2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
The Use of Stability Maps in the Design and
Operation Gas-Lift Wells
UNAM - National Autonomous University of Mexico
PEMEX Exploration & Production
Author(s):
Contact Information:
Y. V. Fairuzov
I. Guerrero-Sarabia
A. Rojas-Figueroa
fairuzov@servidor.unam.mx
Abstract:
Continuous flow gas-lift wells are susceptible to hydrodynamic instability (heading), which may cause cyclic variations
of the wellhead pressure, and oil and gas flow rates. Gas-lift instability is a cause of many operational problems, for
example:



compressor shutdowns caused by pressure and liquid flow rate surges
difficulties in the operation of low pressure separators
excessive gas consumption.
Stability problems in complex multiphase systems can be solved using stability maps. A stability map is a plane (2D)
diagram that shows the regions of stable and unstable operation of the system, as well as its operating limits.
In this paper theoretical and experimental stability maps for gas-lift wells are presented. Field tests were conducted to
investigate the flow stability in a deep offshore gas-lift well. Different gas-lift stability criteria proposed in the literature
are compared. Based on this study, recommendations on the selection of gas-lift stability criteria were developed.
Examples of gas-lift stability map applications are also given.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
Application of Surface-Controlled Gas-Lift
Valves For Natural Gas Cap Lift On BHPB
Lennox Field
Schlumberger
BHP Billiton
Author(s):
Contact Information:
Eric Lovie
Kevin Burke
twhite@houston.oilfield.slb.com
Abstract:
The Lennox field is situated 5 km off the English west coast, part of BHP Billiton’s Liverpool Bay Development in the
Irish Sea.
A combination of increasing facilities back-pressure, decreasing reservoir pressure and increasing watercut
prevented some of the wells from restarting after shut-in. Coiled tubing intervention was used to kick off such wells
but the small unmanned platform meant that this process could only be performed on a campaign basis rather than
as normal production operations, resulting in reduced oil recovery.
In 2003 a Multiphase pump system was installed on Lennox allowing the tubing head pressure to be successfully
‘drawn down’. However, as the lifting problem became more acute, a number of wells required continuous artificial
lift in order to keep them flowing. Continuous gas lift was considered but this posed a number of challenges including:
(1) cost and timescale for topside modifications, (2) the need for increased metallurgy to handle the high H2S content
of the lift gas, (3) poor condition of installed casing, (4) safety implications of increased gas inventories and (5) the
requirement for an Annular Safety Valve as per UK legislation.
The solution to overcome these problems was to use the natural gas cap of the reservoir to provide lift. A surface
controlled gas lift valve, the Schlumberger WRFC-H (Wireline Retrievable Flow Controller - Hydraulic) was installed
in each well and it’s variable choke utilized to provide control of gas from the reservoir. Once the oil layer has been
depleted the WRFC-H can be opened fully, converting the well to gas production.
During 2005 six wells were re-completed in this manner. This paper describes the introduction of WRFC-H valves for
natural gas cap lift in BHP Billiton’s Lennox field and results achieved to date.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
Effect of Operating Valve Performance on
Stability of Gas-Lift Wells
UNAM - National Autonomous University of Mexico
Author(s):
Contact Information:
Y.V. Fairuzov
fairuzov@servidor.unam.mx
I. Guerrero-Sarabia
Abstract:
Continuous flow gas-lift wells are susceptible to hydrodynamic instability (heading), which may cause cyclic variations
of the wellhead pressure, and oil and gas flow rates. Gas-lift instability is a cause of many operational problems, for
example:



