Petroleum Development Oman L.L.C.
Document Title: Entry into a Confined Space
Document ID
Document Type
Security
Discipline
Owner
Issue Date
Revision
PR-1148
Procedure
Unrestricted
Engineering and Operations
Functional Production Manager (UOP)
July 2011
4.0
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this document may be disclosed to others or reproduced, stored in a retrieval system, or transmitted in
any form by any means (electronic, mechanical, reprographic recording or otherwise) without prior written
consent of the owner.
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i
Revision: 4.0
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Document Authorisation
Authorised For Issue – July 2011
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ii Revision History
The following is a brief summary of the 4 most recent revisions to this document. Details
of all revisions prior to these are held on file by the issuing department.
Revision No.
4.0
July-11
Author
Scope / Remarks
Robin Norman UOP6
Refer to Addendum 2 for changes
Apr-11
Added Section 1.9 - ALARP
Rev 3.1
Nov-09
Robin Norman UOP6/
Del Ellbec UOP7
For minor changes refer to Addendum 1
Rev 3.0
Feb-09
Robin Norman UOP6
Revised Sections 2.1 & 2.2.
Added “use of Dragger Tubes” for testing
prior to Confined Space Entry
Added Appendix 1 “Reference Material”
Rev 1
Nov-98
UOP/1
SI-19 re-written in new format.
iii Related Business Processes
Code
Business Process (EPBM 4.0)
EP.71.02
Operate Wells and Facilities
iv Related Corporate Management Frame Work (CMF)
Documents
The related CMF Documents can be retrieved from the CMF Business Control Portal.
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TABLE OF CONTENTS
1
Introduction ............................................................................................................................. 6
1.1
Background ...................................................................................................................... 6
1.2
Purpose ............................................................................................................................ 6
1.3
Distribution / Target Audience .......................................................................................... 6
1.4
Changes to the Document................................................................................................ 6
1.5
Step-out Approval ............................................................................................................. 7
1.6
ALARP .............................................................................................................................. 7
2
Roles and Responsibilities ...................................................................................................... 8
3
Confined Space Entry Procedure ......................................................................................... 10
3.1
Preparation for Confined Space Entry............................................................................ 10
3.1.1
Potential Hazards Associated with Confined Space Entry....................................... 10
3.1.2
Planning and Risk Assessment ............................................................................... 10
3.1.3
Gas Freeing and Flushing ....................................................................................... 12
3.1.4
Working Atmosphere ............................................................................................... 12
3.1.5
Ventilation ................................................................................................................ 14
3.1.6
Positive Isolation ...................................................................................................... 14
3.1.7
Use Naked Flames and Arc ..................................................................................... 14
3.1.8
General .................................................................................................................... 15
3.2
Confined Space Entry Process ...................................................................................... 15
Appendix 1 – Narcotic Effect of Hydrocarbons............................................................................ 19
Appendix 2 – Abbreviations ......................................................................................................... 20
Appendix 3 – Reference Material ................................................................................................ 21
Appendix 4 – User Feedback Page............................................................................................. 22
Addendum 1 – Changes at Revision 3.1 ..................................................................................... 23
Addendum 2 – Changes at Revision 4.0 ..................................................................................... 24
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1
Introduction
1.1
Background
The nature of industry in which PDO operates frequently requires personnel to enter
‘Confined Spaces’ to carry out inspections and / or maintenance and repair work. A
confined space:

Has limited or restricted means of entry or exit

Is large enough for an employee to enter and perform assigned work, and

Is not designed for continuous occupancy by the employee.
A “permit-required” confined space is one that meets the definition of a confined space
and has one or more of these characteristics:
1.2

