a bridge at 1000 Hz and with the rotor positioned so the back-EMF waveform is at the
peak of the sinusoid.
Mutual inductance is the property that exists between two current carrying conductors or coils when magnetic lines of force
from one link with those of the other.
A formation conductivity measuring de-vice utilising electro- magnetic induction principles. The tool consists essentially of a
transmitter coil, a receiver coil and four auxiliary coils to minimise borehole and thin bed effects. A high frequency alternating
current is passed through the transmitter coil and the signal, picked up at the receiver coil is essentially proportional to the
formation conductivity.-The tool is best suited to measure low formation resistivities in wells drilled with high density or nonconductive drilling fluids.
Gas purchased for resale to industrial users.
Inert Gas Generator
Chemically unreactive gases used to flood compartments where there is fire or imminent danger of fire. Inert gases are also
used in the mixture breathed by divers.
For most efficient operation, the system coupling ratio should be selected so that the reflected inertia of the load is equal to the
rotor inertia of the motor.
Benthic organisms that live within the sediment.
Wells drilled to fill in between established producing wells; a drilling program to reduce the spacing between wells in order to
increase production from the field.
Production wells drilled between existing wells to increase recovery of hydrocarbons.
A retrievable packer of which the sealing element is an expandable steel reinforced sleeve. When running in the packer
Information
Mud containing chemicals to prevent loss of water which could damage surrounding formations, and cause build up of filter-
Inhibitor
Any agent which, when added to a system, slows down or prevents a chemical reaction or corrosion. Corrosion inhibitors are
used widely in drilling and producing operations to prevent corrosion of metal equipment exposed to hydrogen sulphide,
carbon dioxide, oxygen, salt water, etc. Common inhibitors added to drilling fluids are filming amines, chromates and lime.
Inhibitor mud
Substances generally regarded as drilling-mud contaminants, such as salt and calcium sulphate, are called inhibitors when
purposely added to mud so that the filtrate from the drilling fluid will prevent or retard the hydration of formation clays and
shales.
Initiating event
A postulated occurrence capable fo leading to the realisation of a hazard.
Page 68 of 310
Injection well
A well used for injecting gas or water into the reservoir formation. When this exercise is required, special injection wells are
drilled into the appropriate part of the reservoir. Gas injection can for suitable reservoirs serve to maintain the field pressure
When water is injected it is usually for the purpose of flooding a field to lengthen the productive life of the reservoir by flushing
out oil which would not otherwise be recovered.
Injection Well [Injector]
Well into which gas or water is pumped to maintain reservoir pressure. Sometimes called an ‘input’ or ‘service’ well. A well
through which water or gas is injected to maintain reservoir pressure and improve ‘sweep’ or a real recovery of reserves.
INMARSAT
Inmarsat
Innage gauge
Input well
Inside Preventer
International Marine Satellite
International Maritime Satellite Organisation System
A measure of the quantity of oil in a tank calculated on the basis of the depth of oil in the tank; the most common method of
gauging a tank.
A well used for injecting water or gas into a formation in a secondary or enhanced recovery or pressure maintenance
operation.
A blowout preventer which is fitted to the inside of the drill-string.
Inspection plate
A flat metal plate fitted with a gasket and bolted over an opening in the gearbox of a pump or-the crankcase of an engine. By
removing the plate an inspection of --he gears or crank and connecting rod bearings can be made. On large, multi-cylinder
engines, inspection windows are large enough to permit a mechanic to enter the crankcase to inspect or change out a bearing.
Installation
The default installation for which the user is assigned to. A list of all available installations is defined within the system.
Installation
Fixed or mobile, used directly or indirectly for the exploration or production of mineral resources. A fixed installation is a
permanent offshore structure that is involved in the production oil or gas which may be constructed of steel or concrete.
InstE
Instruction to Purchasing
Institute of Engineering, [merged with the IP in 2003 to form the Engineering Institute [EI] ]
The Instruction to Purchasing form allows the Project Engineer or Project Manager to make pertinent comments of a
confidential nature to Procurement. It is an internal document, not issued to Suppliers. It is the sole vehicle for instructing
Procurement to proceed with an Enquiry or Purchase Order, and this must be signed by the Project Manager.
Instrument Pig
A pipeline pig fitted with monitoring and gauging devices to check pipe wall thickness and for damage or distortion of the line.
Insulating flange
A flange that incorporates insulating parts to separate the metal parts electrically. Actually: Insulating gasket set.
The rating assigned to the maximum temperature capability of the insulating components in a motor or other piece of
equipment.
The pressure at the bottom of the tubing of a producing well.
Also: Tubing capacity curves, solely relate the passage of fluids - through a tubing string against a. fixed FTHP. They are
independent of a well's IPR. Useful to allow comparison of throughout capacities of different size tubings.
Expenditures incurred by an operator for labour, fuel, repairs, hauling and supplies used in drilling and completing a well for
production.
A tubular connection between the threaded male end of one pipe and the threaded female end (collar) of another. (As
opposed to a threaded - and - coupled joint).
Acting upon each other.
The point or area where two dissimilar products or grades of crude oil meet in a pipeline as they are pumped, one behind
another. The transition layer between oil and water in a tank or separator.
Insulation Class
Intake pressure
Intake pressure curves
Intangible drilling costs
Integral joint
Interaction
Interface
Page 69 of 310
Interface
Interfacial tension
Intermediate string
Intermediate String
Intermittent gas lift
Intermitter
Internal upset
Interruption
Interstitial water
Intrinsically safe
Invert oil emulsion mud
IODP
Iomers
Ion
IOPPS
IOSH
IOYP
IP
IP
IP
IPAA
IPACCS
IPCMS
IPE
IPF
IPM
The term is widely applied in the oil and gas industry as in other industries. However, usage specific to products is in the
interface between two batches of different products in a pipeline system. Unless separation is critical and maintained by an
intervening pig or sphere, the products are allowed the small amount of commingling that occurs, and the combined product or
‘interface’ is drawn off separately at its destination.
The force required to break the surface between two immiscible liquids. The lower the interfacial tension between the two
phases of an emulsion, the greater the ease of emulsification. When the values approach zero, emulsion formation is
spontaneous.
Any casing string between the largest (conductor) and smallest. The tubing string(s) between the long and the short stringing
multiple string completions.
See Casing.
A method of gaslift applied when the formation pressure is so low that even under the highest drawdown conditions that can
be obtained with continuous gaslift insufficient liquid flows from the formation to the borehole.
A time cycle device installed in the supply line to a gaslift well which periodically starts and stops the injection.
An extra-thick wall is provided on the end of pipe at the point where the pipe is threaded in order to compensate for the metal
removed in threading. Conventional pipe has the extra thickness on the outside. Internal upset pipe has the extra thickness on
the inside with a uniform straight wall on the outside. It is often referred to as Internal upset, external flush pipe * Some types
of pipe have both internally and externally upset ends.
The actual definition of work interruption may be different at each site, but could include coffee, smoke breaks and lunch
breaks, fire alarms, suspension of work overnight, emergency situations and shift changes.
Water contained in the interstices or voids of formations.
Electrical equipment which [due to its low power] is incapable of igniting a flammable gas mixture or combustible materials.
An invert emulsion mud is a water-in-oil emulsion where fresh or salt water is the dispersed phase and diesel, crude, or some
other oil is the continuous phase. Water increases the viscosity and oil reduces the viscosity.
Integrated Ocean Drilling Program
Compounds having the same composition and the same molecular weight but differing in properties.
Acids, bases and salts (electrolytes) when dissolved in certain solvents, especially water, are more or less dissociated into
electrically charged ions or parts of the molecules, due to loss or gain of one or more electrons. Loss of electrons results in
positive charges producing a cation. A gain of electrons results in the formation of' an anion with negative charges. The
valence of an ion. is equal to the number of charges borne by it.
Instrumented Overpressure Protection system
Institute for Occupational Safety and Health
Integrated Operations Year Plan
Institute of Petroleum, the organisation in Great Britain primarily responsible for the advancement of the study of petroleum
and its allied products in all their aspects. it is the recognised British standardisation authority for methods of testing petroleum
products.
Intelligent Pigs OR Ingress protection OR Initial pressure
Institute of Petroleum - merged in 2003 with the InstE to form the Energy Institute [EI]
Independent Petroleum Institute of America [see also API, AIP and IP]
Integrated Planning and Cost Control System
Integrated Protection Control and Monitoring System
International Petroleum Exchange
Instrumented Protective Function
Integrated Production Model
Page 70 of 310
IPPC
IPPMM
IPPMP
IPR
IPR
IPR
IPS
IPS
IPSA
IPU
IQA
IR
IR
IRCD
IRN
IRPA
IS
ISA
ISB
ISBL
ISC
ISDX
Isenthalpic expansion
Isentropic expansion
ISM
Iso
ISO
ISO
ISO 14001
Isobar
Isobath
Isobront
Isochore
Isocline
Isodop
ISODP
Isodrosotherm
Isoecho
Isogon
Integrated Pollution Prevention and Control.
Institute of Petroleum, Petroleum Measurement Manual
Institute of Petroleum, Petroleum Measurement Paper
Inflow performance relationship. The relationship between a well's liquid flow rate and drawdown.
Inflow Performance Relationship [graph]
Inward Processing Relief
Interactive Power System
Instrument Protected Signal
Interactive Power System Analysis
Integrated pipeline umbilical OR Integrated production umbilical
Institute of Quality Assurance
Infra-Red
Injection Rate
Injection Rate Control Device
Inspection Release Note
Individual Risk per Annum
Intrinsically Safe OR Industrial Hygiene OR Information Services
Instrument Society of America OR Independent safety auditor
Independent Side Band
Inside Battery Limits
Integrated Services Contractor
Integrated Switching Digital Exchange
Gas expansion through a pressure reducer; the energy released is not utilised.
A gas expansion process in which the energy released is used to drive a power unit, e.g. a turbo expander.
International Safety Management [regulations/code for shipping]
A prefix denoting similarity. Many organic substances, although composed of the same number of the same atoms, appear in
two, three, or more varieties or isomers which differ widely in physical and chemical properties. In petroleum factions there are
many substances that are similar, differing only in specific gravity, for example, iso-octane, iso-butane, iso-pentane and many
other isomers. A prefix denoting equality, such as isobars, isotherms, etc.
Installation Safety Officer
International Standards Organisation OR International Organisation for Standards
International environmental management system standard.
A line of equal or constant pressure.
A line connecting points on the sea bed of equal depth below the surface – a sea bed contour line OR In mapping subsurface
geology, a line connecting points on the top of a formation of equal depth below surface datum/sea level.
A line drawn through geographical points at which a given phase of thunderstorm activity occurred simultaneously.
In a reservoir a line joining points of equal vertical thickness.
A line of equal slope.
A line of equal Doppler velocity on a radar display.
The International Organization of Standardisation Draft Proposal
A line of equal dewpoint.
A line of equal radar reflectivity on a radar display.
A line of constant direction of some vector quantity (usually used to describe the wind direction field).
Page 71 of 310
Isoheight
Isohume
Isohyet
Isohypse
Isolation [Mechanical and Electrical]
Isolation Certificate
Isolation ID
Isolation Standard 1
Isolation Standard 2
Isolation Standard 3
Isolation Standard 4
Isomers
Isopach
Isopentaine
A line of constant geopotential height on a constant pressure surface chart. Because of their ubiquity, they are commonly
A line of constant humidity.
A line of constant amount of precipitation during a given time period.
The same as an isoheight.
The separation of plant and equipment from every source of energy [pressure, electrical and mechanical] in such a way that
the separation is secure.
A document authorising and recording the isolations required for work to be carried out on equipment and/or plant in support
of a Work Permit.
The point of isolation number or tag number that is usually found on the isolation and P& Ids.
The highest standard of process isolation involving positive process Isolation [physical disconnection of pipework] and fitting of
blank flanges and spades.
A process isolation standard involving double block and bleed isolation.
Single valve isolation. This type of isolation is only acceptable in given circumstances.
The lowest standard of process isolation achieved by other devices than those described in Standards 1 to 3 such as stopple
plugs.
Compounds which have the same number and types of atoms in each molecule but differ in molecular structure, e.g. Butane
and iso-Butane, Octane and iso-Octane, etc.
A line joining points of equal stratum thickness. Reservoir formations are sometimes mapped in this way.
A high-octane blending stock for automotive gasoline.
Isopleth
An isopleth map generalizes and simplifies data with a continuous distribution. It shows the data as a third dimension on a
map, thus isopleth maps are more common for mapping surface elevations, amounts of precipitation, atmospheric pressure,
and numerous other measurements that can be viewed statistically as a third dimension. The third dimension is shown by a
series of lines called isopleths which connect points of equal value. The isopleth interval is the difference in value between two
adjacent isopleths. Note, the values of the isopleths drawn on the map are always multiples of the interval. Isopleths never
cross or divide and always form enclosed circles, however, this occurrence may not be in the mapped area.
Isotach
Isotherm
A line of constant wind speed.
A line of constant temperature
Isothermal
At constant temperature. When a gas is expanded or compressed at a constant temperature, the expansion or compression is
isothermal. Heat must be added to expanding gas and removed from compressing gas to keep it isothermal.
Isotope
One of two or more forms of an element differing from each other in atomic weight, and in nuclear but not chemical properties.
Isotope
ISSOW
Issued Permit
ISU
ISU
IT
ITP
ITT
The isotopes of any given element have the same atomic number but have different mass numbers because of varying
numbers of neutrons present in the nucleus. Isotopes may or may not be radioactive. All isotopes of the same element react
the same in chemical reactions.
Integrated Safe System of Work
A Work Permit for work which is currently underway
Information Support Unit
Integrated Services Umbilical
Information Technology
Instruction to Proceed
Invitation to Tender
Page 72 of 310
ITU
IVB
IW
IWIS
IWOCS
IWV
J
J&A
Jack
Jack board
Jack rabbit
Jack Rabbit
Jacket
Jacket
Jack-knife rig
Jack-up rig
Jack-Up Rig
Jam nut
Jars
Jars
JB
JBA
JDT
Jet bit
Jet Hopper
Jet perforating
International Telecommuncation Union
Independent Verifying Body
Injection Well
Intelligent Well Industry Standards
Installation Workover Controls System
Injection Wing Valve
Joule. [Unit of work, energy and heat-transfer. 3.6MJ=1kWh. 2.6845MJ=1hph ]
Junked and Abandoned
An oil well pumping unit powered by a gasoline engine, electric motor, or rod line from a central power. The pumping jack's
walking beam provides the up and down motion to the well's pump rods. See also Pumping unit .
A wood or metal prop used to support a joint of line pipe while another joint is being screwed into it. Jack boards have metal
spikes inserted at intervals to support the pipe at different levels.
A device that is put through casing or tubing before it is to make certain it is the proper size inside; often called Go-devil.
A gauge which is run through casing or tubing before use to check for correct sizing and freedom from obstruction or
distortion.
Steel framework used to support platform topsides
The lower section of an offshore platform which is fixed to the seabed by piles and is mainly below water level. Or the platform
A mast-type derrick whose supporting legs are hinged at the base. When the rig is to be moved, it is lowered or laid down
intact and transported by truck.
A barge-like floating platform with legs that can be lowered to the sea bottom to raise or-jack up the platform above the-water.
Towed to location offshore, the legs of the jack-up rig are in a raised position, sticking up- high above the platform. When on
location, the legs are run down hydraulically or by individual electric motors.
Drilling rigs, production barges, etc. which once floated onto location can raise themselves clear of the water by ‘jacking’
themselves up their legs. They then offer the operating advantages of fixed platforms but unlike piled steel structures, their
stability and load capacity depends on the strength and stability of the sea bed, and closely underlying strata.
A nut used to jam and lock another nut securely in place; the second and locking nut on a stud bolt. After the first nut is threaded and tightened on a stud, a second nut is tightened down on the first nut to prevent it from working loose. English is
Lock nut.
Jars are the main work piece of a wireline tool string. By manipulating the wireline at the surface jarring impacts can be
delivered both in upward and downward direction. The effectiveness of the impacts is largely dependent upon the weight of
stem used and the length of the stroke. Mechanical jars are composed of two pieces linked together much like long chain
links. Another type is the hydraulic jar, which can only deliver upward blows.
Down hole tools inserted in the drill-string when fishing to jerk or jar the fish free by repeated sudden blows. They may also be
Junction Box
Junction Box Assembly
Joint Development Team
A modified form of either a drag bit or roller bit utilising the principle of the hydraulic jet to increase the drilling rate.
A device to hold or feed drilling-mud additives.
An operation similar to gun-perforating except that a shaped charge of high explosives is used to burn a hole through the
casing instead of the gun that fires a projectile in gun-perforating. This use of explosives originated during World War II as a
defensive measure against tanks.
Page 73 of 310
Jettison
JFO
JFOA
JIC
JIP
Jiskoot
JIT
JNCC
JOA
Job Card
Job Complete State
Joint
Joint venture
Joint Venture
Jont
Joule Thompson effect JT
JP
JSA
J-T valve
J-tube
Jug
Jumbising
Jumpered out
Junk
Junk basket
Junk basket
The disposal of water into the environment when it has been sufficiently cleaned; the requirement is 10 to 40 ppm oil in water
in the North Sea depending on the particular area and the source
Joint Facilities Operator
Joint Facilities Operating Agreement
JDT Interface Coordinator
Joint Industry Project
Split Phase Sampler
Just-in-Time
Joint Nature Conservation Committee
Joint Operating Agreement. The document governing operations in a Joint Venture, or prime importance to all participants as
under it they secure, or may lose, rights to production, etc.
A document to pre-plan, record and control work of a low hazard potential, that does not require a Work Permit
The task on the WCC has been completed and it has been returned by the Performing Authority as Complete.
A single length of drill pipe, drill collar, casing or tubing, usually from 20 to 30 feet [6 to 9 m] long, that has threaded
connections at both ends. Several joints screwed together constitute a stand of pipe.
A business or enterprise entered into by two or more partners. Joint venture leasing is a common practice. Usually the partner
with the largest interest in the venture will be the operator.
A common form of risk-sharing in Oil and Gas operations, especially exploration and production. Although they may have
many of the characteristics of partnerships and are often referred to as such, they are usually legally constituted specifically to
avoid partnership implications. See also Joint Operating Agreement.
A length of pipe, casing, tubing or sucker rod usually from 20 to 30 feet long. On drilling rigs, drill pipe and tubing are run the
The Joule Thompson effect [also known as the Joule-Kelvin effect] is the change in temperature that occurs when a gas
expands from a high pressure area to a low pressure area, such as across a valve. In the case of a hydrocarbon gas, a
significant temperature drop can be experienced. Also Referring to the change in temperature observed when a gas expands
while flowing through a restriction without any heat entering or leaving the system. The change may be positive or negative.
For each gas, there is an inversion point that depends on temperature and pressure, below which it is cooled and above which
it is heated. For example, for methane at 100C [212F], the inversion point occurs at about 500 atmospheres [7,350 psi]. The
magnitude of the change of temperature with pressure depends on the Joule-Thomson coefficient for a particular gas. The
Joule-Thomson effect often causes a temperature decrease as gas flows through pores of a reservoir to the wellbore.
Jet Pump
Job Safety Analysis
A throttle valve used to reduce the pressure and temperature of a gas stream, associated with the NGL removal process
An open-ended, J section pipe attached to a jacket structure or to a pipelay vessel to provide a means of installation and
A geophone. A ‘jug hustler’ is the member of a land seismic survey crew who places and retrieves geophones. OR Artificially
made cavern storage in a salt rock formation.
A technique used to enlarge an oil tanker's carrying capacity by cutting the vessel in two amidships and inserting a section
between the halves.
Electrically bypassed
Any small unwanted object ‘lost’ down a well. Junk may be a lost bit, milled pieces of pipe, wrenches or any relatively small
object that must be fished out of the hole.
A type of fishing tool used to retrieve objects lost in the borehole or down the casing.
A fishing tool run in the well when it is necessary to retrieve small parts or lost tools.
Page 74 of 310
Kelly Cock
Kelly Cock
A well abandoned as a result of loss or failure of down hole equipment, which cannot be retrieved by fishing, or repaired.
Rock formed in the second period of the Mesozoic era, between the Triassic and the Cretaceous periods. [from the French,
after the Jura mountains].
Joint Venture
Joint Venture International
Constant
Kilo, thousand [Europe] OR Knot [nautical mile per hour]
Kelly Bushing [see below]
Kelly Bushing Measurement
Kellogg, Brown & Root
Hollow, 1-0 or 54 feet long, square or hexagonal pipe attached to the top of the drilling string and turned by the rotary table
during drilling. It is used to transmit the torque from the rotary table to the drilling string and thus to the bit.
The heavy steel member, three-, four-, six- or eight-sided, suspended from the swivel through the rotary table and connected
to the topmost joint of drill pipe to turn the drill stem as the rotary table turns. It has a bored passageway that permits fluid to
be circulated into the drill stem and up the annulus or vice versa.
A special device that, when fitted to the master bushing transmits torque to the kelly and simultaneously permits vertical
movement of the kelly to make hole. It may be shaped to fit the rotary opening or have pins for transmitting torque. Also called
the drive bushing. See Kelly.
An emergency ‘blowout preventer’ valve inserted between the swivel and the Kelly.
(Upper & lower). Valves which are used to stop backflow through the Kelly.
Kelly Spinner
A mechanism attached to the swivel for rotating the kelly in or out of the top joint of drill pipe, e.g. when adding another stand.
Junked well
Jurassic
JV
JVI
K
k
KB
KBM
KBR
Kelly
Kelly
Kelly bushing
Kelly Valve [lower]
Kerogens
Key Performance Indicators
Key seat
KeyMAN™
Keyway
Keyway
kg
kg, km, kV
KHI
KHz
Kick
Kick
An automatic valve at the lower end of the Kelly which closes when the Kelly is disconnected from the drill-stem, preventing
spillage of mud.
Organic material from which oil or gas matures with time, under burial temperatures and pressures. They differ with origin e.g.
Agreed parameters that measure the overall performance of the company and of specific departments.
A narrow slot worn in the side of the well bore by drill pipe, usually at an abnormal deviation, of a size smaller than the tool
joints or collars. This keyhole type configuration will not allow these members to pass when pulling out of the hole.
A standardised manifold system that is pre-configured to accept the connection of AlphaCPU™ System-Modules™. These
System-Modules™ having any internal configuration from FlowCAP™ to System-Module™ Separation.
A groove or slot in a shaft or wheel to hold a key.
A slot in the edge of the hull of a jackup drilling unit through which drilling tools are lowered and removed from the well being
drilled.
Kilogram
Kilogram, metre, Volt [kilo = 103]
Kinetic Hydrate Inhibitor
Kilohertz
Pressure from down hole in excess of that exerted by the hydrostatic head of the drilling mud or workover fluid. if the pressure
is not controlled by increasing the density, a kick can violently expel the column of drilling mud resulting in a blowout.
An entry of water, gas, oil or other formation fluid into the wellbore during drilling. It occurs because the pressure exerted by
the column of drilling fluid is not great enough to overcome the pressure exerted by the fluids in the formation drilled. If prompt
action is not taken to control the kick, or to kill the well, a blowout may occur.
Page 75 of 310
KLB
km
KN
The start-up of a gaslift well, which means the removal of the column of dead fluid from the tubing by the injection of gas.
The depth in a deviated hole at which the direction changes from vertical to become ultimately the required deviation.
To bring a well into production OR To start the planned deviation of a well from the vertical. The depth at which this occurs is
the Kick-Off Point [KOP].
To stop a well from producing so that surface connections may be removed for well servicing or workover. It is usually
accomplished by circulating water or mud to load the hole and render it incapable of flowing. Also To displace the contents of
a producing well with a liquid having a density which will, when the well is full, balance the formation. This will allow the well to
be worked-over.
Lines connected to the blowout preventer stack through which drilling mud is circulated when the well has been shut in by the
blowout preventers.
A directional well drilled near an out- of -control well to kill it by flooding the formation with water or mud. Wells that have
blown out and caught fire are often brought under control in this manner if other means fail. See also Relief -well .
To displace the contents of a producing well with a liquid having a density which will, when the well is full, balance the
The kinematic viscosity of a fluid is the ratio of the viscosity (e.g. cp. in g/cm sec) to the density (e.g. g/cc) using consistent
units. In several common commercial viscometers the kinematic viscosity is measured in terms of the time of efflux (in
seconds) of a fixed volume of' liquid through a standard capillary tube or orifice.
1000 pounds [weight]
A colloquial term for rock deposited, in conditions rich in organic sediments, which with the necessary burial history has
become a significant source of hydrocarbons. These may have migrated to traps elsewhere.
Kittwake Loading Buoy [defunct]
Kilometer
Kilonewtons
Knockout
A tank or separator vessel used to separate or knock out water from a stream of oil or gas. See also Free water knock out.
Kick off
Kick off point
Kick-off
Kill a well
Kill and choke lines
Killer well
Killing a well
Kinematic visosity
Kip
Kitchen
Knockout (vessel, drum, trap)
Knock-Out Drum
knot
Knuckle buster
Knuckle joint
Knuckle Joint
KO
KO
KOP
kPa
KPI
ksi
KSP
Used to remove only water from the well fluid or all liquid oil plus water from gas. In the case of a water knockout the gas and
liquid petroleum are discharged together and the water is separated and discharged from the bottom of the vessel. A liquid
knockout is used to remove all liquid, oil plus water, from the gas. The water and liquid hydrocarbons are discharged together
from the bottom of the vessel and the gas is discharged from the top.
A tank or vessel used to separate water from oil or liquids from a gas stream.
1 nautical mile/hour [1 knot = 1.150779 mph and 1 mph = 0.8689762 knot]
A wrench so worn or of such poor quality that it will not hold when under the strain of heavy work.
The knuckle joint is a wireline tool similar to a short stem but has a swivel in its mid-section. Its purpose is to provide flexibility
in the string of tools to facilitate taking hold of various tools and also to enable tools to pass through bent tubing where they
may otherwise stand up. The knuckle joint is almost always used below the jars in the string of wireline tools where flexibility is
important.
An universal joint in a drilling tool for deviated drilling which enables the bit to rotate at an angle to the existing borehole.
Kick Off
Knockout OR kicked off [deviated well]
Kick-Off Point
kilopascals
Key Performance Indicator.
Thousands of pounds per square inch [See psi]
Key Service Provider
Page 76 of 310
KV
KVA
KW
KW
kW
KW Callsign
KWV
l
L2 TRA
LA
Laminar flow
Lamination
LAN
Landing Casing
Landing nipple
Lap weld pipe
LAT
Latch on
Laterlog
Lay barge
Lay barge
Lay down
Lay down rack
lb
lbf
kilovolt
kilovolt-ampere
Kittiwake
Killed well
Kilowatt, [a unit of measurement for electrical power]
MKLU7 IMN: 423245710
Kill Wing Valve
Liter
Level 2 Task Risk Assessment. [Requires minimum team of 3 personnel].
Level alarm
A type of streamlined flow for single-phase fluids in which the fluid moves in parallel layers, or laminae. The layers flow
smoothly over each other with instabilities being dampened by the viscosity. Laminar flow occurs in straight pipes when the
Reynolds number is below a critical value, corresponding to a low production rate. Above this value, the flow is turbulent. For
laminar flow in straight pipes, the velocity profile across the pipe is parabolic, increasing from zero at the wall of the pipe to a
maximum at the center equal to twice the mean velocity. Also Fluid elements flowing along fixed streamlines which are
parallel to the walls of the channel of flow. In laminar flow, the fluid moves in plates or sections with a differential velocity
across the front, which varies, from zero at the wall to a maximum toward the centre of flow. 'Laminar flow is the first stage of
flow in a Newtonian fluid; it is the second stage in a Bingham plastic fluid. This type of motion is also called parallel,
streamline, or viscous flow. See also Plug and Turbulent Flow.
A fine layer (~ 1 mm thick) in strata, also called a lamina, common in fine-grained sedimentary rocks such as shale, siltstone
and fine sandstone. A sedimentary bed comprises multiple laminations, or laminae.
Local Area Network
Lowering a string of casing into a well, to rest on the ‘step’ in the hole where drilling at a smaller diameter commences.
Internally profiled tubing nipple with locking and locating recesses and a polished bore in which a mandrel can, by wireline
method, be landed, locked and sealed.
Line pipe or casing made from a sheet of steel, which is formed, on a mandrel. The two edges, tapered to half normal
thickness, are lapped over and welded. See also Seamless pipe .
Lowest Astronomical Tide [level]
To attach elevators to a section of pipe or a tool to the wireline tool string or a tubing string to a packer, etc.
A formation resistivity measuring device utilising electrodes to focus a direct current into the formation. Knowing voltage,
resistivity can be computed. It is best suited for measuring formation resistivities in wells drilled with more saline drilling muds.
A shallow-draft, barge-like vessel used in the construction and laying of under-water pipelines. Joints of line pipe are welded
together and paid out over the stern of -the barge as it is moved ahead. Lay-barges are used in swampy areas, in making river
crossings and laying lines to-offshore installations.
A barge used in the construction and placement of underwater pipelines. Joints of pipe are welded together and then lowered
off the stern of the barge as it moves ahead.
(Sucker rods, tubing or drill pipe) To pull sucker rods, tubing or drill pipe from the well, a joint at a time and to remove it from
the derrick floor to) a nearby horizontal rack.
A storage area for sucker rods, tubing and drill pipe that are removed from a well and laid down rather than set back and
racked vertically in the derrick
Pound; the plural is also lb [libra, libræ]
pound[s] force
Page 77 of 310
lbf/in2
LC
LCC
LCC
LCD
LCN
LCP
LCP
LCV
LD
LDDP
Lean gas
Lean Gas
Lease
LEBC
LECC
LED
Left hand thread
Legal Structure
Legs - oil derrick
LEL
Lens
Lens
LER
LES
Lessons
LEV
LFL
LG
LIC
Licence
LIFT
Lifting
Lifting
Lifting costs
pounds [force] per square inch [psi]
Lost Circulation [drilling fluid] OR level controller
Local Control Centre
Life Cycle Cost
Liquid Crystal Display
Local Control Network
Loss Control Programme
Local Control Panel
Level Control Valve
Laid down OR Loop Diagram
Laid Down Drill Pipe
Natural gas containing little or no liquefiable hydrocarbons.
Gas undersaturated with hydrocarbons, and able to absorb more. See also Fat Oil/Lean Oil.
In the oil and gas industry, a legal instrument giving the right to explore/exploit acreage, primarily onshore. ‘Lease operations’
has come to mean any exploration/production field operation.
Local Emergency Base Controller. It is the role of delivery team leader and his deputies [production & Maintenance
coordinators] at interior. It has been identified as HSE critical for management of emergency response
Local emergency Control Centre
Light Emitting Diode
A pipe or bolt thread cut to be turned counter-clockwise in tightening. Most threads are right-hand, cut to be tightened by
turning clockwise.
The legal structure is fairly simple - there are Acts which produce Regulations.
The four corner-members of the rig, held together by sway braces and girts.
Lower Explosive Limit; [the lowest concentration by volume of combustible gases in mixture with air that can be ignited at
ambient temperature conditions].
A sedimentary deposit of irregular shape surrounded by impervious rock. A lens of porous and permeable sedimentary rock
may be an oil producing-area.
A body of potential reservoir rock enclosed on all sides by sealing strata, so-called because frequently lens-shaped.
Local Equipment Room
Land Earth Station
Information about what has been learned whilst performing the task which is recorded in order that others can benefit from
earlier experiences on similar work.
Local Exhaust Ventilation
Lower Flammable Limit
Level Gauge
Level Indicator Controller
A right to explore for and/or produce hydrocarbons issued by a Government agency, where rights to underlying minerals are
Licence Initiative for Trading http//:www.uklift.co.uk
Refers to tankers and barges taking on cargoes of oil or refined product at a terminal or transhipment point. Producing an oil
well using artificial lifting techniques: pumping, gaslifting.
Collection of a production shipment of crude oil etc. at the point of sale. Also covers bulk e.g. movements of any hydrocarbon
against, e.g. contract entitlements OR Stimulating production flow from a well. See Gas Lift.
The costs of producing oil from a well or field.
Page 78 of 310
Lifting methods
Light crude
Light Crude
Light ends
Light Ends
LIH
LIM
Line Break
Line Fill
Line up clamps
Liner
Liner hanger
Linkage
Liquid gradient
Liquid hydrocarbons
Lithification
Lithology
Lithology
Litre
LIVE
Live Equipment
Live oil
Live Oil
Live State
LKO
LLG
Lloyd’s Register
Methods used to bring the crude from the bottom of the well to the surface (natural flow, artificial lift).
In general terms (not an official classification), crude oil with API gravity of more than 30 degrees.
Generally applied to crude oil with an API gravity of 30 degrees or over. See American Petroleum Institute.
The more volatile products of petroleum refining; e.g. butane, propane, gasoline. See also Heavy ends .
The least dense, more volatile parts of a crude oil stream in distillation. Either a single hydrocarbon or a mixture having a
vapour pressure of 18psia or more. Methane, Ethane, Propane, Butane and Pentane. These gases are usually contaminated
with other compounds such as Hydrogen Sulphide [H2S], Carbon Dioxide [CO2] and water vapour [H2O]. In a refinery FCCU
the “back end” [or “light ends”] where separation of cracked materials is achieved by passing cracked materials through a
series of columns. This process is also known as fractionation.
Left in Hole
Line Insulator Monitor
Opening of drained or undrained lines or equipment by disconnecting flanges, opening valves, breaking pipe joints, removing
blanks or opening ports, and penetrating a line by mechanical or other means
The volume of oil or gas which is needed to fill a pipeline before any deliveries can be made, representing a permanent
inventory requirement.
A device that holds the ends of two joints of pipe together and in perfect alignment for welding. Line-up clamps operate on the
outside of the pipe and are used. on smaller diameter line pipe. Large-diameter pipe - 20 to 36 inch and over - are aligned by
internal, hydraulically operated mandrel-like devices.
A string of casing which is run only into the production area of a well and hung from or cemented up to the bottom section of
the water string to protect the face of the formation and prevent sand or debris from entering the well. Cylinder in the fluid end
of a pump in which the piston moves.
A device to suspend a liner from the bottom section of the last casing string. Usually combined with a pack-off.
A term used to describe an arrangement of interconnecting parts - rods, levers, springs-, joints, couplings, pins -that transmit
motion, power, or exert control.
The pressure a static column of liquid exerts of depth.
Petroleum components that are liquid at normal temperatures and atmospheric pressure.
The process by which unconsolidated sediments become sedimentary rock. Sediments typically are derived from pre-existing
rocks by weathering, transported and redeposited, and then buried and compacted by overlying sediments. Cementation
causes the sediments to harden, or lithify, into rock.
The study and identification of sediments. The character of a rock formation.
The study of rocks and hence the description of different formations encountered by a well.
1 litre = 1,000 cc [or cm3]; 1 [UK] gallon = 4.546 litre
Live means electrically charged
Equipment that is in operation and is the source of energy in the form of electricity, process fluids, radioactive sources,
hydraulic or pneumatic pressure that could be released or discharged in an uncontrolled manner in the event of an incident.
Crude oil, which contains dissolved natural gas when produced.
Crude oil containing volatile gases.
A WCC that has been authorised to go Live from the Authorised State and task can start. Any necessary controls will have to
be implemented before the WCC is permitted to go Live.
Lowest Known Oil [in a reservoir]
Low Level Gas
Lloyd’s Register of Shipping [Verification Authority]
Page 79 of 310
LLSD
LMGV
LMRP
LMV
LNG
LNG
LNG Carriers/Containment
Lo
LO
Load
Load curve
Load factor
Loading arms
Loading rack
Load-on-top system
Local Control Point
Local Drainage
Location
Locator seal assembly
Lock
Locked Closed
Low Level Shut Down
Lower Master Gate Valve
Lower Marine Riser Package
Lower Master Valve [production]
Natural Gas can be liquefied, e.g. at atmospheric pressure by cooling to about - 160 0C (-256 0F). It consists of liquefied
methane (Cl) and ethane (C2) and sometimes includes propane (C3) and butane (C4).
Liquefied Natural Gas, [gaseous at normal temperatures and pressures but held in the liquid state by very low temperatures to
facilitate storage and transportation in insulated vessels]. [See Natural Gas/NGL’s]
In order to transport natural gas, it is cooled to approximately -163 degrees Celsius where it condenses to a liquid at
atmospheric pressure shrinking to approximately 1/600 of its original volume with a density of 420 to 490 kg/m3.
The tanks onboard LNG carriers function, in effect, as big thermos containers wherein the liquid remains boiling for the
duration of voyage.
Some gas is removed to prevent a gradual buildup in pressure; this is known as Boil Off Gas [BOG]. The latent heat of
vapourisation required to turn a small amount of LNG from a liquid to a gas is what keeps the remaining liquid cooled.
Recently, designs have been developed for pressurised transport systems as well, to be called pressurised natural gas [PNG]
carriers, although none have yet been constructed.
At present, there are four containment systems in use for new ships. Two of the designs are of the self-supporting type. The
other two are of the membrane type which are patented designs owned by Gaz Transport and Technigaz [GT&T]. The trend is
toward the membrane instead of the self-supporting types, most likely due to lower construction costs.
Low
Lubricating Oil
A load is a discrete movable object. A hand held or carried tool or machine, while in use for its intended purpose, is not
considered a load
A graph in which the quantity of gas delivered by a plant or system is plotted against intervals of time.
The ratio of the average load over a designated period to the peak load occurring in that period. Usually expressed as a
percentage.
Vertical standpipes with swivel-jointed arms that extend to a tanker or barge's deck connections for loading or discharging
crude oil or products.
An elevated walkway that supports -vertical filling lines and valves for filling tank cars from the top.
System of cleaning the tanks of a crude oil tanker by collecting washings from each tank in one tank, allowing the water to
separate from the oil, then discharging the water overboard, leaving the oil residues in the tank. The next crude oil cargo is
loaded on top of the residues.
A display in a prominent place in each module of all Permits underway in that module.
The movement of reservoir fluids in the immediate vicinity of a flowing well.
The point at which a well is to be drilled.
A packer seal assembly of which the top collar seats (locates) on the bevel of the body of a permanent packer. A straight pull
on the tubing will release the seal assembly from the packer.
A mechanical device, either key or combination type, to hold an energy isolating device in the safe position, usually to prevent
the energizing of a machine or equipment.
A state of Isolation where the isolation device has been physically locked in the closed position, under the control of an
Isolation Confirmation Certificate.
Page 80 of 310
Locked Open
Lockout Box
Log
Log
LOGIC
Login
Logistics Board
Logistics Diary
Logout
LOL
LOLER
Long strings
Looping a line
LOS
Lose returns
Loss of circulation
Loss Prevention
Lost Circulation
Lost Time Accident
Lost workday cases
Lost workdays
Low Voltage
Lower in
LP
A state of Isolation where the isolation device has been physically locked in the Open position, under the control of an Isolation
Confirmation Certificate.