compressor shutdowns caused by pressure and liquid flow rate surges
difficulties in the operation of low pressure separators
excessive gas consumption.
Stability problems in complex multiphase systems can be solved using stability maps. A stability map is a plane (2D)
diagram that shows the regions of stable and unstable operation of the system, as well as its operating limits.
In this paper theoretical and experimental stability maps for gas-lift wells are presented. Field testswere conducted to
investigate the flow stability in a deep offshore gas-lift well. Different gas-lift stability criteria proposed in the literature
are compared. Based on this study, recommendations on the selection of gas-lift stability criteria were developed.
Examples of gas-lift stability map applications are also given.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
Gas-Lift Dynamic Simulation - Best
Practices
Scandpower Petroleum Technology
Author(s):
Contact Information:
Juan Carlos Mantecon
juan.mantecon@scandpowerpt.com
Abstract:
Currently, there are no standards or best practice recommendations on the application of dynamic
simulation techniques for designing and/or optimizing gas-lift wells and systems.
This leads to much unawareness, confusion, and misunderstanding about why and when we should add
value by implementing these advanced techniques.
This presentation sets some guidelines on when to apply steady state simulation, which is the current
standard to analyze our gas-lift wells, and when to apply dynamic simulation (transient analysis).
These guidelines should facilitate oil and gas production companies in the decision making process on when to apply
dynamic simulation as a tool. For instance, the unique features and flow assurance requirements of subsea wells and
flowlines, along with the high associated capital costs, clearly merit detailed dynamic analysis for design
development. Dynamic simulations provide valuable information for savings and reduction of potential problems (risk
reduction) during well completions and production system kick-off operations. The knowledge of the minimum flow
rates required to clean up the wells will have relevant implications on equipment selection (size) and therefore cost
minimization. Furthermore, the ability to predict (what if cases) and be prepared to deal with potential problems not
only can save millions of dollars but can minimise any environmental impact.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
Gas Turbine Inlet Air Fogging
Mee-Fog
Author(s):
Contact Information:
Thomas Mee
thomasmee@meefog.com
Abstract:
Inlet air fogging increases the output of gas turbines by up to 20%, depending on ambient conditions. Fogging can
eliminate production losses associated with hot-day operation of gas turbines and can give a further power boost by
over injecting fog into the compressor, which gives an evaporative inter-cooling effect.
The presentation will show results from inlet air fogging on dual-spool gas turbines used for driving gas-lift
compressors. It will also include experience with installing fog systems on a gas-lift platform in the Persian Gulf.
The presentation will be comprehensive but not too technical.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
I --- New Gas-Lift Technology
Shauna Noonan, ConocoPhillips
Presentation Title:
Company(ies):
Heavy Oil Gas Lift Using the Concentric
Offset Riser
2H Offshore, Inc.
Author(s):
Contact Information:
Adam Szucs
Frank Lim
szucsa@2hoffshoreinc.com
Abstract:
The production of heavy oil presents a number of problems to deepwater operators. A combination of
high fluid density, hence hydrostatic head, and viscosity in the risers tied back to the floating production
vessel limits the oil production rate. The Concentric Offset Riser (COR) offers a solution for convenient
provision of riser base gas lift all in a single arrangement. The injection of gas at the riser base mixes
with and lightens the oil, and hence enhances the production rate from heavy oil reservoirs.
The COR is a pipe-in-pipe riser system suitable for subsea developments tied back to a floating host
vessel. The annular space has many potential uses, one of which is gas lift. The vertical riser is tensioned
at the top with a buoyancy tank, and tied back to the production vessel with a flexible jumper. Such
systems are being implemented in West Africa.
The paper describes the benefits of implementing the COR design for deepwater heavy oil developments.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
II --- Gas-Lift Automation, Optimization
Greg Stephenson, eProduction Solutions
Presentation Title:
Company(ies):
Optimising Production on Mature Gas-Lifted
North Sea Assets – A Case Study
Talisman
Edinburgh Petroleum Services
Author(s):
Contact Information:
Grant Ballantyne
Andrew Shere
Sybille Handley-Schachler
Greg.Stephenson@ep-solutions.com
Abstract:
This paper discusses the application of production optimisation to some of Talisman’s mature, gas-lifted North Sea
assets. For the Claymore, Piper, and Clyde assets, the challenge was to increase production by optimising the usage
of current wells and infrastructure with appropriate capital investment.
This paper illustrates how these challenges were met by building integrated detailed optimisation models using a
commercially available software package. It shows how facility and production constraints were taken into account
during the optimisation process to ensure that optimisation results were directly applicable to field conditions and how