Contains or has the potential to contain a hazardous atmosphere,

Contains a material that has the potential for engulfing the entrant,

Has an internal configuration that might cause an entrant to be trapped or
asphyxiated by inwardly converging walls or by a floor that slopes downward
and tapers to a smaller cross section, and/or contains any other recognised
serious safety or health hazards. These shall include but are not limited to:
o
Process vessels i.e. separators, pressure vessels
o
Storage tanks
o
Compressor enclosures
o
Heaters and boilers
o
Flare and vents systems
o
Cellars and pits
o
Culverts
Purpose
The purpose of this procedure is to provide all personnel, PDO or contract, with clear
and concise instructions for entering or working within a confined space.
1.3
Distribution / Target Audience
This procedure is intended for use production and maintenance personnel and any other
parties tasked with carrying out work covered by this procedure on behalf of PDO.
1.4
Changes to the Document
Responsibility for the upkeep of the Document shall be with the Functional Production
Manager UOP, the Owner. Changes to this document shall only be authorised and
approved by the Owner.
Users of the Document who identify inaccuracy or ambiguity can notify the Custodian or
his/her delegate and request changes be initiated. The Requests shall be forwarded to
the Custodian using the “User Feedback Page” provided in this Document.
The Document Owner and the Document Custodian shall ensure review and reverification of this procedure every 3 years.
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1.5
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Step-out Approval
This procedure is mandatory and shall be complied with at all times. Should compliance
with the procedure be considered inappropriate or the intended activity cannot be
effectively completed or safely performed, then step out approval must be obtained from
the Asset Manager - using the PR-1001e – Operations Procedure Temporary Variance,
prior to any changes or activities associated with the procedure being carried out.
1.6
ALARP
ALARP is the acronym for ‘As Low As Reasonably Practicable’ which simplified means,
‘reducing the risk to a level at which the cost and effort (time and trouble) of further risk
reduction are grossly disproportionate to the risk reduction achieved’. Full Compliance
to PDO Standards and Procedures is a key element in achieving ALARP.
For more details refer to ALARP Definition
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Roles and Responsibilities
Asset Holder

Accountable for ensuring all HSE Procedures are
implemented within the asset
Production Coordinator

Responsible for ensuring that HSE Procedures and
Risk Assessments are conducted and are adhered to
in the area
Responsible Supervisor

Inspect work site with Permit Applicant

Check Job Safety Plan and ensure Risk
Assessments are completed for each Confined
Space Entry.

Authorise the Permit to Work (PTW)

Check Section 2 of the ‘Confined Space Entry
Certificate’

Authorise the isolation on Mechanical Isolation
Certificate

Authorise ‘Entry’ to confined space

Validates PTW
Area Authority

Permit Applicant
Permit Holder

Conduct isolations

Inspection of work site on completion when PTW is
closed

Check Section 2 of the ‘Confined Space Entry
Certificate’1

Authorise ‘Entry’ to confined space2

Applicant for PTW

Conduct safety checks of site and Risk Assessment
with Responsible Supervisor prior to any works being
carried out

Carry out ‘toolbox’ talks prior to works being carried
out

Oversee safety of personnel and work within
‘confined space’

Ensuring strict adherence to all Safety Procedures,
Job Safety Plan, Risk Assessments and Work
Instructions

Checking condition of work site on completion of all
works
1
If delegated by Responsible Supervisor
2
If delegated by Responsible Supervisor
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Check Job Safety Plan and ensure Risk Assessment
controls are adhered to
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Standby Personnel3
3
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
Maintain register of entry / exit of personnel during
work in confined space

Maintain communication and visual contact with all
personnel in the confined space

Maintain emergency rescue equipment at all times
during work in the confined space

Record any incidents during work process
Nominated on the Confined Space Entry Certificates
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3
Confined Space Entry Procedure
3.1
Preparation for Confined Space Entry
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CAUTION: Entry into confined spaces exposes personnel to risk in addition to
those associated with the work / task. Entry into a ‘Confined Space’ should only
be considered if the work cannot be accomplished from an external location.
3.1.1
Potential Hazards Associated with Confined Space Entry
Potential hazards associated with confined space entry are recognised. These hazards
can be any or all of the following:
3.1.2

Oxygen deficiency or enrichment

Flammability (fire and / or explosion)

Residual liquids, or solids and associated toxic or other noxious gases

Chemical hazards

Physical hazards

Number of personnel working within the confined space

Restricted entry / exit

Narcotic and anaesthetic effect of hydrocarbon gas and vapours
Planning and Risk Assessment
The first priority is to consider if the work in the confined space can be limited or
avoided. Alternatives may be:

Residues may be removed from the outside using water jetting or in place
cleaning systems.