A security device used to control the fitting and removal of isolations using keys and padlocks.
A detailed record against depth (or time) of the nature, thickness, content, etc., of the formations and conditions encountered
in a well.
A systematic recording of data, such as a driller’s log, mud log, electrical well log, or radioactivity log. Many different logs are
run in wells to obtain various characteristics of downhole formations.
Leading Oil & Gas Industry Competitiveness
http//:www.logic-oil.com
Provides access to functionality in WAMS that is not available to everyone. Access is gained by entering a User Name and a
Password. The System Administrator initially provides the User name and password.
The board within ARL that holds employee T-cards displaying which employees are assigned to particular
clients/installations/worksites and which employees are available for employment
A diary that is maintained and updated by each Co-ordinator to log enquiry information, record mobilisation requirements and
detail final hours and expenses for payment as per timesheet.
Logging out removes an individuals personal signature and level of authority from the system. It is good practice to logout
when leaving the computer or when it is not going to be used again for some time.
Low Oil Level
Lifting Operations and Lifting Equipment Regulations 1998
The longest tubing string in a multiple string completion.
The construction of a pipeline parallel to an existing line, usually in the same right-of-way, to increase the throughput capacity
of the system; doubling a pipeline over part of its length, with the new section tied into the original line.
Line-of-Sight
Refers to a condition in which less drilling mud or workover fluid is being returned from down hole than is being pumped in at
the top. This indicates that mud is being lost in porous formation, crevices, or a cavern.
A condition that exists when drilling mud or workover fluid pumped into the well through the drill pipe or tubing does not return
to the surface. This serious condition results from the mud being lost in porous formations, a crevice or a cavern penetrated by
the drill.
A systematic approach to preventing accidents or minimising their effects. The activities may be associated with financial loss
or safety issues and will often include many of the techniques defined in this report.
Failure to recover to the surface all the drilling fluids at the same rate as they are pumped down a well, usually because of
escapes into surrounding formations. Casing would normally be set through the relevant formation before proceeding.
An accident resulting in the injured party[ies] being unable to carry out their normal duties for 3 days or more, not including the
day of the accident.
In Safety: Any work injury, other than Permanent Partial Disability, which renders the injured person temporarily unable to
perform any regular job or Restricted Work on any day after the day on which the injury was received.
In Safety: The total number of calendar days on which the injured person was temporarily unable to work as a result of a Lost
Workday Case, or a Permanent partial. Disability.
Normally exceeding extra low voltage but not exceeding 1000 Volt ac or 1500 Volt do between electrical conductors, or 600
Volt ac or 900 Volt do between conductor and earth.
To put a completed pipeline in the ditch. This is done with side-boom tractors that lift the pipe in slings and carefully lower it
into the ditch.
Low Pressure OR line pipe
Page 81 of 310
LPG
LPG
LPO
LQ
LR
LR
LR
LRFD
LRP
LRS
LSA
LSA Material
LSZH
LTA
LTD
LTEL
LTFD
LTI
LTI
LTI frequency
LTMEL
LTOBM
LTS
LTS unit
LTSD
LTX unit
Lub oil
Propane (C3), iso-butane (IC4) and normal butane (NC4) separated from natural gas or crude oil by fractionation or other
processes at atmospheric pressure, liquefied petroleum. gases 'revert to the gaseous state.
Liquefied Petroleum Gas, [essentially propane and butane held in the liquid state under pressure to facilitate storage and
transportation].
Low Pressure Operation
Living Quarters
Lower Reservoir
Lloyds Register
Level Recorder (maintains record of level over several days or months)
Load and Resistance Factor Design
Lower Riser Package
Lloyd’s Register of Shipping
Low Specific Activity OR Life Saving Appliances
Low Specific Activity material. In the context of oil and gas production, the presence of naturally occurring radio-isotopes in oil,
gas and produced water process plant and deposited solids. They result from the removal of daughter isotopes from the
parents, Uranium 238 and Thorium 232.
Low Smoke Zero Halogen
Lost Time Accident – Where the injured party is unable to undertake their normal duties for more than 3 days, not including
the day in which the accident occurred [RIDDOR 95]
Log Total Length
Long Term Exposure Level [over 8 hours]
Long Term Field Development
In Safety: Lost time injuries. The sum of Fatalities, Permanent Total Disabilities, Permanent Partial Disabilities and Lost
Long Term Isolation
In Safety: The number of Lost Time Injuries per million Exposure Hours worked during the period.
Long Term Exposure Limit [over 8 hours]
Low Toxicity Oil Based Mud.
Low Temperature Separator
A low temperature separation unit to depress the dew points of natural gas. In these units the formation of hydrates is avoided
by including the facility for injecting glycol into the gas upstream of the first low temperature point in the system.
Low Temperature Shut Down
A low temperature separation unit, which depresses the dew-point of natural, gas by expansion of the gas. They are designed
in such a way that the gas does not reach hydrate-forming condition upstream of the pressure-reducing choke. Hydrates
formed downstream of the choke are melted in the separator by a heating coil.
Short for lubricating oil or lubricant. Also lube and lubes.
Page 82 of 310
Lubricator
LUMCR
LV
LVDT
LVI
LW
LWD
LWRP
m
m/s2
m3
M710
mA, ml
MAASP
MAC
Macrofauna
MACT
Magnetic Survey
Magnetometer
MAH
MAHP
MAIB
Main Location
Maintenance Management No.
Make a trip
Make Up/Break Out
Manage
Management
Management of Change
Management Representative
The lubricator is a pressure chamber in which the wireline tool string and sub-surface controls are suspended while the swab
valve of the Christmas tree is being opened. It is mostly composed out of two small diameter sections, and one large diameter
section.
The large section is to contain the larger running or pulling tools along with the sub-surface control.
The large section of the lubricators has needle valves. The needle valve is used to bleed the pressure from the lubricator after
the swab valve of the christmas tree has been closed.
Between swab or top valve of the christmas tree and the large section of the lubricator is the blowout preventer. The top end of
the lubricator is packed off by the stuffing box. The sections of the lubricator are joined together with quick unions.
Local Umnanned Control Room
Low Voltage
Linear Variable Displacement Transformer
Low Viscosity Index
Low Water
Logging While Drilling
Lower Workover Riser Package
Metre
Metres per Second squared
Cubic Metres
MF/HF Radiotelephone
Milliampere, millilitre [m indicates 1/1000]
Maximum Allowable Annulus Surface Pressure
Manually Activated Callpoint
Larger benthic organisms.
Maximum Achievable Controlled Technology.
An exploration method, in which an instrument that measures the intensity of the natural magnetic forces existing in the earth’s
An instrument used to measure the intensity and direction of a magnetic field especially that of the earth.
Major Accident Hazard
Major Accident Hazard Pipeline
Marine Accident Investigation Board
A defined sub area within the installation area in which a WCC may be placed. A list of all available locations is defined within
the system and is linked to an area.
Identification number to be stored on the WCC to reference an entry an any appropriate Maintenance Management System
To hoist the drill stem out of the wellbore to perform one of a number of operations such as changing bits, taking the core, and
so forth, and then to return the drill stem to the wellbore.
To assemble/screw together the sections of joints of a string of pipe. “Breaking Out” is the opposite.
Conduct the working of; have effective control of.
Skilful handling.
An established means of managing and controlling changes within an organization.
The person, irrespective of other responsibilities, who has been assigned the authority to establish and maintain a quality
system in accordance with BS EN ISO 9001 and who reports on it's performance to ProTech management for review and as a
basis for improvement.
Page 83 of 310
Management System
Arrangements to ensure that the relevant statutory provisions will be complied with in relation to the site
[onshore/offshore/office] and any activity on or in connection with it.
Mandatory
Obligatory or compulsory. All instructions, requirements, procedures etc., described as mandatory must be complied with.
Mandatory Requirements
The outcome that must be delivered.
An assembly of pipes, valves, and fittings by which fluid from one or more sources is selectively directed to various process
systems. Also A piping arrangement which allows one stream of liquid or gas to be divided into two or more streams, or which
allows several streams to be collected into one.
Operation of a Production Plant that requires constant human supervision on location to manage the process and to take
immediate intervention action during process upsets.
Any transporting or supporting of a load [including the lifting, putting down, pushing, pulling, carrying or moving thereof] by
hand or by bodily force.
Maximum Allowable Operating Pressure
Major Accident Prevention Document
Movements and Personnel System
Management and Administration Regulations [SI 1995/738].
A well, development, etc. whose commercial profitability is in doubt.
International Convention for the Prevention of Pollution from Ships 1973 as modified by Protocol of 1978 relating thereto
[MARPOL 73/78]
The mass number [A] of an atom indicates the nett number of protons and neutrons in the nucleus and therefore identifies the
isotope of the element.
The collar which fits into the rotary table and through which the kelly passes.
A structure placed on poorly consolidated, soft or unstable seabed as a footing for jackup rigs, etc.
Alpha Thames’ valved, in-line, multiported fluid connector which enables simultaneous connection/disconnection of numerous
piping runs.
The function of burial pressures, temperatures, and time which determines whether a source of hydrocarbons will provide oil
or gas.
Master Agreement Vendor
Maximum Allowable Working Pressure
Maximum
Million barrels of oil per day
Thousands of Barrels
Thousands of Barrels per Day.
Minimum Breaking Load
Maritime and Coastguard Agency
Miniature Circuit Breaker
Motor Control Centre
Thousand cubic feet
Manifold Control Module
Thousands of cubic metres per day
Main Control Panel
Management Consultants Register
Multicycle Reverse Valve
Manifold
Manned operations
Manual Handling Operations
MAOP
MAPD
MAPS
MAR
Marginal
MARPOL
Mass Number
Master Bushing
Mat/Mattress
MATE™
Maturity
MAV
MAWP
Max
Mbbl/d
MBbls
Mbd
MBL
MCA
MCB
MCC
Mcf
MCM
mcm/d
MCP
MCR
MCRV
Page 84 of 310
MCS
MD
Md
MD
MDC
MDC
MDF
MDFT
MDS
MDHS
MEA
Mechanical time constant [tm]
[Seconds]
Median Line
MEG
Meiofauna
MEL
MEOH
Mercaptans
MERO
Master Control Station [in the ICC]
Managing Director
Millidarcies [unit of permeability]
Measured Depth [well] OR Mean water depth
Managing Director's Committee
Miniature Detonation Chord [military aircraft canopies]
Main Distribution Frame
Minimum Dry Film Thickness
Material Data Sheet OR Master Display Station
Method of Determination of Hazardous Substances
Monoethanolamine. [A chemical compound used to remove hydrogen sulphide and carbon dioxide from gas streams].
In a simple first order system, the time required for the motor's speed to attain 63.2% of its final value for a fixed voltage level.
Can be calculated from: J is inertia in lb-in./s2 R is resistance in ohms KT is torque constant in lb-in./amp. 8.87 is a
conversion factor tM is calculated in seconds
The boundary between the offshore mineral extraction jurisdictions of two states, by convention drawn equidistant from the
nearest point of land on each side.
Monoethylene Glycol - IUPAC name: ethane-1,2-diol is an alcohol with two -OH groups [a diol], a chemical compound widely
used as an automotive antifreeze. In its pure form, it is an odorless, colorless, syrupy liquid with a sweet taste. Ethylene glycol
is toxic, and its accidental ingestion should be considered a medical emergency.
Ethylene glycol's high boiling point and affinity for water makes it an ideal desiccant for natural gas production. In the field,
excess water vapour is usually removed by glycol dehydration.
Glycol flows down from the top of a tower and meets a rising mixture of water vapor and hydrocarbon gases from the bottom.
The glycol chemically removes the water vapor, allowing dry gas to exit from the top of the tower.
The glycol and water are separated, and the glycol cycles back through the tower.
Benthic organisms sized between 50micro millimeters and 1mm.
Maximum Exposure Level
Methanol
Mercaptans are a group of sulfur-containing organic chemical substances. They smell like rotting cabbage, and are, for the
most part, what make pulp mills smell like pulp mills.
If mercaptans are in the air, even at low concentrations, they are very noticeable.
Pulp mills are the chief source of mercaptans, although they are also found in production processes of some pesticides,
pharmaceuticals and petroleum products. They are also used as an odourizing agent in natural gas.
The human body produces them naturally during digestion of beer, garlic and some other foods.
Dangers of Mercaptans - Not very much is known about the dangers of mercaptans, but current research shows that
mercaptans are less poisonous than hydrogen sulfide [the gas that smells like rotten eggs].
Mercaptans Affect on Health - If there is a leakage or a spill of mercaptans, workers may develop headaches and become
nauseated and vomit. There may be coughing and irritation of the lungs and inflammation of the eyes, nose and throat. If the
concentration is very high, the worker may have difficulty breathing and may turn blue -medically described as "cyanosis".
The worker may then lose consciousness and have generalized muscle spasms.
In organic chemistry, a thiol is a compound that contains the functional group composed of a sulfur atom and a hydrogen atom
(-SH). Being the sulfur analogue of an alcohol group [-OH], this functional group is referred to either as a thiol group or a
sulfhydryl group.
Marine, Emergency Response & Offsites
Page 85 of 310
MES
Metamorphic rock
Metering Separator
Mobile Earth Station
A rock derived from pre-existing rocks by mineralogical, chemical and structural alterations caused by processes within the
earth's crust. Marble is a metamorphic rock.
Separator featuring calibrated liquid chambers are used for metering in either 3-phase or ordinary 2-phase operation. These
vessels register the number of dumps of the calibrated volume of oil and water and are applicable where individual well tests
are desire or where continuous or frequent data are necessary.
Methane
CH4. Chemical compound. Density 0.717 kg/m3. It is the simplest alkane, and the principal component of natural gas.
Burning one molecule of methane in the presence of oxygen releases one molecule of CO2 [carbon dioxide] and two
molecules of H2O: CH4 + 2O2 → CO2 + 2H2O. Because it is a gas [at normal temperature and pressure] and not a liquid or
solid, methane is difficult to transport from the areas that produce it to the areas that consume it. Converting methane to
derivatives that are more easily transported, such as methanol, is an active area of research. Methane is a relatively potent
greenhouse gas with a global warming potential. When averaged over 100 years each kg of CH4 warms the Earth 23 times as
much as the same mass of CO2, however there is approx 220 times as much CO2 in the atmosphere as methane.
Methanol
Also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a chemical compound with chemical
formula CH3OH [often abbreviated MeOH].
It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odour.
At room temperature it is a polar liquid and is used as an antifreeze, solvent, fuel, and as a denaturant for ethyl alcohol. It is
also used for producing biodiesel via transesterification reaction. Methanol is used to inhibit the formation of hydrates
[normally at a process or well start up] and break down those that may have already formed.
Methanol is poisonous, volatile and highly inflammable; it burns with a colourless flame, ie the flame cannot be seen!
Metrology
The Science of Measurement. Metrology is a very broad field and may be divided into three subfields as follows.
Scientific or fundamental metrology concerns the establishment of measurement units, unit systems, the development of new
measurement methods, realisation of measurement standards and the transfer of traceability from these standards to users in
society.
Applied or industrial metrology concerns the application of measurement science to manufacturing and other processes and
their use in society, ensuring the suitability of measurement instruments, their calibration and quality control of measurements.
Legal metrology concerns regulatory requirements of measurements and measuring instruments for the protection of health,
public safety, the environment, enabling taxation, protection of consumers and fair trade.
MF
MFDR
MFGP
MFM
MFO
mg/m3
MGI
Mgmt
MGV
MHAU
MHIDAS
Medium Frequency OR Meter Factor
Manufacturer’s Fabrication Data Report
Main Fire and Gas Annunciator Panel
Multi-phase Flow Meter
Medium Fuel Oil
Milligrams per cubic metre
Miscible Gas Injection. See Enhanced Oil Recovery EOR.
Management
Master Gate Valve. The main and most important valve on the well. When closed should keep the well pressure under full
control. The master gate is part of the Christmas tree. The valve on a gathering station which closes all incoming production in
case of malfunction in the station. The valve is usually provided with an automatic actuator.
Major Hazards Assessment Unit [HSE]
Major Hazard Incident Database
Page 86 of 310
MHSWR
MHWN
MHWS
MHz
Microfauna
Micron
Microstepping
Microwave
Mid-range instability
MIG
Migration
Mil
Mill
Mill Scale
Millidarcy
MILS
MIL-STD
MIM
Min
MIND
Miocene
MIR
Miscible Flooding
Mission
Mitigated or Mitigation
Mitigation
MIU
MIV
ML
MLSS
MLSV
MLW
MLWN
MLWS
mm
Management of Health and Safety at Work Regulations 1999. [Requires that we identify, eliminate, control or handle
potentially harmful operations in a responsible manner].
Mean High Water Neaps
Mean High Water Springs
Megahertz
Benthic organisms sized less than 50 micromillimeters.
Millionth of a metre OR thousandth of a millimetre.
An electronic technique for increasing a step motor's position resolution and velocity smoothness by appropriately scaling the
HF multi-channel radio communications system designed to carry information between two points linked by line-of-sight
transmission.
A phenomenon in which a step motor can fall out of synchronism due to a loss of torque at mid-range speeds. The torque loss
is due to the interaction of the motor's electrical characteristics and the driver's electronics. Some drivers have circuitry to
eliminate or reduce the effects of mid-range instability.
Metal Inert Gas welding
Hydrocarbons are often found in formations other than those in which their organic source was deposited. This movement
often over considerable distances is known as migration. OR A process applied to data recorded, e.g. in a “3-D” seismic
survey, to adjust for the effects of the “oblique” angle at which it was gathered.
Millilitre[s]
A bit for cutting through steel obstructions in a well such as ‘fish’.
Oxides which form on the surface of a steel plate after heating during manufacture.
See Darcy.
Milli-inches OR thousandth of an inch
Military Standard [USA]
Manager's [Management] Information Manual
Minimum
Mineral-insulated non-draining [cable]
Rocks formed in the fourth epoch of the Tertiary period, between the Oligocene and the Pliocene epochs. See Tertiary.
Moving In Rig
An injection/displacement process developed recently to obtain greater oil recovery in many reservoirs. Miscibility is the ability
of two or more substances to mix, without the existence of an interface. The fluids are injected together into a reservoir in a
secondary or tertiary recovery programme – e.g. Gas and LPG, or Carbon Dioxide followed by water.
The way in which Petrofac Production will go about it’s business.
Measures to lessen the severity of the consequences of a hazard.
An action or event which prevents or minimises the effects of an incident or condition.
Moisture, Impurities and Unsaponifiables [grease testing]
Methanol Injection Valve
Mud log, mudlogger
Mudline Suspension System [also MLS]
Mudline Safety Valve
Mean Low Water [e.g. port data]
Mean Low Water Neaps
Mean Low Water Springs
Millimetres
Page 87 of 310
MM
MMB
Mmbbl/d
mmbl
mmboe
MMBTU
MMcf
MMcf/d
MMI
MMO
MMS
MMSC
mmscf
MMSCF
mmscf/d
MMSCFD
mmstb
MMT
MN
MNSL
MODU
Module
MOL
Mole %
Molecular Sieve
Monitoring
Monobuoy
Monopod
Moonpool
MOPO
MOPS
Moss
Million
Module Mounting Base
Million barrels of oil per day
million barrels
Million barrels of oil equivalent
Million British Thermal Units
Million cubic feet
Million cubic feet per day
Man Machine Interface
Mixed Metal Oxide [surface coating]
Maintenance Management Service OR Mineral Management Service [USA]
Maintenance, Modifications and Services Contractor
million standard cubic feet
Million standard cubic feet
Million standard cubic feet per day
Million standard cubic feet per day
million of stock tank barrels
Material Movement Ticket
Meganewton
Mobil North Sea Ltd
Mobile Offshore Drilling Unit
A self-contained, liftable package forming part of the facilities of an offshore installation e.g. accommodation module,
compressor module, drilling module, etc. See also System-Module.
Main Oil Line
Percentage by Mole.
A process of separating hydrocarbon fractions etc. by passing the feedstock through successive absorbent substances which
offer differing degrees of resistance to its passage.
The routine function of regular inspection carried out by a responsible and competent person.
See Single Buoy Mooring.
A small offshore platform, resting on a single columnar ‘leg’, mainly for small satellite developments in shallow waters.
A hole or well in the hull of a ship [usually in the centre] through which equipment pass to gain access to subsea.
Manual of Permitted Operations
Maintenance Operations Planning System
Manual override switch
Moss Rosenberg
Moss Rosenberg Verft A.S., Norway. The spherical tank design uses an unstiffened, spherical, aluminum alloy tank [usually
four to six tanks per ship] that is supported at its equator by a vertical cylindrical skirt, with the bottom of the skirt integrally
welded to the ship’s structure. This free-standing tank is insulated with multi-layer close-cell polyurethane panels.
MOT
Motion Compensator
MOV
MPa
MPE
Main Oil Transfer
A heave compensator. Fitted to cranes etc. to counteract vertical motion caused by the sea.
Motor Operated Valve
Mega Pascal [1 MPa =1 N/mm2], unit of pressure or stress [Mega = 106]
Ministry of Petroleum & Energy [Norway]
Page 88 of 310
MPI
MPT
MQC
MRR
MRT
MSA
MSC
mScfd
MSDS
MSF
MSL
MSP
MSS
MST
mstb
mstb/d
MSTBD
MSV
MSV
MTBE
MTBF
MTD
MTI
MTM
MTO
Mud
Magnetic Particle Inspection
Magnetic Particle Testing. A non-destructive testing method whereby the object is magnetised and minute particles applied
externally. Cracks, etc. can be discerned at the surface. Welds in wellheads, etc. can safely be examined in situ.
Multi Quick Connector
Material Receiving Report
Media Response Team
Marine Safety Agency, now the MCA [part of the DoT]
Metering Supervisory Computer
Millions of standard cubic feet per day
Material Safety Data Sheets
Module Support Frame
Mean Sea Level
Maximum surface pressure
Manufacturers’ Standardization Society of the Valve and Fittings Industry Inc. [USA]
Multipurpose Shuttle Tanker
Thousand stock tank barrels
Thousand stock tank barrels per day
Millions of Standard Barrels per Day
Multi-functional Support Vessel
Multi-Service Vessel
Methyl Tertiary Butyl Ether. A hydrocarbon product significant as one of the major lead-free Octane enhancers for gasolines.
See Anti Knock Compounds. ETBE [Ethyl Tertiary Butyl Ether] has similar properties.
Mean Time Between Failures
Measured Total Depth
Materials Technology Institute of the Chemical Process Industries
Metal To Metal
Material Take-Off
Mud is the name given to drilling fluid which is mainly a mixture of water, or oil distillate, and ‘heavy’ minerals such as
Bentonite or Barites. Mud is pumped into a well at densities calculated to provide a hydrostatic pressure sufficient to overcome
downhole formation pressures.
In addition, the mud is continuously circulated down to the bit, and returns in the annular space outside the drill-string, bringing
with it rock cuttings for inspection and keeping the well clean.
It is also engineered to maintain a thin protective layer of filter-cake on the bore hole wall, without excessive weight which
would decrease the weight on the bit and hence penetration [see Drill String], and also possibly lead to differential sticking and
formation damage.
Mud is pumped from the mud pit [or tank] via the standpipe, rotary hose and gooseneck to the swivel, and into the drill stem.
On return from down hole it is recovered and rock cuttings removed by the shale shakers before re- circulation.
To Mud Up is to increase mud weight and downhole pressure.
To Mud Off is to seal off a formation with heavy filter cake.
A Mud Log is the record of mud make-up and analysis of cuttings recovered.
The composition of mud used in a well is normally supervised by a Mud Engineer.
Page 89 of 310
Mud return line
Mudline
Multi-disciplines
Multilateral
Multiphase
Multiphase Flow
Multiple Completion
Multiplex
Musculo-skeletal
MUST
MV
MVC
MVHJ
MW
MWA
MWCS
MWD
MWD
MWP
MYS
N
N/mm2
N2
NA or N/A
NACE
Naked lights
NAMAS
NAO
A trough or pipe that is placed between the surface connections at the wellbore and the shale shaker and through which
drilling mud flows upon its return to the surface from the hole. Also called flowline.
The seabed, or bed of any body of water where drilling is taking place.
Multi-disciplines refers in general to piping, structural, mechanical, instrumentation and electrical.
Multiple boreholes drilled from an existing single bore well.
A fluid mixture consisting of oil [with water] and dissolved gas. The practice of flowing stabilised well fluids [e.g. oil with high
gas content] in a single pipeline by boosting the pressure to prevent vaporisation of the dissolved gases.
Simultaneous flow of liquid and gas, or of different liquids, through a pipeline or other vessel [e.g. oil/gas, gas/water, oil/water].
A well perforated and completed to produce simultaneously but independently from more than one formation. Also known as
Multipay Well.
Relating to or being a system of simultaneous control of two or more functions e.g. electro/hydraulic controls.
Relating to muscles and bones.
Modular Underwater Separation Technology; predecessor of AlphaPRIME™ and AlphaCPU™
Master Valve
Measurement Validation and Comparison
Manifold Valve Hydraulic Jumper
Megawatts [=106 watts]
Mineral Workings [Offshore Installations] Act 1971.
Module Weight Control System
Measurement While Drilling. [Down hole instrument systems used to monitor and control continuously the direction of the well
bore to the high degree of accuracy needed for e.g. horizontal drilling].
Measurement While Drilling OR Mean water depth
Maximum Working Pressure
Minimum Yield Strength
Newton [unit of force]
Newton[s] per square millimetre; unit of pressure or stress
Nitrogen Oxide
Not applicable
National Association of Corrosion Engineers [USA]
All flames, fires, exposed in incandescent material, electric welding arcs, lamps of an unapproved pattern, and portable handor power-operated equipment liable to cause sparking or produce flame.
National Material Accreditation Service
Nominated Area Operator. The person in charge of a specialised work area [for example Local Operator/Driller].
Page 90 of 310
NaOH
Sodium hydroxide, also known as lye, caustic soda and [incorrectly, according to IUPAC nomenclature] as sodium hydrate, is
a caustic metallic base. Sodium hydroxide forms a strong alkaline solution when dissolved in a solvent such as water.
It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water,
soaps and detergents and as a drain cleaner.
Worldwide production in 1998 was around 45 million tonnes. Sodium hydroxide is the most used base in chemical
laboratories.
Pure sodium hydroxide is a white solid; available in pellets, flakes, granules and as a 50% saturated solution.
It is deliquescent and readily absorbs carbon dioxide from the air, so it should be stored in an airtight container. It is very
soluble in water with liberation of heat.
It also dissolves in ethanol and methanol, though it exhibits lower solubility in these solvents than potassium hydroxide. It is
insoluble in ether and other non-polar solvents.
A sodium hydroxide solution will leave a yellow stain on fabric and paper.
Naphtha
A collective name given to a range if distillate fractions covering heavy gasolines and some of the lighter kerosene distillates.
NAPP
NAS
Native Gas
Noise Attenuation Prioritisation Procedure
National Aeronautical Society
Gas originally discovered in a reservoir as distinct from injected gas. See also Associated Gas.
Producing a reservoir by means of its natural pressure – without pressure maintenance. [Also Flush Phase, Primary
Production, etc.]
Term used to describe the flow of fluids from a well using only the natural energy of the reser-7oir and produced fluids.
A procedure in which gamma rays naturally given off or emitted by rock formations, cut through by the wells borehole, are
measured. A radiation detector is lowered into the hole and picks up gamma rays emitted by the rock. The signals are
transmitted to a recording device at the surface. See also Gamma ray logging .
Gaseous forms of petroleum consisting of mixtures of hydro-carbon gases and vapours, the more important of which are
methane, ethane, propane, butane, pentane, and hexane; gas produced from a gas well.
Liquid hydrocarbon mixtures, generally consisting primarily of propane and heavier hydrocarbons. Exceptionally ethane may
be included.
Natural Gas is primarily Methane and also some Ethane with small quantities of entrained heavier fractions, such as Propane,
Butane, etc. These, and others, are readily condensed from the Natural Gas flow and are known as Natural Gas Liquids, or
NGL’s, as distinct from Liquid Natural Gas [LNG] which is Methane/Ethane refrigerated to the liquid state. NGL may be
produced from condensate reservoirs.
Those liquid hydrocarbon mixtures containing essentially pentanes and heavier hydrocarbons which have been extracted from
natural gas.
The time that elapses between successive occurrences of any phenomenon, such as two successive wave-crests or the
resulting movements of heave, roll, etc. of a floating vessel.
= 1.852 km
Arrangement of 12 transmitting stations
System for the automatic reception of local [coastal] weather and navigational information [518 KHz]
Note well [nota bene [Latin]] OR Nominal Bore
Narrow Band Direct Printing
Non Conformance Report [quality]
Network Control Station
Natural Depletion
Natural flow
Natural Gamma ray logging
Natural gas
Natural gas liquids
Natural Gas/NGL’s
Natural gasoline
Natural Period
Nautical mile
Navarea
Navtex
NB
NBDP
NCR
NCS
Page 91 of 310
NCS
NDB
NDE
NDFT
NDT
Near Miss
Needle valve
NEL
NEMA
Neoprene
NER
NESBACS
NEST
Net calorific value
Net oil computer
Network
Neutron log
Newton
Newtonian fluid
Next Button
NFSD
NGL
NGL
Norwegian Continental Shelf
Non-Directional Beacon
Non-Destructive Examination
Nominal Dry Film Thickness
Non Destructive Testing. [Methods of inspecting and testing the quality or integrity of vessels or equipment which do not
involve removal or testing to destruction of representative sections].
An unplanned, undesired sequence of events, which in another set of circumstances would have resulted in an accident or
incident.
A valve used on small, high-pressure piping where accurate control of small amounts of l1quid or gas is desired. The tongue
of the valve is a rod that 1:apers to a point and fits into a seat which permits fine adjustments.
National Engineering Laboratory [East Kilbride, Scotland]
National Electrical Manufacturer's Association. Acronym for an organization which sets standards for motors and other
industrial electrical equipment.
A mixture of natural and petroleum-based synthetic rubber highly resistant to chemical attack.
New Entrants Reserve
North East Shetland Basin Area Communications System
Noise Exposure Status Tables
The net calorific value at constant pressure of a gaseous fuel is the number of heat units produced when unit volume of the
fuel, measured under standard conditions, is burned in excess air in such a way that the materials after combustion consist of
the gases carbon dioxide, sulphur dioxide, oxygen, nitrogen and water vapour, and that the pressure and the temperature of
the gaseous fuel, the air and the materials after combustion are one standard atmosphere and 25 0C. This value is derived
from the measured gross figure.
An instrument which continuously measures the instantaneous water cut and flow rate, and records the cumulative volumes of
net oil and water flowing through the instrument.
A computer based system which allows multiple users to share information and resources.
A well log that responds primarily to the hydrogen index of the formation and thus, with lithological, salinity and/or hydrocarbon
corrections, measures porosity.
The tool consists of a neutron source (Am-Be or Pu-Be) and neutron or gamma-ray detectors.
High energy neutrons are moderated or slowed down by all atoms in the formation, but the highest moderation comes from the
neutron collisions with the hydrogen atoms in the formation.
The detectors detect either epithermal or thermal neutrons, or gamma-rays of capture. In conjunction with other logs, this log
is used to differentiate between oil and gas in the reservoir.
A unit of force that, when applied to a body of mass one kilogram, gives it an acceleration of one meter per second squared
[1 N = 1 kg ms -2 ].
The basic and simplest fluids from the standpoint of viscosity consideration in which the shear force is directly proportional to
the shear rate. These fluids will immediately begin to move when a pressure or force in excess of zero is applied. Examples of
Newtonian fluids are water, diesel oil and glycerine. The yield point as determined by direct-indicating viscometer is zero.
Moves from the present location forward to the next stage [the opposite to the Back button].
National Facility for Scientific Diving [UK]
Natural Gas Liquid[s]; a mixture of hydrocarbon liquids which include butane and ethane obtained from natural gas. It may be
produced from condensate reservoirs but more probably produced as a by-product of oil production.
Natural Gas Line
Page 92 of 310
Non upset
Non-BP Company
Non-conformance
Non-Government Organisation
Network Interface Module
A short length of pipe with threads on both ends or with weld ends.
The material man who serves the drilling rig or production crews; the person who makes certain all supplies needed are on
hand.
A short length of pipe with connections at both ends. To Nipple Up is to assemble pipe valves etc. especially a blowout
preventer. A Nipple Chaser is a materials man whose job is to obtain and have ready for shipment to the rig the various tools,
supplies, etc. needed.
To put together fittings in making a hook up; to assemble a system of pipes, valves and nipples as in a Christmas tree,
wellhead or BOP stack.
Near Infra-Red.
Not Intrinsically Safe
Network Interface Units
nautical mile
Newton metre[s], unit of torque
Norwegian Maritime Directorate
North Module Support Frame
Non Methane Volatile Organic Compound
Not Normally Manned
Not Normally Manned Installation
Nitrogen Dioxide
National Oceanic and Atmospheric Administration [USA]
Northern Office Block
The colloquial name for conventional onshore wellhead production beam pumps.
The specially strengthened junction of tubular components in a conventional steel platform jacket. There are several on each
leg and also at the meeting of cross-members.
Non-Operators Forum OR Northern Offshore Federation
National Ocean Industries Association [USA]
A sound detection system inside a logging tool designed to pick up vibrations caused by flowing liquid or gas down hole. The
device is used to check the effectiveness of a squeeze job to estimate the gas flow from perforated format etc.
The quoted but not necessarily the actual size or diameter of tubulars, tools and other equipment. There may be a
manufacturing tolerance on internal and/or external sizes/ diameters. The actual size can be smaller or larger than the nominal
size.
Pipe end having the same O.D. and I.D. as the pipe.
A company outside the BP Group, or a company or other legal entity where BP does not have operational control.
Any deviation from specified requirements.
Non-conformance
The nonfulfilment of specified requirements. Any action or inaction which contravenes the mandatory controlling documents.
Non‑Hazardous Area
A Non Hazardous Area is an area in which flammable atmospheres are not expected to be present so that special precautions
for the construction, use and maintenance of electrical apparatus are not required (see Appendix 3).
Non-sparking tools
Hand tools made of bronze or other non-ferrous alloys for use in areas where flammable oil or gas vapours may be present.
NGO
NIM
Nipple
Nipple chaser
Nipple etc.
Nipple up
NIR
NIS
NIU
nm
Nm
NMD
NMSF
NMVOC
NNM
NNMI
NO2
NOAA
NOB
Nodding Donkey
Node
NOF
NOIA
Noise log
Nominal size
Page 93 of 310
NORM
Normal soltion
Normalising
NORSOK
NOS
NOSA
NOx
Nozzle
NPD
NPF
NPI
NPS
NPSH
NPV
NRV
NS
NTC - Negative Temperature
Coefficient
NTS
NUI
NUI
NVP
NW
NWECS
Ø
O&G
O&G UK
O&M
O/S
O2
Objective Evidence
Objectives
Obligation Well
OBM
Observation
OBSROV
Naturally Occurring Radioactive Material. In North Sea operations synonymous with LSA material but primarily containing the
isotopes Lead 210 and Polonium 210, not necessarily as significant deposits but as very thin coatings on process plant.
A solution of
A heat treatment of steel. The steel is heated above a critical temperature and air-cooled. Normalising refines the grain
structure, makes the structure more uniform and improves machinability.
Norwegian Standards for the Offshore Petroleum Industry
Nett Oil Sands
National Offshore Safety Agency [Australia]
Oxides of nitrogen
A flanged inlet or outlet connection on a pressure vessel.
Norwegian Petroleum Directorate
Norwegian Petroleum Society
Net Profit Interest
Nominal Pipe Size
Nominal [or Nett] Pump Suction Head
Net present value; an assessment of the long-term profitability of a project made by adding together all the revenue it can be
expected to achieve over its full life and deducting all the costs involved, discounting both future costs and revenue at an
appropriate rate. The net present value of a field is maximised by achieving early oil and low initial CAPEX.
Non-Return Valve
No Show OR Nitrogen Supply
A negative temperature coefficient thermistor is used to detect and protect a motor winding from exceeding its maximum
temperature rating. Resistance of the device decreases with an increase in temperature.
National Transmission System OR Norwegian Technology Centre OR Not to scale
Normally Unattended Installation
Norsk Undervannsintervensjon
No Visible Porosity
North West
North West European Continental Shelf
Diameter [Also used by electrical engineers to denote phase e.g. 440 V, 3-phase supply.]
Oil and Gas
Oil and Gas UK
Operations & Maintenance
Out of Service
Oxygen
Qualitative or quantitative information, records or statements of fact pertaining to the quality of an item or service or to the
existance and implementation of a mangement system element, which is based on observation, measurement or test and
which can be verified.
Specific, quantifiable, measurable end result within a timescale.
A well undertaken as part of the process of earning a concession.
Oil Based Mud
Statement of fact made during an audit and substantiated by objective evidence.
Observation Remotely Operated Vehicle
Page 94 of 310
o
C
OCB
Occupational illness
OCIMF
OCNS
OCS
OCU
OD
Odorant
Degrees Centigrade
Offshore Certification Bureau OR oil circuit breaker
An abnormal condition or disorder, other than one resulting from an injury, caused by exposure to environmental factors
associated with employment. It includes acute or chronic illnesses and diseases caused by inhalation, absorption, ingestion, or
direct contact
Oil Companies International Marine Forum
Offshore Chemical Notification Scheme
Outer Continental Shelf
Operators Control Unit
Outside Diameter
A substance with a penetrating smell or ‘stench’ which is added to a gas supply to assist detection of leaks, etc. Although toxic
Odourant
A chemical compound added to natural gas to produce a detectable unpleasant odour to alert householders should they have
even a small leak in the house piping. Odourants are used also in liquids or gases being stored or transported to detect leaks.
OE
OEC
OEC
OECD
OEL
OES
Oil Equivalent
ORMAT Energy Converter
Other End Connector
Organisation for Economic Co-operation and Development
Occupational Exposure Limit
Occupational Exposure Standard
Off the shelf
Said of products or equipment that are ready and waiting at a supplier's warehouse and can be taken off the shelf and shipped
immediately. Refers also to techniques and procedure that have been perfected and are ready to be employed on some jobs.
Offset
Offset Well
Offsite Facilities [Offsites]
OFLU
OGITF
OGP
OHMS
OHTC
OIAC
OIH
Oil and gas separator
Oil base mud
A wellbore which is set off from the vertical.
A well drilled to ‘mirror’ a production well drilled near the boundary of a neighbouring concession, on a common reservoir, in
Ancillary or service plant which is distant from the main process plant. [e.g. Water treatment, power generation, laboratory etc.]
It is sometimes applied to service installations in general, particularly at refineries.
Oil Fluorescence
Oil & Gas Industry Task Force
International Association of Oil & Gas Producers
Occupational Health Management System
Overall Heat Transfer Coefficient. [Represents the loss of calorific energy per system length unit [e.g. steel pipe plus thermal
insulation]. W/m°K
Offshore Industry Advisory Committee [UK]
Oil In Hole
An item of production equipment used to separate liquid components of the wellstream from gaseous elements.