the asset model was able to predict and describe the complex interdependencies between wells, processing facilities,
and gas-lift compressors and equipment.
As a result of this asset optimisation, gas-lift designs were modified, the allocation of lift gas to wells was revised,
wells were identified for re-routing to different production manifolds, and process equipment settings were adjusted.
This paper discusses the details and the effects of these changes and shows how through this process significant
increases in production with minimal capital expenditure were predicted by the model and the gains later achieved in
the field.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
II --- Gas-Lift Automation, Optimization
Greg Stephenson, eProduction Solutions
Presentation Title:
Company(ies):
Integrated Field Modeling for Production
Optimization
Dubai Petroleum Company
Edinburgh Petroleum Services
Author(s):
Contact Information:
Clint Chester Olmstead
Manickam S. Nadar
Laurence Ormerod --- Presenter
manickam.nadar@e-petroleumservices.com
Abstract:
Operating an integrated production network can be a complex process. Production optimization involves operating at
peak performance and resource allocation to the different fields. System upsets in one field can create problems in
others. Changes to operating parameters, producing wells and the network distribution systems require re-iterations
of the set points for entire system for optimization.
Dubai Petroleum Company is operating four fields offshore of the United Arab Emirates. The complexity of modeling
and maintaining accurate models is challenging. Dubai Petroleum Company has implemented integrated field
models for the production optimization and gas distribution systems. This presentation will outline the development
process and timeline used to implement such a system, the results and benefits of the optimization and how it has
impacted the business of the company. Finally, progress towards the next logical step - real time optimization.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
II --- Gas-Lift Automation, Optimization
Greg Stephenson, eProduction Solutions
Presentation Title:
Company(ies):
Gas-Lift Surveillance and Optimization
Shell Global Solutions
Author(s):
Contact Information:
Ron Cramer
Ronald.Cramer@shell.com
Abstract:
Description of gas-lift optimization/surveillance problems, opportunities and solutions in light of customer experience.
Emphasis will be placed on importance of knowing what the wells are producing in real time and relating that to
injection gas rates. Cost effective approaches using minimal, commodity instrumentation and interfaces between
software applications also will be discussed.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
III --- Gas-Lift for Tension Leg Platforms
Jerry Robinson, Weatherford
Presentation Title:
Company(ies):
Gas-Lift in TLP Wells
Weatherford
Author(s):
Contact Information:
Jerry Robinson
Abstract:
Deepwater TLP completions in the Gulf of Mexico present several challenges for traditional gas lift methods. One of
the first challenges is the mere fact that these types of wells are often located in water depths that can be as much as
6,500’. This deepwater environment dictates that special consideration be given, but not limited to: (1) Method of
unloading the riser section, (2) Gas lift injection pressure for kickoff and operating, (3) Gas lift injection rate
requirements, (4) Gas lift mandrel running OD’s, (5) Location of subsurface safety valve, (whether gas lift mandrels
will be run above, below, or both, (6) Temperature profiles for accurately predicting static and flowing temperatures
for setting nitrogen charged valves, and (7) accurate reservoir modeling to predict wells’ initial and future productivity.
Gas lift designs and equipment selections from several deepwater projects will be presented to address some of
these issues as well as the importance of accurate future reservoir performance information and what can be done in
its absence to insure successful, effective gas lift performance.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
III --- Gas-Lift for Tension Leg Platforms
Jerry Robinson, Weatherford
Presentation Title:
Company(ies):
Deepwater Gas-Lift: Issues and
Considerations when Gas Lifting in a
Deepwater Environment
Shell Offshore
Author(s):
Contact Information:
Nora Ghobrial
nora.ghobrial@shell.com
Shell recently started up it’s first deepwater gas lift project at Ram/Powell and found that
gas-lifting in a deepwater environment poses a unique set of challenges. This presentation highlights the
differences between Deepwater and Shelf environments including the safety issues involved and several
project design and execution considerations when pursuing deepwater gas lift. Well design, facility
design, and operational readiness items to consider are included.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
III --- Gas-Lift for Tension Leg Platforms
Jerry Robinson, Weatherford
Presentation Title:
Company(ies):
TLP Gas-Lift Design
Author(s):
Mike Johnson
Patrick Hyde
ExxonMobil
Contact Information:
mike.k.johnson@exxonmobil.com
Abstract:
ExxonMobil will present plans for the implementation of gas lift in new deepwater development.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
IV --- Field Reviews / Best Practices
Tom Nations, ConocoPhillips
Presentation Title:
Company(ies):
Integrated Gas-Lift System Optimization
Using Dynamic Simulation: A West African
Subsea Field Case
Scandpower Petroleum Technology
Author(s):
Contact Information:
Maria Alejandra Nass