In some cases it may be possible to see inside without entering by using a
boroscope.

Use of non invasive inspection techniques
If the work is to be carried out in a confined space a risk assessment shall be completed
covering all activities that will be carried out both inside and outside of the space.
Personnel selected for confined space entry shall have the correct level of competence,
experience and knowledge as indicated by the risk assessment. It will be necessary to
include Vendors / 3rd parties or HSE professionals in this task.
The risk assessment will consider but is not limited to:
Page 10

Previous contents of the confined space

Internal temperature and humidity of confined space

Ingress of substances

Oxygen deficiency or oxygen enrichment

Residues

Contamination

Physical dimensions including internal structures or obstacles

Nature of any work itself, including concurrent activities.
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The maximum number of personnel required to work in the confined space
The outcome of the risk assessment process shall be a Job Safety Plan approved by
the Responsible Supervisor, who shall determines what mitigation must be put in place
based on the Risk Analysis.
Where the risk assessment indicates that properly trained individuals can work for
periods without supervision, it should be ensured that they are competent to follow the
established safe system of work and have been provided with adequate information and
instruction about the work to be done.
The Permit Applicant shall prepare a rescue plan as part of the Risk Assessment
Process suitable for the agreed maximum number of personnel and covering each
entry. This document should be reviewed and approved by the Responsible Supervisor.
Some examples of possible inclusions to the rescue plan are:

Number of personnel required to provide effective rescue.

The equipment required for immediate use

Contingency plans for loss of communication

Safest route of access and egress with respect to casualty handling

Removal of unnecessary obstacles, which will hinder rescue operations
NOTE: These issues may limit number of people in confined space
The Permit Applicant must appoint a trained rescue team before work begins. For
efficient functioning, a rescue team must consist of at least two persons. The Permit
Applicant must be sure that the designated rescue team can be deployed quickly in an
emergency and that they will be able to function effectively. If assistance is required this
shall be provided by the Area Fire Service.
The rescue team must be equipped with suitable personal protective equipment to
enable them to function efficiently.
Rescue plans covering the maximum permitted number of personnel will be agreed and
practiced before any entry takes place. If it is not possible or practicable to perform
training exercises before entry, it is the Permit Applicant responsibility to ensure all
parties with responsibilities under this plan are competent in their roles.
Entry into a confined space shall be controlled by a PTW.
All persons holding safety competent roles e.g. gas tester, must be have valid PDO
Passports showing their qualifications.
Personnel required to work safely in confined spaces must have had adequate training
and experience in the particular work involved. Training standards must be appropriate
to the task, and to the individual's roles and responsibilities, so that work can be carried
out.
In order to achieve the above the following conditions require being satisfied and / or
detailed in the Job Safety Plan prior to entry into a confined space:
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
All entries into a confined space shall be controlled by the PTW system

When entry is required, the confined space shall be physically isolated from all
sources of hazardous substances, and from all sources of energy or motive
power

Hazardous substances contained within the confined space shall be displaced,
and the space suitably cooled and ventilated;

The confined space shall be tested for the presence of hazardous substances
and for acceptable oxygen content. If conditions for safe entry cannot be
achieved or guaranteed, additional precautions to be applied, e.g. the use of
breathing apparatus
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CAUTION: Additional to the use of Portable Multi-Gas Testers confined
spaces that have contained hydrocarbons shall be tested using a PhotoIonization Detector (PID – e.g. Draeger tube) to confirm that Occupational
Exposure Levels are complied with before an entry is made. This is
particularly important for the very low exposure limits of the carcinogenic
compounds such as Butane, Pentane and Benzene.
3.1.3