The term oil-base mud is applied to a special type drilling fluid where oil is the continuous phase and water the dispersed
phase. Oil-base mud contains blown asphalt and usually 1 to 5 percent water emulsified into the system with caustic soda or
quick lime and an organic acid. Silicate, salt and phosphate may also be present. Oil-base muds are differentiated from invertemulsion muds (both water-in-oil emulsions) by the amounts of water used, method of controlling viscosity and thixotropic
properties, wall-building materials, and fluid loss.
Page 95 of 310
Oil Based Mud
Oil catcher
Oil Column/Gas Column
Oil Field
Oil Geology
Oil in place
Oil operator
Oil ring
Oil sand
Oil spill
Oil string
Oil String
Oil trap
Oil/Water Contact
OILC
Oiler
Oilpatch
OIM
OIM
OIMS
OIP
OIR/7
OIS
OIW
OLE
Olefins
OLF
Oligocene
OMS
On stream
OOIP
OPC
Drilling mud in which the solids are suspended in a hydrocarbon distillate rather than water. This has operational advantages
particularly in deeper or technically difficult wells, but can make the detection of formation hydrocarbons more difficult.
A large basin in production installations in which drainage water and surface liquids (rain, wash water, waste oil) are collected
and the oil separated from the water. Also called Skimming pit.
The vertical distance between points of highest and lowest known oil or gas in a reservoir.
A group of hydrocarbon reservoirs in a common geological setting OR A single reservoir, the subject of actual or planned
development.
Specialised geology which deals exclusively with sedimentary basins and the sources of hydrocarbons.
Crude oil estimated to exist in a field or a reservoir; oil in the formation not yet produced (and not necessarily producible).
See operator
A metal ring that runs on a horizontal line shaft, in the bearing well which has a supply of lube oil. As the ring slowly rotates
through the well of oil it deposits oil on the shaft. Oil rings are generally made of brass and are used on relatively slow-moving
shafts.
A porous sandstone formation containing oil.
A mishap that permits oil to escape from a tank, a well, an oil tanker or a pipeline.
The final string of casing set and cemented directly above the producing zone or through it.
The inner or production string of casing in a well.
A potential oil trap is a reservoir rock, which is sealed off at-the top by a formation impervious to the passage of Fluids and
from which fluids cannot escape laterally owing to the geological configuration of the layers. Oil traps can be broadly divided
into structural and stratigraphic traps.
The lower end of the column in a reservoir with underlying water. This may be graduated or occur in formations where it is
hard to detect.
Offshore Industry Liaison Committee [a UK union]
An oil well, particularly an oil discovery well.
A colloquial reference to exploration and production activity.
Offshore Installation Manager. The person on an offshore platform with statutory responsibilities for safety, etc., similar to
those of a ship’s captain.
Offshore Installation Manager
Operations Integrity Management System
Oil In Place
Official Log Book
Offshore Installation Supervisor
Oil-In-Water
Object Linking and Embedding - see OPC
The group of hydrocarbons known as Alkenes.
Oil Industry Association [Norway]
Rock formed in the third epoch of the Tertiary period. See Tertiary.
Operations Management System
Term used for a processing plant, a refinery or pumping station that is operating
Original Oil In Place
OLE for Process Control - see OLE
Page 96 of 310
OPEC
Open Flow
Open hole
Open Hole
Open-loop
Operating Tasks
Operator
Operator
Operator
OPET
OPEX
OPITO
OPOL
OPPS
OPS
OPU
ORA
Organic substance
Organic/Organic Chemicals
Orifice fitting
Orifice flanges
Orifice meter
Orifice Meter
Orifice plate
Originator
O-ring
ORM
Organisation of Petroleum Exporting Countries. Oil producing and exporting countries in the Middle and Far East, Africa, and
South America that have organised for the purpose of negotiating with oil companies on matters of oil production, prices,
future concession rights.
Producing a well without chokes or beans. Unrestricted production normally for testing or maintenance purposes.
An uncased well bore; the section of the well bore below the casing; a well in which there is no protective string of pipe.
An uncased section of well borehole.
A system in which there is no feedback. Motor motion is expected to faithfully follow the input command. Stepping motor
systems are an example of open-loop control.
Tasks carried out by personnel who run BP facilities and production units which require interface with plant and equipment and
are necessary to ensure ongoing plant operations [e.g. sample taking, filter element replacement, etc].
An actuating device; a mechanism for the automatic and/or remote operation and/or control of units of an installation.
Operators are usually air or hydraulically actuated. Their main use is for opening and closing stops and valves. Also called
Actuator..
A worker who is responsible for the operation of a small plant or a unit of a larger plant during his working shift.
The company or other organisation responsible for conducting operations on a concession, on behalf of itself and any other
concession holders, [non operators]. The operator usually has the largest share of equity participation OR An oil industry
worker, someone controlling process plant etc OR the mechanism activating a valve, etc.
Organisations for the Promotion of Energy Technology
Operating Expenditure
Offshore Petroleum Industry Training Organisation
Offshore Pollution Liability Agreement. [An industry co-operative insurance and self-insurance scheme between operators in
the European continental shelf and adjacent coastal areas covering costs of major pollution clean up].
Over Pressure Protection System
Office of Pipeline Safety [USA]
Oil Purification Unit
Operational Risk Assessment OR Operation Readiness and Assurance
A material that is or has been part: of a living organism. Oil, although classified as a mineral, is an organic substance derived
from living organisms.
Substances derived from living organisms, such as oil in the natural state.
An orifice plate holder used instead of orifice flanges when frequent orifice plate changes have to be made. Basically a
chamber holding a removable orifice plate.
Special pipe flanges between which an orifice plate is clamped, used when measuring flow rates by orifice meter.
A flow rate measuring device on a pipeline that measures the pressures upstream and downstream of a restricting orifice
placed in the line enabling the volume to be calculated.
An instrument which measures the flow of a fluid in a pipeline by monitoring a controlled flow through a small aperture.
A disc with a restricting orifice in it, placed in a flow stream to measure the rate of flow through a pipe. From the pressures
measured upstream and downstream of the plate the rate of flow can be calculated.
A competent person who has completed the permit signatories course originates Work Permits. This would normally be a
discipline supervisor.
A circular rubber gasket used in flanges, valves and other equipment for making a joint pressure tight. O-rings in cross section
are circular and solid.
Output Relay Module
Page 97 of 310
Orogeny
ORRI
OS
OS&D
OSBL
OSC
OSCAR
OSCP
OSD
OSM
Osmosis
OSPAR
OTC
OTL
OTS&F
OUOOC
Outage gauge
Outcrop
Outcrop
Outside Worker
Outstep well
Overdue State
Overlift
Overload capacity
Overpressure
Overshot
Overshot
OVI
OWC
OWL
OWS
The process of shrinking, cooling and ‘wrinkling’ of the earth’s crust, leading to the formation of mountains, synclines,
anticlines etc.
Over Riding Royalty Interest
Operations Superviser
Over, Short and Damaged Report
Outside Battery Limits
On Scene Commander
Optical Scanning Apparatus for Ropes
Oil Spill Response Contingency Plan
Offshore Safety Division [of the HSE] OR Operational shutdown.
Onshore Site Manager [or SM].
Osmosis is the diffusion of a solvent (frequently water) through a semi-permeable membrane, from a solution of low solute
Oslo Paris Commission - Convention for the Protection of the Marine Environment in the North East Atlantic.
Offshore Technology Conference
Operations Team Leader
Odour Taste, Stain and Fluorescence
Inter Union Offshore Oil Committee
A measure of the oil in a tank by finding the distance between the top of the oil and the top of the tank and subtracting this
measurement from the tank height.
A subsurface rock layer or formation that, owing to geological conditions appears on the surface in certain locations. That part
of a strata of rock that comes to the surface.
The appearance of occurrence of a rock formation at the surface.
A classified worker who is employed in CONTROLLED areas designated by another employer.
A well drilled beyond the proven limits :)of a producing field in order to investigate a possible extension of the hydrocarbon
accumulation.
A state of the Live WCC that has not been returned at the end of the shift period. It is indicated by a letter ‘O’ within the icon
for that WCC.
Collecting more crude oil etc. than a production participant or purchaser is entitled to at any one time. See also Underlift.
The ability of a drive to withstand currents above its continuous rating. It is defined by NEMA as 150% of the rated full-load
current for standard industrial DC motors for one minute.
Formation pressure which is higher than the hydrostatic pressure.
A fishing tool; a specially designed barrel with gripping lugs or slips on the inside that can be slipped over the end of tubing or
drill pipe and lowered into the hole and over the upper end of the lost pipe. The lugs take a friction grip on the pipe, which can
then be retrieved. A fishing tool to recover wireline tools or equipment lost in the hole.
A fishing tool with a socket to fit over, enclose, and grip the top end of the fish for pulling out.
Oil Vulnerability Index
Oil Water Contact
Outstanding Work List
Operator Work Station OR oily water separator
Page 98 of 310
Oxy acetylene welding
Oxygen scavenger
P&A
P&ID
P&IDs
P&M
P&P
P&P
PA
Pa
PA
PABX
Packer
Packer
Packer fluid
Packer milling tool
Packing
Packing gland
PAGA
PAH
PAPA
Paraffin
Paraffin based crude
Paraffin wax
Paraffins
The use of a mixture of oxygen and acetylene in heating and joining two pieces of metal. When the weld edges of the two
pieces are molten, metal from a welding rod is melted onto the molten puddle as the welder holds the tip of the rod in the
flame of the torch. Oxygen and acetylene are used also in cutting through metal. The intense heat generated at the tip of the
cutting torch (about 3,500 'F) literally melts away the metal in the area touched by the flame.
Chemical used to remove oxygen.
Plug and Abandon
Piping and Instrumentation Diagram
Process and Instrument Diagrams.
Procurement and Materials
Porosity and Permeability OR porous and permeable
Process and Power
Public Address
Pascal
Public Announcement OR Public Address OR Personal Assistant OR Performing Authority
Private Automatic Branch eXchange
A subsurface tool used to provide a seal. between the tubing and the casing (or open hole wall) of a well to prevent the vertical
movement of fluids past this sealing point.
A piece of downhole equipment, consisting of a sealing device, a holding or setting device, and an inside passage for fluids,
used to block the flow of fluids through the annular space between the tubing and the wall of wellbore by sealing off the space
between them. It is usually made up in the tubing string some distance above the producing zone. A packing element expands
to prevent fluid flow except through the inside bore of the packer and into the tubing. Packers are classified according to
configuration, use, and method of setting and whether or not they are retrievable [that is, whether they can be removed when
necessary, or whether they must be milled and drilled out and thus destroyed].
Any fluid placed in the annulus between the tubing and casing above a packer. Along with other functions, the hydrostatic
pressure of the packer fluid is utilised to reduce the pressure differentials between the formation and the inside of the casing
and across the packer itself.
A milling tool to remove permanent packers from a well. The tool mills away only the outer par-:s of the packer. It does not mill
the body, which is recovered with the tool.
Any tough, pliable material - rubber or fibre - used to fill a chamber or gland around a moving rod or valve stem to prevent the
escape of gas or liquid; any yielding material used to effect a pressure-tight joint. Packing is held in place and compressed
against a moving part by a follower, an adjustable element of the packing gland.
A stuffing box; a chamber that holds packing material firmly around or against a moving rod, valve stem or wireline to prevent
Public Address and General Alarm
Polycyclic Aromatic Hydrocarbons
Prepare to Abandon Platform Alarm
A white, odourless, tasteless, and chemically inert waxy substance derived from distilling petroleum; a crystalline, flammable
substance composed of saturated hydrocarbons.
Crude oil containing little or no asphalt materials; a good source of paraffin, quality motor lubricating oil and high-g kerosene,
usually has lower non-hydrocarbon content than an asphalt-base crudeWax of solid consistency having a relatively pronounced crystalline structure, extracted from certain distillates from petroleum,
shale oil etc. Refined paraffin wax has a very low oil content; it is white with some degree of translucency, almost tasteless and
odourless and slightly greasy to the touch.
The alkane hydrocarbons
Page 99 of 310
PARIS
Partial pressure
Participation
Participation
Particle
Passbook
Passivation
Password
Pay out time
Pay String
Pay zone
Pay Zone/Horizon
PB
PBD
PBT
PBU
PC
PC
PC
PCB
PCB
PCC
PCF
PCF
PCM
PCN
PCO
PCP
PCP
Production and Reporting Information System
Partial pressure of a component of' a mixture in vapour liquid equilibrium is that part of the pressure which is contribute by that
component.
A type of joint venture between a host country and an inter-national oil company holding concession rights in that country.
Participation may be voluntary on the part of the oil company or as the result of coercion by the host country.
This usually refers to rights retained by a state when granting a concession, primarily to acquire part of the production at stated
terms, but sometimes also to participate on a full equity basis in any production development.
A minute unit of matter, usually a single crystal, or of regular shape with a specific gravity approximating that of a single
crystal.
A passbook approved for use under the Outside Workers Regulations 1993 and used to record details of personal information,
medical fitness for work with ionising radiation estimated doses while working in other employers controlled areas.
Is the process of making a material passive in relation to another material prior to using the materials together. For example,
prior to storing hydrogen peroxide in an aluminium container, the container can be passivated by rinsing it with a dilute solution
of nitric acid and peroxide alternating with deionized water. The nitric acid and peroxide oxidizes and dissolves any impurities
on the inner surface of the container, and the deionised water rinses away the acid and oxidised impurities. Another typical
passivation process of cleaning stainless steel tanks involves cleaning with NaOH [caustic soda] and citric acid followed by
nitric acid [up to 20% at 120F] and a complete water rinse. This process will restore the film, remove metal particles, dirt, and
welding generated compounds [e.g. oxides].
In the context of corrosion, passivation is the spontaneous formation of a hard non-reactive surface film that inhibits further
corrosion. This layer is usually an oxide or nitride that is a few atoms thick.
An alphanumeric code linked to a username which must be entered correctly before gaining access to that user account.
The time elapsed from the start of a project until the time at which the cumulative cash deficit is zero.
The production or inner string of casing.
The formation drilled into that contains oil and/or gas in commercial quantities.
A formation containing producible hydrocarbons.
Petrofac Brownfield
Plugged Back Depth
Production Bore Test
Pressure Build-up
Politically Correct
Personal Computer
Permit Co-ordinator
Poly-Chlorinated Biphenyl
Polychlorobiphenyls OR printed circuit board
Production Choke - Close
Platform Co-ordination Facility
Pounds per Cubic Foot
Physical Condition Monitoring
Personnel Certification in Non-destructive testing
Production Choke – Open OR parent company overheads
Pipeline Competent Person
Process Control Panel
Page 100 of 310
PCP
PCP
PCR
PCS
PCT
PCV
PCVC
PCVO
PD
PDA
PDC
PDG
PDI
PDO
PDQ
PDR
PDS
PDT
PE
PE
PEA
Peak or peak load
Peak shaving
Peak shaving LNG plant
Progressing-cavity Pump
Permit Co-ordination Point
Process Control Room
Process Control System OR Platform Control Station OR Pressure Control System
Patent Co-operation Treaty OR Pressure Control Tester
Production Choke Valve OR Pressure Control Valve
Production Choke Valve – Close
Production Choke Valve - Open
Pressure Directive OR pig detector
Pressure Differential Alarm
Pressure Differential Controller
Permanent Downhole Gauge OR Pressure Differential Gauge
Pressure Differential Indicator OR Pig detector indicator.
Plan for Development and Operation
Production, Drilling and Quarters platform
Procedure Development Request
Project detailed description
Pressure Differential Transducer
Petroleum Engineering
Polyethylene
Production Engineering Association
The maximum load of gas consumed or produced by an unit or group of units in a stated period of time.
Any of several methods of arranging production and storage of natural gas and crude oil to deal with demand variations the
most economic way,
A liquefied natural gas plant that supplies gas to a gas pipeline system during peak-use periods. During slack period! the
liquefied gas is stored. With the need for additional gas, the liquid product is gasified and fed into the gas pipeline.
Peak torque [Tpk] [lb-in]
The maximum torque a brushless motor can deliver for short periods of time. Operating PacTorq motors above the maximum
torque value can cause demagnetization of the rare-earth magnets. This is an irreversible effect that will alter the motor
characteristics and degrade performance. This is also known as peak current. Not to be confused with system peak torque,
which is often determined by amplifier peak current limitations, where peak current is typically two times continuous current.
PEC
PED
Pedestal
PEL
Pelagic
Personal Equipment Connector [military aircraft] OR Predicted Environmental Concentration.
Petroleum Engineering Division [of the Department of Energy] OR Pressure Equipment Directive [EC]
A large-diameter, vertical tube onto which a crane is attached.
Platform Emergency Line OR Production Emergency Line OR Petrofac Engiineering Limited.
Organisms inhabiting the water column of the sea.
Page 101 of 310
Pellistor
Pending State
Penetration rate
Pentane
PEP
Perforate
Perforating
Perforating gun
Perforating Gun
Perforation
Performance Standards
Permanent Materials
Permanent packer
Permanent partial disabilities
Permanent retrievable packer
Permanent total disabilities
Permanent type completion
Permeability
A pellistor is a solid-state device used to detect gases which are either combustible or which have a significant difference in
thermal conductivity to that of air. The word "pellistor" is a combination of pellet and resistor. The detecting element consist of
small "pellets" of catalyst loaded ceramic whose resistance changes in the presence of gas. The pellistor was developed in the
early 1960's for use in mining operations as the successor of the flame safety lamp and the canary. The catalytic pellistor as
used in the catalytic bead sensor works by burning the target gas; the heat generated producing a change in the resistance of
the detecting element of the sensor proportional to the gas concentration. The thermal conductivity (TC) pellistor works by
measuring the change in heat loss (and hence temperature/resistance) of the detecting element in the presence of the target
gas.
A WCC that has been checked and authorised to move from the Requested State to the Pending State by the appropriate
authority.
The rate in feet or metre per hour at which the drill proceed to deepen the well bore.
Pentane, C5 always exists as a liquid as far as we as operators are concerned.
Project Execution Plan OR Procurement Execution Plan
Perfing. To pierce the casing wall and cement to provide holes through which formation fluids may enter or to provide holes in
the casing so that materials may be introduced into the annulus between the casing and the wall of the borehole. Perforating is
accomplished by lowering a perorating gun, or perforator, into the well; the perforator fires electrically detonated bullets or
shaped charges.
To make holes through the casing opposite the producing formation to allow the oil or gas to flow into the well.
A device lowered on electric cable for perforating casing at a point opposite a reservoir formation to permit the product-of fluid
from the formation. The gun which uses bullets or shaped explosive charges is fired sideways from the control point at the
surface.
A perforating gun is a cylindrical tool loaded with explosive charges which are triggered opposite the pay zone, perforating the
casing in many places.
Holes punched in the casing of a well at the pay zone to be produced, to allow oil or gas to enter the well.
Agreed level of performance to be achieved. Must be specific and measurable.
Permanent Materials shall mean those materials forming a permanent part of the finished project
A packer whom once set forms an integral part of the casing. The tubing can be released from the packer and can be pulled,
leaving the packer in the well. The packer cannot be recovered as such, but it can be destructively removed, e.g. by milling._ It
is sometimes termed a production packer or a retainer production packer.
In Safety: Any Work Injury which results in a complete loss, or permanent loss of use, of any member or part of the body any
permanent impairment of functions of parts of the body, regardless of any pre-existing disability of the injured member of
impaired body function.
A packer with the same characteristics as the permanent packer but which can, when desired, be released and recovered,
entirely, from the well.
In Safety: Any Work Injury, which incapacitates an employee permanently and results in termination of employment.
A well completion methods for flowing or gas lift wells for which the subsurface equipment is selected and installed In such a
way that it, together with the wellhead assembly, can remain in place, undisturbed, throughout the normal producing life of the
well. It should only be removed in case of casing or tubing repairs or work-over. (Previously called: Permanent type well
completion - PTWC).
A measure of the resistance offered by rock to the movement of fluids through it. Permeability is one of the important
properties of sedimentary rock containing petroleum deposits. The oil contained in the pores of the rock cannot flow into the
well bore if the rock in the formation lacks sufficient permeability. Such a formation is referred to as tight. The unit of
permeability is the darcy.
Page 102 of 310
Petrology
The degree to which a body of rock will permit a fluid to flow through it. It is a function of the shape of the capillary pore spaces
and the degree to which pores are connected.
A measure of ease with which a fluid flows through the connecting pore spaces of a rock or cement. The unit of measurement
is the millidarcy OR the fluid conductivity of porous medium OR the ability of a fluid to flow within the interconnected pore
network of porous medium.
A formal and detailed document containing location, time, equipment to be worked on, Hazard identification,
mitigation/precaution measure used, naming those authorizing the work and those performing the work.
The single Central Point where the location and status of all Work Permits are displayed and conflicts highlighted
The person appointed to co-ordinate the issue of Work Permits, certificates and identify conflicts at the worksite
A rack that will display copies of Work Permits together with any relevant documentation on which work has been Authorised,
Issued or Suspended
The Permit to Work [PTW] system is a crucial element of the Petrofac Production Services Safety Management System [SMS]
that ensures that any potentially hazardous work done is carried out in a safe and controlled manner. However, the work
permit itself does not make the job safe, it must be used in the correct manner by the person in charge of the work, those
doing the work and by the person issuing the permit.
An approved management system used to control work in a safe manner.
The ability of a material to polarise in response to an applied electric field [ie: Coalescer fluids]
An isolation carried out, without the need for an ICC, by a Competent Electrical Person for himself and not for any third party,
which is removed at the end of his shift period.
An Isolation that is intended for short duration, relatively low risk tasks only. They can only be carried out by a competent
Isolation Authority and they are only valid for one shift.
Isolations not requiring an Isolation Confirmation Certificate carried out by an authorised competent Performing Authority and
identified by a Personal Isolation Label [Mechanical or Electrical].
An oversize tool for a small job; an extension added to the handle of a wrench to increase the lever-age.
Petrochemicals are chemical feedstocks and intermediates derived from petroleum.
In its broadest sense, the term embraces the whole spectrum of hydrocarbons - gaseous, liquid and solid. In the popular
sense, petroleum means crude oil.
Literally ‘rock oil’. Can include products, but normally means crude oil.
A specialist in the properties and behaviour of hydrocarbons in their natural reservoirs and under production conditions. While
a geologist normally provides estimates of hydrocarbons-in-place, a petroleum engineer would normally provide the estimate
as to how much of it could be produced [recoverable reserves] under what conditions, and at what rate.
A large area where reservoirs show common origins and characteristics.
Native asphalt, solid and semi-solid-bitumen, including oil-impregnated rock or sands from which oil is recoverable by special
treatment. Processes have been developed for extracting the oil, referred to as synthetic crude.
The study of rocks, their origin, chemical and physical properties and distribution.
Petrophysical engineering
Petrophysics for short, involves all information that contributes to formation evaluation: logging, cuttings, cores and well tests.
pf
PFD
PFD
PFEER
PFM
Power Factor
Personal Flotation Device; lifejacket.
Process Flow Diagram
Prevention of Fire and Explosion and Emergency Response Regulations [SI 1995/743].
Petrofac Facilities Management
Permeability
Permeability [perm]
Permit
Permit Co-ordination Point
Permit Co-ordinator
Permit Rack
Permit to Work
Permit to Work
Permittivity
Personal Isolation
Personal Isolation 1
Personal Isolation 2
Persuader
Petrochemicals
Petroleum
Petroleum
Petroleum Engineer
Petroleum Province
Petroleum tar sands
Page 103 of 310
PFML
PFP
PFS
PFS
PG
PGB
PGP
PGS
Ph
ph
PH
Phase
Phenol
Photogrammetric
Photon log
Phytoplankton
PI
PIAS
PIC
PIC
Picking
PICS
PICT
Pig
Pig
Petrofac Facilities Management Limited
Passive Fire Protection
Process Flow Scheme
Project Functional Description
Plate Girder
Permanent Guide Base
Power Generation Platform
Petroleum Geo-Services
An abbreviation for potential hydrogen ion. The pH numbers range from 0 to 14 and are indices of the acidity (below 7) or
alkalinity (above 7) of the fluid, the 7 being neutral.
phase
A scale of alkalinity or acidity running from 0 to 14, with 7 representing neutrality, 0 maximum acidity and 14 maximum
alkalinity.
One of two or more fluids as in a production fluid [i.e. oil, gas, water] See also Ø above for electrical engineering context of
phase. See also multiphase.
Phenol, also known under an older name of carbolic acid, is a toxic, colourless crystalline solid with a sweet tarry odor. Its
chemical formula is C6H5OH and its structure is that of a hydroxyl group [-OH] bonded to a phenyl ring; it is thus an aromatic
compound. The word phenol is also used to refer to any compound that contains a six-membered aromatic ring, bonded
directly to a hydroxyl group [-OH]. In effect, phenols are a class of organic compounds of which the phenol is the simplest
member. Phenol has a limited solubility in water [8.3 g/100 ml]. It is slightly acidic. Phenol can be made from the partial
oxidation of benzene or benzoic acid, by the cumene process, or by the Raschig process. It can also be found as a product of
coal oxidation.
The use of still photography to capture dimensional information for transposing to drawings.
An unfocussed density log used in the evaluation oil gravel placement in gravel packs. (A Dresser Atlas tool).
Free floating microscopic plants.
Productivity Index / Indices OR Proportional Integer [flow control]
Production Information Accounting System
Person In Charge
Pressure Indicator/Controller
The process of physically removing items from stock against a list of requirements [e.g. a Parts list]s list
Pull-In and Connection System
Pull-in and Connection Tool
A cylindrical device inserted in a pipeline for the purpose of sweeping the line clean of water, rust, or other foreign matter.
'When inserted in the line at a trap, the pressure of the fluid stream behind it pushes the pig along the line Pigs or scrapers are
made with tough, pliable discs that fit the internal diameter of the pipe, thus forming a right sea as it moves along cleaning the
pipe walls.
Bullet-shaped, cylindrical or spherical capsules which are inserted into a pipeline flow and travel along it with the fluid. Their
primary purpose is to scrape the pipeline clean or rush, wax, or other deposits, or in a gas pipeline, slugs or liquid from low
points in the line. Caliper Pigs also measure the pipeline as they travel, and ‘smart’ or ‘intelligent’ pigs contain various
instruments to monitor pipeline condition and integrity. Pig Launchers and Pig Traps are the arrangements of valves etc.
through which pigs are inserted into and extracted from a line.
Page 104 of 310
Piles
Pillow Tanks
Pilot plant
PIMS
Pin end or male end
Pinch Out
Pinching a valve
Pinger
Pinhole
PINS
PIP
Pipe clamp
Pipe Facing Machine
Pipe rack
Pipe ramp
Pipe rams
Pipe range
Pipe spool
Pipe tongs
Tubular steel shafts driven into e.g. the sea bed to anchor a structure. Sometimes known as pins, piles are usually driven
through the centre of tubular platform legs or through external sleeves or ‘skirts’ attached to the legs OR there are numerous
uses of piles in ports and in foundations for all heavy plant, onshore and offshore.
Collapsible synthetic rubber/fabric storage tanks which can be easily transported and deployed in, e.g. military operations or
difficult terrain.
A small version of the full-scale plant in which a laboratory pursues development work, after bench-scale investigation of a
new process has shown promise.
Pipeline Integrity Monitoring System.
Externally threaded pipe end, which screws into a box-or female end.
The thinning out and disappearance over a distance of a formation e.g. an oil bearing sandstone between layers of
impermeable rock.
Closing a valve part way to reduce the -flow of liquid or gas through it.
A source of sound [e.g. an ‘air gun’] for an underwater seismic survey.
A small hole in the tubing string. In a crude and inefficient gaslift system one or more pinholes at fin-creasing depth in a tubing
string are used for gas injection into the tubing.
Permit Information System
Pipe-In-Pipe OR Production Inspection Plan.
In drilling, a collar fitted to a string of pipe to stop it dropping if the slips fail to hold it.
A machine for cleaning and preparing the butt ends of pipe joints for welding.
Where stands of drill pipe are stacked vertically in a derrick ready for use. Racks or frames are also sometimes used to store
tubulars horizontally in yards and on offshore decks, and when transporting them offshore.
A sloping ramp from the pipe storage area up to the working floor of a drilling rig.
Hydraulic rams in a blowout preventer which are shaped to fit around the drill-stem and seal the annulus. Blind Rams are
designed in extreme emergency to shear through the drill pipe and seal the well completely.
API standard pipe length. For tubing two ranges are available: Range 1: 20-24 ft. long, Range 11: 28-32 ft. long. Of these two
the Range II is most widely used in Group operations. For casing or 5 tubing and larger often Range III- 34-ft. or more, is used.
A single length of pipe with flanged ends
Long-handled wrenches chat grip the pipe with a scissor-like action; used for screwing threaded pipe connections. The head
(called the butt) is shaped like a parrot's beak and uses one corner of a square tong key, held in a slot in the head, to bite into
the surface of the pipe in turning it.
Pipeline
A system of connected lengths of pipe, usually buried or laid on the seabed, used for transporting production fluid [oil or gas].
Piping
PIR
PIT
Pre-fabricated production or process system piping of 2-inch bore or larger. [See also tubing.]
Problem Improvement Report
Pull-In Tool
Asphalt: a dark brown to black bituminous material found in natural beds and is also produced as a black, heavy residue in oil
refining.
The connecting piece between the crank on a shaft and another working part. On cable tool rigs the pitman transmits the
power from the band-wheel crank to the walking beam, on a pumping unit from the gearbox crank to the walking beam.
Pitch
Pitman
Page 105 of 310
Pitot tube
PIV
Pkr
Plan
Planimeter
Plant
Plastic flow
plastic fluid
Plastic viscosity
Plat
Plate interceptor
Plate tectonics
Platform
Platts
PLBM
PLC
PLEM
Plenum
Plenum
PLET
PLIS
PLIS
PLL
PLMV
PLOCS
A measuring device for determining gas-flow rates. The device consists of a tube with a 1/8th-inch inside diameter inserted in
a gas line horizontal to the lines longitudinal axis. The impact pressure of the gas flow at the end of the tube compared to the
static pressure in the stream are used in determining the flow rate.
Production Isolation Valve
Packer
The function of task [work] identification, interaction and sequencing including, preparation and completion requirements, to
achieve an outcome.
A device, which mechanically determines the average reading of, recorded values on recorder charts.
Land, building and equipment.
The flow of liquid (through a pipeline) in which the liquid moves as a column; flowing as a river with the centre of the stream
moving at a greater rate than the edges which are retarded by the friction of the banks (or pipe wall). See also Turbulent and
Laminar flow .
A complex, non-Newtonian fluid in which the shear force is not proportional to the shear rate. A definite pressure is required to
start and maintain movement of the fluid. Plug flow is the initial type of flow and only occurs in plastic fluids. Most drilling muds
are plastic fluids. The yield point as determined by direct- indicating viscometer is in excess of zero.
The plastic viscosity is a measure of the internal resistance to fluid flow attributable to the amount, type and size of solids
present in a given fluid.
An official concession map in the USA – hence any official concession map.
A waste water de-oiler. The wastewater is carried through an assembly of inclined parallel Plates. Oil droplets will collect and
coalesce on the plates and float along the plates to the surface where it is collected.
The study of the formation and movement of the “plates” of which the earth’s crust is formed.
An immobile offshore structure from which development wells are drilled and produced. Platform rigs may be built of steel or
concrete and may be either rigid or compliant. Rigid platform rigs, which rest on the seabed, are the caisson-type platform, the
concrete gravity platform, and the steel jacket platform. Compliant platform rigs, which are used in deeper waters and yield to
water and wind movements, are the guyed-tower platform and the tension-leg platform.
Platts is a provider of energy information around the world that has been in business in various forms for more than a century
and is now a division of The McGraw-Hill Companies. Products include Platts Energy Economist, industry news and price
benchmarks for the oil, natural gas, electricity, nuclear power, coal, petrochemical and metals markets. The president of Platts
is Victoria Chu Pao.
Production Linear Block Manifold
Programmable Logic Card / Controller
Pipeline End Manifold
A room or enclosed area where the atmosphere is maintained at a pressure greater than the outside air. Central control rooms
at refineries are usually kept at pressures of a few ounces above the surrounding atmosphere to prevent Potentially explosive
gases from seeping into the building and being ignited by electrical equipment. Some offshore drilling and production platforms
are provided with 'Plenums as a safety measure.
An enclosure such as a control room where for safety reasons the air pressure is kept higher than outside, to prevent
Pipeline End Termination [usually a skid or sled]
Pipeline Integrity System
Process-Level Information System
Potential Loss of Life per annum OR Probable Loss of Life.
Production Lower Master Valve
Pipeline Operations Central North Sea
Page 106 of 310
PLQ
PLS
PLS System
PLT
PLT
Plug
Plug back
Plug flow
Plug valve
Plug/Plug and Abandon
Plugging a well
Plunger
Plunger lift
Plunger pump
PM
PMA
PMR
PMT
PMV
PNEC
PNG
PO
POA
POB
POH
Poles
Policy
Polished rod
Polycyclic Hydrocarbons
Personnel / Permanent Living Quarters
Plastic Limit State
The ARL personnel database which holds all current, ex and potential employee information.
Plant Leadership Team
Production Logging Tool
To fill a well's borehole with cement or other impervious material to prevent the flow of water, gas or oil from one strata to
another when a well is abandoned; to screw a metal plug into a pipeline to shut off drainage or to divert the stream of oil to a
connecting line to stop the flow Of Oil or gas.
To seal off the bottom section of a well bore, usually with cement, to prevent the inflow of fluid from that portion of the hole.
The movement of a material as a unit without shearing within the mass. Plug flow is the first type of flow exhibited by a plastic
fluid after overcoming the initial force required to produce flow,
A type of quick--opening pipeline valve constructed with a bored through rotating central core or plug which seals against the
valve seats, placed perpendicular to the valve bore in the valve's inlet and outlet ports. The valve can be opened or closed with
one-quarter turn of the plug.
To seal a well, or part of a well with cement, e.g. before producing from a higher formation, sidetracking, or leaving the well
permanently sealed and abandoned.
When a well is abandoned for any reason, either temporarily or permanently, it must be sealed off to ensure that no escape of
any kind can occur. This sealing off is generally accomplished by insertion of a plug of cement.
The piston in The fluid end of a reciprocating plunger pump. The piston in a subsurface oilwell pump.
A method of recovering oil using a steel plunger or swab. The plunger is propelled from the lower end of the tubing string to
the surface by compressed gas, which enters the tubing through one or several gas inlet valves spaced at intervals in the
string. As it rises, a column of liquid is lifted to the surface where it is discharged into the flowline. The force of gravity then
pulls the plunger to bottom for another load of liquid.
A reciprocating pump in which plungers moving forward and backward or up and down in cylinders draw in a volume of liquid
from the suction line and push the fluid out into a discharge line.
Preventative Maintenance OR Project manager
Particular Material Appraisal
Planned Maintenance Routine
Project Management Team
Production Master Valve
Predicted No Effect Concentration
Portable Networks Graphic.
Purchase Order
Purchase Order Amendment
Persons on Board
Pulled Out of Hole [also POOH]
Refers to the number of magnetic poles arranged on the rotor of the brushless motor. Unlike an AC motor, the number of
poles has no direct relationship to the base speed of the motor.
Plan of action pursued by the Company [BP] with which all personnel must comply.
A smooth brass or steel rod that works through the stuffing box or packing gland of a pumping well it is the uppermost section
of the string of sucker rods, attached to the walking beam of the pumping jack.
Hydrocarbons whose carbon atoms form a ring or rings e.g. Cyclohexane.
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Polymer
A substance formed by the union of two or more molecules of the same kind linked end to end into another compound having
the same elements in the same proportion but a higher molecule weight and different physical properties, e.g.
paraformaldehyde.
Polymer
Two or more molecules of the same kind, combined to form a compound with different physical properties – e.g. Polyethylene.
PON
Petroleum Operations Notice
A flatbottomed vessel [“barge”] for transporting structures etc. to an offshore installation site. OR A submerged or semi
submerged part of a floating drilling rig structure designed to assist flotation, containing ballast tanks.
The elements of a floating roof tank that provide buoyancy airtight, metal tanks that float on the fluid and support the moveable
deck structure of the roof.
Sucker rod made in short lengths of 2' to 8' for use in making up a string of pumping rods of the correct length to connect to
Pull Out Of Hole [drilling]
An Oil Pool is a reservoir or group of reservoirs sharing a common pressure system. OR In a refinery or blending plant, the
Gasoline Pool is the average Octane value of the gasolines produced/available.
A buoy which is normally submerged but will surface in response to an acoustic signal. Often used to mark the position of
wellheads. [Also, colloquially, “Yoo hoo” buoy].
Prevention of Oil Pollution Act
A device that controls the rate of flow of fluid in a line or opens or shuts off the flow of fluid completely. When open, the
sealing surface of the valve is moved away from a seat; when closed, the sealing surface contacts the seat to shut off flow.
The direction of movement of the valve is usually perpendicular to the seat. Popper valves are used extensively as pneumatic
[air] controls on drilling rigs and as intake and exhausts valves in most internal-combustion engines.
Pontoon
Pontoons
Pony rods
POOH
Pool
Pop Up Buoy/Recall Buoy
POPA
Poppet Valve
Porcupine
Porosity
Porosity
Ported nipple
POS
POS
POS Vision
POSA
Positive displacement meter
Positive displacement pump
Positively isolated
Posted price
A cylindrical steel drum with steel bristles protruding from its surface pipe-cleaning pig for swabbing a sediment laden pipeline.
The amount of void space in a formation rock, usually expressed as percent voids per bulk volume. Total porosity refers to the
total amount of pore space in a rock, regardless of whether or not that space is accessible to free fluid penetration Effective
porosity refers to the amount of interconnected pore space. available to free fluid penetration.
The volume of free space between the grains of a rock capable of holding fluid, [gas or liquid]. It is expressed as a percentage
of total gross rock volume.
A landing nipple which contains ports and internally honed sections above and below the ports for pack-off to provide
Persons on Site
Petrofac Operations Services
“We aspire to effectively plan, control, and implement our document projects in a manner that delivers optimum reputational
and financial value to ourselves and to our client[s]”.
Processing and Operating Services Agreement
A flow meter which measures the flow rate by splitting the flow of fluids into separate known volumes based on the physical
A pump that displaces or moves a measured volume of liquid on each stroke or revolution a pump with no significant slippage
a piston, plunger or rotary pump.
Isolation by mechanical means such as physical disconnection or the insertion of a blank or slide plate.
The price an oil purchaser will pay for crude oil of a certain API gravity and from a particular field or area. Once literally posted
in the field, the announced price is now published in newspapers. With government control affect almost all aspects of the
industry, prices of oil and gas are not permitted to be set by the industry's supply and demand requirements as they once
were.