maria.alejandra.nass@scandpowerpt.com
Abstract:
Gas lift is widely used as an artificial lift method for oil production. Many wells are completed today with gas lift valves
providing that they will become useful when reservoir pressure start declining or when water cut starts increasing.
Gas lift can be used not only for continuous lift but also for particular situations such as start-ups or clean ups.
Because of their nature, Gas lift systems have to be designed taking into account all the possible changes throughout
the life of the well and the field itself. Current gas lift design is usually performed with steady-state tools, making it
difficult for factors such as transient thermal and transient production phenomena to be taken into account.
In this study a dynamic multiphase flow simulator was used. Emphasis was placed on modeling the dynamics of the
integrated production system. The study allowed establishing the deepest injection point based on the available
compressor pressure for a range of gas lift rates. Another objective was to assure that instabilities in the flow regime
(i.e. slugging) would be avoided by choosing the right depth for the operating valve in all of the wells; additionally,
maximizing oil flow rate as excessive gas lift rates can hurt production.
Having the system as an integrated model (wellbores, annulus for gas lift injection and flowlines) allowed accounting
for the possible interaction of each element and helped in determining an optimal setting depth envelope for the gas
lift valves based on early, mid and late field life production data. The advantage of using this approach is that the total
network is modeled; for example, the effect of instabilities in one particular well can be seen on others as
backpressures in the system are also being modeled, etc.
This study also comprised the analysis of shutdowns and the dangers of possible hydrates formation for two different
cases. First, it was possible to find the critical steady-state flow rate to avoid hydrate formation after a 12 hrs
shutdown. Second, a detailed cool down analysis in the vicinity of the wellhead (un-insulated part of the completion)
was also made.
In addition to the critical steady state flow rate, it was also possible to conclude on the choke opening (with cases
including gas lift injection) that would lead to severe slugging problems. These results were later combined with the
setting depth for the GL valves in order to narrow down the region where flow stability could be guaranteed.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
IV --- Field Reviews / Best Practices
Tom Nations, ConocoPhillips
Presentation Title:
Company(ies):
PerfLift – Gas-Lift Case Studies in Gas Well
De-watering Applications
Schlumberger
Author(s):
Contact Information:
Robert “Boots” Rouen
twhite@houston.oilfield.slb.com
Abstract:
This presentation will review the application of perforation gas-lift (PerfLift) and case studies for numerous U.S. land
wells. This unique gas-lift system allows operators to unload and produce oil or gas wells in the perforated intervals
by increasing the critical velocity required to maintain and increase production. The novel tool string geometry allows
for gas injection and gas-lift functionality below the production packer.
The applications reviewed in the presentation include installations in 4-1/2-in. (2 completions), 5-1/2-in. and 7-in.
casing strings that have netted sustained gas production while maintaining continuous water production that would
normally prevent the wells from flowing. The success of these installations provides a solution to the prevalent gas
well de-watering problems existing in Brownfield markets while expanding the applicability of gas-lift systems.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
IV --- Field Reviews / Best Practices
Tom Nations, ConocoPhillips
Presentation Title:
Company(ies):
US Gas Lift Experience
ExxonMobil
Author(s):
Contact Information:
Rodney Bane
rodney.k.bane@exxonmobil.com
Abstract:
ExxonMobil uses a variety of methods for collecting Gas Lift surveillance data from our onshore and offshore US
fields. This presentation will review the three key methods used to collect data, troubleshoot problems, and plan
optimizations. The collection of Bottomhole Pressure Data (flowing and static pressures) using company owned and
operated wireline units will be discussed. A gas lift troubleshooting process using rotating offshore Gas Lift
Technicians will be described. Current and planned use of Automation for Gas Lift operations will be reviewed.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
IV --- Field Reviews / Best Practices
Tom Nations, ConocoPhillips
Presentation Title:
Company(ies):
Kuparuk Gas-Lift Optimizer
ConocoPhillips
Author(s):
Contact Information:
Kenneth Martin
K.L.Martin@conocophillips.com
Abstract:
In 2005, ConocoPhillips Alaska installed a near-real-time optimization system at Central Processing Facility 3 in the
Kuparuk River Unit.
This system, based on Petroleum Experts GAP software, is connected to the local automation system through
proprietary software and Petroleum Expert's OpenServer product.
The new optimizer replaced an existing company-developed optimization program which used the "equal-slope"
method of gas-lift optimization.
Central Processing Facility 3 is constrained on the amount of gas that can be processed, and within these constraints
the optimizer was able to predict an increase of 200 BOPD over the existing system which did not account for back
pressure.