Provision of personal protective clothing and equipment (personal gas detectors
if required), access and egress, standby personnel, and rescue plans

When a person is in a confined space a standby person shall be in attendance
at all times and the responsible supervisor shall ensure that this person is
authorised and fully briefed on the activity to be undertaken

Additional hazards, including concurrent activities in the vicinity of, or within, the
confined space are considered

When entry to a confined space is required using breathing apparatus, only
those persons trained and deemed competent in the use of the breathing
apparatus shall be allowed to enter the confined space

All personnel involved in the confined space entry shall made aware of the
hazards
Gas Freeing and Flushing
Tanks, towers and vessels that have contained hydrocarbon or toxic materials shall
require gas freeing and ventilation before entry4 can be made.
Gas freeing shall be in accordance with PDO Procedures, PR-1073 - Gas Freeing,
Purging & Leak Testing of Process Equipment (Excluding Tanks) and PR-1079 - Gas
Freeing and Purging of Tanks Procedure. Once gas freed and drained5 the confined
space can be opened and ventilated. This method may be employed where high
concentrations of toxic gases are encountered.
Flushing with water (produced if available) shall be used on pipework, tanks, towers and
vessels to remove heavy hydrocarbon deposits before opening for cleaning and / or
maintenance and repair.
3.1.4
Working Atmosphere
Gas testing of confined spaces shall only be carried out by an Authorised Gas Tester
and shall be as specified on the PTW and recorded on the Confined Space Entry
Certificate and the Additional Gas Test Record form (if required).
OXYGEN
Confined spaces may only be entered when the atmosphere inside has been certified as
having a safe oxygen (between 20%-21%) content as indicated by approved PDO
detection apparatus.
WARNING: If the oxygen content is less than 20% the vessel MUST not be
entered.
4
This may not be the case if the tank or vessel is to be washed and cleaned prior to gas freeing
and ventilation. In such cases personnel entering the space shall be equipped with breathing
equipment.
5
When using water to gas freeing tanks, towers and vessels ensure that high level vents or man
ways / access hatches are open to prevent drawing and negative pressure and risking collapse.
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FLAMMABLE
Entry into confined spaces where there is any possibility of flammable vapours, gas
testing with an approved PDO explosive meter shall be carried out and recorded. This
meter must be capable of measuring hydrocarbons in an inert atmosphere if the
confined space has been subjected to gas freeing using nitrogen. (examples are
Ray Systems MX6 or MSA Tankscope.) The frequency of subsequent testing shall be
stipulated on the PTW. If a reading greater than 0% is indicated the Responsible Person
or his delegate must be notified and any required restrictions or precautions to be taken
shall be entered on the "Confined Space Entry Certificates".
Flammable process hydrocarbon vapours are also hazardous due to their potential
narcotic / anaesthetic effects, and can result in irrational behaviour, loss of
consciousness, or even death. Hazardous concentrations can be related to flammability
limits (Refer to Appendix 1). Continuous ventilation shall be established within these
spaces where possible.
TOXIC
Where toxic vapours may be present and continuous ventilation is not considered
possible or feasible, each man entering the confined space shall wear positive pressure
respiratory6 protection.
If NORM or Mercury is suspected then the necessary external and internal tests MUST
be carried out by competent persons and the results checked and confirmed by the
Production Chemists. If the tests are outside the specified limits, the confined space
should be ventilated continuously and re-tested at regular intervals until acceptable.
Further information on NORM and Mercury can be obtained in:
SP-1170 - HSE Specification - Naturally Occurring Radioactive Materials (NORM)
PR-1515 - Control of HSE Risks of Dealing with Mercury in PDO Facilities
INTERNAL TEMPERATURE & HUMIDITY
For entry to spaces like Waste Heat Recovery Units of gas turbines, additional hazards
may exist. These hazards exist due to the operational service where the space has been
subjected to high temperature. Hazards such as internal temperature, humidity and hot
surfaces should be included in the risk assessment, and suitable controls put in place.
These controls could for example, result in work duration being reduced accordingly.
BREATHING APPARATUS
For entry in to a confined space without the use of breathing apparatus, tests may
include but are not limited to:

Oxygen (between 20%-21%)

H2S shall be no greater than 1ppm

Benzene shall be less than 1ppm, but preferably zero

Hydrocarbons in air less than 2% LEL but preferably zero (see Table)
<2%
Entry allowed without BA
≥2% and <10 or atmosphere Entry only with BA
unsustainable
≥ 10%
No entry allowed
6
Respiratory protection for each man in the confined space and for the Standby Personnel must
be provided where the Responsible Supervisor / Permit Holder consider it necessary. At least
one properly connected air mask shall be available outside of the confined space for rescue
purposes. This should be included on the JSP.
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CAUTION: If it is considered that the breathable atmosphere cannot be guaranteed then
entry shall be completed wearing breathing apparatus.
3.1.5
Ventilation
Ventilation shall be employed to make the atmosphere inside of the confined space able
to ‘support life’. Where the atmosphere in the confined space is flammable or toxic,
forced ventilation will be employed to extract and clean air be allowed to replace that
extracted by natural circulation from a low point.
WARNING: Outside air shall not be forced in to expel the flammable atmosphere
as this may cause an explosive mixture being formed.
When dealing with vessels and tanks etc, that are have a risk of pyrophoric deposits
being present within the internals reference should be made to PR-1077 – Preparation
of Static Equipment for Internal Maintenance and Inspection Section 4.2 Confined Space
Entry.
3.1.6
Positive Isolation
Before any entry is permitted to a confined space positive isolation shall be carried out
as required.
Process equipment and systems shall be positively isolated as detailed in PR-1076 –
Isolation of Process Equipment.
MECHANICAL
Mechanical isolations shall be carried out using ‘spades and blind’ where applicable, or
removal of spool pieces where applicable.
ELECTRICAL
Electrical shall be isolated at the MCC or switchboard. All isolations should be carried
out by a ‘competent person’ and be tagged in accordance with SP-1104 - Electrical
Safety Rules and the issue of an Electrical Isolation Certificate which shall be attached
to the PTW.
3.1.7
Use Naked Flames and Arc
Strict control shall be exercised on the use of ‘naked flames or arc welding’ equipment
inside or in the vicinity of confined spaces where flammable vapours are or could be
present. Such works shall require a ‘Hot Work Permit’ to be in force.
Fixed and portable fire equipment, correct for the type of work being undertaken, shall
be provided at and adjacent to the work place.
WARNING: CO2 or dry powder type extinguishers shall not be used inside of
confined spaces when personnel are inside. Accordingly water shall not be used
if ‘live’ electrical equipment is being used inside the confined space. In the event
of a fire personnel shall be evacuated as quickly and safely as possible.
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3.1.8
General
PERSONAL PROTECTION EQUIPMENT (PPE)
Correct PPE shall be worn at all times while the work is being undertaken. Specialised
PPE required for specific tasks shall be made available to all personnel involved. The
requirements of specialized PPE shall be made on the Job Safety Plan.
SAFETY HARNESSES / LIFELINES
Safety harnesses shall be provided for all persons working inside the confined space if
the work involves scaffolding or ‘raised’ platforms. Suitable ‘strong points’ shall be made
available if not already provided.
Lifelines shall be used at all times by personnel inside the confined space.
PORTABLE POWER TOOLS
Where practical power tools used within confined spaces shall be ‘pneumatic’. Use of
electrically powered equipment shall be kept to a minimum and be in accordance with
SP-1111 - Temporary Electrical Supplies for Construction & Maintenance Work.
The preference shall also be made to adopt pneumatic lighting for confined spaces
rather than those powered from electrical circuits.
3.2
Confined Space Entry Process
The following process shall be followed or adapted when undertaking work which
requires ‘entry into a confined space’.
The following Permits and Certificates are associated with Confined Space Entry:

Permit to Work (PTW)

Confined Space Entry

Mechanical Isolation

Additional Gas Test Record

Electrical Isolation
The Permits and Certificates shall be completed, signed and attached to the PTW with a
Job Safety Plan (including Risk Assessment) and all relevant drawings and documents.
1.
When confined entry is required to undertake maintenance, repair or
modification it must be accessed if a full or partial process shutdown of the
facility or system is required.
2.
If a shutdown is not required then proceed to Step 3.
If a shutdown is required this shall have been planned in to the 90 day
‘Integrated Activity Plan’ and provisions made (deferment) for the loss in
production.
If the shutdown has not been planned then a ‘variance’ to the ‘Integrated
Activities Plan’ shall be required to be made. This shall require the correct
approvals and authorisations being obtained.
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CONFINED SPACE
ENTRY REQUIRED
DOES CONFINED SPACE
ENTRY REQUIRE PROCESS
SHUTDOWN?
YES
NO
NO
OBTAIN NECESSARY
PERMISSIONS AND APPROVALS
IS THE PROCESS SHUTDOWN
PLANNED?
YES
PERMIT APPLICANT
RAISES PERMITS, CERTIFICATES
AND JSP
RESPONSIBLE SUPERVISOR
REVIEWS
NO
PERMIT TO WORK
AUTHORISED?
YES
VESSEL/TANK/EQUIPMENT
PREPARED FOR ISOLATION AND
ENTRY
HAVE ALL SAFETY PRECAUTIONS
BEEN APPLIED?
PERMIT TO WORK AND
CERTIFICATES ISSUED TO
PERMIT HOLDER
NO
YES
ISOLATION CARRIED OUT BY AREA
AUTHORITY
PERMIT HOLDER CONDUCTS TRIC
TALK
CARRYOUT WORK WITHIN THE
CONFINED SPACE AS DEFINED ON
THE PERMIT TO WORK
VESSEL/TANK/EQUIPMENT
DRAINED/GAS FREED AND
VENTILATED
ARE PERIODIC GAS TEST
REQUIRED?
YES
AREA AUTHORITY/GAS TESTER
TO PERFORM PERIODIC
GAS TESTS
NO
INITIAL GAS TESTES CARRIED OUT
BY THE AREA AUTHORITY/
REGISTERED GAS TESTER
CLOSURE INSPECTION BY AREA
AUTHORITY BEFORE CLOSURE OF
CONFINED SPACE AND
DE-ISOLATION
NO
ARE GAS TESTS WITHIN
THE REQUIREMENTS FOR
CONFINED ENTRY TO PROCEED?
YES
NO
PERMIT TO WORK CLOSED
OUT?
NO
CONFINED SPACE ENTRY
AUTHORISED?
YES
YES
VESSEL/TANK/EQUIPMENT
HANDED BACK TO
PRODUCTION
WORK
COMPLETE
Confined Space Entry Process Flow
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3.
The ‘Permit Applicant’ shall complete the PTW and the Confined Space
Entry Certificate as required. Depending on the nature of the work to be
undertaken additional Certificates such as Mechanical7 and Electrical
Isolation may be required.
4.
The permit applicant and the ‘Responsible Supervisor’ shall inspect the work
site and identify all hazards. The permit applicant and responsible supervisor
shall produce and agree a Risk Assessment which will form the basis of a
‘Job Safety Plan’ which shall be approved by the responsible supervisor.
5.
The responsible supervisor shall:

authorise the PTW

authorise the isolation on the Mechanical Isolation Certificate

check the ‘Confined Space Entry Certificate’ safety precautions
(Section 2)

approve the risk assessment and Job Safety Plan
6.
Once authorised the PTW and all other required certificates shall be issued
to the ‘Permit Holder’ to undertake the work.
7.
The area authority shall oversee or undertake the required isolation in
accordance with the mechanical isolation certificate and ensure that
electrical isolations have been made and certified by the competent electrical
person. The isolations shall be signed for on the PTW and / or the
Mechanical / Electrical Isolation Certificates.
8.
The permit holder shall complete the TRIC and conduct a TRIC talk’ to
ensure that personnel working on the job are aware of the safety hazards,
the risk assessment contents, control measures required and emergency
response procedures.
The permit holder shall oversee the provision of all necessary safety
equipment and that the correct tools and PPE are provided.
9.
The Area Authority shall check that all safety precautions have been taken
and that all required equipment for the confined space entry is available.
10.
Once the PTW has been validated by the area authority the
vessel/tank/equipment can be drained, gas freed and opened for ventilation.
11.
The initial gas test shall be taken when the confined space has been
ventilated or prepared for entry. When gas freeing using nitrogen has taken
place a meter capable of measuring hydrocarbons in an inert atmosphere
shall be used. The gas test shall be conducted by the area authority or
registered gas tester. The results are entered on the Confined Space Entry
certificate.
12.
Once the gas tests have been conducted and the confined space conforms
to the requirement the authorisation can be issued by the responsible
supervisor / area authority. The authorising authority shall sign the
appropriate section of the Confined Space Entry certificate.
7
Isolations can be entered on the PTW, however if the isolation is complex a Mechanical
Isolation Certificate is used. This may be backed by additional documents if more space is
required.
Page 17
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CAUTION: Before entry shall be authorised confined spaces that have
contained hydrocarbons shall be tested using a Photo-Ionization
Detector (PID – e.g. Draeger Tube) to confirm that levels Butane,
Pentane and Benzene (highly narcotic) are below OEL and % volume
required to produce surgical anaesthesia.
13.
The work can be carried out within the confined space in accordance with
that defined on the PTW. The permit holder shall oversee the work and
ensure that ‘entries’ and ‘exits’ are logged on the Confined Space Entry
certificate.
The appointed ‘standby man/men’ shall maintain communication with the
personnel inside the confined space and also the area authority / CCR.
Page 18
14.
Additional gas tests (including PID if considered necessary) shall be carried
out in accordance with the PTW. These gas tests shall be entered at the
correct intervals on the Confined Space Entry certificate or the Additional
Gas test Records sheet.
15.
On completion of the work the permit holder shall oversee the ‘normalisation’
of the work site. The confined space shall be inspected and all ‘entry and
exit’ records checked before closure is authorised. Inspection and
authorisation for closure shall be given by the area authority or responsible
supervisor.
16.
On closure the Permit Holder carry out reinstatement testing of the
equipment / vessel and remove or oversee the removal of all isolations with
the Area Authority. The Area Authority shall be close out the PTW.
17.
The vessel/tank/equipment shall be handed over to production and brought
back into service.
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Appendix 1 – Narcotic Effect of Hydrocarbons
The following links shall take the user of this procedure to sites where reference information can
be obtained on:
Exposure Limits:
http://www.hse.gov.uk/coshh/table1.pdf
Lower Explosive Limits / Lower Flammable Limits
http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html
General Description of the Immediate Hazards Associated with Hydrocarbon Releases
http://www.hse.gov.uk/offshore/notices/sn_04_04.htm
Anaesthetic Effects of Hydrocarbon Gas
It requires around 4 breathes to become affected by the vapours - irrespective of
concentration. It requires the same number of breaths of uncontaminated air to return to
normal.
Page 19
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Appendix 2 – Abbreviations
CCR
Central Control Room
MCC
Machinery Control Centre
ALARP
As Low As Reasonably Practical
CCR
Central Control Room
HSE
Health Safety and Environment
LEL
Lower Explosive Limit
PPE
Personal Protection Equipment
PTW
Permit to Work
Page 20
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Appendix 3 – Reference Material
PDO Codes of Practice
CP-115 - Operate Surface Product Flow Assets - CoP
PDO Specifications
SP-1104 - Electrical Safety Rules
SP-1111 - Temporary Electrical Supplies for Construction & Maintenance Work
SP-1170 - HSE Specification - Naturally Occurring Radioactive Materials (NORM)
PDO Procedures
PR-1001e – Operations Procedure Temporary Variance
PR-1066 - Emergency Response document Part III Contingency Plan, Volume III
Production Operations
PR-1073 - Gas Freeing, Purging & Leak Testing of Process Equipment (Excluding
Tanks)
PR-1076 – Isolation of Process Equipment
PR-1077 – Preparation of Static Equipment for Internal Maintenance and Inspection
PR-1078 - Hydrogen Sulphide Management
PR-1079 - Gas Freeing and Purging of Tanks Procedure
PR-1081 - The Buddy System
PR-1172 - Permit to Work System
PR-1515 – Onsite Mercury Management Procedure
PDO Guidelines
Other Documents
ALARP Definition
Page 21
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Appendix 4 – User Feedback Page
PR-1148 – Confined Space Entry User Feedback Page
Any user who identifies an inaccuracy, error or ambiguity is requested to notify
the custodian so that appropriate action can be taken. The user is requested
to return this page fully completed, indicating precisely the amendment(s)
recommended.
Name:
Ref ID
Page Ref:
To:
Date:
Brief Description of Change Required and Reasons
UOP7
Custodian of Document
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PR-1148 - Confined Space Entry
Date:
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Addendum 1 – Changes at Revision 3.1
Page
Changes
7
Section 1.5 Roles and Responsibilities
Production Supervisor – “and Risk Assessments” added
Responsible Supervisor – “and ensure Risk Assessments are” added
Area Authority – “and ensure Risk Assessment controls are adhered to” added
Permit Applicant – “and Risk Assessment” added
8
Section 1.5 Roles and Responsibilities
Permit Holder – “Risk Assessments” added
10
Section 2.1.1 – “Number of personnel working within the confined space” and “The
maximum number of personnel required to work in the confined space “ added
11
3rd para “as part of the Risk Assessment Process suitable for the agreed maximum
number of personnel for each” added
“NOTE: These issues may limit number of people in confined space” added
6th para “covering the maximum permitted number of personnel” added
13
FLAMMABLE
“This meter must be capable of measuring hydrocarbons in an Inert
atmosphere if the confined space has been subjected to a nitrogen purge.
(examples are Ray Systems MX6 or MSA Tankscope.)” statement made bold and
examples added
15
Step 4 – “and responsible supervisor shall produce and agree a Risk Assessment
which will form the basis of” added
17
Step 11 – “When nitrogen purging has taken place a meter capable of measuring
hydrocarbons in an inert atmosphere shall be used.” added
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Addendum 2 – Changes at Revision 4.0
Page
Changes
General
Added New Front page / Added new Owner / Moved related documents to Appendix
3 Reference Material / moved roles and Responsibilities to Section 2 / Renamed
Appendix 1 / changed “purging” to “gas freeing” to align with PR-1073
Page 7
Section 1.1 Background – removed last two para’s. Not necessary
Section 1.2 Purpose – Changed to read “The purpose of this procedure is to provide
all personnel, PDO or contract, with clear and concise instructions for entering or
working within a confined space.”
Page 8
Section 1.4 Changes to Document – added ‘shall’ in place of “should” in last para
Page 10
Section 3.1.2 – changed 2nd para to “If the work is to be carried out in a confined
space a risk assessment shall be completed covering all activities that will be carried
out both inside and outside of the space.”
Re-ordered last after “The risk Assessment will ---“ and removed “atmosphere”
Page 13
1st para after bullets – changed to read “The outcome of the risk assessment process
shall be a Job Safety Plan approved by the Responsible Supervisor, who shall
determines what mitigation must be put in place based on the Risk Analysis”.
Page 20
Amended the Process Flow diagram – moved the TRIC talk between “isolation
Carried Out” and “Vessel / tank / equipment drained / gas freed and ventilated”
Amended procedural steps to capture changes
Pages
19-22
Page 24
Re-arranged Appendices.
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