Page 108 of 310
Potassium Hydroxide
An inorganic compound with the formula KOH, which along with sodium hydroxide, is a prototypical "strong base". It has many
industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive nature. KOH is
noteworthy as the precursor to most soft and liquid soaps as well as numerous potassium-containing chemicals. KOH is highly
basic, forming strongly alkali solutions in water and other polar solvents. These solutions are capable of deprotonating many
acids, even weak ones. In analytical chemistry, titratons using solutions of KOH are used to assay acids. See TAN.
Potential
The production possibility of a well. Optimum potential: The rate at which the well can produce with the optimum completion
equipment installed. Present potential: The rate at which the well can produce with the present completion equipment installed.
Potential
POTS
POU
Pour point depressant
Pour point test
Power end of a pump
Power factor
Power takeoff PTO
Power tight makeup
Power tong
Power tools
PP
PPA
ppb
PPC
PPD
PPD
PPE
PPM
ppm
PPM
ppm
ppm[v]
PPS
PPS
pptf
PQG
PR
PR
PRC
PRC
A test of the maximum rate at which a well can produce oil and/or gas.
Production Offshore Telephone System
Programme Organisation Unit
A chemical agent added to oil to keep it flowing at low temperatures.
The lowest temperature at which an oil will flow in a lab test, measured under specified conditions.
The end of a pump body where the drive shaft and gearbox are located.
Ratio of true power [kW] to apparent power [kVA].
A wheel, hub, or sheave that derives its power from a shaft or other driving mechanism connected to an engine or electric
motor, the end of a power shaft designed to take a pulley.
A screwed connection made up to the recommended torque value.
An air or hydraulically-powered mechanism for making up a breaking out joints of drill pipe, casing, tubing or suck
Equipment operated hydraulically or by compressed air for making up or breaking out drill pipe casing, tubing and r and for
tightening or loosening bolts and nuts.
Pressure Point (test point)
Petroleum Productions Act
parts per billion
Pollution Prevention and Control
Pour Point Depressant. [Chemical compounds added to a very viscous or waxy oil to prevent it thickening at low temperatures
to the point where it will not flow].
Pour Point Depressant
Personal Protective Equipment
Parts per million. Unit weight of solute per million unit weights of solution (solute plus solvent), corresponding to weight-percent
parts per million
Planned Preventative Maintenance OR Project programme manager
Parts per million
parts per million [by volume]
Planned Platform Shutdown
Polyphenylene sulphide
psi [pounds per square inch] per thousand feet
Permanent Quartz Gauge
Public Relations
Performance Requirement level in accordance with API Specification 6A
Preparation/Reinstatement Certificate
Pressure Recorder & Controller
Page 109 of 310
PRE
Precipitate
Pre-job
Premium joint
Prepacked liner
Press
Pressure Bomb
Pressure drop or loss
Pressure Habitat
Pressure maintenance
Pressure Maintenance
Pressure surge
Pressure Vessel
Pressure/vacuum relief valve
Primary Discipline
Primary Hazard
Primary recovery
Prime mover
Prime mover
Priority
PROAct™
Probability
Procedure
Procedure Development Request
Procedures
Process
Process
Process Deliverer
Process Owner
Pitting resistance equivalent OR Project reliability engineer
Material that separates out of solution or slurry as a solid.
An activity which is required prior to a task or work being undertaken.
All tubing and casing threaded connections that have one or more special features, such as higher strength, better sealing
properties, faster make-up, internally streamlined and recess free, etc. as compared with API connections.
A slatted or perforated liner with a sheath of plastic consolidated sand or gravel around it. This filter medium is a high quality
round grain sand bonded together as a unit with high strength thermosetting resin.
Pressure
A down hole pressure recording capsule used in well-monitoring.
The pressure lost in a system due to the flow of the fluid in it.
A sealed chamber in which divers can rest between shifts without decompression.
Secondary recovery method. Water or gas is injected into the producing formation to maintain or raise its pressure.
The process of keeping reservoir pressure at the optimum level during production, normally by water or gas injection to
replace fluids extracted.
A sudden, usually short-duration increase in pressure. When pipe or casing is run into a hole too rapidly, an increase in the
hydrostatic pressure results, which may be great enough to create lost circulation. Pressure surges can also occur when
starting up pumps or compressors or when opening or closing valves
A tank or process chamber built to hold fluids under pressure whether for production, refining, or other purposes. Can also be
designed to withstand external pressure.
A safety valve mounted on a tank which bleeds off excess pressure and also will allow air (or gas) to enter in case of a
pressure drop in the tank.
The lead discipline carrying out the task. A list of all available disciplines are defined within the system
A broad category of the main hazard that may be applicable, i.e. Hydrocarbon Break-in. This is usually broken down into
secondary hazards that more specifically identify the hazard concerned.
A recovery method in which the energy in the formation itself suffices to drive liquid or gas to the borehole.
The term describes any source of motion in the oil field it refers to engines and electric motors the power source.
An internal-combustion engine or a turbine that is the source of power for driving a machine or machines.
An indicator of the priority of the task. Low – can be carried out at any time. Medium –Must be carried out in the next seven
days. High – Urgent must be carried out immediately.
Alpha Thames’ subsea, electric, linear actuator, offering precise and fast operation of choke valves and modulation pressure
or flow control valves. It is unique in that it is the first available subsea electric actuator that combines the benefits of electric
actuation with the performance required for modulating control valve duties.
The likelihood of the consequence of a hazard occurring.
A detailed document either in paper or electronic form which sets out sequential or parallel actions which shall be followed by
those engaged in carrying out an activity.
The form used for changes or suggested improvements to any procedure, including the PTW system.
Documented control mechanisms that support processes.
A sequence of activities that describes how Petrofac delivers its services.
A detailed description of a management system or a production operation.
Based on the accepted standard or measurable outcome - the person responsible for developing and documenting a process
within a process area.
Ultimate responsibility and thereby accountability for a specific process area measured by an accepted standard or
measurable outcome.
Page 110 of 310
Procurement Cycle
Procurement Plan
PROD
Produced water
Producing platform
Product/Service
Production
Production Casing String
Production log
Production packer
Production Payment Loan
Production Plateau
Production platform
Production Platform/Facility
Production Separator
Production string
Production Testing
Production Tubing String
Production Well/Producer
The Procurement cycle is the detailed series of steps necessary to take an item of goods or services from initial specification
and preparation of enquiry requisition through to delivery to site or completion of work. The stages from initial requisition
preparation through to Purchase Order placement follow a standard pattern, with recognisable intermediate milestones which
enable Planning and Management to simply identify progress on the Project.
The Procurement Plan is a list of all anticipated or actual requisitions on a Project. It comprises requirements produced by
each Originating Engineer for his particular discipline or package.
Production
Formation water removed from the oil and gas in the process separators
An offshore structure with a platform raised above the water to support a number of producing wells. In offshore operation as
many as 60 wells are drilled from a single large platform by slanting the holes at an angle from the vertical away from the
platform, When the wells are completed, the drilling equipment is removed and -the platform is handed over to production for
operation of the producing wells.
Output that an organisation supplies to a purchaser / client / another department.
The full scale extraction of hydrocarbon reserves. Also the reserves extracted. Gross Production: Total production before
deducting royalties. Net Production: Gross production, minus royalties, multiplied by the company's fractional working interest.
OR Refinery/petrochemical operations resulting in a yield of products.
The innermost steel lining of a well cemented in place and perforated for production in the pay zone. Note that production
tubing is inserted inside this casing. [See production tubing string]
A wireline device run in a production or injection well. Services and devices include continuous flowmeter, gradiomanometer
(for measuring borehole fluid specific gravity), manometer (for measuring borehole, pressures), temperature log, calliper,
radioactive tracer log, casing collar locator, fluid sampler, water cut meter, etc. The first five can be run sequentially or
simultaneously with one sonde.
A trade name for a certain type of permanent packer.
A loan repayable out of production from a well or field.
The period during which a field is capable of producing at or near its maximum average rate.
An offshore structure built for the purpose of providing a central receiving point for oil or gas produced in an area offshore. The
production platform supports separators, tanks treaters, and pump units for moving the oil or gas to storage through a
submarine pipeline.
Production platforms are of varying types depending on environment [water depth etc. and reservoir needs]. Semi-submersible
and ship-shaped vessels developed from the respective off-shore drilling rig concepts are also used as Production facilities.
Where several inter-dependent platforms are clustered in a development they are known as a Production Complex.
Main process vessel used primarily for the separation of gas, oil [and condensate] and water
A string of pipe suspended inside the production casing string of a completed well. The well produces either by flowing
naturally or by artificial lift through the production string or tubing.
A production test concerns the capability to produce [productivity] of a well and its effects on the reservoir produced. A
production test may continue for several months where extensive data is necessary prior to final commitment to development
expenditures etc.
The string of pipe installed inside the casing of a production well, to a point just above the reservoir through which the fluids
are produced. It may be 2” to 5” diameter or more, depending on the production flow and pressures anticipated. Unlike the
casing, the tubing is designed to be replaced during the life of a well, if required
A development well specifically for the extraction of reservoir fluids.
Page 111 of 310
Production Wellhead and Tree
Productive Horizon
Productivity index PI
Productivity test
Productivity/Productivity Index
Profiling
Programme materials
Project materials
Prong
Propane
Propane C3H8
Proppants
Proppants
Proprietary Data
Prorationing
PRP
PS
PSA
PSC
PSC
PSD
PSDP
Pseudoplastic fluid
PSG
psi
The assembly of casing head, tubing head, connections and well-control valves fitted to a producing well. The “Christmas
Tree” is the name given to the complete assembly of valves, connecting flanges etc.
A pay zone. See also Horizon.
The PI of a well is a value given in terms of the quantity of liquid (oil and water) produced per day per unit different pressure
across the face of the producing interval.
A test of a well's capacity to produce, usually conducted at different rates.
The continuous productive capacity of a well. The Index is measured as volume produced [e.g. barrels per day] divided by the
drop in pressure [p.s.i.] to achieve that flow rate starting with a “shut in” pressure.
Shallow seismic surveying by echosounder techniques.
Materials required on the basis of the drilling programme.
Materials required for special construction projects.
A prong is a round bar of steel of special shape usually screwed into running and pulling tools in order to open, shear or
puncture equalising devices, or to keep wireline equipment open while running in the hole.
C3H8 Liquified propane, propane gas. Appearance colourless odourless gas [a small amount of an unpleasant-smelling gas
such as a thiol may be added to provide warning in the event of a leak.] Melting point -188C Boiling point -44.5C Critical
temperature 96.67C Critical pressure 41.94atm Vapour density 1.55 Flash point -104C [open cup] Explosion limits 2.4% 9.5% Autoignition temperature 468C Stable. Incompatible with strong oxidizing agents. Highly flammable. May form explosive
mixtures with air.
A natural gas compound used as feed stock for the manufacturing of plastics, solvents and fibres. It can be stored and
transport under pressure as a liquid at atmospheric temperatures (bottle gas) and is used as fuel for sale to domestic and light
industrial consumers where piped gas is not available.
Material used in hydraulic fracturing for holding open the cracks made in the formation by the extremely high pressure applied
in the treatment the sand grains, beads, or other miniature pellets suspended in the fracturing fluid that are forced into the
formation and remain to prop open the cracks and crevices permitting the oil to flow more freely.
Sand, gravel or other particles or “beads” used in hydraulic fracturing of a formation, to allow oil to flow more freely by wedging
into the cracks etc. created and preventing them reclosing.
Primarily data obtained from the owner of a seismic survey record under confidentiality undertaking. It can also include all
confidential information acquired as part of sole or joint operations.
Restriction of production in a multi-concession system in proportion to field capacities and ownership interests. This may be by
government regulation or due to a period of under-capacity or e.g. maintenance in a pipeline system.
Pipeline Resonsible Person
Performance Standard OR pressure switch
Production Sharing Agreement OR pressure set at
Production Sharing Contract. A type of concession in which part of the return to the host government is delivered as produced
Production Sharing Contract
Process Shutdown OR Pressure Safety Disc [a rupture disc which fails at high pressure and/or temperature, to protect
vessel from damage]
Process Shut Down Panel
A complex non-Newtonian fluid that does not possess Thixotropy. A pressure or force in excess of zero will start fluid flow. The
apparent viscosity or consistency decreases instantaneously with increasing rate of shear until at a given point the viscosity
becomes constant. An example of a pseudoplastic fluid Ls guar gum in fresh or salt: water.
Process Safeguarding System
pounds per square inch [also lbf/in2]
Page 112 of 310
psi[a]
psi[g]
psia
psig
PSL
PSL
PSPA
PSR
PSR
PSRC
PSS
PSS
PSSR
PSSV
PST
PSU
PSV
PT
PTB
PTC - Positive Temperature
Coefficient
PTIV
PTO
PTT
PTW
PTWCC
Public Address
PUL
Pull-In
Pulling Casing
Pulling Out
Pulling rods
Pulling the casing
Pulling tools
Pulling tools
Pulling tubing
Pulling unit
pounds per square inch [absolute]
pounds per square inch [gauge]
pounds per square inch, absolute pressure
pounds per square inch, gauge pressure
Platform Status Lights
Product Specification Level in accordance with API Specification 6A
Petroleum and Submarine Pipe-lines Act
Procurement Status Report
Pipeline Safety Regulations [SI 1996/825].
Project Safety Review Committee
Production System Simulator
Product Specification Sheet
Pressure Systems Safety Regulations [2000]
Production Sub Surface Safety Valve [isolation]
Personal Survival Techniques.
Power Supply Unit
Process Safety Valve OR Production Swab Valve
Pressure Transducer
German Cerifying House for flammable Ex equipment
A Positive Temperature Coefficient Thermistor [is used to detect and protect a motor winding from exceeding its maximum
temperature rating. Resistance of the device increases with an increase in temperature].
Production / Test Isolation Valve
Power Take Off
Pressure and Temperature Transducer
Permit to Work
Permit to Work Control Centre
System also known as the PAGA and Tannoy that allows transmission of messages to the workforce throughout the plant.
This may be used for the broadcast of routine and emergency instructions.
Performance Unit Leader
Winching the end of a subsea pipeline or flowline into a connecting chamber or wellhead, or through a “J” tube riser guide to
the rig deck.
Retrieving casing from a well [where possible] before abandonment.
Retrieving and stacking the drill-string on reaching target depth.
The operation of removing the pumping or suckerrods from a well e.g., to retrieve the bottom-hole pump for repairs or
replacement.
Removing the casing from the hole after abandoning the well. Prior to plugging the well with mud and cement, as much of the
casing as can be pulled is retrieved. It is rare that all the casing can be removed from the hole. Often part of the string must be
cut off and left in the hole.
In wireline work is used to retrieve a mandrel. from a landing nipple.
Taking the drill pipe and bit out of the hole. If the tools are to be run again (put back in the hole), the drill pipe is unscrewed in
two or three-joint sections (stands) and stacked in the derrick.
The operation of removing the tubing from a well.
A well service rig used in pulling rods and tubing from the well.
Page 113 of 310
Pull-out torque
Pulsation dampener
Pulse rate
Pulse Width Modulation [PWM]
Pulse Width Modulation [PWM]
Pump joint
Pump off
Pump rod
Pump, casing
Pump, double displacement
Pump, duplex
Pump, simplex
Pump, staionary barrel
Pump, submersible
Pump, travelling barrel
Pump, triplex
Pump, tubing
Pumping unit
Pumping unit, air balanced
The maximum friction load, at a particular inertial load, that can be applied to the shaft of a synchronous motor [running at
constant speed] and not cause it to lose synchronism.
Various devices for absorbing the transient, rhythmic surges in pressure that occur when fluid is pumped by reciprocating
pumps. On such pumps air chambers are installed on discharge lines, which act as air cushions. To protect pressure gauges
and other instruments from the incessant. Pounding, fine-mesh, sieve-like discs are placed in the small tubing or piping to
which the gauge is attached the arrangement filters out much of the surging which can damage delicate gauges.
The frequency of the step pulses applied to a step motor driver. The pulse rate, multiplied by the resolution of the motor/driver
1. A PWM controller [amplifier] switches DC supply voltage on and off at fixed frequencies. The length of the on/off interval or
voltage waveform is variable.
2. Pulse width modulation [PWM], describes a switch-mode [as opposed to linear] control technique used in amplifiers and
drivers to control motor voltage and current. PWM offers greatly improved efficiency compared to linear techniques.
A pump connected to a source of power a pipeline pump and engine.
To pump a well at such a rate that the fluid level is maintained at the pump's standing valve.
A class of down hole pumps in which the barrel, plunger and standing valve are assembled and lowered into the well through
the tubing. When lowered to its pumping position, the pump is locked to the tubing to permit relative motion between plunger
and barrel. The locking device is a hold-down, and consists either of cups or a mechanical, metal-to-metal seal. Also called
Insert pump.
A subsurface pump designed to pump oil up through the casing instead of the more common method of pumping through
A type of down hole, rod pump that has plungers placed in tandem and operated simultaneously by the pump rods.
A double acting, two cylinder, constant displacement, reciprocating piston or plunger pump.
A one-cylinder steam pump used in refineries and processing plants. Simplex pumps are simple, direct-acting pumps with the
steam piston connected directly to the pump's fluid plunger.
A down-hole pump, operated by rods, in which the barrel remains stationary and the plunger moves up and down.
A bottom-hole centrifugal pump for use in wells when large volumes of liquid have to be lifted. Submersible pumps are
installed at the bottom of the tubing string and are driven by an electric motor installed above the pump.
A down-hole pump, operated by rods, in which the barrel moves up and down over the plunger, instead of the plunger
reciprocating in the barrel as in stationary barrel pumps.
A single acting, three cylinder, constant: displacement, reciprocating plunger pump.
A class of down hole pump in which the barrel of the pump is an integral part of the tubing string. The barrel is installed on the
bottom of the string of tubing and is run into the well on the tubing string. The plunger assembly is lowered into the pump
barrel on the string of sucker rods.
Installation at surface of a pumping well used to change the rotary motion of the prime mover to an up-and-down movement of
the suckerrods.
An oil well pumping jack equipped with a piston and rod that works in an air chamber to balance the weight of the string of
sucker rods. The device is attached to the well end of the walking beam and, acting as a shock absorber, does away with the
need for counterweights on the rear end of the walking beam and/or the cranks.
Pumping unit, beam balanced
An oil well pumping unit that carries its well-balancing weights on the walking beam on the end opposite the pump rods. The
weights are usually in the form of heavy iron plates added to the walking beam until they balance the pumping loads.
Pumping unit, crank balanced
An oil well pumping unit that carries its counter-weights and the two cranks that flank the unit's gearbox. The pumping loads
are balanced by sliding the counterweights along the cranks. The walking beam on this type unit is short and is not used as a
balancing member.
Page 114 of 310
PUMV
Pup joint
Pup Joint
PUQ
Production Upper Master Valve
A joint of pipe shorter than standard length any short piece of usable line pipe or tubing.
A joint of pipe of non-standard length, to make up a string of tubulars to an exact required total length.
Production, Utilities & Quarters [platform, etc.]
Purge
To maintain gas flow in an over-rich or lean concentration in order to avoid the build-up of oxygen and an explosive mixture
Purging
Cleaning the interior of pipes and vessels to eliminate inflammable matter, usually with a “safe” gas such as nitrogen.
A piece of lumber or a tree limb that has a notch or fork; it is used to push against a small tree to force the tree to fall in a
certain direction.
Provision and Use of Work Equipment Regulations 1998 [SI 1992/2932].
Process Variable OR Pressure valve [located on the pipeline]
Pore Volume OR pressure, velocity [factor]
Polyvinylchloride
Physical Vapour Deposit [Piston rings - top ring and oil control rings are coated with Chromium, or Nitrided - possibly plasma
sprayed, or have a PVD ceramic coating].
Pressure Volume Transducer OR Pressure, Volume, Temperature data OR study usually related to a test of a reservoir
formation or well
Potable Water
Pipeline Works Authorisation
Post-Weld Heat Treatment
Pulse Width Modulated Drive[s] [as in VSD’s]
Produced Water Re-Injection
Production Wing Valve
The chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly
steam. Usually understood to be anhydrous [without water].
This phenomenon commonly occurs whenever solid organic material is heated strongly in absence of oxygen, e.g. when
frying, roasting, baking, toasting.
Even though such processes are carried out in a normal atmosphere, the outer layers of the material keep its interior oxygenfree. [Which is why the outer layer oxidizes [burns] but not the inside.].
The process also occurs when burning compact solid fuel, like wood. In fact, the flames of a wood fire are due to combustion
of gases released by pyrolysis, not combustion of the wood itself.
Thus, the pyrolysis of common materials like wood, plastic and clothing is extremely important for fire safety/fighting.
Push Pole
PUWER
PV
PV
PVC
PVD
PVT
PW
PWA
PWHT
PWMD
PWRI
PWV
Pyrolysis
Pyrophoric Scale
Q
Q Unit
Q&Q
QA
Carbon steel lines and equipment that carry gas or liquids containing hydrogen sulphide may develop a layer of pyrophoric
scale [iron sulphide] on their internal surfaces. When these lines or equipment are opened up, oxygen from the atmosphere
will react with the pyrophoric scale to produce spontaneous burning. If hydrocarbons or other combustible substances are
present during this reaction, an explosion may result. May be found in vents, drains, heat exchangers, inside vessels, filters,
demisters, valves of reciprocating compressors, pig traps.
Fluid Flow Rate
An unit used in overall assessment of energy resources. It is equal to 1018 British Thermal Units [BTU].
Quantity and quality
Quality Assurance. A sequence of planned and systematic actions necessary to provide adequate confidence that a product or
service will satisfy given quality requirements.
Page 115 of 310
QC
QCP
QM
QMS
QMS
QRA
QRS
QT
Qty
Quadrillion
Qualified Inspector
Qualified Person
Qualitative risk assessment
Quality Assurance
Quality Control
Quenching
Quiet Rig
R&D
R/T
Rabbit
Rabbit
RACI
RACI 1
RACI 2
RACI 3
RACI 4
RACI 5
Racked In
Racked Out
Racking pipe
Rad
RAD
Radiation
Quality control. The operational techniques and activities that are used to ensure that a quality product or service will be
produced.
Quality control procedure
Quality management
Quality Management System
Quality Management System
Quantitative Risk Assessment – involves calculations to assist with the identification of risks and to determine the frequency,
magnitude and consequence of hazardous events.
Quantitative risk study
Qualification test
Quantity
In the oil and gas industry, the U.S. definition is used, e.g. 1015 not 1024 as internationally accepted.
An experienced supervisor or craftsman who has demonstrated their ability or competency to inspect equipment.
An experienced craft person who has been approved by the craft supervisor.
Risk assessment based on actual operational experience, engineering standards, and sound engineering judgement.
Those planned, systematic and preventative actions, which are required to ensure that products and services will meet
specified requirements.
Inspection, test or examination to ensure that materials products and services conform to specified requirements.
A heat treatment of steel. The steel is heated above a critical temperature and rapidly cooled by contact with liquids, gases or
solids.
A drilling rig insulated and equipped to operate with minimum disturbance of sensitive onshore environments such as built-up
areas.
Research and Development
Radiotelephony
A device that is run through a pipe to clean the line or test for obstructions. See also Pig, Go-Devil and Scraper .
A small pig for flowlines
Responsible, Accountable, Consult, Inform.
Responsible - owns the problem / project
To whom 'R' is Accountable - who must sign off [Approve] in work before it is effective
Can be Supportive - can provide resources or play a role in implentation RASCI
To be Consulted - has information and/or capability to complete the work
To be Informed - must be notified of results but need not be consulted
A term used where an electrical breaker has been physically re-connected to the bus bars, enabling the electrical supply to be
turned on if required.
A term used to describe positive electrical isolation where an electrical breaker has been physically disconnected form the bus
bars and locked in that position.
The act of placing stands of pipe in orderly arrangement in the derrick while hoisting pipe from the well bore.
Old unit of absorbed dose. Now superseded by the Gray.
Risk Assessment Declaration [Form].
Transfer of energy in the form of atomic particles and electromagnetic rays emitted by radioactive atoms. Unstable nuclei emit
radiations of three main types - alpha and - beta particles and gamma rays - but under certain types of decay circumstances
neutrons and X-rays can also be emitted.
Page 116 of 310
Radiation Weighting Factor
Radioactive
Radioactivity
Radioactivity logging
Radionuclide
RAL
Ralog
RALQ
RAM
RAM
RAM, SHEAR
Ramex
Rat hole
Rat hole
Rate of shear
Raw Gas
RBGL
RBI
RBP
RCC
RCM
RCM
RCMS
RCP
RCR
REAct™
Reamer
Reamer
Numerical values assigned to different radiations depending on the type and energy of the radiation. The number compares
the ability of the particular radiation to cause biological damage with that of 200 KeV X-rays.
Material defined in terms of the Radioactive Substances Act 1993 and the Ionising Radiations Regulations 1985.
The process of radioactive decay in which unstable atoms of an element undergo spontaneous transformation into more
stable product atoms by emitting charged particles and/or electromagnetic radiation. The product atoms may or may not be
radioactive. If radioactive, decay continues until a non-radioactive isotope is achieved.
Method of logging a well by measuring natural or induced radiation from a formation. Forms of radioactivity logging are natural
gamma ray logging, neutron logging and density logging.
A shortened form of radioactive nuclide, practically synonymous with radioisotope or radioactive isotope.
Colour definitions issued by RAL, Deutsches Institut für Gütesicherung und Kennzeichnung e.V.
Radioactive Log
Replacement Additional Living Quarters
A closure -mechanism on a blow-out preventer stack; a hydraulically operated type of valve designed to close in a well as with
a conventional valve or to close on tubing or drill pipe and maintain high-pressure contact. A hanging and sealing device to
suspend tubing from a ram-type cubing head.
Random Access Memory OR Reliability, Availability and Maintainability [Study]
A closure mechanism in a well's blowout preventer stack fitted with chisel-like jaws that are hydraulically operated. When the
ram is closed on the pipe the jaws or blades cut the pipe, permitting the upper section to be removed from the BOP stack.
Cost of Reliability
A cased hole below the derrick floor to contain the Kelly.
A hole in the drilling floor in which the kelly joint is kept when not in use. 1. a hole in the rig floor, 30 to 35 feet [9 to 11 meters]
deep, which is lined with casing that projects above the floor and into which the kelly and swivel are placed when hoisting
operations are in progress.
2. a hole of a diameter smaller than the main hole and drilled in the bottom of the main hole.
v: to reduce the size of the wellbore and drill ahead.
The rate at which an action, resulting from applied forces, causes or tends to cause two adjacent parts of a body to slide
relatively to each other in a direction parallel to their plane of contact. A measure of the shear value of a fluid.
Natural gas before removal of water, sand and other impurities
Riser Base Gas Lift System
Risk-Based Inspection
Retrievable bridge plug
Remote Control Centre
Reliability Centred Maintenance
Riser control module OR Reliability-centred maintenance
Reliability Case Management System
Reliability Case Plan
Reliability Case Report
Alpha Thames’ subsea, electric, fail-safe, linear actuator for the operation of isolation valves. [REAct™ Mk II is being
developed and tested under licence by BEL Valves.]
A tool used to enlarge or straighten a borehole; a milling tool used to cut the casing down hole. Reamers are run on the drill
string and are built with cutting blades or wheels that can be expanded against the walls of the hole.
A bit designed to enlarge a borehole. It may be included in the drill string just above a conventional bit.
Page 117 of 310
Reaming
Reaming
Recess free joint
Recip
Recompletion
Recovery factor
Recovery Factor
Recovery method
Recycling [Gas]
Reduced sparking tool
Redundancy
Reef
Reel vessel
Re-Entry
Re-Entry
Reeve
Refinery
Refinery gas
Reflux
Regeneration
Regex
Regular
Reject Button
Rekief well
During drilling operations the sides of the bit become worn with a resulting tendency to drill a well smaller than was originally
intended. Reaming is the operation employed to enlarge the hole to the size originally planned.
An operation to restore a well bore to its original diameter [occasionally, a wellbore will cave in].
A joint which has neither a gap between pin end and box member nor a difference between the IDs of pin and box when made
up power-tight.
Reciprocating, reciprocate
The modification of an existing well for the purpose of producing oil or gas from a different producing formation.
The percentage of oil that can be ultimately withdrawn from reservoir rock is known as recovery factor. It is an important factor
for calculating oil reserves, i.e. the total volume of oil that should be recoverable.
The ratio between the volumes of oil and/or gas produced and produceable from a reservoir and the oil and/or gas originally in
place.
Method by which formation fluids are driven to the borehole
Reinjection of produced gas into a gas/condensate reservoir to maintain pressure for optimum recovery of condensates.
A tool made of non-ferrous or other material less likely to produce sparks that will ignite a flammable mixture.
The performance of the same function by a number of identical but independent means.
A reservoir, usually limestone, deposited in marine conditions. As the name implies, it is frequently elongated, and early high
production may not be sustained without pressure support.
A ship or barge specially designed to handle pipeline that is wound onto a large reel. To lay the pipeline, the vessel pays out
the pipe off the reel at a steady rate onto the seabed. The pipeline is first constructed at an offshore facility where it is welded,
coated, inspected, and wound onto the reel.
To re-establish contact with the well's borehole after having moved off location.
Inserting the drilling, testing or logging string etc. into the wellhead.
To pass [as a rope] through a hole or opening in a block or similar device.
Installation for the refining of crude oil to produce a number of basic refined oil products.
A gas resulting from oil refinery operations consisting mainly of hydrogen, methane, ethylene, propylene and the butylenes.
Other gases such as nitrogen and carbon dioxide may also be present.
Backflow into a contacting tower of condensed liquid to control temperature in the tower at or near the re-entry PO or for
additional stripping.
The action during motor braking, in which the motor acts as a generator and takes kinetic energy from the load, converts it to
electrical energy, and returns it to the amplifier.
Cost of Lost Production
An activity that is required to take place regularly will be defined by the site and should cover the normal, typical, activities and
explain the frequency of that work. Regularly is used to indicate activities that must occur frequently enough to ensure the ongoing safety of the work force. For some activities this might be annually, for others it could be every few minutes.
Provided where the user is required to make a decision to reject a conclusion for instance a Level 2 Task Risk Assessment
[TRA].
Directional well, drilled to intersect a WE11 that is flowing wild, through which heavy drilling fluid is pumped down to kill the
blowout well. See also Killer well .
Page 118 of 310
Relative Density
Relative Permeability
Relief valve
Relief Well
Rem
Remote terminal unit
Remotely dangerous area
Remotely dangerous location
Rep
Repeatability
Repetitive Motion/ Strain
Repressuring
Req.
Req'n
Requested By
Requested State
Requirements
Requisition
1. the ratio of the weight of a given volume of a substance at a given temperature to the weight of an equal volume of a
standard substance at the same temperature. For example, if 1 cubic inch of water at 39 degrees F weighs 1 unit and 1 cubic
inch of another solid or liquid at 39 degrees F weight 0.95 unit, then the relative density of the substance is 0.95. In
determining the relative density of gases, the comparison is made with the standard of air or hydrogen.
2. the ratio of the mass of a given volume of a substance to the mass of a like volume of a standard substance, such as water
or air.
The radio of effective permeability to absolute permeability. The relative permeability of rock to a single fluid is 1.0 when only
that fluid is present, and 0.0 when the presence of another fluid prevents all flow of the given fluid. Compare absolute
permeability, effective permeability.
A valve that will open automatically when pressure gets too high.
A second well deviated from a safe distance to a bottom-hole location close to a “blowout” well and produced so as to reduce
the pressure in the blowout. See also Killer Well.
Old unit of equivalent dose, now superseded by the Sievert
The telemetry unit on a remote site which handles input and output process signals and converts these signals into a suitable
code for transmission over a communication link (radio, cable).
Definition of an area so far as there is a remote danger, which may arise from electrical causes.
Any point at or near the head of any producing well, or at or near the head of any well being drilled into an oil sand where the
pressure conditions are normal, where in the absence of control measures a leakage or emission of petroleum would be
normally likely to do so only in the remote eventuality of a failure of the control measures. A location in which any flammable
liquid, gas or vapour, although processed, handled or stored, is so well under condition of control that its liability to produce a
dangerous atmosphere in sufficient quantity to constitute a hazard is likely to occur only under abnormal conditions.
Person
The degree to which a parameter such as position or velocity can be duplicated.
Pains or discomfort involving muscles, nerves, and/or joints which result in reduced mobility and reduction in the ability to
function. They may be caused by strain endured in repetitive work tasks. They can occur when the same action is repeated
frequently. Examples: computer keyboarding, vibrating tools, assembly, or loading tasks.
The re-injection of natural gas into a reservoir to restore or maintain reservoir pressure. A secondary recovery method.
Require. Requisition
Requisition [see]
A field in the WCC that is automatically populated with the users name by the system.
A WCC that has been raised to carry out a particular task. It may or may not be complete depending on the level of
authorisation of the Requester.
The activities, tasks or deliverables that must be completed to comply with the Mandatory Requirements
A Requisition is a document issued by Engineering to Procurement via Document Control specifying in detail what has to be
bought.It will provide the full requirements for the goods or services to be purchased, together with clear Performance Criteria.
A requisition may be for enquiry or for purchase.
Page 119 of 310
Reserves
The old classification was: PROVEN reserves - those quantities of oil known with reasonable certainty to be present and to be
commercially recoverable. PROBABLE reserves - reserves contained in probably oil-bearing parts adjacent to proven-oilbearing areas, or additional reserves that are likely to be obtained if secondary recovery is applied.
POSSIBLE reserves - oil that may be expected from a field from areas outside the proven and probable areas or from more
remote enhanced recovery possibilities. Reserves are nowadays nearly always represented using an expectation curve, which
correlates cumulative probabilities with minimum reserves.
The expectation curve for known fields is usually given in the form of 3 parameters:
Low - 15% chance that the reserve will be lower.
Medium - 50% chance that the reserve will be either higher or lower.
High - 15% chance that the reserve will be higher.
The expectation of reserves is usually also quoted, i.e. 1/3 x (low + medium + high).
For unappraised areas and further discoveries (geological) chance factors are used in addition.
Reserves/Recoverable Reserves
Oil or gas that it is anticipated can be produced. Technical Reserves are theoretically producible at a gross operating margin
by e.g. normal primary or secondary recovery methods, whole Commercial Reserves are restricted to volumes recoverable at
an acceptable profitability. The detailed definitions are important in oil and gas financial and other information, and are quoted
more fully in Section 6 in the form currently approved by the Society of Petroleum Engineers.
Reserves/Recoverable Reserves
Reservoir
Reservoir
Reservoir drive mechanism
Reservoir Pressure
Reservoir Pressure
Reservoir Rock
Residual Oil
Residual Risk
Oil or gas contained in underground rock formations called reservoirs. Proved reserves are the estimated quantities that
geologic and engineering data demonstrate can be produced with reasonable certainty from known reservoirs under existing
economic and operating conditions. Recoverable reserves are those that can be produced using all known primary and
enhanced recovery methods
A porous and permeable sedimentary rock (sandstone. limestone, dolomite, etc.) , containing quantities of oil and/or gas
A subsurface porous permeable rock body in which oil and/or gas is stored. Most reservoir rocks are limestones, dolomites,
sandstones, or a combination of these. The three basic types of hydrocarbon reservoirs are oil, gas and condensate. In a
typical oil reservoir, these fluids occur in different phases because of variants in their gravities. Gas, the lightest, occupies the
upper part of the reservoir rocks; water, the lower part; and oil, the intermediate section. In addition to its occurrence as a cap
or in solution, gas may accumulate independently of the oil; if so, the reservoir is called gas reservoir. Associated with the gas,
in most instances, are salt water and some oil. In a compensate reservoir, the hydrocarbons may exist as a gas, but, when
brought to the surface, some of the heavier ones condense into a liquid.
The process in which reservoir fluids are caused flow out of the reservoir rock and into a wellbore by natural energy. Gas
drives depend on the fact that, as the reservoir is produced, pressure is reduced, allowing the gas to expand and provide the
driving energy. Water-drive reservoirs depend on water pressure to force the hydrocarbons out of the reservoir and into the
wellbore.
The pressure at the face of the producing formation when the well is shut in. It is equal to the closed-in pressure (at the
wellhead) plus the pressure of the fluid column in the hole.
The pressure at reservoir depth in a shut-in well.
Formations containing interconnected pores or fissures and voids which may serve as reservoirs for oil or gas.
The dense, viscous “Heavy Ends” of the barrel, remaining after extraction of higher-value fractions.
The remaining risk after all proposed improvements to the facility under study have been made.
Page 120 of 310
Resin
Resistance, Hot [RH][Ohms line-toline]
Resistivity
Resistivity Logs
Resolution
Resolver
Resonance
Responsible Person
Responsible Person
Restart torque
Restricted work case
Restricted workdays
Retained Isolation 1
Retained Isolation 2
Retention time
Retrievable packer
Semisolid or solid complex, amorphous mixture of organic compounds having neither definite melting point nor tendency to
crystallise. Resins may be a component of compounded materials that can be added to drilling fluids to impart special
properties to the system, wall cake, etc.
The motor's terminal resistance value specified at the hot winding temperature, which is at the motor's maximum rated
temperature.
The electrical resistance offered to the passage of a current, across a one metre cube of material, expressed in ohm metres;
the reciprocal of conductivity.
Any of a number of basic logs on which some aspect of formation resistivity has been recorded. Most resistivity logs derive
their readings from 10 to 100 cuft of material about the sonde. See also Laterolog and Induction log . Micro resistivity logs
derive their readings from a few cubic inches of material near the borehole wall.
The smallest increment into which a parameter can be broken down. For example, a 1000 line encoder has a resolution of
1/1000 of a revolution.
An electromagnetic feedback device which converts angular shaft position into analog signals. These signals can be
processed in various ways, such as with an RDC [resolver-to-digital converter] to produce digital position information. There
are two basic types of resolvers; transmitter and receiver. A transmitter-type is designed for rotor primary excitation and stator
secondary outputs. Position is determined by the ratio of the sine output amplitude to cosine output amplitude. A receiver-type
is designed for stator primary excitations and rotor secondary output. Position is determined by the phase shift between the
rotor output signal and one of the primary excitation signals.
Oscillatory behavior caused by mechanical limitations.
A person, irrespective of other responsibilities, who is assigned responsibility for a procedure, including it's development and
maintenance.
A suitably trained and experienced individual who has been formally assessed as competent and has been given specific
actions or areas of responsibility by an accountable person.
The maximum friction load, at a particular inertial load, that can be applied to the shaft of a synchronous motor without causing
it to lose synchronism when accelerating to a constant speed from standstill.
In Safety: Any Work Injury which results in a work assignment after the day the Accident occurred that does not include all the
normal duties of the person's-regular job. The restricted work assignment must be meaningful and pre-established or a
substantial part of a regular job.