This presentation will discuss the development, implementation, and initial results of the optimization system.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
IV --- Field Reviews / Best Practices
Tom Nations, ConocoPhillips
Presentation Title:
Company(ies):
Rigless Gas Lift Conversion – A Success
Story
Petroleum Consulting Ltd.
Author(s):
Contact Information:
Fortune Bikoro
fb@petroleumco.co.uk
Abstract:
MLC-1 is the only oil producer from the MLC satellite field located in block 405a onshore Algeria. It is part of the MLN
field development operated by Burlington Resources. The MLN field oil production operations started mid-2003, and
MLC-1 was open to production in December 2003.
The field has a defined maximum efficiency rate, or MER rate of 4,070 bopd, that it should not exceed. Within the first
year, the oil production rate dropped from 4,200 bbls/d to 1,500 bbls/d due to reservoir depletion. There is no
pressure support either by gas or water injection or any other producing well in the MLC field.
MLC-1 is a vertical well with 4.5” tubing to surface, stabbed into a 4.5” liner over the reservoir section. The well was
completed with completion brine left in the annulus. The well is tied back to a facility which separates oil and gas
from a number of fields and re-injects gas into other reservoirs at around 400bar. Therefore a high pressure gas
source is available.
Gas lift was identified as the best option to arrest the decline and return oil production to the MER rate. The gas lift
conversion was carried out without requiring a rig and without re-completing the well to install unloading valves. In
simple terms, the tubing was perforated with a tubing punch at the lowest possible point in the tubing above the
packer. Following this, the annulus between the 4.5” tubing and 9 5/8”casing was cleaned up and the perforations
straddled with a gas lift valve head system fitted with one way check valve to prevent fluid entering the annulus. The
annulus content was displaced using a high pressure gas source taken from the re-injection compressor at the
nearby facility.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
V --- Challenging Applications
Ken Hilse, Weatherford
Presentation Title:
Company(ies):
Gas-Lift for Steam Assisted Gravity
Drainage (SAGD) Developments
ConocoPhillips
Author(s):
Contact Information:
Shauna Noonan
Shauna.G.Noonan@conocophillips.com
Abstract:
The heavy oil recovery method by steam-assisted gravity drainage (SAGD) has become very prevalent in the
Canadian tar sands region. Billions of dollars are being spent on SAGD pilots and commercial developments. SAGD
is a thermal recovery method that utilizes twin parallel horizontal wells (one above the other as close as 5 m / 16 ft
apart) with steam injected into the top horizontal well and production lifted from the bottom. When steam is injected
into the upper wellbore, it creates a "steam chamber" within the surrounding reservoir. The resulting heat transfer
lowers the viscosity of the oil near the steam / crude interface and allows it to drain by gravity to the horizontal
production well below.
During the life of a SAGD well, it is likely to be completed with a method for artificially lifting production. Gas-lift is
one such method used for a SAGD producer, however it has come with its share of problems for many operators.
This presentation will provide an overview into the operational challenges of a SAGD producer, what types of gaslift designs and equipment have been used, what problems have been observed with these particular completions
and how the various operators have tried to solve them.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
V --- Challenging Applications
Ken Hilse, Weatherford
Presentation Title:
Company(ies):
Gas-Lift Well Diagnostics in A Non-Ideal
World
Shell EP Europe
Author(s):
Contact Information:
Wim der Kinderen
Wim.DerKinderen@Shell.com
Abstract:
Gas lift optimisation is easy when well and system models are calibrated and all relevant instruments and control
devices are operational. It is a lot more cumbersome, but still possible, to diagnose problems and optimise the
system if limited information is available. That is in particular relevant for subsea wells, where over-injecting lift gas
reduces overall production. Repair of subsea instrumentation is expensive, so often an acceptable workaround has to
be found. In many cases, information that is not readily available can be derived from other signals, using simple
models or empirical relationships. For example, the annulus pressure correlates with injection flowrate, and - for
subsea wells - the wellhead temperature drops when cold lift gas is mixed with hot well fluids. This is illustrated using
actual data trends.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
V --- Challenging Applications
Ken Hilse, Weatherford
Presentation Title:
Company(ies):
A Status Report on Gas Lift Systems in
Beaver Lodge Madison Unit Horizontal
Completions
Weatherford
Author(s):
Contact Information:
Ron Schmidt
kfangmeier@hess.com
Amerada Hess Corp.
Garth Hill, Dale Fredrickson, Jeff Hermann,
and Keith Fangmeier
Abstract:
Horizontal completions provide many artificial lift challenges in the mature Beaver Lodge Madison Unit (BLMU). The
Madison formation @ approximately 8400’ is naturally fractured and partially pressure depleted reservoir. BLMU
productivity is enhanced 5x-20x of a vertical completion by placement of horizontal drain holes orthogonal to the
natural fractures. Presently the following forms of gas lift are utilized in the BLMU:

Conventional gas lift with IPO valves—Tubing flow & 1200 psi GL system

Single point injection with orifice— Tubing flow & 1200 psi GL system

Single point injection with orifice— Tubing flow & 2200 psi GL system

Single point injection with orifice--Annular flow & 1200 psi GL system

Intermittent flow—Tubing flow & 1200 psi GL system
Partially pressure depleted reservoirs, unfavorable horizontal flow geometries, non-optimum casing designs, salt
saturated formation water, and naturally fractured reservoirs are a partial list of challenges encountered when
optimizing BLMU gas lift completions.
The following paper provides lessons learned and an overview of the above gas lift systems with an emphasis on the
BLMU single point injection completions.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
VI --- Gas-Lift Components
Jim Holt, Baker
Presentation Title:
Company(ies):
Sealing Gas-Lift Equipment
Greene, Tweed Oilfield Group
Author(s):
Contact Information:
Ron Edwards
redwards@gtweed.com
Abstract:
Sealing of gas-lift valves is one of those processes that can be relatively easy or a major headache. Some refer to
seals as “black and evil” or the weakest link in a valve. Nothing is more frustrating than to spend hours trying to get a
successful hydrostatic seal, dealing with a valve that is communicating or trying to pull a valve that is stuck. This
paper will answer the following questions:

What are the compatibility and temperature issues with various elastomeric compounds?