In Safety: Total numbers of calendar days counted from the day of starting Restricted Work until the person returns to his
regular job.
Isolations which are required to remain in place but no work is being carried out within the isolation boundary [sometimes
known as long-term Isolations]
An isolation that has to remain in place for operational reasons without an associated Work Control Certificate [e.g. when
waiting for spares or when plant or equipment has been removed from service].
The time a fluid in a continuous process remains in a vessel or a tank.
A packer, which forms an integral part of the tubing, string. The packer is run on the tubing; after setting it can be released and
Page 121 of 310
Retrograde Condensation
Retrograde gas concentrate
Rev
Reverse circulation
Reverse emulsion
Reworking a Well
Reynolds number
Reynolds number (Re)
RFCC
RFM
RFQ
RGIT
RH
Rheology
In some reservoirs, mainly deep gas/condensate reservoirs, [gas/oil ratio between 5,000 and 100m,000 cu.ft. per barrel] where
temperatures and pressures are high, a progressive decrease in reservoir pressure as result of production will gradually lead
to separation of liquids [heavier molecules] from natural gases in the reservoirs. These liquids are mainly lost to production,
being “by passed” by the more mobile gas. “Recycling”, reinjection of produced gas to maintain pressure, is used to postpone
this problem until an acceptable proportion of recoverable liquids has been produced.
A liquid hydrocarbon (condensate) formed in deep formations as the-reservoir pressure is reduced through production of
natural gas. As the pressure is reduced, the gas condenses to form a liquid instead of the usual pattern of liquid changing to
gas. Hence the term retrograde gas condensate. As liquefaction occurs, the formation rock is wet by the condensate which
may then be partly unrecoverable
Revision
Normal course of drilling or workover fluid circulation is downward inside the drill pipe or tubing and upward in the well's
annulus. On special occasions, this normal circulation is sometimes reversed and the fluid returns to the surface through the
drill pipe or tubing after being pumped down in the annular space. To kill producing wells or to bring them back in a flowing
condition the reverse circulation method is usually applied.
In most oil field emulsions oil is the continuous phase and water is the dispersed or internal phase. The reverse type, which is
fairly rare is the opposite: the continuous phase is water and the internal phase is oil.
Maintenance work on a well to stimulate production. This may involve cleaning out silt deposits etc., or stimulation techniques
such as fracturing or acidizing.
In fluid mechanics and heat transfer, the Reynolds number is a dimensionless number that gives a measure of the ratio of
inertial forces to viscous forces and, consequently, it quantifies the relative importance of these two types of forces for given
flow conditions.
Reynolds numbers frequently arise when performing dimensional analysis of fluid dynamics and heat transfer problems, and
as such can be used to determine dynamic similitude between different experimental cases.
They are also used to characterize different flow regimes, such as laminar or turbulent flow.
Laminar flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterised by smooth, constant
fluid motion; while turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces which tend to produce
random eddies, vortices and other flow fluctuations.
A dimensionless number, Re, that occurs in the theory of fluid dynamics. The diameter, velocity, density and 'viscosity
(consistent units) for a fluid flowing through a cylindrical conductor are related as follows: Re - (diameter) x (velocity) x
(density) / (viscosity) Or DVр/µ. The number is important in fluid hydraulics calculations for determining the type of fluid flow,
i.e. whether laminar or turbulent. The transitional range occurs approximately from 2000 to 3000;below 2000 the flow is
laminar, above 3000 the flow is turbulent.
Ready for Commissioning Certificate
Request for Materials
Request for Quotation
Robert Gordon Institute of Technology
Relative Humidity
The science that deals with deformation and flow of matter.
Page 122 of 310
Rheology
RICG
RIDDOR
Rig
Rig
Rina
Ringing
RIPHH
Riser
Riser clamps
Riser pipe
Risk
Risk
Risk
Risk Analysis
Risk Assessment
Risk Assessment
RISKEX
RIV
RKB
RMS
The study of the deformation and flow of matter under the influence of an applied stress. The term was coined by Eugene
Bingham, a professor at Lehigh University, in 1920, from a suggestion by a colleague, Markus Reiner. The term was inspired
by Heraclitus's famous expression panta rei, everything flows. In practice, rheology is principally concerned with extending the
classical disciplines of elasticity and [Newtonian] fluid mechanics to materials whose mechanical behaviour cannot be
described with the classical theories. It is also concerned with establishing predictions for mechanical behaviour [on the
continuum mechanical scale] based on the micro- or nanostructure of the material, e.g. the molecular size and architecture of
polymers in solution or the particle size distribution in a solid suspension.
Resin Impregnated Garbon Graphite [eg as used in machanical seals].
Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995.
Mast or derrick complete with equipment to perform drilling or workover operations. Colloquial: the drilling location during
drilling operations.
A collective term to describe the permanent equipment needed for drilling a well. It has come to include the onshore and
offshore vehicles, mobile platforms, or vessels on which the equipment is installed.
Italian classification [verification] society
Oscillation of a system following a sudden change in state.
Royal Institute of Public Health and Hygiene
A pipe through which fluid travels in an upward direction. Or, an offshore operation the term riser pipe refers to the large
diameter pipe, which extends from the blowout preventer stack on the sea floor to a semi -submersible rig. See also Marine
riser . Also A pipe which connects a rig or platform to a subsea wellhead or pipeline during drilling or production operations.
Clamp[s] used to secure the riser to the jacket
The pipe [from the blowout preventer] and special fittings used on floating offshore drilling rigs to establish a seal between the
top of the wellbore, which is on the seabed, and the drilling equipment, located above the surface of the water. A riser pipe
serves as a guide for the drill stem from the drilling vessel to the wellhead and as a conductor of drilling fluid from the well to
the vessel. The riser consists of several sections of pipe and includes special devices to compensate for any movement of the
drilling rig caused by waves. It is also called a marine riser. The vertical portion of a subsea pipeline [including the bottom
bend] arriving on or departing from a platform.
Possibility of loss, injury, damage, or exposure to hazard or danger.
A factor expressed as a number, which is the product of the Hazard Effect.
A combination of probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of the
occurrence. The likelihood of a specified undesired event occurring within a specified period or in specified circumstances. It
may be either a FREQUENCY [the number of specified events occurring in unit time] or a PROBABILITY [the probability of
specified event following a prior event] depending on the circumstances.
An imprecise term which infers the quantified calculation of probabilities and risks without taking any judgments about their
relevance. A term equivalent to risk estimation in Royal Society terms.
The quantitative evaluation of the likelihood of undesired events and the likelihood or harm or damage being caused together
with the value judgments made concerning the significance of the results.
The process of hazard identification and the assessment of the potential for identified hazards to be realised in any given
activity.
Cost of Risk
Rapid Intervention Vessel
Rotary Kelly Bushing
Root Mean Square OR Reliability management system
Page 123 of 310
RMS Current - Root Mean Square
Current
RMS Torque - Root Mean Square
Torque
RNAV
RNLI
RO
ROAct™ Actuator
Rock a well
Rock dumping
Rod
Rod block
Rod hanger
ROI
ROL
Roles
Roll a tank
Roller Bit
Roller Bit
RON
Root Cause Analysis
ROP
Rope socket
ROS
ROT
Rotameter
Rotary drilling
In an intermittent duty cycle application, the RMS current is equal to the value of steady state current which would produce the
equivalent motor heating over a period of time.
In an intermittent duty cycle application, the RMS torque is equal to the value of steady state torque which would produce the
equivalent motor heating over a period of time.
Racal Navigation
Royal National Lifeboat Institution [UK]
Reverse Osmosis (RO) is a separation process that uses pressure to force a solution through a membrane that retains the
solute on one side and allows the pure solvent to pass to the other side.
More formally, it is the process of forcing a solvent from a region of high solute concentration through a membrane to a region
of low solute concentration by applying a pressure in excess of the osmotic pressure.
This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute
concentration, through a membrane, to an area of high solute concentration when no external pressure is applied. The
membrane here is semipermeable, meaning it allows the passage of solvent but not of solute.
The membranes used for reverse osmosis have a dense barrier layer in the polymer matrix where most separation occurs. In
most cases the membrane is designed to allow only water to pass through this dense layer while preventing the passage of
solutes (such as salt ions).
This process requires that a high pressure be exerted on the high concentration side of the membrane, usually 40–70 bar
(600–1000 psi) for seawater, which has around 24 bar (350 psi) natural osmotic pressure which must be overcome.
Alpha Thames’ subsea, electric, rotary actuator for the operation of rotary isolation valves.
To agitate a dead well by alternately bleeding and shutting in the pressure on the casing or tubing so that the well will start to
Deposition of rocks onto subsea pipelines, to provide protection against anchors and trawlnets, when burying the pipe is
impracticable. Rocks and gravel may also be dumped around subsea wellheads and jacket legs to repair scour damage.
A suckerrod. or An engine's connecting rod. or A piston rod.
A light travelling block for the hoisting of suckerrods.
A rack with finger-like projections on which rods are hung when pulled from the well; a vertical rack for hanging lengths of
Return on Investment
Rig on Location
The documented description of personnel functions within a management structure.
To agitate a tank of crude oil with gas or by circulation for the purpose of mixing small quantities-of chemical with the oil to
The rock-cutting tool on the bottom of the drill string made with three or four shanks welded together to form a tapered body.
A rotary drilling bit which penetrates by pulverising the rock with its toothed wheels.
Research Octane Number
A formal process designed to determine the key causation factors in an incident or accident.
Remotely Operated Pickup OR rate of penetration
A device for securing the end of a steel cable into a connecting piece - a clevis, hook or chain. A metal cup or socket (like a
whip socket) into which the cable end is inserted and which then is filled with molten lead or babbitt, or in the case of piano
wire fastened with a special knot.
Required On Site
Remotely Operated Tool; an ROV with tool attached
A variable area type flow meter. It consists of a tapered metering tube and a float, which is free to move up and down within
the tube. The fluid to be measured enters at the bottom of the vertically mounted tube, passes upward around the float, and
out at the top. The position of the float inside the tube is an indication of the rate of flow.
Drilling procedure based on rotating a bit. and drill pipe carrying a mud circulation system.
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Rotary Hose
Rotary Hose
Rotary pump
Rotary rig
Rotary table
Rotary table
Rotor
Roughnecks
Round trip
Round Trip
Roustabouts
Routine
ROV
ROVSV
Royalty
RPE
RPLQ
rpm
RPM
RR
RSD
RT
RTD
RTI
RTJ
RTMS
RTMS
RTO
High pressure rubber or steel hose some 60 ft long connected to the rotary swivel for conveying circulating mud to the
drillstring. See also Mud hose .
The mud supply hose from the standpipe to the swivel.
A positive displacement pump consisting of rotary elements cams, screws, gears or vanes - enclosed in a case; employed,
usually in handling small volumes of liquid at either high or low pressures. Because of the close tolerances in the meshing of
the gears or cams, rotary pumps cannot handle liquids contaminated with grit or abrasive material without suffering excessive
wear or outright damage.
A derrick equipped with rotary drilling equipment, i.e. drilling engines, draw works, rotary table, mud pumps and auxiliary
equipment, a modern drilling unit capable of drilling a borehole with a bit attached to a rotating column of steel pipe.
A heavy, circular casting mounted on a steel platform just above the derrick floor with an opening in the centre through which
the drill pipe and casing must pass. The table is rotated by power transmitted from the draw works and the drilling engines. In
drilling, the Kelly-joint fits into the square opening formed by the Kelly bushings placed in the table opening.--As the table
rotates, the Kelly is turned, rotating the drill column and the drill bit.
The principal component of a rotating, or rotary machine, used to turn the drill stem and support the drilling assembly. It has a
bevelled gear arrangement to create the rotational motion, and an opening into which bushings as are fitted to drive and
support the drilling assembly.
The moving part of the motor, consisting of the shaft and magnets. These magnets are analogous to the field winding of a
brush-type DC motor.
Members of the drilling crew; the driller's assistants who work on the derrick floor, up in the derrick racking pipe, tend the
drilling engines and mud pumps, and on trips operate the pipe tongs breaking out or unscrewing the stands of drill pipe.
Pulling the drill pipe from the hole to change the bit and running the drill pipe and new bit back in the hole. On deep wells,
round trips or trips, as more commonly called, may cake 24 hours, three 8-hour shifts.
Recovering the drill string from the bottom of the well to the surface and returning it to continue drilling. This may be e.g. to
replace the bit. “Tripping” is arduous and interrupts “making hole”.
A production or drilling employee who does manual labour on and around production installations and drilling rigs.
A procedure that does not vary in its execution.
Remotely Operated Vehicle [WROV = Work Class Remotely Operated Vehicle].
Remotely Operated Vehicle Support Vessel
Usually a fixed percentage of a specified crude or gas value per unit produced, to be paid to the host government. It is a fixed
charge independent of profit or loss.
Responsible Person Electrical. The person appointed to ensure that all electrical work is carried out safely and properly.
Replacement Permanent Living Quarters
Revs per Minute
Replacement Process Module
Research Report
Returnable Steel Drum OR Relative Standard Deviation
Radiographic Testing
Resistance Temperature Device, [an accessory usually mounted on a blower to monitor the bearing temperature]
Reliability Threat Identification
Ring-Type Joint
Real Time Management System
Real Time Monitoring System
Real Time Operations
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RTR
RTS
RTU
Running tool
Room Temperature Resistance
Return to Service
Remote Telemetry Unit
In wireline work, is used to lower a mandrel into the hole and to place it in the selected landing nipple.
Running-In/Running Casing
Inserting any tubular or tool into a well is known as running-in. Assembling and lowering in a string of casing is running casing.
Rupture disc
RV
RVP
RVP
A thin, metal plug or membrane in a fitting on a pressure vessel or line made so as to blow out or rupture when the pressure
exceeds a predetermined level; a safety plug.
Relief Valve
Reid vapour pressure. The pressure caused by the vaporised part of a liquid and the enclosed air and water vapour, as
measured under standardised conditions in standardised apparatus: the result is given in pounds per square inch at 100*F,
although normally reported simple as RVP in lb.. There is no simple relation between RVP and the true vapour pressure of the
liquid. RVP gives s indication of the volatility of a liquid, e.g. gasoline.
Reid Vapour Pressure. [A standard oil industry measure of vapour pressure, in p.s.i. at 100°F [38°C]. The absolute vapour
pressure of a petroleum product in pounds per square inch [or kilopascals] at 100F [37.8C]. See TVP for a fuller explanation].
SAC
Residual Vapour Pressure OR Rendezvous Point
Slope and Deflection
Safety and Operations
Search and Rescue
Shutdown
The density of development drilling on a reservoir expressed in acres per producing well.
Slug Suppression System
Spectra-Tek Sentinel 500 microcomputer
An environment of coastal sedimentation characterized by arid or semiarid conditions above the level of high tide and by the
absence of vegetation. Evaporites, eolian deposits and tidal-flood deposits are common in sabkhas.
Systems Acceptance Certificate OR Special Area of Conservation
Sack
Cement, mud, chemicals and other solids used in drilling are supplied to the rig and measured into the well in sacks [SAX].
RVP
S&D
S&O
S&R
S/D
S/P or Spacing pattern
S3
S500
Sabkha
Sacrificial anode
Saddle
Saddle bearing
SADIE
SAEP
SAFE
Safe area
In a cathodic protection system, the sacrificial anodes form the positive electrodes. A sacrificial anode is a block or bar of nonferrous metal selected to be of a more noble material than that of the structure being protected. It is attached to the
submerged part of a steel structure [or a ship’s hull]. The sacrificial anode is gradually eroded in preference to the structure,
thereby preventing structural corrosion.
A clamp, fitted with a gasket, for stopping the flow of oil or gas from a hole or a split in a pipeline; a device for making
temporary repairs to a line. The clamp conforms to the curve of the pipe and is held in place by U-bolts that fit around the pipe
and extend through the clamp.
A broad, heavy bearing located on top of the Samson post to support the walking beam on a cable tool drilling rig or an oil well
pumping unit (jack)
Safety Alert Database and Information Exchange [funded by UKOOA and the HSE].
Senior Authorised Electrical Person
Slapper Activated Firing Equipment
Any area, no part of which lies within a dangerous area or a remotely dangerous area.
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Safe atmosphere
Safety Audit
Safety belt
Safety Checklist
Safety Critical Task
Safety Evaluation
Any atmosphere not falling within the definition of dangerous atmosphere and incapable of ignition or causing toxic condition
dangerous to human life.
A critical examination of all, or part, of a total operating system with relevance to safety.
A belt, secured to the derrick by means of-a short rope, and worn by personnel working aloft to limit their fall should they slip or
overbalance.
A worksite checklist detailing the expected hazards and the controls to be put in place before work can safely start and those
to be observed doing the work
A safety critical task is one which presents a safety hazard to those undertaking the task. In the context of active monitoring, it
may also be one which has the potential to cause an environmental incident or a disruption to production
An alternative term for safety report used, in particular, for the assessment of pipelines.
Safety latch
A bar or other device fitted across; the opening of a hook or other load carrying suspension to prevent the rope, sling bail, link
or other equipment slipping off the hook.
Safety relief valve
Automatic valve used to prevent excessive overpressure in vessels, equipment and piping systems handling either liquids or
gases (and ,vapour). Definitions of terms. Operating pressure: Pressure at which the vessel normally operates. Design
working pressure: Maximum allowable working pressure. Set pressure: pressure at which the valve opens. Resetting
pressure: pressure at which the valve closes. Overpressure: Pressure increase over the set pressure while the valve is
relieving. Accumulation. The part of the overpressure which is higher than the design working pressure. Maximum relief
pressure (without fire): 110% of the design working pressure. Maximum relief pressure (with fire): 120% of the design working
pressure. Blow down: Difference between the set pressure and the resetting pressure. Superimposed backpressure: The
constant pressure in the vent headers. Build-up backpressure: The increase in pressure in the vent headers during relieving.
Safety Report
Safety slide
The presentation of a justification for the safety of an installation. [NB use in connection with CIMAH Regulations]. Previously
known as the Safety Case.
A means of escape from the fourble or monkey board in case of emergency. It consists of an inclined escape line, to which is
suspended a travelling carriage equipped with an adequate braking device.
Safety System Inhibit
A device or software used to prevent the executive action of an emergency shutdown system or fire and gas detection system.
SAGE
SAL
SALM
Scottish Area Gas Evacuation
Single Anchor Loading OR Submerged Anchor Loading System
Single Anchor Leg Mooring; [a compliant monopod version of the SBM tanker-loading buoy, used in deeper water].
The product formed by neutralization of an acid and a base. The term is more specifically applied to sodium chloride.
Neutralisation is an important reaction in many aspects of mud control and treatment.
A plug of rock salt, driven up through the covering layers. The porous strata it passes through are sealed off by reason of the
impermeability of salt to oil and gas. These strata may then function reservoir rocks.
A dome that is caused by an intrusion of rock salt into overlying sediments. A piercement salt dome is one that has been
pushed up so that it penetrates the underlying sediments, leaving them truncated. The formations above the salt plug are
usually arched so that they dip in all directions away from the centre of the dome, thus frequently forming traps for petroleum
accumulations.
Subsea Actuation Module
Subsea Accumulator Module
A heavy, vertical member that supports the walking beam of a pumping unit (jack).
Salt
Salt dome
Salt dome
SAM
SAM
Samson post
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Sanction to Test and Temporary
Changes
Sand
Sand consolidation
Sand content
Sand control
Sand line
Sand pump
Sand reel
Sanded up
Sap No
SAR
SAS
SASS
SAT
SAT
SATCO
SATCOM
Satellite navigation/comms.
Satellite station
Satellite well
Saturated hydrocarbons
Saturated oil
Saturated solution
Saturation
Saturation diving
The formal authorisation and control of the removal and re-instatement of part, or all, of the isolation scheme for the purposes
of testing the item of plant or equipment. A Sanction to Test or a Temporary Change must not affect the overall isolation
scheme, which will be reinstated after the testing has been completed.
A loose granular material resulting from the disintegration of rocks, most often silica.
A form of sand control which involves the process of injecting chemicals into the naturally unconsolidated. formation to provide
in-situ grain-to-grain cementation.
The sand content of a fluid is the insoluble abrasive solids content rejected by an ASTM 325 screen. It is usually expressed as
the percentage bulk volume of sand in a fluid. This test is an elementary type in that the retained solids are not necessarily
silica or may not be altogether abrasive. For additional information concerning the kinds of solids retained on the ASTM 325
screen, more specific tests would be required. The quantity of sand carried by a crude stream is often expressed as p.t.b.
(pounds per thousand barrel).
A technique for coping with sand from unconsolidated (loose, unpacked) formations that migrate (drift or wash) into down hole
equipment or into the borehole.
A wireline (cable) used on a drilling rig to raise and lower the bailer or sand pump in the well bore. Logging devices and other
lightweight equipment are also lowered into the hole on the sand line.
A cylinder with a plunger and valve arrangement used for sucking up the pulverised rock, sand and water from the bottom of
the well bore. Mare effective than a simple bailer. Shell pump sludger.
A small hoisting drum on which the sand line is spooled and used to run the bailer or sand pump on a cable tool rig. The sand
reel is powered by contact with the band wheel.
A well clogged by sand that has drifted and washed into the well bore from the producing formation by the action of the
formation fluid.
Saponification Number
Search and Rescue
Safety and Unified Automatic System
Survey autonomous semi-submersible
Site Acceptance Tests[s]
Saturated
Senior Air Traffic Control Officer
Satellite Communications
Communication satellites are extensively used to fix or locate positions offshore to the accuracy necessary for oil and gas
operations.
See Flow station.
Usually a single well drilled offshore by a mobile offshore drilling unit to produce hydrocarbons from the outer fringes of a
reservoir.
Hydrocarbon molecules which cannot absorb any more hydrogen atoms without subdividing to release carbon valencies for
further hydrogen.
A crude oil at reservoir conditions that cannot contain any more solution gas.
A solution is saturated if it contains at a given temperature as much of a solute as it can retain. At 680F it takes 126.5 lb. salt
to saturate 1 bbl of fresh Water.
The extent to which the pore space in a formation contains hydrocarbons or connate water. The extent to which gas is
dissolved in the liquid hydrocarbon.
Diving performed over long periods at high submerged pressures. Instead of depressurising after each shift, the diver lives in
a [hyperbaric] pressure chamber onboard the DSV. See also decompression chamber.
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Saturation pressure
SAW
Saw slotted liner
SAX
Saybolt seconds
sbgi
SBHP
SBM
SBSV
SBV
SC
SCADA
Scarper trap
Scavengers
SCBA
SCC
SCC
SCE
scf
SCF
Scf/bbl
Scf/d
Scf/Stb
SCG
Scheduling
Schilling apparatus
Schlumberger
Schlumberger
The pressure at which gas begins to be released from solution in oil.
Submerged Arc Welding
See Slotted liner .
Sacks [e.g. cement]
Unit of viscosity, mainly used in commercial specifications.
Society of British Gas Industries, the trade association of the British onshore gas industry.
Static Bottom Hole Pressure
Single Buoy Mooring; A single-point buoy mooring for loading and unloading tankers. Oil is fed to or from the centre of the
SBM from below, and the mooring gear and loading hoses can swivel above the buoy through a full revolution. The tanker
moors bows-on and weather vanes around the buoy, presenting the minimum frontal area to the combined forces of wind and
waves.
Standby/safety Support Vessel
Standby Vessel
Site Controller
Supervisory Control and Data Acquisition OR subsea controls and data acquisition.
A facility on a pipeline for inserting and retrieving a scraper or pig. The trap is essentially breech-loading tube isolated from the
a pipeline by valves. The scraper is loaded into the tube like a shell into a shotgun; a hinged plug is closed behind it, and line
pressure is then admitted to the tube behind the scraper. A valve is opened ahead of the scraper and it is literally pushed into
the line and moved along by the fluid pressure.
Chemical-additives which remove or inactivate impurities or undesired materials in a mixture or process.
Self Contained Breathing Apparatus
Sulphide Stress Cracking OR Surface Compression Chamber OR Stress Corrosion Cracking.
Supplementary Control Certificate. A task may require risk assessments that are additional or supplementary to the work
being carried out. The assessments for Lifting Operations and Manual Handling can be performed and recorded through the
use of Supplementary Control Certificates.
Safety Critical Element
Standard Cubic Feet
Stress Concentration Factor OR Single column floater [also known as spar]
Standard cubic feet per barrel
Standard cubic feet per day
Standard cubic feet per stock tank barrel
Software Configuration Guide
The systematic identification of activities into a time based work flow process.
Officially Bunte-Schilling apparatus: An effusiometer used to determine the specific gravity of a gas. The working is based on
the fact that the time taken by equal volumes of gases to flow through a small orifice under the same conditions of pressure
are proportional to the square roots of their respective densities or specific gravities.
Trade name of a pioneer electrical well-surveying company. In many areas it is common practice to speak of an electric well
log as a Schlumberger-log even though the log was made by another company.
http://www.glossary.oilfield.slb.com/
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Schoepentoeter
SCL
SCM
SCMMB
SCO
SCOMS
Scotch blocks
Scouring
Scouring
SCR
SCR
SCRAMS
Scraper
Scraper pig
Scraper, pipeline
Scratchers
Screen
Screen analysis
Screen liner
Screw pump
Scrubber
A proprietary Shell vane type inlet device that is commonly used for introducing gas/liquid mixtures into a vessel or column.
The purpose of a Schoepentoeter™ is to decrease the momentum of the feed, perform a first stage separation of solids and
liquid from the gas and achieve an even gas distribution across the vessel cross section. This is obtained by splitting the feed
mixture into a series of flat jets. The Schoepentoeter™ inlet device allows for considerable reductions of the vessel height and
inlet nozzle size.
Safety Checklist
Subsea Control Module
Subsea Control Module Mounting Base
Stabilised Crude Oil
Stabilised Crude Oil Metering Station
Wedge shaped wheel chocks
The erosion or washing away of the sand/clay covering of a buried subsea pipeline. Scouring caused by sea currents is a
serious problem for under-sea lines. Excessive scouring causes spanning, the hanging of a section of the line up to several
feet off bottom. If allowed to go uncorrected the pipeline welds crack or the pipe ruptures from its unsupported weight. Subsea
lines are inspected for scouring and spanning by side-scan sonar devices or by diver inspection.
The process by which tides and currents carry away loose sedimentation from around a fixed object on the seabed such as a
platform leg or pipeline.
Silicon Controlled Rectifier
Safety Case Regulations [SI 1992/2885] OR Steel catenary riser OR selective catalytic reduction.
Surface controlled reservoir analysis and management system.
A device for cleaning the inside of casing in a well.
A device for cleaning the inside of a pipeline.
A pig; a cylindrical, plug-like device equipped with scraper blades, wire brushes, and toothed rollers used to clean
accumulations of wax rust and other foreign matter from pipelines. The scraper is inserted in the line at a trap and is pushed
along by the pressure of the moving column of fluid. See also Pig .
Collars with wire bristles fitted to the outside of casing to remove filter cake from the well bore to help to ensure a good cement
A tubular sieve inserted in a well bore to hold back loose sand and rock without letting oil and gas enter the well.
Determination of the relative percentages of substances, e.g. the suspended solids of a drilling fluid or sand in oil, passing
through or retained on a sequence of screens of decreasing mesh size. Analysis may be by wet or dry methods. Referred to
also as Sieve analysis.
A liner made from a slotted or perforated pipe with a special wire wrapped around it. Lugs impressed in the wire provide the
required slot spacing.
A constant displacement pump in which fluid is-propelled axially in a constant, uniform flow through the action of spirally
grooved rotors.
A separator for removing liquids and solids from a gas stream.
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Scrubber
Scrubbing
SCS
SCSC
SCSSSV
SCSSV
SCSSV
SCU
SD
SDB
SDB
SDC
SDRL
SDRP
SDS
SDU
SDV
Sea line
Seal
Seal
Seal assembly
Seal pot
Sealed source
Seamless pipe
Search Button
sec
Scrubbers are usually two-phase, vertical vessels. The scrubber is NOT used as a primary separation means at a well, and
are recommended only for:
1. Secondary operation to remove carryover fluids from process equipment such as the absorber and the Liquid Dust
Scrubber.
2. Gas line separation downstream from separator and where flow lines are not long.
3. Very high GOR flow streams that is, to "scrub" small amounts of liquid from a gas stream.
4. Flare scrubbers or vent scrubbers are placed in gas outlet streams from production separators to remove any residual
liquids left or any condensates that may have formed in the line, prior to flaring or venting.
5. Suction and discharge scrubbers are placed upstream and downstream of gas compressors.
6. Fuel gas scrubbers remove residual liquid from gas just prior to its use as a fuel.
7. Pipeline scrubbers remove condensate from gas streams flowing through long pipelines.
Purifying a gas by putting it through a water. oil or chemical wash; also the removal of entrained water and the removal of
liquid from a gas stream.
Subsea Control System
Subsea Control System Computer
Subsea Controlled Sub Surface Safety Valve
Surface Controlled Subsurface Safety Valve
Surface Controlled Subsurface Safety Valve OR Subsea Safety Valve
Surface Control Unit
Sand Detector OR shut down OR stream day
System Data Base
Subsea Distribution Box
Single Disciplinary Check
Supplier Document Requirement Listing
Smoke Detection Repeater Panel
Safety Data Sheet OR Supplier Document Schedule.
Subsea Distribution Unit
Subsea Distribution Valve OR Shutdown valve
Submarine pipeline; line laid on the ocean floor from offshore wells to production platform and to receiving stations on shore.
Line laid from shore terminal to loading buoy(s).
Thin strip of metal, imprinted with serial numbers, used to seal a valve in an open or closed position. The metal strip has a
locking-snap on one end into which the free end is inserted, locking it securely. Seals are used on tanks in a battery to prevent
the undetected opening or closing of a valve. Packing-off device to prevent escape of gas or liquid.
An impermeable fault or stratum of rock beneath or behind which hydrocarbons can accumulate. See also reservoir.
A pack-off assembly run on the tubing, which packs off in the bore of a permanent packer.
A type of flame arrestor to prevent backward travel of lames in vent lines.
A device that encapsulates the radioisotope so that it can be handled with greater safety or energized devices that can be
turned off.
Pipe made without an axial seam; pipe made from a billet or solid cylinder of hot steel and hot-worked on a mandrel into a
tubular piece without a seam.
A button in the WCC / ICC / Workpack Wizards that enables the user to search for similar documents to use as a template for
a new document.
Second
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Second API
Second end connection
Secondary Hazards
Secondary Location
Secondary Migration
Secondary porosity
Secondary recovery
Secondary recovery
Sediment
Sedimentary basin
Sedimentary rock
Sedimentary rocks
Seepage
SEERAD
Segregation
Seismic methods
Seismic survey
Self-elevating drilling unit
A unit of viscosity as measured with a Marsh funnel according to API procedure.
Applies to umbilicals and flexible pipeline; having raised the first end through a j-tube to the platform, the umbilical or pipe is
laid away from it toward the other [second] end, which is then terminated, connected, or left on the seabed to be picked up at a
later stage .
These are sub-sets of Primary hazards that more specifically narrow down that area of concern i.e. Hydrocarbon Break-in is
broken down into Secondary Hazards of Breaking Containment and Venting.
A list of other locations that a task may be carried out in but is not deemed to be the Main location of the task.
The movement of generated hydrocarbons into a reservoir after their expulsion, or primary migration, from a source rock.
Porosity developed after the original deposition of a formation, e.g. by the action of water on soluble components of the rock,
The process applied when the energy in the formation itself is not sufficient to drive the maximum recoverable amount of liquid
or gas to the borehole, and is supplemented by injection of products common to the formation (water, gas). These processes
are also called Pressure maintenance project See also Tertiary recovery and Enhanced recovery .
Production of fluids from a reservoir by water or gas injection and pressure maintenance rather than by blow down or natural
primary recovery.
The unconsolidated grains of minerals, organic matter or preexisting rocks, that can be transported by water, ice or wind, and
deposited. The processes by which sediment forms and is transported occur at or near the surface of the Earth and at
relatively low pressures and temperatures. Sedimentary rocks form from the accumulation and lithification of sediment.
Sediments are classified according to size by the Udden-Wentworth scale.
An extensive area [often covering thousands of square miles] where substantial amounts of unmetamorphised sediments
occur. Most sedimentary basins are geologically depressed areas [shaped like a basin]. The sediment is thickest in the
interior and tends to thin out at the edges. There are many kinds of such basins, but it is in these formations that all the oil
produced throughout the world has been found.
A rock composed of materials that were transported to their present position by wind or water. Sandstone, shale and limestone
are sedimentary rocks.
Rocks formed by the accumulation on land or in water of mineral or skeletal particles. They can be transported by air or by
water as discrete particles (e.g. sand grains) or originate by chemical precipitation from water (e-g- rock salt). Sedimentary
rocks generally have a layered structures known as bedding or stratification.
A natural oil spring which occurs at the surface where there is a fissure connecting to the reservoir. The presence of a
seepage indicates that a reservoir formation exists in the vicinity but does not guarantee that a well drilled nearby will produce
oil. It may be that the seepage has, over the ages, leaked most of the recoverable oil.
Scottish Executive Environment and Rural Affairs Department
The separation of different fluid phases in the vertical flowing column of a well.
Exploration or production methods in which charges of explosives or other energy sources generate shock waves in the
surface layers of the earth which are recorded by seismometers placed-at varying distances from the explosion.
An exploration method in which strong, low-frequency sound waves are generated on the surface or in the water to find
subsurface rock structures that may contain hydrocarbons. The sound waves travel through the layers of the earth’s crust. At
formation boundaries, some of the waves are reflected back to the surface where sensitive detectors pick them up.
Reflections from shallow formations arrive at the surface sooner than reflections from deep formations, and since the
reflections are recorded, a record of the depth and configuration of the various formations can be generated. Interpretation of
the record can reveal possible hydrocarbon-bearing formations.
An offshore drilling rig, usually with a large hull. It has a mat or legs that are lowered to the seabed and a main deck that is
raised above the surface of the water to a distance where it will not be affected by the waves. Also called a jackup drilling rig.
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SEM
Semi submersible
SEPA
Separator
Separator
Separator
Separator gas
Serious near miss
Service tools
Service well
Service well
Services Subcontracts
Servo
Servomechanism
Servomotor
SES
SESAM
Subsea Electronics Module
A floating offshore production and or drilling unit that has pontoons and columns that, when flooded, cause the unit to
submerge in the water to a predetermined depth. Living quarters, storage space, etc. are assembled on the deck.
Semisubmersible rigs are either self-propelled or towed to a site and either anchored or dynamically positioned over the site,
or both. In shallow water, some semi submersibles can be ballasted to rest on the seabed. Semi submersibles are more
stable than drill ships and ship-shaped barges and are used extensively to drill wildcat wells in rough waters such as the North
Sea. Two types of semisubmersible rigs are the bottle-type semisubmersible and the column-stabilised semisubmersible. See
floating offshore drilling rig.
Scottish Environmental Protection Agency
A pressure vessel (either horizontal, vertical or spherical) used for the separating of well fluids into gaseous and liquid
components.
A cylindrical or spherical vessel used to separate the components in streams of mixed fluids. See oil and gas separator.
Are mechanical devices used for primary separation to remove and collect liquid from natural gas, which is normally
accomplished with the aid of centrifugal force.
The terms oil and gas separator, separator, stage separator, and trap all refer to a conventional oil and gas separator. These
separating vessels are normally used near the wellhead, manifold, or tank battery to separate the fluids produced from oil and
gas wells into oil and gas or liquid and gas. They must be capable of handling "slugs" or "heads" of well fluids.
Production Separator
Also called "bulk separator" or "primary separator", is used to separate one or more combined wellstreams at a well site,
gathering center, plant or offshore platform. It can be two or three-phase. "Primary" separation indicates it is the first process
of separation the produced fluids have encountered. If located in a plant, the production separator might be very large and
handle the production from a whole field. In large plants, several production separators are often used in parallel.
Test Separator
Is usually, connected parallel to a production separator.
It is normally sized to handle one well at a time. Individual wells can be segregated from the main production stream at the well
manifold and processed through the test separator where the separated phases are then measured. The products are then
recombined with the main stream products.
Natural gas separated from the oil by a separator.
Any work related event or incident, which under slightly different conditions, would have resulted in a fatality, lost time accident,
or OSHA recordable incident.
A variety of down hole equipment used in drilling, completion and workover of oil and gas wells.
A non-producing well used for injecting water or gas into the reservoir or producing formation in pressure maintenance or
enhanced recovery programs; also a salt-water disposal well.
See injection well
Minor contracts for the provision of specified services
Short for servomechanism or servomotor.
An automatic device for controlling large amounts of power with a small amount of force. An example of a servomechanism is
the power-steering on an automobile. A small force on the steering wheel activates a hydraulically-powered mechanism that
does the real work of turning the wheels.
A power-driven mechanism that supplements a primary control operated by a comparatively small force. See also
Servomechanism .
Ship Earth Station
Super Element Structural Analysis Modules
Page 133 of 310
SET
Set back
Set casing, to
Set pressure
Setting point
Settling tank
Settling time
Severity
Sewer
SF
SFC
SFF
SFT
SG
SGC
Shale
Shale
Shale shaker
Shale shaker
Shaped charge
Shaped charge perforation
Shark jaws
SHE
Shear
Solid Expandable Tubulars
The space on the derrick floor where stands of drill pipe or tubing are set back and racked in the derrick. Off-shore drilling
platforms often list the stand capacity of their set backs as an indication of their pipe-handling capability and capacity. On
transportable, mast-type derricks used on land, set backs are outside the derrick proper.
To cement casing in the hole. The cement is pumped down the casing to the bottom of the well and forced up a certain
distance into the annular space between casing and the rock wall of the drill hole. It is then allowed to harden, thus sealing off
upper formations that may contain water. The small amount of cement left in the casing is drilled out in preparation, for further
operations.
See under Safety relief valve.
The depth to which a string of casing is set and cemented.
A tank employed for separating two liquids, which are not miscible, e.g. oil and water. If the liquids do not form an emulsion
they separate into layers according to their specific gravities, and these layers can be drawn off from different levels in the
tank.
The time required for a parameter to stop oscillating or ringing and reach its final value.
In Safety: Total Lost Workdays during the period covered divided by the total of Lost Workday Cases plus permanent Partial
Disabilities, and represents average away days.
Gases found in sewers are Sulphurated Hydrogen and Methane. Both are toxic, flammable and may burn explosively within
their flammable limits.
Safety Factor
Sequential Function Chart
Scottish Fishermans Federation
Seabed Functional Testing OR Norwegian Pollution Control Authority OR Surface Flow Tree
Specific Gravity
Stephen Gillespie Consultants Limited [Gateway Business Park, Beancross Road, Grangemouth FK3 8WX.
www.sgcltd.co.uk ]
Fine-grained clay rock (mixture of clay and silt) with slate-like cleavage. Shale may form the cap of a hydrocarbon-bearing
reservoir; sometimes it is also a source--rock for hydrocarbons.
A very fine-grained, muddy sedimentary rock with low porosity and consequently poor reservoir potential.
Any of several mechanical devices for removing cuttings and other large solids from the mud. Common examples are vibrator
screen, rotating cylindrical screen, etc. See also Mud screen .
A vibrating screen used to remove cuttings from the circulating fluid [mud] in rotary drilling operations. The size of the
openings in the screen should be carefully selected to be the smallest that will allow 100% flow of the fluid. Also called a
shaker.
A relatively small container of high explosive that is loaded into a perforating gun. Upon detonation, the charge releases a
small, high-velocity stream of particles [a jet] that penetrates the casing, cement and the formation.
A perforation technique using shaped explosive charges instead of steel projectiles to make holes in casing, Quantities of
explosives are made up in special configurations and detonated at the bottom of the hole against the casing wall to make the
perforations.- See also Gun perforating, Jet perforating .
Jaws that emerge from ship’s deck [typically of an anchor handling vessel] to grip cable fittings
Safety, Health and Environment. [Acronym used to refer to groups that support safety, health and environmental activities
within ExxonMobil organizations, for example, Upstream SHE].
See Rate of shear
Page 134 of 310
Sheave
Shell method series SMS
SHEQ
Shielding
Shift
Shift change
Shims
Ship-shaped barge
Shock loading
Shoe
Shoestring sand
Short trip
Shorting cable
Shot hole
Shrink fit
SHS
Shut in
Shut in pressure
Shutdown
Shut-in pressure
Shuttle tanker
SI
SI
SI
SI
SI
SI 289
SIA
A grooved pulley or wheel; part of a pulley block: a sheave can be on a fixed shaft or axle (as in a rig's crown block) or in a
free block (as in block and tackle) or travelling block.
A private publication of the Shell Group setting out special methods to be used in carrying out laboratory tests on petroleum
products.
Safety, Health, Environment and Quality
A means of reducing the radiation doses received by persons in proximity to a source of Ionising Radiations. Shielding can be
achieved by placing an absorbing medium around the source
See Tour.
A period of time during which one work shift stops working and another commences.
Thin sheets of metal used to adjust the fit: of a bearing or to level a unit of equipment on its foundation. For fitting a bearing, a
number of very thin (.001 to .030-inch) shims are put between the two halves of the bearing (between the box and cap). Shims
are added or removed until the bearing fits properly on the journal.
A floating offshore drilling structure that is towed to and from the drilling site. The unit has a streamlined bow and squared-off
stern, a drilling derrick usually located near the middle of the barge, and a moon pool below the derrick through which drilling
tools pass to the seabed.
A load that produces extremely high peak torques for very short durations. This type of load is associated with conveyorized
grinding, crushing and separation processes.
A strengthened fitting on the end of a string of casing to protect the tubulars and to help direct the cement to the annulus.
Thin, often elongated streaks of reservoir sand completely surrounded by impermeable layers.
Pulling the drill string part way out of the hole. Short trips may b-e-necessary to raise the drill up into the protective string of
casing to avoid having the drill string stuck in the hole by a cave-in or sloughing of the wall of the borehole below the protective
casing during interruptions in the drilling operations,
Lugged copper conductor for exterior lightning protection
A hole drilled to receive explosives for blasting operations in seismic shooting.
An extremely tight fit as the result of shrinking one metal part around another. A heated part is placed around a companion
piece, and as the heated part cools, a shrink fit results. Conversely, an expansion fit may be made by c4goling a part (a valveseat insert, for example) to extremely low temperature with dry ice and placing the part in position. As it returns to normal
temperature, a tight expansion fit will result.
Substance Handling Sheets
To close a valve on a well so that it stops producing, said of a well on which the valves are closed.
Pressure at the top of a well when it is shut in,
A term denoting that work has been temporally stopped, as on an oil well or a plant.
The pressure in a shut-in well; the static pressure.
A moderate-sized oil tanker used to transport oil from larger vessels to port.
Scale Inhibitor
Structural Integrity
Statutory Instrument
Standing Instruction [Platform]
System Internationale [International System of Units] OR Statutory Instrument OR Shut in
Offshore Installations [Construction and Survey] Regulations, Statutory Instrument No 289 [1974] were revoked in 1998 in
favour of Design and Construction Regulations 1996.
Smoke Ingress Analysis OR Systems Integration and Automation
Page 135 of 310
Sialic layer
SIBHP
SIC
Side door sleeve
Side elevators
Side pocket mandrel
Side tracking
Side wall core/sample
Sidescan sonar
Sidetrack
Side-tracked well
Sidewall coring
SIEP
Sierpinski gasket
Sieve analysis
Sievert
SIF
Sight glass
Signatures Button
SIL
SILD
Silica gel
Silt
SIMOPS
The upper layer of the earth’s crust, in which prospective reservoirs are found, so called from the predominance of silicon and
aluminium in its composition.
Shut-in bottom hole pressure
Speed Indicating Controller (controls speed of turbine or pump)
A device which can be run as part-of a tubing string which can be opened or closed by wireline methods to provide
communication between tubing and casing. Basically it consist, of a ported tubing nipple in which a slotted inner sleeve can be
shifted to open or close it.
Casing or tubing elevators with a hinged latch that opens on one side to permit it to be fastened around the pipe and secured
A ported tubing nipple with an eccentric chamber in which a (gaslift) valve can be installed by wireline method. The bore of the
tubing is not restricted or obstructed by the valve in place.
Drilling past a fish in the hole or after plugging back to reach -other objectives or targets. This operation is usually
accomplished by use of a down hole motor and bent sub.
A sample of-rock taken from the wall of the well's borehole.
Acoustic survey equipment towed close to the seabed, used for surveying pipelines [see also sonar].
Creation of new section of the wellbore for the purpose of detouring around an obstruction in the main borehole or to access a
new part of the reservoir from an existing wellbore.
A well that has been re-drilled from an intermediate depth. Wells are re-directed or sidetracked for various reasons, usually
because of technical problems deeper in the original well.
Obtaining rock samples from the sides of a well bore using a special tool.
Shell International Exploration & Production BV
A form of fractal geometry based on a triangle. It has a fractal dimension D = ln 3/ln 2 = 1.58....
A Sierpinski carpet uses a square instead of a triangle and has a fractal dimension D = ln 8/ln 3 = 1.89....
See Screen analysis.
SI unit of radiation dose equivalent. It replaces the rem [1 Sv equals 100 rem]. Some types of radiation do more damage than
others for the same absorbed dose – for example, an absorbed dose of alpha radiation causes 20 times as much biological
damage as the same dose of beta radiation. The equivalent dose in sieverts is equal to the absorbed dose of radiation in
grays multiplied by the relative biological effectiveness. Humans can absorb up to 0.25 Sv without immediate ill effects; 1 Sv
may produce radiation sickness; and more than 8 Sv causes death.
Safety Integrity Function
A glass tube in which the height of a liquid in a tank or pressure vessel may be observed. The glass tube is supported by
fittings that extend through the vessel wall thus allowing the fluid in the tank to assume a corresponding level in the glass. Also
called Level gauge glass.
A button that is used to invite other signatories to the authorisation session. For instance in the Permit Meeting when both the
OIM and the Asset Owner are required to authorise WCCs / Workpacks.
Safety Integrity Level OR Safety Integrity Level
Sampling integrated logging device [for well testing without producing hydrocarbons to the surface].
A porous substance consisting of Si02. Silica gel is one of dry desiccants used as adsorbing agent in gas dehydration.
Materials that exhibit little or no swelling whose particle size generally falls between 2 microns and API sand size, or 74
microns (200-mesh). A certain portion of dispersed clays and barite for the most part also fall into this same particle-size
range.
Simultaneous Operations. Any two or more sets of activities carried out concurrently by different organisations or under
different management systems that, because of their proximity or other factors, could interact adversely with each other.
Page 136 of 310
Simultaneous Operations
Single
Single buoy mooring system
Single Point Accountable
Single point mooring system
SIREN
SIRP
SIS
SIS
SIT
SIT
SIV
SIWHP
Skid
Skid mounted
Skidding the rig
Skimmer
Skimmer
Skimming pit
Slack off
SLD
Sleeve
Slick line
Sliding side door sleeve
Slim hole drilling
Sling
Sling
Slinger
Slip joint
Slip velocity
Separate activities or works, taking place at the same time with the potential to impact on each other.
A joint of drill pipe or tubing.
An offshore floating platform (20 to 35 feet in diameter) connected to pipelines from the shore for mooring and loading or
The person in the organization [site/Business Unit] who has been appointed as being accountable for the delivery and
performance of an activity.
An offshore system to which the production from several wells located on the seabed is routed, and to which a tanker ship ties
up in order to load the produced oil. The tanker is moored to a single point on the buoy and is thus free to rotate around the
buoy, depending upon wind and current directions.
Subsea Investigation and Reporting of Events Network, organised by the SUT.
Safe Isolation and Reinstatement of Plant
Substance Information Sheets
Swedish Standards Institution
Site Integration Test
System or Site Integration Testing
Scale Inhibitor Valve OR scale injection valve
Shut-In Wellhead Pressure
[= SIBHP – static head]
Steel framework used to contain equipment; it is usually transportable
Refers to a pumping unit or other oil field equipment that has no permanent or fixed foundation but is welded or bolted to metal
runners or timber skids. Skid-mounted units are usually readily movable by pulling as a sled or by hoisting onto a truck.
Moving the derrick from one location to another without dismantling the structure; transporting the rig from a completed well to
another location nearby by the use of skids (heavy timbers), rollers, and a truck or tractor. Transportable folding or jack-knife
rigs are seldom skidded; they are folded down to a horizontal position and moved on a large, flatbed truck.
A type of oil spill clean-up device propelled over the water that sucks or paddles the oil into a tank.
Equipment for removing the surface layer of oil from an oil spill, or from an effluent water separator tank that is designed for
the purpose.
See Oil catcher.
To lower a load or ease up on a line.
Single Line Diagram
See Side door sleeve .
A solid steel wire used for wireline operations; also called Piano wire. See also Wireline.
See Side door sleeve.
A means of reducing the cost of a well by drilling a smaller diameter hole than is customary for the depth and the types of
formations to be drilled through. A slim hole permits the scaling down of all phases of the drilling and completion operations,
i.e., smaller bits, less powerful and smaller rigs (engines pumps, draw works) smaller pipe and less drilling mud.
A wire Loop for use in lifting heavy equipment.
A wire or rubber and fabric strop used to connect the crane hook to the item to be lifted for lifting.
Or Load Handler. Person with a responsibility for attaching lifting accessories to loads, hooking up pre-slung cargo containers,
drilling tubulars and other equipment to a crane.
A special sleeve-like section of pipe run in the drill string to absorb the vertical motion of a floating drilling platform caused by
wave action.
The difference between the annular velocity of the fluid and the rate at which a cutting is removed from the hole.
Page 137 of 310
Slippage
Slips
Slips
Slop tank
Slop tank
Slotted liner
Sloughing
Sloughing
Sludge
Slug
Slug catcher
Slug catcher
Slurry
Slurry
SMACS
SMCS
Occurrence in two-phase flow when the heavier phase (liquid) is by passed by the lighter phase (gas).
Wedge-shaped toothed pieces of metal that fit inside a bowl and are used to support tubing, casing or drillpipe. The slips on
packers hold the packer firmly wedged against the casing wall.
Metal wedges which are set in the annulus at the drilling floor to grip and support tubulars while sections are added or
removed.
On a products pipeline, a tank in which off-specification products or interface-mix is stored. At a marine terminal and on
tankers, a tank for holding the oil/water mix from a vessel that has washed down its compartments. Any vessel used for
retaining contaminated oil or water until it can be properly disposed of.
Temporary storage for water that is contaminated with oil.
Liner with saw-slotted openings to act as a sieve against sand influx into a well.
The partial or complete collapse of the walls-of a hole resulting from incompetent, unconsolidated formations, high angle or
repose, and wetting along internal bedding planes.
Crumbling or disintegration of the wall of the borehole.
Engine sludge: insoluble product formed from fuel combust products and from lubricating oils in internal combustion engines
and deposited on parts outside the combustion space. Tank sludge: material collected at the bottom of oil storage tanks.
An accumulation or pocket of liquid or gas formed in a pipeline as the flowing fluid pressure decreases. Slugs also form in
multiphase pipelines when gas breaks out of solution.
A large separator for removing liquid slugs at its destination without disrupting the gas flow.
Or surge drum, is a separator designed to separate bulk liquid-gas flow streams which are surging or slugging. The slug
catcher may be also serving as a production separator, in which case better separation is required. Properly designed it should
smooth out the intermittent flow.
A mixture of water and special grade cement, which is, pumped into the well -to cement a casing string or to plug off a lost
circulation zone or to plug back a bore-hole. Slurries are thin so they can be pumped and to enable the cement to penetrate
cracks and crevices and to fill all voids.
A mix of cement and water used in drilling/cementing OR solid particles or crushed fragments in a liquid for pipeline
transportation.
Subsea Mimic and Control System
Standard Machinery Control System
Smokeless flare
A specially constructed flare for the safe disposal of hydrocarbon vapours or, in an emergency, process feed that must be
disposed of. Smokeless flares are equipped with water or steam jets at the mouth of the stack to promote the complete
combustion of the vented gases. The jets of water or steam induce greater airflow and cools the flame resulting in complete
combustion without smoke or ash. Also used on offshore rigs to burn produced crude oil during a production test.
SMS
SMSF
SMYS
Snepper
SNG
SNR
SNS
Snubbing
SO2
Safety Management System OR Swedish Material and Mechanics Standard
South Module Support Frame
Specified Minimum Yield Strength [pipe]
A wireline cutter.
Synthetic Natural Gas
Senior
Southern North Sea
A procedure for servicing wells that are under pressure. Tubing, packers and other down hole tools are withdrawn from the
Sulphur Dioxide
Page 138 of 310
SOAEFD
Societal Risk
Socket
Sodium bichromate
SOF
Sol
SOLAS
Solenoid
Solid alkanes
Solubility
Solute
Solution
Solution gas
Solution gas drive
Solution gas field
Solvent
Sonar
Sonic log
Sonolog
SOP
SOPEP
SOR
Soup
Soup
Sour corrosion
Sour crude
Sour gas
Sour oil/gas
Sour service trim
Source rock
Scottish Office, Agriculture, Environment and Fisheries Department
The relationship between frequency and the number of people suffering from a specified level of harm is a given population
demonstration of the realisation of specified hazards.
See Wireline socket .
Na2Cr2O7. Also correctly called sodium dichromate. See also Chromate .
Solid Oxide Fuel [fuel cell technology]
A general term for colloidal dispersions, as distinguished from true solutions.
Safety of Life at Sea 1974
An electrical unit consisting of a coil of wire in the shape of a hollow cylinder and a moveable core. When energised by an
Hydrocarbon fractions which are solid at normal temperatures. See also alkanes.
The degree to which a substance will dissolve in a particular solvent.
A substance which is dissolved in another (the solvent).
A mixture of two or more components that form a homogeneous single phase. Example solutions are solids dissolved in liquid,
liquid in liquid, gas in liquid.
Natural gas dissolved and held under pressure in crude oil in a reservoir. See also Solution-gas field .
See Dissolved-gas drive.
An oil reservoir deriving its energy for production from the expansion of the natural gas in solution in the oil. As wells are drilled
into the reservoir, the gas in solution drives the oil into the well bore and up to the surface.
Liquid used to dissolve a substance (the solute).
Sound and ranging; the use of sound echoes to locate objects underwater.
See Acoustic log.
Trade name of an acoustic well sounder.
Standard Operating Procedure
Shipboard Oil Pollution Plan
Statement of Requirement
Nitro-glycerine used in shooting a well. Nitro in its pure form is a heavy, colourless, oily liquid made by treating glycerine with a
mixture of nitric and sulphuric acids. It is usually mixed with absorbents for easier handling. Nitro, when used in well shooting,
is put in tin torpedoes, 4 to 6 inches in diameter, and lowered into the well on a line. The bottom of each torpedo can is made
to nest in the top of the-preceding one, so as may cans as necessary for the shot can be lowered in and stacked up; the size
of the shot depends upon the thickness and hardness of the formation to be fractured
Nitro-glycerine. It is used in explosive fracturing of a downhole formation.
Corrosion due to the presence of H2S in gas.
Crude ails containing an amount of sulphur and sulphur compounds which break down upon refining to liberate troublesome
quantities of corrosive sulphur compounds. This is a relative term.
Gas containing objectionable amounts of sour-smelling and very toxic contaminants, e.g. hydrogen sulphide and other
corrosive sulphur compounds.
Oil or gas with a relatively high content of [odorous, poisonous or corrosive] sulphur compounds such as hydrogen sulphide.
A designation by manufactures of oil field fittings and equipment that their products have finishes resistant: to corrosion by
hydrogen sulphide (H2S) and other corrosive agents in sour oil and gas. See also Sour gas .
The sediment/rock in which fossil deposits are formed into hydrocarbons which may then migrate into different porous
formations.
Page 139 of 310
SOV
SOx
SPA
Spacing
SPAR
Sparker
SPB
SPBM
SPC
SPCM
SPCP
SPE
Spear
Special Area of Conservation
Special clearance coupling
Special Protection Area
Specific gravity
Specific heat
Specified Requirements
Specs
Sphere
Sphere launcher
Spider
Spider
Spider deck
Spin up
Spinner
Spinning chain
Spinning tong
SPJ
SPL
Solenoid Operated Valve
Oxides of Sulphur
Single Point Accountability OR Special Protection Area
Distance between wells producing from the same zone.
A very large, manned SBM incorporating oil storage.
Part of an echosounder for gauging the thickness of soft seabed deposits.
Surface Process Blowdown
Single Point Buoy Mooring; [see SBM for definition].
Semi-permanent circular
Subsea Power and Control Module
Subsea Power and Control Pod
Society of Petroleum Engineers
Fishing tool for retrieving pipe or cable lost in the borehole.
Areas considered to be important for certain habitats and non-bird species of interest in a European context. One of the main
mechanisms by which the EC Habitats and Species Directive 1992 and 2007 amendments will be implemented.
Coupling with a smaller O.D. than the standard, sometimes needed in wells where space is limited (e.g. multiple string
completions).
Sites designated by the UK Government to protect certain rare or vulnerable species and regularly occurring migratory species
of birds.
See Gravity, specific.
The number of calories required to raise I g of a substance I Deg. Centigrade.
Either of the following applies: a] Requirements prescribed by the purchaser and agreed with the supplier in a contract for
products or services b] Requirements prescribed by the supplier which are perceived as satisfying a market need
Specifications
A solid or inflatable rubber or plastic ball used to remove liquids accumulated in gas pipelines.
A type of scraper trap used to insert spheres into a pipeline.
The hinged, latching device attached to the elevators (the hoisting arms that lift pipe and casing in the derrick). Elevatorsspider is a unit, and is attached to the travelling block hook for hoisting pipe, casing and tubing out of the hole and lowering in.
The spider is manually locked around a Length of tubing just below the tool joint. Some advanced types of elevator spiders are
air operated. See also Tubing spider .
A power-operated set of slips for gripping tubulars
The lowest deck on an offshore drilling rig below the rig floor.
To screw one stand of drill pipe or tubing rapidly into another with a spinning chain. After making up the joint in this manner,
the heavy pipe tongs are applied to make the joint tight.
A powered spanner or wrench for gripping and rotating drill pipe when screwing or unscrewing the joints. Previously, the
spinning chain was wrapped around each joint turn and pulled on the cathead [winch] to rotate it.
A light chain used by the drilling crew on the derrick floor when running and pulling tubing or drill pipe. After a joint has been
broken or loosened by the pipe tongs, the spinning chain is given several turns around the pipe and when the chain is pulled,
the pipe is rotated counter-clock-wise and quickly unscrewed.
An air operated power tong used to spin up pipe.
Steel Pile Jacket
Subsea Pig Launcher
Page 140 of 310
Splash zone
Splash zone
SPM
SPOC
Spontaneous potential
Spool/spool piece
Spot charter
Spread
Spread
SPS
SPS 1
SPS 2
SPU
SPU
Spud
Spud can
Spudding in
Squeeze
Squeeze a well
Squeeze job
Squeeze kill
Squib shot
The area where waves of ocean or lake strike the support: members of offshore platforms and production installations; the
water line. The splash zone is particularly subject to corrosion because of the action of both (salt) water and air.
The part of an offshore structure that is regularly exposed alternately to atmosphere and water or spray; it is consequently
highly prone to corrosion.
Single Point Mooring
Single Point of Contact
The difference of potential (DC voltage) between a moveable electrode in the borehole and a distant reference electrode usually at surface. This measurement is recorded as a log trace and is used for correlation between wells and for calculating
formation water resistivities (salinities).
A short section of pipe with flanges or threaded connections at each end. It may be of any length required to make up pipeline
or casing to the exact required length.
A one-voyage tanker charter or one-well rig charter, as opposed to a time charter.
A contractor's men and equipment assembled to do a major construction job, a spread may be literal, as the men and
equipment are strung out along the right-of-way for several miles. On well work-over, or other jobs, the spread is a
concentration of the equipment for the work.
Any complete set of equipment and ancillary vessels or vehicles for a designated task e.g. diving spread.
Subsea Production System
Surface Process Shutdown. An SPS1 is a downstream process upset only.
Surface Process Shutdown. An SPS2 is an upstream process upset.
Strategic Performance Unit OR Syntactic Polyurethane
Subsea Pigging Unit OR Syntactic Polyurethane
The initial penetration of the ground or seafloor / the start of the drilling operation. To begin drilling; to start [or re-start] the
hole. May also be used to describe the process of setting the legs of a jack-up into the seabed.
A cylindrical device, usually with a pointed end, that is attached to the bottom of each leg of a jackup drilling unit. The pointed
end of the spud can penetrates the seabed and helps to stabilise the unit whilst it is drilling.
The starting of the drilling operations of a new hole.
To insert cement under pressure into the poorly sealed annulus of a well, past the existing material. Also method used to inject
chemicals down production tubing from well head.
A technique to seal off with cement a section of the well bore where a leak or incursion of water or gas occurs; forcing cement
to the bottom of the casing and up the annular space between the casing and the wall of the borehole to seal off a formation or
plug a leak in the casing; a squeeze job,
Usually a secondary cementing job where cement is pumped into the formation through the bottom of the casing or through
perforations to obtain a shut-off of undesirable fluids.
A method of well killing: killing fluid is pumped down the tubing, drill pipe or-casing to push its contents back into the formation
without fracturing the formation. Also called Bull-heading.
An explosion set off in a producing well to stimulate production. See stimulation, also soup.
Page 141 of 310
Stabilised flow
Stabilised well
These motors are probably the simplest and most rugged of all electric motors. They consist of two basic electrical
assemblies: the wound stator and the rotor assembly. The rotor consists of laminated, cylindrical iron cores with slots for
receiving the conductors. On early motors, the conductors were copper bars with ends welded to copper rings known as end
rings. Viewed from the end, the rotor assembly resembles a squirrel cage, hence the name squirrel- cage motor is used to
refer to induction motors. In modern induction motors, the most common type of rotor has cast-aluminum conductors and
short-circuiting end rings. The rotor turns when the moving magnetic field induces a current in the shorted conductors. The
speed at which the magnetic field rotates is the synchronous speed of the motor and is determined by the number of poles in
the stator and the frequency of the power supply.
A special threadless tool joint for large-diameter pipe, especially conductor pipe, sometimes used on offshore drilling rigs.
When the box is brought down over the pin and weight is applied, a locking device is actuated to seat the joints. Because no
rotation is required to make up these joints, their use can save time when the conductor pipe is being run. Squnch Joint is a
registered trademark of Vetco Offshore Inc.
Sulphate Reducing Bacteria
Subsea [when referring to reservoir depth below the seabed] OR subsurface OR Stainless steel OR Steam Supply
Sub-Sea/Sea Level
Semi Submersible Accommodation Vessel [Flotel]
Single Side Band
Sulphide Stress Cracking
Speed Switch High [alarms at high speed]
Speed Switch High High [shuts down the turbine or pump due to overspeed]
Subsea Isolation Valve
Subsea [Safety] Isolation Valve
Systems Supervisor [Production]
Site of Special Scientific Interest
Subsurface Safety Valve
Subsea Test Tree
Shutdown Safety Valve OR Surface Safety Valve
Spring Tidal Amplitude
To make a connection by inserting one device into another.
Guiding and lowering a pin-end joint into the box-end of the preceding joint before make-up.
A platform erected in the derrick at an elevation of about 20 to 40 feet above the derrick floor. The derrick man or other
crewmembers work on this board while casing is being run in a well. Derived from the term to stab meaning to guide a joint
while it is being screwed into another joint or section.
Crude oil from which gases that are volatile at normal surface conditions have been removed in order to meet commercial sale
specifications. Also known as stock tank oil.
A sustained rate of flow from a well without pressure drop; this is determined by well testing.
A well in which the formation pressure is balanced by the weight of the mud column.
Stakeholder
Any individual or groups of people who are affected by, or have an interest in, the activities and/or outcome of the project.
Stall Torque
Stand
The amount of torque developed with voltage applied and shaft locked, or not rotating. Also known as locked-rotor torque.
Connected joints of drill pipe or tubing racked in the derrick when a round trip is being made. Two joint stands are called
Standard conditions of pressure and temperature, plus agreed corrections, to which all gas volumes are corrected for
purposes of comparison and payment.
Squirrel Cage Motor
Squnch Joint
SRB
SS
SS/SL
SSAV
SSB
SSC
SSH
SSHH
SSIV
SSIV
SSP
SSSI
SSSV
SSTT
SSV
STA
Stab
Stabbing
Stabbing board
Stabilised crude oil
Standard conditions
Page 142 of 310
Standby Man
Standing valve
Standpipe
Start up
Static electricity
Station bills
Stationary barrel pump
Stator
Statutory Instruments, Notices and
STB
Stb
stb/d
STD
Steam drive
Steam injection/flooding
Steam pump
Steam soak
Steel-jacket platform rig
STEL
Stem
Step angle
Step out well
Step-out well
STH
STHP
Sticking
Stiffness
A person who attends the work site and observes the task being carried out, with the sole responsibility to obtain immediate
help in the event of an emergency and provide a communication link with the control room.
The bottom valve, installed in the stationary part of a subsurface pump; the--inlet valve of the pump.
The pipe that conveys the drilling mud from the mud pump to the swivel. The standpipe extends part way up the derrick and
The commencement of production from a commissioned and tested installation and bringing it to working status.
The electricity generated by the relative movement of unlike materials such as oil/pipeline, oil/water, plastic granules/ vessel;
or by the operation of equipment such as-driving belts.
Posters specific to a particular installation which describe what to do in emergencies.
See Pump, stationary barrel.
The non-moving part of the motor. Specifically, it is the iron core with the wire winding in it that is pressed into the frame shell.
The winding pattern determines the voltage constant of the motor.
MHSW Regulations 1999 (SI 1992 No.2051).
Stock Tank Barrels
Stock tank barrels; volume of oil measured in barrels at normal temperature [68° F] and atmospheric pressure.
Stock tank barrel per day
Sexually-transmitted diseases
A tertiary recovery method. The reservoir is heated by the injection of steam in one or more wells with the result that the
viscosity of the oil is reduced and its flow is correspondingly eased.
Techniques used to lower the viscosity of residual oil in the reservoir and to assist it to flow to a well. [See also enhanced oil
recovery.]
A reciprocating pump that receives its power from steam. Steam is piped into the pump's steam chest and from there it is
admitted to the power cylinder where it acts upon the pump's power pistons, driving them to and fro as the steam valves open
and close. The fluid end of the pump is driven by the steam pistons. On production stations gas is sometimes used instead of
steam.
A tertiary recovery method. A predetermined volume of steam is injected into a well for a certain period to soak the formation
around it. After this period the well is put back on production.
A rigid offshore drilling platform used to drill development wells. The foundation of the platform is the jacket, a tall vertical
section made of tubular steel members. The jacket, which is usually supported by piles driven into the seabed, extends
upward so that the top rises above the waterline. Additional sections that provide space for crew quarters, the drilling rig, and
all equipment needed to drill are placed on top of the jacket. See platform rig.
Short Term Exposure Level
Stems, sometimes called Sinker bars, are essentially round rods providing the mass required in jarring operations and to
facilitate lowering of wireline tools in the hole. The effectiveness of the impact delivered by the jars may be increased or
decreased by increasing or decreasing the total weight of stems used. Also called Weight bar .
The angular distance the shaft rotates upon receipt of a single step command.
A well drilled adjacent to a proven well but located in an unproven area; a well located a step out from proven territory in an
effort to determine the boundaries of a producing formation. See also Appraisal well .
An appraisal well specifically aimed at locating the lateral limits of a reservoir, which may later be used for production.
Side-Tracked Hole
Static Tube Head Pressure
Jamming of the drill string in the well borehole usually caused by a high DP and a build-up of mud solids on the rock face.
The ability to resist movement induced by an applied torque. Stiffness is often specified as a torque displacement curve,
indicating the amount a motor shaft will rotate upon application of a known external force when stopped.
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Stimulation
Stimulation
The technique of getting more production from a down hole formation. Stimulation may involve acidising and hydraulic
fracturing.
Methods such as acidizing [chemical] or fracturing [pressure] or the use of explosives designed to break up “tight”, lowpermeability reservoir rock in the vicinity of a well so that oil can flow freely into the bore.
Stinger
A tubular steel support frame attached to the stern of a pipelay vessel to control the bending of the pipe as it enters the water.
STL
STMEL
Submerged Turret Loading
Short Term Exposure Limit [15 minutes]
A device for making threads on the end of a joint of pipe or length of rod; an adjusta5le frame holding a set of steel dies or
cutting teeth that is clamped over the end of the pipe to be threaded. When properly aligned the dies are rotated clockwise in
the frame, cutting away excess metal, leaving a course of threads.
Sometimes called reaction stoichiometry to distinguish it from composition stoichiometry, is the calculation of quantitative
(measurable) relationships of the reactants and products in a balanced chemical reaction. The Stoichiometric Concentration is
the ideal fuel / air mixture for combustion. This is approximately 2 volumes of oxygen for every volume of methane. Since
roughly only 20% of air is oxygen a balanced mixture of methane and air would be in a ratio of 10:1.
Stock Tank Oil Initially In Place [stabilized crude oil].
Safety Training Observation Programme
A type of plug valve usually installed on small-diameter piping; pet cock.
To hot-stab and insert a link or diverter loop into pipework.
The tank space available for storing crude oil in production installations (e.g. terminal).
Incorrect name for a safety valve installed in the well's tubing below the surface to shut the well in when the flow of oil or gas
reaches a predetermined Excess rate. Primarily used on offshore, bay, or townsite locations, the tubing valve acts as an
automatic shut-off in the event there is damage to the Christmas tree resulting in uncontrolled, excess, flow. Officially termed
Subsurface Controlled Subsurface Safety Valve (SSCSSV).
A surface pipe which is driven into the ground before spudding in a well. It serves to provide a circulation system for the drilling
fluid and to prevent caving in and wash-out of the surface layer.
Standard Temperature and Pressure
In tank calibration the measurement of the external diameter of a cylindrical tank by stretching a steel tape around each
course of the tank's plates and recording the measurement. Measuring stands of pipe in the derrick.
The long term plans for the business direction.
A type of reservoir capable of holding oil or gas, formed by a change in the characteristics of the formation - loss of porosity
The cracking which results from a combination of stress and corrosion.
A process of reducing residual stresses in a metal object by heating to a suitable temperature and holding for a proper time at
that temperature. This treatment may be applied to relieve stresses induced by casting, quenching, normalising, cold-working,
or welding.
The angle of inclination from the horizontal of an exposed strata of rock. A good well discovery of oil or gas in commercial
quantities: a hit.
Name originally given to the suspended cable and tools of the cable tool drilling method, but now applied equally to strings of
drill pipe, casing, tubing, etc. in rotary drilling. Bit, drill collars and drill pipe are drill string items.
The entire length of casing, tubing, sucker rods, or drill pipe run into a hole.
Stock and dies
Stoichiometric
STOIIP
STOP
Stopcock
Stopple
Storage
Storm choke
Stove pipe
STP
Strapping
Strategies
Stratigraphic trap
Stress corrosion cracking
Stress relieving
Strike
String
String
Page 144 of 310
Strip chart
Stripper well
Stripping
Stripping
Stripping gas
Stripping job
Stripping tower
Structural trap
STT
STT
STTD
Stuck
Stuffing box
Sub
Subject Matter Expert
Sublittoral
Submersible drilling barge
Submersible pumping
Subsea blowout preventer
Subsea completion
Subsea template
Substitution
Substructure
In lieu of the circular chart for recording data, strip charts are sometimes used. Strip charts, as long as 35 to 40 feet, need not
be changed more than once a month if the operator desires. Also, the speed at which the long chart moves through the meter
is adjustable So the recording of fluctuations may be spread out, permitting more accurate readings.
An oil well producing less than 10 barrels a day. Most stripper wells are pumped only a few hours a day. In 1980 there were
approx. 400,000 stripper wells in the U.S. producing some 20 percent of the country's oil with an average of approx. 2.9
bbls/day per well.
To remove small particles from a fluid stream. To obtain a high purity of glycol used in, gas dehydration processes, stripping
gas is sometimes used to remove water particles from the glycol.
The removal or replacement of drill pipe or tubing strings from a well under pressure using a stripping BOP.
Gas, normally process gas used to assist in the purification of a liquid by reducing the partial pressure of gaseous
contaminants to encourage vaporisation.
Pulling rods and tubing simultaneously when the sucker-rod pump is stuck in the tubing.
Or stripping column. A vessel in which stripping gas is brought into intimate contact with the liquid to be stripped.
A type of reservoir containing oil and/or gas formed by movements of the earth's crust which seal off the oil and gas
accumulation in the reservoir forming a trap. Anticlines, salt domes and faulting of different kinds form structural traps. See
also Stratigraphic trap.
Sanction to Test. [A situation that requires special handling of WCC and their isolations and may cause associated permits to
be temporarily suspended whilst Testing is carried out].
Surface Test Tree
Sidetracked Total Depth
Refers to the drill pipe, tubing or casing inadvertently becoming fastened in the hole. May occur while drilling is in progress,
A packing gland; a chamber or box to hold packing material compressed around a moving pump rod, valve stem or wireline by
A short length of tubing containing a special tool to be used down hole. A section of steel pipe used to connect parts of the drill
string which because of difference in thread design, size of other reason, cannot be screwed together. An adapter.
An acknowledged expert in a particular field.
Below the level of low tide.
A barge-like vessel capable of drilling in deeper water than the smaller and simpler barge platform. The submersible drillingbarge has a drilling deck Separate from the barge element proper. When floated into position offshore in water as deep as 299
feet, the barge hull is flooded and as it slowly sinks, the drilling platform is simultaneously raised on jacking-legs at each
corner of the barge, keeping the drill platform well above the water surface.
A method of pumping liquid from wells using a centrifugal pump the shaft of which is connected to an electric motor, and of
such a size that it may be lowered into the well on the tubing together with an insulated cable from the surface.
A blowout preventer placed on the seabed for use by a floating offshore drilling rig.
The method of completing production wells in which the wellheads are located on the sea floor as opposed to on the deck of a
production platform. The oil or gas from a sub-sea completion is piped from the wellheads to a fixed platform, a loading buoy,
or to shore for processing.
A device placed on the seabed to facilitate the drilling of wells. When a template is used, the wells are drilled through the
template and completed by the mounting of subsea xmas trees.
Replace; serving or causing to serve a function in place of another person or thing.
The sturdy platform upon which the derrick is erected. Substructures are from 10 to 30 feet high and provide space beneath
the derrick floor for the blowout preventer valves.
Page 145 of 310
Subsurface safety valve
Suckerrod
Suckerrod hanger
Suckerrod, hollow
SUDU
Sulphide stress cracking
Sulphur Hexafluoride
Superimposed back pressure
Supersaturation
Supplier
Supplier Shortlist Meeting
SUPT
Surface control unit
Surface pipe
Surface safety valve
Surface string
An automatic shut-off device, which can be installed in tubing strings of flowing oil and gas wells, and gaslift, wells. It will
automatically close off the tubing either due to unacceptable increases in the flow rate or on a signal from the surface.
Steel rod which together with other rods will form a string that connects the pump inside a well's tubing down hole to the
pumping jack on the surface.
See Rod hanger.
In certain applications, slim-hole pumping, hollow sucker rods are used, serving the dual purpose of rod and production tubing
in the same string. Traveling-barrel pumps are most often used with hollow-rod pumping. The rods are attached to the cage or
pull-tube (traveling barrel) the pump is installed in the seating nipple, or a packer-type pump anchor is used.
Subsea Umbilical Distribution Unit
Cracking of metallic materials due to exposure to fluids containing hydrogen.
Is an inorganic compound with the formula SF6. It is a colorless, odorless, non-toxic and non-flammable gas [under standard
conditions]. SF6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a
hypervalent molecule.
Typical for a nonpolar gas, it is poorly soluble in water but soluble in nonpolar organic solvents. It is generally transported as a
liquified compressed gas. It has a density of 6.13 g/L at sea level conditions.
Of the 8000 tonnes produced per year, most of the SF6 goes into three applications: firstly as a gaseous dielectric medium or
other use in the electrical industry, which accounts for 6000 tonnes; secondly as an inert gas for the casting of magnesium;
and thirdly as an inert filling for windows.
SF6 is used in the electrical industry as a gaseous dielectric medium for high-voltage [1 kV and above] circuit breakers,
switchgear, and other electrical equipment, often replacing oil filled circuit breakers [OCBs] that can contain harmful PCBs.
SF6 gas under pressure is used as an insulator in gas insulated switchgear [GIS] because it has a much higher dielectric
strength than air or dry nitrogen.
See under Safety relief valve.
If a solution contains a higher concentration of a solute in a solvent than would normally correspond to its solubility at a given
temperature, this constitutes super saturation. This is an unstable condition, as the excess solute separates when the solution
is seeded by introducing a crystal of the solute. The term supersaturation is frequently used erroneously for hot salt muds.
Any individual or organisation who supplies materials, products or services to our company.
The meeting held between Client and the Project to agree those bids to be evaluated fully
Superintendent
A surface installation used to control the action of a surface controlled subsurface safety valve. Under normal operating
conditions the unit will exert hydraulic pressure on the valve to keep it open. When pre-set sensors detect an abnormal
condition the hydraulic pressure will be relieved and the valve will close.
The first string of casing to be set in a well. The length will vary in different areas from a few hundred feet to three or four
thousand feet. Some states require a minimum length to protect fresh-water sands. On some wells, it is necessary to set a
temporary conductor pipe, which should not be confused with surface pipe as described here. See also Conductor .
An automatic shut-off device which can be installed on the Christmas tree or flowline of a flowing oil well, a gas well or a gaslift
well. It will automatically close off or divert the flow in case of abnormal conditions.
See Conductor.
Page 146 of 310
Surface tension
Surfactant
Surfactant
Surge tank
SUS
Suspend
Suspended Permit
Suspension
Suspension
Suspensoid
SUT
SUTA
SUTU
SV
SVI
SVol
SVQ
SW
Swab
Swab valve
Swab Valve
Swabbing
Swabbing
Swage
Swahe nipple
SWAT
SWD
Sweet
Sweet corrosion
Sweet crude
Generally, the force acting within the interface between a liquid and its own vapour which tends to maintain the area of the
surface at a minimum and is expressed in dynes per centimetre. Since the surface tension of a liquid is approximately equal to
the interfacial tension between the liquid and air, it is common practice to refer to values measured against air as surface
tension, and to use the term interfacial tension for measurements at an interface between two liquids, or a liquid and a solid.
A material which tends to concentrate at an interface. Used in drilling fluids to control the degree of emulsification,
aggregation, dispersion, interfacial. tension, foaming, defoaming wetting, etc.
Also known as tensides, are wetting agents that lower the surface tension of a liquid, allowing easier spreading, and lower the
A vessel on a flow line whose function is to receive and neutralise sudden, transient rises or surges in the stream of liquid.
Surge tanks often are used on systems where fluid flow by heads owing to entrained gas. A large size separator working at
near atmospheric pressure used in production stations instead of a tank.
Saybolt Universal Seconds [unit of oil viscosity]
To leave a productive well safely closed in for a prolonged period. Often done after the drilling phase but before the completion
and X-mas tree are installed, until more wells are available for completion.
A Work Permit for work which has been underway but is currently stopped.
The state of a solid or liquid when its particles are mixed with and buoyed in another - liquid but are not dissolved by it. A
suspension of a liquid in a liquid is called an emulsion.
Temporary removal, withholding or postponement.
A mixture consisting of finely divided colloidal particles floating in a liquid. The particles are so small that they dc not settle but
are kept in motion by the moving molecules of the liquid (Brownian movement).
Society for Underwater Technology
Subsea Umbilical Termination Assembly
Subsea Umbilical Termination Unit
Swab Valve OR Support Vessel
Single Valve Isolation
Standard Volume
Scottish Vocational Qualification.
Salt Water OR Suspended Well OR Saturated Water
A cup type device that closely fits the inside of tubing and is pulled on wireline up through the tubing to lift fluid from it.
The top valve in the Christmas tree, through which wireline work is carried out.
Subsea tree mounted valve used during workover
Operation of a lifting device to bring well fluids to the surface when the well does not flow naturally. This is a temporary
operation to determine whether or not the well can be made to flow. In the event the well does not flow after being swabbed, it
is necessary then to install artificial lifting equipment to bring liquid to the surface.
The lowering of the hydrostatic pressure in the hole due to the upward movement of the drill pipe and/or tools. Also the use of
wireline equipment to clean a well by scooping out liquids.
A heavy, steel tool, tapered at one end, used to force open casing or tubing that has collapsed down hole in a well.
An adapter; a short pipe fitting, a nipple, that is a different size on each end, e.g. 2-inch to 3-inch 2-inch to 4-inch.
Subsea Well Abandonment Tool
Salt Water Disposal
Having a good odour; a product free of sulphur compounds.
Corrosion due to the presence of C02 in gas streams in which no H2S is present.
Crude oil containing no sulphur compounds and having a good odour
Page 147 of 310
Sweet gas
Hydrocarbon gas free from sulphur compounds.
Sweetening
A process used to remove hydrogen sulphide [H2S] and carbon dioxide [CO2] from a gas stream. These components are
removed because they can form acidic solutions when they contact water, which will cause corrosion problems in gas
pipelines.
In a sweetening process, different types of ethanolamine can be used, including monoethanolamine [MEA], diethanolamine
[DEA], diglycolamine [DGA] and methyldiethanolamine [MDEA]. Hydrogen sulfide and carbon dioxide are absorbed by the
ethanolamine and sweet gas leaves at the top of the absorber.
The ethanolamine is heated and acid gas [hydrogen sulfide and carbon dioxide gases] and water vapor are obtained. The
water is removed while the acid gas can be flared or further treated in a sulfur recovery unit to separate out elemental sulfur.
Finally, the lean ethanolamine is returned to the absorber.
SWI
SWIFT
SWIS
Switching Log Book
Swivel
Swivel
SWL
SWL
SWOT
Synchronism
Synchronous Motor 1
Salt Water Injection
Structured 'What If' Technique [reliability study method]
Site Welding Instruction Sheet
The Switching Log Book is a document for recording all switching operations for main electrical feeders operating at 415 Volt
ac and above. Each substation shall have its own Switching Log Book (or other suitable recording system authorised by the
Asset). In the case of generating plant, this log book can be kept in the generation station control room rather than the
substation housing the associated switchgear. The Switching Log Book (or other suitable recording system authorised by the
Asset) shall record the date, time and operation carried out, whether a work permit or Isolation Confirmation Certificate has
been issued or cancelled and the signature of the person carrying out the switching.
A tool that is the connecting link between the hoisting gear in a derrick-and the rotating Kelly in a drilling string. The weight of
the string rests on a heavy roller bearing in the body of the swivel. Drilling fluid is forced into the hollow Kelly via the rotary
hose, which connects the slush pump with this body.
A rotary tool that is hung from the rotary hook and travelling block to suspend and permit free rotation of the drill stem. It also
Still-Water Level
Safe Working Load
Strengths, Weaknesses, Opportunities and Threats Analysis
A motor rotating at a speed corresponding correctly to the applied step pulse frequency is said to be in synchronism. Load
torques in excess of the motor's capacity [rated torque] will cause a loss of synchronism. This condition is not damaging to a
step motor.
The construction of the synchronous motors is essentially the same as the construction of the salient- pole alternator. In fact,
such an alternator may be run as an ac motor.
Synchronous motors have the characteristic of constant speed between no load and full load.
They are capable of correcting the low power factor of an inductive load when they are operated under certain conditions.
They are often used to drive dc generators. Synchronous motors are designed in sizes up to thousands of horsepower.
They may be designed as either single-phase or multiphase machines. The discussion that follows is based on a three-phase
design.
Page 148 of 310
Synchronous Motor 2 continued
Syncline
Syncline
Synergy
Synthetic oil
System
System Custodian
System-Module Booster™
System-Module Separation™
System-Module™
TA
TA
Tack weld
Tag Number
Tailing out rods
Tally
TAN
TAN
Tank
Tank bottoms
To understand how the synchronous motor works, assume that the application of three-phase ac power to the stator causes a
rotating magnetic field to be set up around the rotor.
The rotor is energized with dc [it acts like a bar magnet]. The strong rotating magnetic field attracts the strong rotor field
activated by the dc. This results in a strong turning force on the rotor shaft.
The rotor is therefore able to turn a load as it rotates in step with the rotating magnetic field. It works this way once it’s started.
However, one of the disadvantages of a synchronous motor is that it cannot be started from a standstill by applying threephase ac power to the stator.
When ac is applied to the stator, a high-speed rotating magnetic field appears immediately. This rotating field rushes past the
rotor poles so quickly that the rotor does not have a chance to get started. In effect, the rotor is repelled first in one direction
and then the other.
A synchronous motor in its purest form has no starting torque. It has torque only when it is running at synchronous speed. A
squirrel-cage type of winding is added to the rotor of a synchronous motor to cause it to start. The squirrel cage the outer part
of the rotor.
A trough-like geological structure in which the strata dip toward the centre or axis of the syncline. Opposite: Anticline.
A downward, trough-shaped configuration of folded, stratified rocks. Compare with anticline.
Working together - the term used to describe a situation where different entities cooperate advantageously for a final outcome.
Simply defined, it means that the whole is greater than the individual parts. If used in a business application, it basically means
‘teamwork’. A dynamic state in which combined action is favored over the sum of individual component actions. Behavior of
whole systems unpredicted by the behavior of their parts taken separately. More accurately known as emergent behavior. The
cooperative action of two or more stimuli or drugs.
A term applied to oil recovered from coal, oil shales and tar sand.
Interdependent processes and procedures which describe how Petrofac is organised to manage its core capabilities.
An individual nominated as the owner of all data held within that system.
Alpha Thames’ multiphase pumping module with integral power and control equipment. This forms part of the AlphaCPU™.
A processing module, containing either two-phase or three-phase separation equipment with or without liquid booster pumps
and sand removal. This forms part of the AlphaCPU™.
An all-electric, retrievable module that forms an integrated system and that can accommodate a wide range of equipment and
sub-systems.
Technical Authority. [Is responsible for technical advice to the OIM in the approval of any deviation from the isolation
standards including the use of any non standard devices. The TA is also responsible for carrying out periodic checks on Long
Term Isolations].
Termination Assemblies [DIN rail mounted field I/O signal]
Spot-welds temporarily joining two joints of pipe to hold them in position for complete welding.
A number given to all items of equipment to uniquely identify them.
Unscrewing and stacking rods horizontally outside the derrick. As a rod is unscrewed, a worker takes the free end and, as the
elevators holding the other end is slacked off, he walks the rod to a rack where it is laid down.
A record of measured length of drill pipe, tubing or casing.
Tangent to Tangent
[drawing item dimension]
Total Acid Number. The amount of potassium hydroxide in milligrams that is needed to neutralize the acids in one gram of oil.
Vessel for holding, measuring, or transporting liquids.
Oil-water emulsion mixed with free water and other foreign matter that collect in the bottoms of stock tanks and large crude
storage tanks. Periodically, tank bottoms are cleaned out by physically removing the material or by the use of chemicals which
separate oil from water permitting both to be pumped out,
Page 149 of 310
Tank bottoms
Tank dike
Tank dipping
Tank dipping
Tank farm
Tank mixer
Tank pit
Tank table
Tanker
Tap
Tapping a line
Tar
Tar sands
TARDIS
Tariff
TAS
Task
Task Description
Task Risk Assessment
TB
TBA
TBC
TBL
TBN
TBV
TC
TCC
TCE
TCF
TCMS
TCP / IP
TCR
TCRT
TCS
Fluid in a tank below the pump suction/outlet, not normally evacuated.
A mound of earth surrounding an oil tank to contain the oil in the event of a rupture in the tank, a fire, or the tank running over.
Also called Firewall or Bund wall.
See Dip (to).
The initial action in determining the contents of storage tanks. A weighted line is lowered through a “well” in the roof of the
tank, and the level of the contents and/or underlying water marked. The volume represented by the difference in level is then
calculated by reference to tank tables.
A group of large riveted or welded tanks for storage of crude oil or product. Large tank farms cover several square miles.
Motor-driven propeller installed on the shell of a storage tank to stir up and mix tank sediments with the crude. The propellershaft protrudes through the shell , with the motor mounted on the outside. Turbulence created by the prop thrust causes the
BS&W to remain suspended in the oil as it is pumped out.
An area surrounded by a fire or bund wall and containing one or more tanks.
A printed table showing the capacity of a tank per unit height from bottom-to the top gauge point. Tank tables are made from
dimensions furnished by tank strapping, often carried out by an independent third party. See also Strapping.
Any mobile storage unit for the bulk transport of crude oil, gas or products; usually refers to marine transport.
A notched tool used to cut inside threads. A fishing tool having the shape of a tapered prong with thread dies on the outside
Cutting into a pipeline to install a branch connection.
See Asphalt
Sands impregnated with oil in the form of asphalt or bitumen which can be mined for its extraction.
Tracking Action Register Document Information System.
Any volume-based or tonnage-based rental charge for the use of an installation or equipment, e.g. pipeline tariff, processing
Technical Authoring Standard[s].
An activity in support of a piece of work.
An accurate description of the task to be performed.
A means of identifying work related hazards, assessing the possibility of those hazards being realised and defining the
mitigating actions and controls required to reduce the risk.
Total Blowdown
To Be Advised
To Be Confirmed
Federation of Norwegian Manufacturing Industries
Total Base Number is a measure of a lubricant's reserve alkalinity. It is measured in milligrams of potassium hydroxide per
Tubing back pressure valve. A non-return valve which can be installed in the top of a tubing string of a well as a safety against
blowout when the Christmas tree is removed.
Tree Cap
Thermofor Catalytic Cracking
Tons of Coal Equivalent [see tons equivalent, below]
Trillion Cubic Feet, 1012 ft3, 1012 cu ft
Tripod Catenary Mooring System
Transmission Control Protocol over Internet Protocol
Continuous Rated Torque [lb-in]. The maximum allowable continuous torque a motor can handle without exceeding the motor
temperature limits
Tree Cap Running Tool
Throughput Control System
Page 150 of 310
TDR
TDS
TDU
Team [teamwork]
The amount of torque at zero speed, which a motor can continuously deliver without exceeding its thermal rating. Determined
by applying DC current through two windings with rotor locked, while monitoring temperature. Specified with motor windings at
maximum rated temperature, with motor in 25 degrees C ambient, mounted to a heat sink. Refer to individual specs for heat
sink size.
Temperature Control Valve
Total or Terminal Depth [the achieved [drilled] depth in a well at any one time OR target depth [for a well]. ]
Trade Discipline File. Potential employee CV applications that are filed by discipline and year of application - Roustabouts
‘97/Roustabouts ‘98/Roustabouts ’99.
Time Domain Reflectometry - testing to evaluate impedance values and variations along a transmission line such as cables
Top Drive System
Tool Deployment Unit
A group of people working towards a common aim or objective.
Technical Authority
The individual with the detailed knowledge of the document. Not always the person who wrote the document but signed it off.
TCS Continuous stall torque [lb-in]
TCV
TD
TDF
Technical Knowledge or Experience
Tectonics
TEG
TEL
Telemetry
Telescoping joint
Temp
Temperature bomb
Temperature conversion
Temperature gradient
This may include:
Adequate knowledge of electricity.
Adequate experience of electrical work.
Adequate understanding of the system to be worked on and a practical experience of that class of system.
Understanding of the hazards which may arise during the work and the precautions which need to be taken.
Ability to recognise at all times whether it is safe for work to continue.
The process of formation and evolution of the earth’s solid surface crust. [See also Plate tectonics.]
Tri-ethylene Glycol
Tetra Ethyl Lead. [An organometallic compound with the formula [CH3CH2]4Pb. Once a common additive in gasoline [petrol],
TEL usage was largely discontinued because of the toxicity of lead. It is still used as an additive in the aviation fuel known as
avgas].
A method of communicating data from/to remote instrumentation systems to a central control system using radio satellite, fibre
optics or cable links. Also associated with the remote control of process equipment.
A tool consisting of two sliding tubes which, when installed in a string of tubing can absorb elongation or contraction of that
string.
Temperature
A capsule containing instruments for measuring well temperatures down a well.
Cº = 5/9 (Fº - 32º)
Fº = 9/5 Cº + 32º
See Gradient .
Temperature log
Recording temperature variations down hole by the use of an electrode containing a length of platinum wire that readily
assumes the temperature of the drilling mud, gas or water in the hole. One important use of the logging device is to determine
the location of cement in the annular space between casing and well bore after a cement job. The curing or hardening. cement
gives off heat which alters the temperature gradient in the well bore and which can be detected by the tool.
Tempering
A heat treatment of steel. It consists of reheating a quenched or normalised steel to a suitable temperature below the critical
temperature for an appropriate time and cooling back to room temperature. This process makes the steel tougher at a small
loss in strength.
Page 151 of 310
Template
Temporary Earth
TEMPSC
Tender
Tension leg platform
Tensioner system
Tension-leg platform
TENV - Totally Enclosed NonVentilated
TER
Terminal
Terminal
Tertiary
Tertiary recovery
Test coupons
Test header
Test separator
Test tank
Tethered platform
Tf
TFCC
TFL
TFL
TFLCC
This usually refers to a structural framework within which subsea wellheads are grouped. It may also refer to a prepared
foundation or “mattress” for soft or shifting seabed on which a jackup rig can be stably installed.
A Temporary Earth is one which is applied to electrical equipment to maintain otherwise non‑earthed equipment to be
effectively earthed for the duration of an activity. An approved Temporary Earth Notice should be attached to the temporary
earth.
Totally Enclosed Motor Propelled Survival Craft
The barge anchored alongside an offshore drilling platform. Usually contains living quarters, storage space, and the mud
system.
A semi-submersible drilling platform held in position by multiple cables anchored to the ocean floor. The constant tension of
the cables makes the platform immune to heave, pitch and roll caused by wave action, conditions that affect conventional
semi-submersibles.
A system of devices installed on a floating offshore drilling rig to maintain a constant tension on the riser pipe despite any
vertical motion made by the rig. The guidelines must also be tensioned, and a separate tensioner system is provided for them.
A compliant offshore drilling platform used to drill development wells. The platform, which resembles a semisubmersible
drilling rig, is attached to the seabed with tensioned steel hawsers or tubes. The buoyancy of the platform applies tension to
the hawsers or tubes. See platform drilling rig.
Acronym describing a type of motor enclosure, which has no outside air going into it. It is cooled only by convection to the
frame, which is usually finned.
Telecomms Equipment Room
A crude oil or gas liquid storage plant where all the production from one or more fields is collected and from where the crude
or gas is delivered to tanker, refinery or pipeline. A jetty or pier equipped to load and unload tankers.
Usually refers to a loading or unloading facility in a transportation system for oil or gas; also covers associated processing and
storage facilities.
Period or rock system divided into Palaeocene, Eocene, Oligocene, Miocene and Pliocene epochs or series OR the third set
of windings on a transformer or set of connections OR Third [lower] class/order
The process applied when the energy in the formation itself is not sufficient to drive the maximum recoverable amount of liquid
or gas to the borehole, and is supplemented by injection of products which are foreign to the formation, to either maintain or
increase the formation pressure and/or to change the formation and/or product properties (steam, oxygen, carbon dioxide,
etc.). See also Secondary recovery; Enhanced recovery .
Small samples of materials - metals, alloys, coatings, plastics and ceramics - which are subjected to heat, cold, pressure,
humidity and other conditions of stress to test durability and performance under simulated operating conditions.
A header on a flow station manifold, which collects the production from a well on test and transfers it to a test separator.
A separator in a flow station used to separate the gas from the liquid produced by a well on test.
A production tank in a flow station in which the rate of liquid production of a well is incasured.
A variant of the tension-leg platform.
Time to fatality
Time–Frequency Cross Correlation
Through Flow Line
Through Flow Line. [A system for inserting workover tools or instruments into a subsea well completion through the
production gathering line or flowline].
Through Flow Line Control Centre
Page 152 of 310
Tg
TGB
TH
THC
The Company
Therm
Thermal protection
Thermal Radiation
Thermal recovery
Thermal resistance [Rth] [°C/watt]
Thermal time constant [Tth]
[minutes]
Thermic Reaction
Thermie
Thermite
Thermocline
Glass Transition Temperature. This is the temperature at which an amorphous solid, such as glass or a polymer, becomes
brittle on cooling, or soft on heating.
More specifically, it defines a pseudo second order phase transition in which a supercooled melt yields, on cooling, a glassy
structure and properties similar to those of crystalline materials e.g. of an isotropic solid material.
Tg is usually applicable to wholly or partially amorphous solids such as common glasses and plastics [organic polymers].
It is important to note that the glass transition temperature is a thermodynamic parameter, and thus parametrically depends on
the melt cooling rate.
Thus the slower the melt cooling rate, the lower Tg. In addition, Tg depends on the measurement conditions, which are not
universally defined.
Temporary Guide Base
Tubing Hanger OR Tight Hole
Total Hydrocarbon Content
Petrofac Production Services [PPS], and where appropriate, any subsidiary company
One hundred thousand BTU.
A thermal sensing device mounted to the motor to protect it from overheating. This is accomplished by disconnecting the
motor phases from the drive in an over temperature condition.
Thermal (infra red) radiation is the transfer of energy by electromagnetic waves.
Enhanced oil recovery based on heating the oil in the reservoir by steam injection or sub-surface combustion [fire flood].
An indication of how effectively a unit rids itself of heat; a measure of temperature rise per watts lost. In Pacific Scientific
literature, it is the specified value from the motor windings to the ambient, under locked rotor conditions.
The time required for a motor to attain 63.2% of its final temperature for a fixed power input.
Example: The thermite reaction involves a mixture of iron oxide and aluminum that has been placed in a flower pot and
covered with potassium permanganate. Some glycerin is poured over the potassium permanganate and eventually begins to
react.
When the iron oxide-aluminum mixture is ignited, a very vigorous reaction occurs and a molten metal can be seen dropping
from the flower pot into a bucket of sand below.
The reaction is extremely exothermic, a great deal of heat is given off. When the product of the reaction is examined a large
piece of white hot iron has fallen into the sand at the bottom of the apparatus.
This illustrates that aluminum is an extremely strong reducing agent and also that this reaction is very highly exothermic.
A megacalorie (15ºC value) = 4.1855 MJ.
A pyrotechnic composition of aluminium powder and a metal oxide which produces an aluminothermic reaction known as a
thermite reaction. It is not an explosive, but can create short bursts of extremely high temperatures focused on a very small
target for a short period of time.
The aluminium is oxidized by the oxide of another metal, most commonly iron oxide [rust]. The products are aluminium oxide,
free elemental iron, and a large amount of heat. The reactants are commonly powdered and mixed with a binder to keep the
material solid and prevent separation.
The reaction is used for thermite welding, often used to join rail tracks. Other metal oxides can be used, such as chromium
oxide, to generate elementary metal. Copper thermite, using copper oxide, is used for creating electric joints in a process
called cadwelding. Some thermite-like mixtures are used as pyrotechnic initiators such as fireworks.
Pronounced temperature incline.
Page 153 of 310
Thermocouple
Thermowell
THFP
Thief
Thief hatch
A temperature measuring device. The thermocouple is based upon the principle-that a small electric current will flow through
dissimilar wires properly welded together at the ends, when on junction is at a higher temperature than the other. The welded
ends are known as the hot junction which is placed where the temperature is to be measured. The two free ends are carried
through leads to the electromotive force detector, known as the cold junction. When the hot junction is heated, the milli-volts
can be measured on a temperature scale.
A small diameter pipe nipple, closed at the bottom, which protrudes into a pipeline and in which a temperature sensitive
element can be mounted.
Top Hole Flowing Pressure
A metal or glass cylinder with a spring actuated closing device that is lowered into a tank to obtain a sample of oil, or to the
bottom of the tank to take a column of heavy sediment. The thief is lowered into the tank on a line that when jerked will trip the
spring-valve enabling the operator to obtain a sample at any desired level.
An opening in the top of a tank large enough to admit a thief or other oil-sampling equipment.
Thief zone
A very porous formation down hole into which drilling mud is lost. Thief zones, which also include crevices and caverns, must
be sealed off with a liner or plugged with special cements or fibrous clogging agents before drilling can resume.
Thief zone
A porous, fractured or vuggy formation in a well, into which drilling fluid escapes. It must be plugged or lined with casing.
Thieving a tank
Thimble
Third Party
Third party gas
Taking samples of oil from different levels in a tank of crude oil, and from the bottom to determine the presence of sediment
and water with the use of a thief.
Metal eye used on slings
Any individual or company not operating on behalf of Petrofac Production Services or it’s Insurance Brokers or it’s Insurance
company.
Term used to describe gassold direct from oil company to parties other than British Gas, the previous monopoly holders.
Thixotropy
The ability of fluid to develop gel strength with time. That property of a fluid, which causes it to build up a rigid or semi-rigid gel
structure if allowed to stand at rest, yet can be returned to a fluid state by mechanical agitation. This change is reversible.
Thixotropy 1
The quality of fluids, such as drilling mud and some clays, to set when left undisturbed but to become fluid again when force or
pressure is applied. This can be important when selecting drilling sites, e.g. for jack-up rigs, as well as in mud engineering.
Thixotropy 2
The property of some non-newtonian pseudoplastic fluids to show a time-dependent change in viscosity; the longer the fluid
undergoes shear, the lower its viscosity. A thixotropic fluid is a fluid which takes a finite amount of time to reach an equilibrium
viscosity when introduced to a step change in shear rate. However, this is not a universal definition; the term is sometimes
applied to pseudoplastic fluids without a viscosity/time component. It is important to note the distinction between thixotropic
fluid and shear-thinning fluid. The former displays a decrease in viscosity over time at a constant shear rate, while the latter
displays decreasing viscosity with increasing shear rate. Fluids which exhibit the opposite property, in which shaking for a time
causes solidification, are called rheopectic, sometimes called anti-thixotropic, and are much less common.
THP
THP
Thread compound
Thread protector
Tubing head pressure.The pressure at the top of the production tubing upstream of the wellhead bean.
Tubing Head Pressure
A special compound used on tubular joints to lubricate the threads and to seal the voids between mating thread surfaces. Also
called Dope.
A threaded cap or lightweight collar or nipple screwed onto or into the ends of tubular goods (pipe, casing and tubing) to
protect the threads from damage as the pipe is being handled.
Page 154 of 310
Thread run out
Threaded and coupled joint (T+C)
Thribble
Throttle
THRT
Thrusters
THT
Thumper
Ti
TI
TIC
Tie in
Tie-in
TIG
Tight formation
Time map
TIPP
Titration
TLP
TLQ
TLV
Tmax
TML
TMR
TMS
TNS
ToC
TOC
TOE
TOFS
That part of the threaded taper where the roots of threads disappear towards the pipe body (threads not fully engaged).
A tubular connection of two threaded male pipe ends joined by a threaded coupling.
A stand of drill pipe or cubing made up of three joints. See also Fourble, Double.
Regulation of fluid flow by a throttling valve or fixed orifice
Tubing Head Running tool
Fixed or steerable [directional or azimuth] propellers on a vessel which enable it to be manoeuvred with great accuracy.
Tubing Head Temperature
See Vibroseis
Time to Impairment
Temperature indicator
Temperature Indicating Controller
An operation in pipeline construction in which two sections of line are connected; a loop tied into the main line; a lateral line to
a trunk line.
The action of connecting one pipeline to another or to equipment [such as a KeyMAN™ or manifold]. Pipeline tie-in commonly
describes the connection itself. Also known as tie-back.
Tungsten Inert Gas [welding]
A reservoir formation that has poor porosity or permeability conditions and does not allow free flow of fluid from the formation
into the hole.
A contoured map of a subsurface geological formation based on the time taken to reflect seismic impulses rather than the
subsequently computed/interpreted depths on a depth map.
Training and Information PowerPoint Presentation [KCA Deutag]
A method, or the process of using a standard solution for the determination of the amount of some substance in another
solution. The known solution is usually added in a definite quantity to the unknown until a reaction is complete.
Tension Leg Platform
Temporary Living Quarters
Threshold Limit Value - now defunct and superceded by Occupational Exposure Limit [OEL]
Maximum Wave Period Corresponding to Hmax
Tetra Methyl Lead
Triple Mode Redundant (logic solvers)
Time Management Solutions
Telecomms and Navaids System
Table of Contents OR Top of Casing [annulus] OR Top of Cement
Total Organic Content
Tons of oil equivalent [see tons equivalent, below]
Toolbox ??
Page 155 of 310
Toluene
Tong
Tonnage, marine
Tons equivalent
Tool joint
tool pusher
Tool string
Tool trap
Toolbox Talk [TBT]
Toolpusher
TOPA
Topsides
Torque
Also known as methylbenzene or phenylmethane, is a clear, water-insoluble liquid with the typical smell of paint thinners,
redolent of the sweet smell of the related compound benzene.
It is an aromatic hydrocarbon that is widely used as an industrial feedstock and as a solvent.
Like other solvents, toluene is also used as an inhalant drug for its intoxicating properties.
A common solvent, able to dissolve: paints, paint thinners, silicone sealants, many chemical reactants, rubber, printing ink,
adhesives (glues), lacquers, leather tanners, and disinfectants.
It can also be used as a fullerene indicator, and is a raw material for toluene diisocyanate (used in the manufacture of
polyurethane foam) and TNT.
Industrial uses of toluene include dealkylation to benzene, and the disproportionation to a mixture of benzene and xylene in the
BTX process. When oxidized it yields benzaldehyde and benzoic acid, two important intermediates in chemistry.
It is also used as a carbon source for making Multi-Wall Carbon Nanotubes. Toluene can be used to break open red blood
cells in order to extract hemoglobin in biochemistry experiments.
Toluene can be used as an octane booster in gasoline fuels used in internal combustion engines.
Toluene at 86% by volume fueled all the turbo Formula 1 teams in the 1980s. Inhalation of toluene fumes can be intoxicating,
but in larger doses nausea-inducing.
Toluene may enter the human system not only through vapour inhalation from the liquid evaporation, but also following soil
See Pipe tong .
A marine measurement term. Gross tonnage is the total internal volume of the hull and all superstructures, such as deck
houses, etc. being expressed in tons of 100 cubic feet, or approximately 2.83 cubic meters. Dead-weight tonnage (d.w.t.) Is
the weight of the cargo, stores, bunkers and water that the ship can lift, expressed in long tons (2240 lb. or 1016 kg).
An expression of the thermal value of one fuel in terms of another, e.g. TCE, TOE.
Heavy steel couplings that are screwed or welded to the end of the drill pipe to join the individual lengths to make up a drill
string. Tool joints have coarse tapered threads, which permit fast and frequent coupling up and breaking of joints.
A supervisor of drilling operations in the field. A toolpusher may have one drilling well or several under his direct supervision.
Drillers are directed in their work by the toolpusher.
A term used in wireline operations which consists of rope socket, stems, jars, knuckle joints. To this is connected the -running
or pulling tool with the sub-surface controls.
A safety device sometimes installed at the lower and of a wireline lubricator to prevent a string of tools from dropping down the
well in case of inadvertently running the tool string into the top of the lubricator and breaking the wireline.
A comprehensive brief carried out by the Performing Authority where the Task Risk Assessment, work specification
precautions, and conditions associated with carrying out the work are communicated to the work party.
The location supervisor for the drilling contractor. The toolpusher is usually a senior, experienced individual who has worked
his way up through the ranks of the drilling crew positions. His job is largely administrative, including ensuring that the rig has
sufficient materials, spare parts and skilled personnel to continue efficient operations. The toolpusher also serves as a trusted
advisor to many personnel on the rigsite, including the operator's representative, the company man.
Terminal Operators Procedures Agreement
Upper part of a fixed installation which sits on top of the jacket and consists of the decks, accommodation and process
equipment.
A measure of the force or effort applied to a shaft causing it to rotate. On a rotary rig this applies especially to the rotation of
the drill stem in its action against the bore of the hole, Torque reduction can usually be accomplished by the addition of various
drilling-fluid additives.
Page 156 of 310
Total depth
Total Exposure
TOUK
Tour
An expression of the relationship between input current and output torque. For each ampere of current, a fixed amount of
torque is produced.
Variations in the torque produced by a motor resulting from the supply current deviating from the required sine wave. This
often occurs as a function of pulse width modulation used in VSDs.
A tool for applying a turning or twisting motion to nuts, bolts, pipe or anything to be turned and which is equipped with a gauge
to indicate the force or t-torque being applied. Torque wrenches are useful in tightening a series of bolts or nuts with equal
tension, as on a flange or engine head.
Defined as the motor's holding torque divided by the inertia of its rotor. The higher the ratio, the higher a motor's maximum
acceleration capability will be.
The greatest depth reached by a well bore.
Exposure for a 2 week cycle
Tullow Oil UK
A period of day or night work laid down for operating and maintenance personnel. Also called Shift.
Town gas
Gas piped to consumers from a gas plant. The gas can comprise both manufactured gas and natural gas used for enrichment.
TP
TPA
TPC
TPS
TQ
TQS
TR
TRA
TRA
Test Pressure
Transportation and Process Agreement.
Target Performance Criteria
Total Platform Shutdown
Technical Query
Total Quality System
Temporary Refuge
Total Risk Analysis
Task Risk Assessment.
A team of not less than 3 personnel. [They carry out a Task Risk Assessment led by a person trained to Lead Level 2 Risk
Assessments].
A person who has been trained in Task Risk Assessment Procedures and is able to take part in a Task Risk Assessment as a
Team Member or Team Leader.
The ability to determine the product history through markings and records.
A system of steam pipes or electric elements fitted to vessels or pipelines to keep them warm so that very heavy viscous
crude oil will flow freely.
The bringing of a person to a desired degree of proficiency in some activity or skill. Training should only be carried out by
people who have been assessed as being competent to train.
An instrument for converting one form of energy into another e.g. enabling acoustic signals to be used in controlling a subsea
well.
A large, deep-water terminal where crude oil and products are delivered by super-tankers (LCCV) and transhipped by smaller
tankers. Such terminals have large storage capacities and high-volume unloading facilities to accommodate the mammoth
vessels that carry more than two million barrels of oil each trip
An acoustic device which, on receiving a preset acoustic signal, transmits a response.
A number expressing the maximum radiation dose rate at 1 metre from the external surface of a package. Where the dose is
measured in uSv/h, the TI value is obtained by dividing this figure by 10. The number expressing the transport index should be
rounded up to the first decimal point.
Layers of buried rock strata that are arranged so that petroleum accumulates in them.
Torque Constant [KT = lb-ft./A]
Torque ripple
Torque wrench
Torque-to-inertia ratio
TRA Team
TRA Team Member
Traceability
Tracing
Training
Transducer
Transhipment terminal
Transponder
Transport Index
Trap
Page 157 of 310
Travelling barrel pump
See Pump, travelling barrel .
Travelling block
The large, heavy-duty block hanging in the derrick or mast and to which the hook is attached. The travelling block supports the
drillstring and travels up and down as it hoists the-pipe out of the hole and lowers it in. The travelling block may contain up to
six sheaves depending upon the loads to be handled and the mechanical advantage necessary. The wireline from the hoisting
drum on the draw works runs to the derrick's crown block and down to the travelling block's sheaves.
Travelling block
An arrangement of pulleys or sheaves, through which drilling line is reeved and which moves up and down the derrick or mast.
The travelling block is suspended from the crown block from which the hooks and swivel are, in turn, suspended. See block.
Travelling valve
TRC
Trench
TRFCV-H
TRI
TRIC
TRIF
Trigger Time
Trillion
Trip
Trip
Trip gas
Triplex pump
Tripping the bit
Trips
Tropo
TRSCSSV
TRSSSV
TRSV
TRT
Trunk line
Trunk lines
TSA
tscf
TSCJ
TSD
TSI
TSP
The valve installed in the reciprocating part of a subsurface pump; the outlet valve of the pump.
Thornton Research Centre
A narrow excavation with a width no greater than 15 feet.
Hydraulic Tubular Retrievable Flow Control Valve.
Temporary Refuge Impairment
Tool Box Risk Identification Card OR Transmit/Receive Interface Controller
Temporary Refuge Impairment Frequency [or Figure]
Actual time the tool was in use in hours
The oil and gas industry uses the U.S. definition, namely one million million, 1012.
See Round trip .
The operation of hoisting the drill stem from and returning it to the wellbore. Shortened form of “making the trip”. See make a
trip, also round trip, short trip OR the automatic action of a control system in stopping a process if a predetermined value is
achieved
High pressure gas in a well which must be carefully controlled when withdrawing the drill string [making a trip].
A reciprocating pump with three plungers working in three cylinders. The triplex pump discharges fluid more evenly than a
duplex or two-plunger pump, as it has a power stroke every one-third of a revolution of the crankshaft compared to every half
revolution for the duplex pump.
Removing the bit from the hole and running it in again. (In removing the bit the drill pipe must be pulled a stand at a time in
order to reach the bit). See also Round trip.
Surges arising from unstable hydrocarbon flow through flowlines, which can cause the pressure to peak, to the extent that it
may lead to production shut down.
Tropospheric
Tubing Retrievable surface-controlled subsurface safety valve
Tubing Retrievable Sub Surface Safety Valve
Tubing Retrievable Safety Valve
Tree Running Tool
A main pipeline: between production installations, between terminal and refinery, from offshore platforms to shore, etc.
Long distance pipelines, as distinct from field, gathering or branch lines. [Similar definition for telephone systems lines.]
Thermally Sprayed Aluminium
Trillion Standard Cubic Feet
Tree Supply Control Jumper
Temporarily Shut Down
Temporarily Shut In
Time Series Processor
Page 158 of 310
TSR
TSW
TT
Temporary Safe Refuge
Tube Socket Weld
Temperature Transducer
Tube bundle
The name given to the tubes in the core of a heat exchanger, The tubes or pipes, all the same length, are spaced equidistant
apart in parallel rows and are supported by perforated end-plates thus forming a bundle. Very often also called tube nest.
OR
Through Tubing
Tubing pump
Tubing spider
Tubular goods
See Production string .
Small-diameter pipe that is run into a well to serve as a conduit for the passage of oil and gas to the surface. OR Small bore
A down hole, anchoring device run in a string of tubing that clamps against the wall of the casing. The tubing anchor prevents
the breathing of the tubing, the cyclic up and down movement of the lower section of tubing as the well is pumped by a rod
pump.
A travelling block hanging in a production mast or derrick, for hoisting tubing in and out of the hole.
A small platform high in the derrick where a derrick man stands to rack drill pipe or tubing' as it is being pulled and set back.
Also called Monkey board.
See Intake pressure curves .
Production through the-production tubing.
A device screwed on top of a tubing string used to suspend the string from the wellhead and to seal the annulus formed by the
tubing and the casing.
Incorporated in a tubing head [similar to a casing hanger].
A unit, attached to the uppermost casing head or smallest casing string, which serves to suspend the tubing and to see the
annular space between the tubing and casing.
Similar to the casing head, the tubing head is installed at the wellhead on the production tubing; it seals off the annulus
between the casing and the tubing, and carries the connections for production flowlines.
See Pump, tubing .
A tapered bowl in which slips to support the tubing during Running or pulling, fit.
Refers to drill pipe, casing, well tubing and line pipe; a generic term for any steel pipe used in the oil fields.
Turbine flowmeter
An instrument that measures rates of flow in a pipeline by the electric current generated by a small rotor inserted in the line.
Tubing
Tubing
Tubing anchor
Tubing block
Tubing board
Tubing capacity curves
Tubing flow
Tubing hanger
Tubing hanger
Tubing head
Tubing head
Turbine meter
Turbo drilling
Turbulant flow
Turnkey contract
A flow meter in which fluid is passing a rotor and causing it to turn with an angular velocity that is proportional to the fluid linear
velocity and, therefore, the volumetric flow rate.
Drilling procedure whereby the bit is rotated by a turbine, which is attached to the bottom of the drilling string. This turbine is
driven by the drilling fluid.
Fluid flow in which the velocity at a given point changes constantly in magnitude and the direction of flow; pursues an erratic
and continually varying course. Turbulent flow is the second and final stage of flow in a Newtonian fluid it is the third and final
stage in a Bingham plastic fluid. See Velocity, critical and Reynolds number .
A fixed price contract for construction, drilling a well, etc. with the contractor taking the risk of non-completion. A true “turnkey”
involves the contractor funding the operations until start up.
Turnkey contractor
A contract in which a drilling contractor agrees to furnish all materials and labour and do all that is required to drill and
complete a well in a workman-like manner. When on production he delivers it to the owner ready to turn the key and start the
oil running into the tank, all for an amount specified in the contract. Also used for engineering and production contracts.
Turntable, rotary drilling
See Rotary table .
Page 159 of 310
TUT
TUTU
TV
TVBDF
A production turret [a cylindrical buoy] is built into a cavity similar to a moon-pool in a floating ship-shaped production facility.
The turret is connected to subsea wellheads by flexible hoses, and is moored in a fixed orientation. The ship/facility containing
the process, storage and offloading equipment is free to rotate or “weathervane” around the turret to present an optimum
profile to wind and sea.
Topside Umbilical Termination
Topsides Umbilical Termination Unit
True Vertical
True Vertical Below Drill Floor
TVD
True vertical depth. The vertical distance between a point in a well and the surface (as opposed to the depth along the hole).
TVD
TVDSS
True Vertical Depth; [the vertical distance below surface datum reached by a deviated well].
True Vertical Depth Subsea [below seabed]
TVP
True Vapour Pressure is the pressure of the vapour in equilibrium with the liquid at 100 F [it is equal to the bubble point
pressure at 100F].
The calculated Reid Vapor Pressure of the stream is based on ASTM D323-99a Standard Test Method for Vapour Pressure of
Petroleum Products.
Reid Vapour Pressure is the vapour pressure of a chilled sample of gasoline or other fuel as measured in a test bomb at 100F.
The Reid Vapour Pressure differs from the True Vapour Pressure of the sample due to sample vapourisation and the
presence of water vapour and air in the confined space resulting from the Reid Vapour Pressure test method.
To presaturate the sample for the Reid Vapour Pressure test, the streams are flashed at 1 atm and 33 F, and the resulting
liquid product is then combined with air at the rate of 4 parts air and 1 part liquid. Next the system is flashed at constant
volume at 100F.
The resulting gauge pressure is the Reid vapour pressure. Because of this procedure, the Reid Vapour Pressure may be
significantly different from the "True Vapour Pressure" if the Reid vapour pressure exceeds 26psi. The Reid vapour pressure
is applicable only for gasoline, volatile crude oil, and other volatile petroleum products.
It is not applicable for liquefied petroleum gases. [The vapour pressure test method for LPG is ASTM D1267 which is not
currently implemented in ProMax].
TW
Temperature Well [a thermowell used to protect a temperature measuring element from the harsh environment of a process]
TWA
Time Weighted Average
To twist a joint of drill pipe in two by excessive torque applied by the rotary table. Many failures which result in parting of the
drill pipe in the well bore are erroneously referred to by this term.
A portable ladder that supports at least 250 pounds [113 kilograms] of weight.
A portable ladder that supports at least 300 pounds [136 kilograms] of weight.
Identification of the category of isolation such as: Single, Personal or Boundary.
Unserviceable [i.e. not fit for service]
Universal Asynchronous Receiver / Transmitter
Universal Control Module
Unit Control Panel
Upper Explosive Limit
Unburnt Hydrocarbons
Ultra High Frequency
Page 160 of 310
Turret moored
Twist off
Type I Ladder
Type IA Ladder
Type of Isolation
U/S
UART
UCM
UCP
UEL
UHCs
UHF
UHMPE
UHP
UK
UKAS
UKCS
UKDCC
UKOCC
UKOOA
UL
Ullage
Ullage
ULS
Ultrasonic testing
Ultraviolet light
UMC
UMC
UMGV
Unassociated natural gas
Unattended operations
Uncomformity
Unconformity
Underground storage
Underream
Underreamer
Undersaturated oil
Underwater habitat
Undrained Lines
Ultra High Molecular Polyethylene [rope]
Ultra High Pressure
United Kingdom
United Kingdom Accreditation Service
United Kingdom Continental Shelf
United Kingdom Dispatching and Co-ordination Centre
United Kingdom Operations Co-ordination Centre
United Kingdom Offshore Operators Association Ltd - http//:www.oilandgas.org.uk
Underwriters Laboratories Inc. [USA]
The volume of space in a container unoccupied by contents. Hence ullaging, a method of gauging the contents of a tank by
measuring the height of the liquid surface from the top of the tank. See also Dip, Innage and Outage .
Unused storage, tanker, pipeline or process plant capacity.
Ultimate Limit State
A non-destructive testing method in which ultrasonic waves [sound waves of frequencies too high to be heard] are beamed at
an object, and the reflected energy measured.
Light waves shorter than the visible blue-violet waves of the spectrum. Crude oil, coloured distillates, residuum, a few drilling
Underwater Manifold Centre
Underwater Mateable Connector
Upper Master Gate Valve
Gas produced from reservoirs from which only gas can be produced economically. Gas produced from condensate reservoirs,
which produce relatively large amounts of gas per volume of liquid hydrocarbons.
See also Associated natural gas .
Operation of a plant in which personnel are absent from the plant for short periods of time but operations are continuously
monitored 24 hrs a day e.g. during the day shift, personnel are available for the control room and the plant.
During the night shift, a limited crew is available for plant intervention operations that have been subjected to a risk based
assessment. Process upsets in the night shift [low criticality], are normally left until the start of the dayshift.
The night shift crew, under the direction of the Shift Supervisor, would still be expected to respond to HSE related Safety
Critical repair/reinstatement requirements, and production deferment disturbances/upsets after an appropriate risk
assessment.
A surface of erosion that separates younger strata from older rocks. In an angular unconformity the older strata generally dip
more steeply than the younger strata.
Lack of continuity in deposition between rock strata in contact with one another, corresponding to a gap in the stratigraphic
record. OR the surface of contact between two rock beds in which there is a discontinuity in the ages of the rocks.
In certain areas where there are underground caverns petroleum and products are stored for future use. All caverns are not
suitable; some are not naturally sealed and would permit the stored oil to leak into subsurface water sources.
To enlarge the size of the borehole of the well by the use of an underreamer.
A type of drilling tool used to enlarge the diameter of the borehole in certain down hole intervals. The underreamer is made
A crude oil at reservoir conditions that could contain more solution gas than it actually does.
An air chamber or structure such as a diving bell in which divers can live whilst not working, or a chamber where work can be
carried out such as a subsea enclosure or hyperbaric welding chamber.
Any line or equipment system that has not been drained or flushed clear through existing drains, vents, or bleed valves.
Page 161 of 310
Union
Unipolar driver
Unitisation
Unmanned operations
UNS
Up dip
Up dip well
Updip
UPS
Upset
Upset
Upstream
Upstream
URP
USD
User
Username
USG
USM
USV
UT
UTA
Utilisation factor
UTM
UV
U-value
V
V belt
V door
Vacancy Board
A pipe connecting assembly consisting of two halves with. mating sealing surfaces, which can be screwed together. A union
makes a joint, which permits easy installation, removal or replacement of lengths of pipe, valves or vessels in piping systems.
A step motor driver configuration that uses a unipolar power supply and is capable of driving phase current in only one
direction. The motor phase winding must be center tapped [6 or 8 lead] to operate with a unipolar driver. The center tap is
used instead of providing the current reversal of a bipolar driver.
A term denoting the joint operation of separately owned producing fields in a pool or reservoir. Unitisation makes it
economically feasible to undertake cycling, pressure maintenance, or enhanced recovery programmes.
Operation of a purpose designed plant that allows for periods of operations in which there are no human supervision on
location and no immediate intervention to process upset whilst maintaining the required design level of production availability.
Periods of unmanned operations will be followed by manned periods in which the planned maintenance routines and
corrective/breakdown work will be executed.
Universal Numbering System
Proceeding or lying upwards in the direction of inclination of strata to the horizontal.
A well located high on a structure where the hydrocarbon bearing formation is found at a shallower depth.
A term used in a hydrocarbon reservoir that is not flat. That is, an area of a structure where the top of the formation is higher
[e.g. offshore, nearer the sea level] than the point under consideration.
Uninterruptible Power Supply
Pipe ends of drill pipe, tubing and casing having an increased wall thickness to accommodate the thread. Pipe may be
The thickening or increased diameter at the joints of tubulars to provide the necessary strength.
A term referring to industry operations before the refinery and marketing operations, i. e. production handling and transport.
Situation in a system at a point before the point of reference (e. g. upstream pressure temperature).
Used to describe the area from what a fluid flows from e.g. the well.
Unity Riser Platform [for Forties Pipeline System].
Unplanned Shutdown OR Unit Shut Down
An individual who has or requires access to one or more computer applications.
An alphanumeric code unique to each user which defines the account to be used on a system.
United States Gallons
Ultrasonic Meter
Underwater Safety Valve
Ultrasonic Testing
Umbilical Termination Assembly
The ratio of the maximum demand on a system or part of a system to the rate capacity of the system or part of the system
Universal Transverse Mercator [more accurate co-ordinate system than the geographical system because it takes into
account the variations in the earth’s sphere]
Ultraviolet
Measure of thermal efficiency
Volts OR Volume.
A type of endless V-shaped belt used in transmitting power from an engine's or motor's grooved drive-pulley to the grooved
sheave of a pump, compressor, or other equipment. The V-belt is used in sets of two to twenty belts depending upon the
power to be transmitted.
The opening in the derrick opposite the draw works used for bringing in drill pipe and casing from the nearby pipe racks.
The boards within ARL that are used to log enquiry details for the purpose of communication.
Page 162 of 310
Vacuum relief valve
Vacuum truck
Valence
Valence / valency
Validity Period
Values
Valve actuator
VAM
Vam
Vapour lock
Vapour pressure
Vapour pressure
Vapour tension
VCP
VDT
VDU
Vent
Vent
Vent stack
Venturi meter
Verified fit for use
Verify
Vertical lift performance
VESDA
VESL
VFC
VFD
VG
VHF
VHS
Vibrating screen
Vibroseis
VID
A safety valve which will allow air or gas to enter a system or vessel in case of a pressure drop.
A tanker truck where the tank is constantly kept at a certain vacuum to facilitate sucking up liquids. Often used in oilfields to
clean up oil or other spills.
The tendency of elements to form compounds through a shift of electronic structure.
The valency is a number representing the combining power of an atom, i.e. the number of electrons lost, gained, or shared by
Maximum period that a WCC is current and live work can be carried out under its control.
Petrofac Production guiding principles.
See Operator .
A trade name of a widely used premium tubing and casing joint.
Trade name for casing thread produced by the Vallourec company of France.
A condition that exists when a volatile fuel vaporises in an engine's fuel line or carburettor preventing the normal flow of liquid
fuel to the engine. To handle gas lock or vapour lock the gas must be bled off the system by removing a line or loosening a
connection, or the lines and carburettor cooled sufficiently to condense the gas back to a liquid.
The pressure exerted by a volatile liquid at a certain temperature at a vapour/liquid ratio of zero. See also Reid vapour
pressure .
The pressure exerted by the vapour from a substance, and also the pressure required to prevent a liquid from vaporising.
See Vapour pressure .
Vertical Control Panel
Video Display Terminal
Visual Display Unit
Open outlet to prevent pressure build-up or under pressure in a vessel or system.
A pipe or fitting on a vessel that can be opened to the atmosphere
Open ended pipe and support framework used to discharge vapours into the atmosphere as a safe location above the
installation, without combustion.
An instrument for measuring the volume of flowing gases and liquids. It consists of two parts the tube through which the fluid
flows and a set of indicators that show the pressures, rate of flow, or quantity discharged. The tube, in the shape of an
elongated hourglass, is flanged into a pipeline carrying the fluid. The effect of the tube is to increase the velocity and decrease
the pressure at the point where the tube's diameter is reduced. The relationship between the line pressure and the pressure at
the narrow waist of the tube is used in computing the rate of flow.
Equipment that has been inspected by a competent person, who has confirmed that it is fit for use for a specified period and
completed a written record of the inspection.
To determine conformance to specified requirements.
Behaviour of the liquid flow rate as a function of the vertical pressure loss from the bottom of the tubing to the tubing head.
Very Early Smoke Detection and Alarm
Very Essential Lighting
Virtual File Cabinet
Variable Frequency Drive
Vetco Gray
Very High Frequency
Vertical Helical Scan [as in video machines]
A sieve-like part of the shale shakers for separating rock cuttings and mud returned from a well.
Wave generation for acoustic [seismic] and magnetostrictive applications
Vane Inlet Distributor - such as in a separator vessel.
Page 163 of 310
View Linked Button
VIM
Viscosimeter
Viscosity
Viscosity
Viscosity index
Viscous Damping [KDV] [lb-in./kRPM]
Vision
VIV
VMC™
VOC
Volatile
Volatility
A button provided when another WCC / ICC / Workpack has been used as a template for the current document allowing the
user to view the original document for comparison, if required.
International vocabulary of basic and general terms in metrology.
Instrument for measuring viscosities. Absolute viscosity is determined by a capillary type instrument. The time required for a
sample to flow through known length of glass capillary is registered.
Results are often given in centistokes or centipoises. In the petroleum industry the viscosity is generally determined in
standardised instruments consisting of a container with a hole or jet in the bottom. Various type are in use, viz. in the UK, the
Redwood I and Redwood II, in the USA the Saybolt Universal and Saybolt Furol and on the European continent the Engler
viscosimeter.
Results with the Redwood and Saybolt viscosimeters are expressed in seconds, those with the Engler in Engler degrees.
The internal resistance offered by a fluid to flow. This phenomenon is attributable to the attractions between molecules of a
liquid, and is a measure of the combined effects of adhesion and cohesion to the effects of suspended particles, and to the
liquid environment. The greater this resistance, the greater the viscosity. See also Apparent viscosity, Plastic viscosity,
Kinematic viscosity and Marsh funnel viscosity .
See CST Centistokes and Centipoise. The minimum viscosity for fuel transfer is determined by the maximum viscosity
acceptable by the transfer pump.
If the actual viscosity at transfer is lower than the pump design, the rate of transfer will be faster than the rated capacity of the
pump.
The viscosity of a fuel is its resistance to shear or flow, and is a measure of the fuel's adhesive/cohesive or frictional
properties.
This arises because of the internal molecular friction within the fuel producing the frictional drag effect. There are two related
measures of fuel viscosity which are known as dynamic and kinematic viscosity.
Dynamic viscosity is also termed absolute viscosity and is the tangential force per unit area required to move one horizontal
plane with respect to the other at unit velocity when maintained a unit distance apart by the fluid. In SI units the theoretical unit
is the Poise.
As these units are large, it is usual to divide them by 100, to give a smaller unit called the centipoise [cP].
Kinematic viscosity is the ratio of the absolute viscosity to the density.
In SI units, the theoretical unit is the Stokes.
As these units are large, it is usual to divide them by 100, to give a smaller unit called centistokes [cSt], and these are the units
used for marine fuel.
For either dynamic or kinematic viscosity to be meaningful a reference temperature must be quoted.
A term to indicate the viscosity/temperature relation of an oil.
Inherent losses are present in all motors which result in lower torque delivered at the output shaft than developed at the rotor.
Losses which are proportional to speed [i.e. speed dependent terms such as windage, friction, eddy current] are related
through the motor's viscous damping constant, measured as the slope of the damping curve.
What Petrofac production wants to achieve.
Vortex Induced Vibration
Alpha Thames’ Valved Multiported Connector – enables the simultaneous connection of a number of piping runs.
Volatile Organic Compound
Term applied to materials, which have a sufficiently high vapour pressure at normal temperatures to evaporate readily at
normal atmospheric pressure and temperature. It implies a high degree of volatility.
The extent to which light products or oil vaporise; the ease with which a liquid is converted into a gaseous state.
Page 164 of 310
Volatility
Voltage constant [KE] [V/kRPM peak,
line-to-line]
VOR
Vortex meter
VOWD
VP
VPC
VRU
VSD
WaGE
Waiver
Walking beam
Wall cake
Wall cleaner
Wall scraper
Wall sticking of drill pipe
WAMS
WAP
Wash over pipe
Wash tank
WAT
WATCH
Water based mud
Water block
Water bottom
The readiness with which a liquid converts to its gas state; highly volatile liquids include the light hydrocarbon fractions.
May also be termed back-EMF constant. When a motor is operated, it generates a voltage proportional to speed, but opposing
the applied voltage. The shape of the voltage waveform depends upon the specific motor design. For example, in a brushless
motor, the waveshape may be trapezoidal or sinusoidal in nature. All Pacific Scientific brushless motor designs have a
sinusoidal voltage constant. For a sine waveform, the voltage constant can be measured from line-to-neutral or line-to-line and
expressed as a peak value or RMS value.
Variation Order Request
A meter to measure flow rates. A type of' a turbine meter, however with a large part of the rotating mechanism outside the flow
stream.
Value of Work Done
Vapour pressure
Venture Production [North Sea Developments] Limited
Vapour Recovery Unit [as in a refinery]
Variable Speed Drive
Wood and Gas Export OR Equipment
The voluntary relinquishment or surrender of some known right or privilege.
A heavy steel beam supported by the Samson post that transmits power from the engine via the cranks, and pitman to the
sucker rods. The walking beam oscillates on the Samson post imparting an up-and-down motion to the sucker rods of a well.
The solid material deposited along the wall of the hole resulting from filtration of the fluid part of the mud into the formation.
See also Filter cake.
A scraping or cutting device attached to the lower joints of casing in the string for the purpose of cleaning the wall of the
borehole in preparation for cementing. There are numerous types of scratching, raking and cutting devices designed to
remove the clay sheet or filter cake deposited by the circulating drilling mud.
Mechanically cleaning the walls frees the production formation from the caked mud and also enlarges the hole diameter
through the production zone making for more efficient oil flow into the well bore.
See Wall cleaner .
A condition down hole when a section of the drill string becomes stuck or hung-up in the deposit of filter cake on the wall of the
borehole due to excess differential pressure. See also Differential sticking .
Work Activity Management System
Wax Appearance Point
A pipe run at the end of drill pipe or tubing which can slide over a fish left in the hole to wash out the space between the fish
and the wall of the hole and thus free the fish which will make fishing operations easier.
See Dehydration tank .
Wax Appearance Temperature
Working Group Assessment of Toxic Chemicals
Drilling fluid based on suspension of solids, such as bentonites, in water.
Reduction of the permeability of a formation caused by the invasion of water into the pores (capillaries). The decrease in
permeability can be caused by swelling of clays'- thereby shutting off the pores, or in some cases by a capillary block of the
pores due to surface tension phenomena.
Water accumulated at (or sometimes added to) the bottom of the oil in a dehydration or storage tank. In cases where the tank
bottom is very uneven, the water level assists in the accurate measurement of the oil content of the tank.
Page 165 of 310
Water coning
Water cut
Water drive
Water drive
Water drive reservoir
Water flooding
Water injection
Water knockout
Water loss
Water re-injection
Water saturation
Water separation
Water string
Water table
Waterflood
Watering out
Wave period
Wave recorder
Wax
WBM
WC
WCC 1
WCC 2
WCC ID
WCC Viewer
WCP
WCT-BOP
WD
The encroachment of water in a well bore in a water-drive reservoir owing to an excessive rate of production. The water below
the oil moves upward to the well bore through channels, fissures, and permeable streaks leaving the oil side-tracked and bypassed.
The amount of water present in crude oil expressed as a percentage of gross volume of crude oil at 60'F or 150C.
The force of water under pressure below the oil formation that when the pressure is released by producing the oil, drives the
oil to surface through the well bore.
Where a hydrocarbon reservoir is in contact with an underlying water table, the formation pressure will drive the water into the
rock pores vacated by produced fluids, thus tending to maintain reservoir pressure and assist production.
A reservoir rock in which the oil is displaced by the pressure of formation water, which encroaches on an oil-bearing formation
either from the flanks of the structure or from below.
The process of injecting water into a reservoir formation for the purpose of secondary recovery by flooding out the oil towards
production wells. Special injection wells are drilled for this purpose.
The injection of produced water or water from the host in order to boost production from the reservoir
See Free water knockout .
See Fluid loss .
The disposal of produced water into a disposal well [not for boosting the reservoir].
The proportion of water in the pore spaces of a reservoir. See Porosity.
Removing the water from a production flow of oil or gas. There are several techniques including settlement, heating and
electrostatic precipitation particularly for breaking down water-oil emulsions.
A string of casing set and cemented directly above the oil-bearing formation. See also Oil string .
The level in the earth below which rock pores are saturated with water.
A method of increasing oil recovery from an existing reservoir. Water is injected to force unrecovered oil out of reservoir rock
When the proportion of water in production from a well is so high that it must be shut in.
The time separating successive crests of similar waves passing a given point.
An instrument which measures and records the height and frequency of waves.
Paraffin waxes are found in crude oil and may be a significant proportion of it, requiring special treatment to allow the oil to
flow freely at surface conditions.
Water Based Mud
Water Cut OR Wildcat
Work Control Certificate. [An electronically produced work control document, a form of work permit].
Work Control Certificate. [Supported by Risk Assessments in all cases. Where applicable, Isolation Confirmation Certificates,
which incorporate both Mechanical and Electrical Isolations, supported by Isolation Labels].
A unique identification number for all Work Control Certificates within the system. This number is system generated and
entered as a field in the WCC Wizard.
A tool within the database that through the use of filters enables the user to view, in summary, WCC’s in any state e.g.
Pending, Authorised, Live, etc. Personnel with the correct level of authorisation and who are logged in to the system can
move WCC’s to another state e.g. from Authorised to Live.
Work Control Pack. A term given to a collection of Work Control Certificates [WCC’s] that cover a multi-discipline or large
workscope job on the same equipment e.g. Gas turbine overhaul. The WCC’s will normally require the same Boundary
Isolations. The WCP will organise the relationships [e.g. Start / Finish or Live / Live] of the WCC’s to establish the phases of
isolation etc.
Wireline/Coiled Tubing BOP
[blowout preventer]
Water Depth OR Water Disposal [well]
Page 166 of 310
Weather window
Weathered crude
Weathering
WEELs
Weight bar
Weight indicator
Weight indicator
Weld fillet
Welding bug
Well
Well
Well completion
Well completion
Well killing
Well logging
Well logging
Well permit
Well platform
Well programme
Well programme
Well pulling
Well pulling hoist
Well servicing
Well servicing
Well shooter
The period of relativity good [summer] weather within which a given offshore operation can take place. A weather window can
also occur in winter, but is usually hard to predict and of short duration.
Crude oil which has lost an appreciable quantity of its volatile components owing to natural causes (evaporation) during
storage and handling..
Permitting crude oil to stabilize by venting its volatile fractions to atmosphere [not now practised] OR the process acting on
exposed geological strata.
Working Group on European Exposure Limits
See Stem .
An instrument which indicates the total load or line tension at the point on the wireline which actuates it.
A large instrument on the rig floor which displays the weight of the drill string, and hence the pressure on the drilling bit.
In overlapping surfaces, the weld makes a fillet in the angle formed by the end of the overlap.
Welding head of an automatic welding process.
A hole drilled or bored into the earth, usually cased with metal pipe for the production of gas or oil. Also, a hole for the injection
under pressure of water or gas into a subsurface rock formation.
Normally steel-lined boreholes drilled to search for or exploit hydrocarbon reservoirs.
See Completion methods .
The activities and methods necessary to prepare a well for the production of oil and gas; the method by which a flowline for
hydrocarbons is established between the reservoir and the surface. Also The process by which a finished well is either sealed
off or prepared for production by fitting a wellhead.
See Killing .
A record of geological formations penetrated during drilling, including technical details of the operation.
The recording of information about subsurface geologic formations. Logging includes records kept by the driller and records of
mud and cutting analyses, core analyses, drill stem tests, and electric, acoustic and radioactivity procedures.
Government Permission to drill a well. Obtaining this is frequently a detailed process.
An offshore structure with a platform above the surface of the water that supports the producing well's surface controls and
flow piping. Well platforms often have primary separators and well-testing equipment. See also Producing platform .
The step by step procedure for drilling, casing and cementing a well. A well programme includes all data necessary for the tool
pusher and drilling crews to know, formations to be encountered, approximate depth to be drilled, hole sizes, bit types,
sampling and coring instructions casing sizes and methods of completion - or abandonment if the well is dry.
The engineering design and technical/operational plan for drilling a well, completing and testing it [as applicable].
See Well servicing
A movable hoisting unit used for repairs and light work-overs of production wells. Often equipped with a telescoping or folding
mast to work on those wells which have no production derrick.
A term used to describe routine subsurface maintenance or light repair operations on production wells. Mainly pulling and
running of tubing and/or suckerrods. Also called Well pulling.
Bringing a completed well into production, and subsequent maintenance work performed on an oil or gas well to improve or
maintain the production from a formation already producing. Usually, it involves repairs to the pump, rods, gas-lift valves,
tubing, packers, etc.
An explosives expert who uses explosions to stimulate production.
Page 167 of 310
Well testing
Wellhead
Wellhead 1
Wellhead 2
Wellhead 3
Wellhead cellar
Wellhead platform
Wellhead separator
WELs
WEO
Wet gas
Wet gas
Wet job
Wet oil
Wet tree
Wet weld
Wetting
Wetting agent
WGM
WGR
WH
What’s This Help
WHCST
Whipstock
Testing in an exploration or appraisal well is directed at estimation of reserves in communication with that well, in addition to
well productivity. Testing in a production well also monitors the effects of cumulative production on the formation.
Tests basically consist of a series of measurements of pressures, fluid flows and temperatures down hole [PVT] in a controlled
sequence of “flowing” and “shut-in” periods for recovery of stable reservoir conditions.
The time taken to recover is also recorded. Various forms of well stimulation may also be built into the sequence. Tests will
also include the functioning of well equipment.
The housings and spools plus valves, hangers and seals in which the casing and tubing strings are supported. The X-mas tree
fits on top of the wellhead.
Wellhead is descriptive of a location or function [including the X tree and hang offs] rather than a specific item of equipment.
Permanent equipment used to secure and seal the casings and production tubing and to provide a mounting for the Christmas
Tree. See Production Wellhead.
Steel equipment installed at the surface of the well containing an assembly of heavy duty hangars and seals -the wellhead is
used to support the weight of casing strings hung from it and to contain well pressure
The control equipment fitted to the top of a well casing, incorporating outlets, valves, blowout preventers etc.
A cellar on the well location in which the wellhead is situated.
An offshore platform designed to support only wellheads [including trees etc] and associated piping, production fluids being
transferred to a shore gathering station or nearby platform for processing.
The first process vessel in a production operation, operating at or near wellhead pressures.
Workplace Exposure Limits
Well Engineering Operations.
Petroleum gas containing such quantities of the lower members of the paraffin hydrocarbon series (propane, butane, etc.) that
the recovery of liquid products from that gas may be economical. Natural gas saturated with or having a high content of water
vapour.
Natural hydrocarbon gas containing significant amounts of naturally liquid hydrocarbons.
Pulling tubing or drillpipe full of oil, water or mud. As each joint or stand is unscrewed, the contents of the pipe empties onto
the derrick floor, drenching the roughnecks.
Crude oil with a water content above refinery specifications (e.g. more than 0.3%).
A subsea wellhead “tree” which is exposed to the water rather than enclosed.
Underwater welding as opposed to normal atmospheric welding or hyperbaric chamber welding.
The adhesion of a liquid to the surface of a solid.
A substance or composition which, when added to a liquid, increases the spreading of the liquid on a surface or the
penetration of the liquid into a material.
Wet Gas Meter
Water Gas Ratio
Well Head
This is a quick reference help provided by clicking on the icon that has a question mark beside an arrow and dragging it to a
part of the screen that help is required for.
Wellhead Connector Seal Test [isolation valve]
Wedge-shaped device used in deviated drilling to deflect and guide the bit away from vertical.
Page 168 of 310
Whipstock
Whitaker capsule
WHO
WHP
WHSIP
WI
WI
Wild well
Wildcat
WIMS
WIN
Winch
Windlass
Window mill
Wing valve
Wing Valve
Wire rope
A tool for deviated drilling, basically a wedge-shaped block which is lowered into the well to divert the bit onto a chosen path at
an angle to the original hole. Also An inclined wedge placed in a wellbore to force the drill bit to start drilling in a direction
away from the wellbore axis. The whipstock must have hard steel surfaces so that the bit will preferentially drill through either
casing or rock rather than the whipstock itself. Whipstocks may be oriented in a particular direction if needed, or placed into a
wellbore blind, with no regard to the direction they face. Most whipstocks are set on the bottom of the hole or on top of a highstrength cement plug, but some are set in the openhole.
A type of survival capsule.
World Health Organisation
Wellhead Pressure OR Wellhead Platform OR Wellhead Protector [subsea] OR Wellhead Pad
Wellhead Shut-in Pressure
See Wobbe Index. The main indicator of the interchangeability of fuel gases such as natural gas LPG and Town Gas and is
frequently defined in the specifications of gas supply and transport utilities. Wobbe Index = higher heating value/[square root of
gas specific gravity].
The Wobbe Index is used to compare the combustion energy output of different composition fuel gases in an appliance [fire,
cooker etc.]. If two fuels have identical Wobbe Indices then for given pressure and valve settings the energy output will also be
identical.
Typically variations of up to 5% are allowed as these would not be noticeable to the consumer. The Wobbe Index is a critical
factor to minimise the impact of the changeover when analyzing the use of SNG fuels such as propane-air mixtures.
Water Injection OR working interest
A well out of control, a blowout.
A well drilled in an area, which is unproven. The drilling of a wild cat demands special safety precautions as the down hole
formation and pressure conditions are unknown. Also A well drilled in an area where no oil or gas production exists. With
modern exploration methods and equipment, about one wildcat out of every seven proves productive, but not necessarily
profitable, OR to drill wildcat wells, OR [nautical] the geared sheave of a windlass used to pull anchor chain.
Well Integrity Management System
Work Instruction Number
A device used for pulling or hoisting by winding rope or cable around a power-driven drum or spool.
A windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is
rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound around the winch,
pulling a weight attached to the opposite end. Windlasses are sometimes used on boats to raise the anchor as an alternative
to a vertical capstan. They can also be used to raise water from a well.
A downhole cutting tool used to cut an aperture laterally in the casing through which to sidetrack or deviate the well.
Valve on a Christmas tree, which will close off or allow flow from the well to the flow line.
A valve located on the side of a Christmas tree or temporary surface flow equipment, such as may be used for a drillstem test.
Two wing valves are generally fitted to a Christmas tree. A flowing wing valve is used to control and isolate production, and the
kill wing valve fitted on the opposite side of the Christmas tree is available for treatment or well-control purposes. The term
wing valve typically is used when referring to the flowing wing.
A cable composed of steel wires twisted around a central core of fibre or steel wire to create a rope of great strength and
considerable flexibility. Wire rope is used as drilling line [in rotary and cable-tool rigs], coring line, servicing line, winch line, etc.
It is often called cable or wireline. However, wireline is a single slender metal rod, usually very flexible. Compare wireline.
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Wireline
Wireline 1
Wireline 2
Wireline BOP
Wireline cutter
Wireline grab
Wireline socket
Wireline spear
Wireline stem
Wireline tools
Wireline truck
WIST
WL
WLT
WO
Wobbe index
Wobbe index 1
Wobbe index 2
WOCM
WOCP
Any line of wire or cable used for down hole operations. Three types are usually distinguished: piano, braided and electric
wireline. The former is a thin, single-strand line of high tensile steel, the braided is a multiple strand line, both used to lower
instruments or tools into a well and/or install, retrieve or operate wireline equipment e.g. subsurface safety valves installed in
tubing.
The braided wire is used for heavier wireline equipment. Electric wirelines are normally used for surface recording instruments,
e.g. those used for making electric logs.
A small-diameter metal line used in wireline operations; also called slick line. A system in which a flexible cable and reel is
used to lower log or maintenance equipment down a well, rather than a rigid drill string, with considerable savings of
equipment, manpower and time.
The term wireline usually refers to a cabling technology used by operators of oil and gas wells to lower equipment into the well
for the purposes of a well intervention. In its simplest and most used form, the wireline simply consists of a single strand of
metal wire most commonly 0.108 or 0.125 in diameter [sometimes referred to as slickline].
In other cases, the wire will be composed of braided strands, rendering it stronger and heavier [called braided line]. Braided
line can contain an inner core of insulated wires which provide power to equipment located at the end of the cable [called
electric line or E-line] and provides a pathway for electrical telemetry for communication between equipment at each end of the
cable.
Also called wireline valve, is a ram or flapper-equipped device, which can be used on wellheads to prevent or control blowouts.
It consists of a housing with some form of resilient packing element designed to close around the wire to effect a positive shutoff.
A tool to cut wireline within or below the tubing at the lowest possible point ' This may be necessary when the tool string is
stuck and cannot be pulled.
Also called wireline spear, is a tool to fish wireline that has broken inside the well.
A tool which provides the means by which the wireline is fastened to the tools.
See Wireline grab .
See Stem .
Special tools or equipment made to be lowered into the well's tubing on a wireline, e.g. plugs, chokes, gaslift valves, safety
valves, etc.
A service vehicle on which a wireline winch is mounted for use in down hole wireline work.
Well Integrity Status Tool
Work Leader
Wire Line Test
Work Order OR Workover
Heating value of gas in BTU (Density of gas relative to air).
An expression of the heating value of a gas flame, used in gas marketing. It is derived by dividing the gross calorific value of
the fuel by the square root of its specific gravity, expressed in, e.g. mega joules per cubic metre or BTU per cubic foot.
The Wobbe Index [WI] is the main indicator of the interchangeability of fuel gases such as natural gas LPG and Town Gas
and is frequently defined in the specifications of gas supply and transport utilities. It is used to compare the combustion energy
output of different composition fuel gases in an appliance [fire, cooker etc.]. If two fuels have identical Wobbe Indices then for
a given valve setting the energy output will also be identical. Typically variations of up to 5% are allowed as these would not be
noticeable to the consumer. The Wobbe Index is a critical factor to minimise the impact of the changeover when analyzing the
use of SNG fuels such as propane-air mixtures.
Workover Control Module
Workover Control Panel
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WOCS
Woodcase thermometer
Work
Work Categorisation List
Work Control
Work Control Pack Number
Work injury
Work Leader
Work Permit
Work Permit User[s]
Work Planning
Workforce
Working Interest
Working load
Working pressure
Workover
Workover
Workover fluid
Workover rig
Worksite
Workstation
World scale
WoW Time
WP
WPQR
WPS
Wrist pin
WRSCSSV
WS
WSD
WSE
WSW
Workover Control System[s]
A thermometer used by gaugers in taking the tank temperature the temperature of the oil in the tank as contrasted to the
temperature of the sample oil to be tested. The thermometer is encased in a copper (formerly wood) frame to which a line is
attached for lowering the thermometer into the oil.
An activity made up of a number of different tasks.
Guidance to categorise work activities within the ISSoW.
An established means of controlling the completion of work.
A discreet number that is given to every Work Control Pack [WCP]. No two WCPs will have the same number.
In Safety: An injury or illness, regardless of severity, which arises from a single event (or a number of events close together in
time) in the course of employment.
A responsible person appointed to be in direct control of the specific activities covered by a Work Permit at the worksite.
The document that authorises work to be performed under controlled conditions at the worksite
Any personnel working with a Work Leader under the control of a Work Permit.
A systematic process of identifying and listing work and determining when such work will be carried out.
BP employees and every employee of any other company or other legal entity that has been engaged to perform work on BP
Premises.
The interest in an oil and gas leasehold which is subject to the payment of the expenses of development, operation and
maintenance of a well and is subject to the payment of Landowner's Royalty and Overriding Royalty Interests.
The load imposed by workers, material, and equipment
The pressure at which a system or item of equipment is designed to operate. Normal pressure for a particular operation
Re-entry into a completed well for modification or repair work
A maintenance job on a well usually to replace equipment or to stimulate production. Re-entry into a completed well for
modification or repair work.
Any type of fluid used in the workover operation of a well.
Normally a smaller, portable version of the main drilling derrick which can be used to carry our work over operations on
installations which do not have a permanent derrick.
The location of the activity, work or tasks.
A computer connected to a network from which a user can run software applications.
A reference table of freight rates between most ports in the world. Actual freight contracts are usually fixed at World scale for
the route plus or minus a percentage factor that reflects freight market conditions.
Time when a rig or installation vessel is “waiting on weather” to moderate before operations can continue.
Working Pressure
Welding Procedure Qualification Record
Welding Procedure Specification
The steel cylinder or pin connecting the rod to the engine' or pump's piston. The wrist pin is held in the apron or lower part of
the piston by a friction fit and a circular, spring clip.
The upper end of the connecting rod is fitted with a lubricated bushing, which permits the rod to move on the pin. A piston pin,
gudgeon pin. The pin which connects the pitman of a pumping unit to the crank.
Wireline Retrievable Surface Controlled Subsurface Safety Valve
Water Supply
Working Stress Design
Written Scheme of Examination
Water Supply Well
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wt
WT
WWT
X over
X tree
Xaloy
XOV
X-Reference
XTRT
Yield
Yield point
Yield Point YP
Yield strength
Yield value
ZCSC
Zone
Zone
Zooplankton
ZWCS
zz
zzz end
weight
Wall Thickness
Waste Water Treatment
Crossover [piping]
Christmas tree
A low-friction alloy used for facing drilling tools, etc.
Crossover Valve
Cross Reference. Refers to other control documents that affect or are affected by the WCC on which the cross reference is
noted.
Christmas Tree Running Tool
The total amount of product of a refinery process or of all products of all processes of a refinery compared with the equivalent
amount of feedstock.
A “Refinery Yield” for a given crude oil feedstock and refinery will include a table of amounts of all products derived from a
barrel or ton[ne] of crude minus the refinery’s own usage for fuel, flaring and other losses.
Since refineries commonly use several feedstocks simultaneously, such a yield is often measured or predicted on the basis of
adding incremental feedstock to a fixed throughput.
In drilling-fluid terminology, yield point means yield value. Of the two terms yield point is by far the most commonly used
expression.
The force needed to start a fluid flowing, i.e. to overcome its viscosity or thixotropy OR with reference to materials, the point at
which material changes from elastic deformation to permanent [plastic] deformation resulting in failure or rupture.
For steels used in the manufacturing of tubular goods the API specifies the yield strength as the tensile strength required to
produce a total elongation of 0.5 and 0.6 percent of gauge length.
The yield value (commonly called yield point) is the resistance to initial flow, or represents the stress require to start fluid
movement. This resistance is due to electrical charges located on or near the surfaces of the particles.
Zakum Central Super Complex
An interval of a subsurface formation containing one or more reservoirs; that portion of a formation of sufficient porosity and
permeability to form an oil or gas reservoir.
The interval between two depths in a well containing a reservoir or other distinctive characteristics OR Specific areas where
restrictions apply eg safety zone, hazardous zone [around an offshore installation], danger zone [military activity area], etc.
Free floating microscopic animals.
Zakum West Super Complex
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See also Cave-in .
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