Chemical compatibility

Temperature limitations

What are the various modes of failure of gas lift seals?

Weeping

Delayed failure

Sudden communication

Rolling

Damage to seal gland

Contamination

Explosive Decompression

Poor manufacturing processes

How critical is the seal gland?

Surface finish

Corrosion, pits, and wear

Contaminates

Coatings

Why can’t I get a get successful hydrostatic test?

Why are some seals difficult to install?

Installing dry

Improper use of grease

Overfill

Why are some valves difficult to extract?

What about non-elastomeric seals in place of elastomeric?

Why are some seals doomed to fail?

Cost

Mind set

Preference

Aesthetics
How would seal assemblies vary for different environments?
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
VI --- Gas-Lift Components
Jim Holt, Baker
Presentation Title:
Company(ies):
Gas-Lift Bellows
Senior Flexonics
Author(s):
Contact Information:
Doug Isham
DIsham@seniorauto.com
Abstract:
Senior Flexonics manufactures gas-lift Bellows. These are 3-ply bellows in two different sizes. Inconel gas-lift
bellows have been made in the past. The functional requirements of gas-lift bellows were defined in the late 1950’s
early 1960’s by gas-lift valve manufactures. Monel 400 is the most common material used for gas-lift bellows and
was chosen for its corrosion resistance, economy, and ease of process.
We manufacture gas-lift bellows beginning with seam-welding of the three tubes or plies. Additional processing
brings the tubes to their final wall thickness. The tubes are telescoped together to make the three plies. The tubes
are then mechanically bulge formed which starts the formation of the corrugations. A roll forming process (a
mechanical spin and roll form process using grooving dies and an arbor) is done until the bellows come into final
dimension specification. Final form also now defines the bellows functional characteristics. The bellows are then
circumferentially circle welded to seal the plies together to make them leak proof. Units are Vacuum leak tested to
detect bad product and inspected for dimensional conformity.
Typical failure modes during the manufacturing process are inadequate circle welds on the plies, which is detected
during the leak test operation. The most common field failure is fatigue failure. The bellows plies will fatigue and split
or crack on the inner or outer corrugation bend radius due to being over worked (cycled) or subject to conditions
over-n-above their design limits.
When comparing the bellows with respect to their theoretical designed limitations versus how they are being used
today in their applications, it has many in the industry surprised and wondering just how the bellows survives under
the conditions they are subjected to.
Notes:
2006 Gas-Lift Workshop
Technical Presentations
Session:
Session Chair:
VI --- Gas-Lift Components
Jim Holt, Baker
Presentation Title:
Company(ies):
Gas-Lift Valve and Gas-Lift Mandrel
Metallurgy, Welding, and Testing
Baker Oil Tools
Author(s):
Contact Information:
Jim Holt
james.holt@bakeroiltools.com
Abstract:
Gas-Lift Mandrels and Gas-Lift Valves are being exposed to service conditions today that require careful selection of
materials and processes. This presentation is to review standard selected materials mostly used in the industry for
specific service conditions. Discussions will include materials strength, corrosion resistance and conditions suitable
for service conditions.
Mandrels and gas lift valves are an assembly of many components. To complete the assembly of these products
requires fabrication processes which includes welding and brazing processes. Discussions for typical fabrications
and processes will be discussed.
Any time there are fabrication processes used, there needs to be inspection methods at hand to verify the quality of
those processes being preformed. A brief review of those inspection methods will be discussed in this presentation.
Notes: