Transcript 2000 ASME/API Gas-Lift Workshop

2001 ASME/API Gas-Lift Workshop
Routine Validation Testing
of Every Gas-Lift Valve
Informal Presentation
by
Naiza Abdullah, Brunei Shell Petroleum
Ken Decker, Decker Technology
Cleon Dunham, Oilfield Automation Consulting
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Validation Testing
of Every Gas-Lift Valve
Outline
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Brief history
Business justification for routine testing
How the tester works
Intended operational use
Field experience
Outstanding issues
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
A Brief History
History
• Only the Ptro test is performed routinely
• In 1995, API RP 11V2 provided standards for
testing and modeling gas-lift valves
• In 1996, the Valve Performance Clearinghouse, an
industry JIP, was formed to implement 11V2
• Typically, the VPC tests one valve of each type
• Purpose of Gas-Lift Valve, Automatic Validation
Tester (GLV-AVT) is to test every gas-lift valve
– Before it is run
– After it is pulled
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Business Justification
Rationale for testing each valve
• Not all valves of a specific type are manufactured
to the original specifications
• Some companies are not API certified
• Some valves may be damaged in handling
• Many operating companies re-run used valves
• Operating conditions in wells vary
Operators need a high degree of assurance
that valves will perform as intended
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Business Justification
Justification for pre-installation testing
• Screen out valves that will not perform as
intended
– Due to manufacturing faults or limits
– Due to handling problems
– Due to setting problems
• Know actual valve characteristics
– May be different than "typical" valve tested by VPC
– Use actual characteristics in gas-lift programs
• Evaluate various valves types/sources
– If a given valve type/model is routinely unsatisfactory
– If a used valve should not be re-run
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Business Justification
Justification for post-installation testing
• Evaluate valve condition
– Can it be re-dressed and re-run, or
– Should it be discarded
• Learn
– How well did the valve survive in the well's environment
– Is a different valve type needed in this environment
– Is a different valve metallurgy needed
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
How the Tester Works
Quick, simple test of each gas-lift valve
• Insert valve in test fixture – 1" and 1.5" available
• Apply nitrogen pressure (from N2 bottle)
• Conduct these tests, under computer control
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Feb. 6, 2001
Opening pressure
Closing pressure
Port leak rate
Load rate of bellows and/or spring
Maximum effective stem travel
Back check valve leak rate
Port/bellows ("R") ratio
Bellows failure and/or dome leak
2001 ASME/API Gas-Lift Workshop
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AVT Front Panel
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2001 ASME/API Gas-Lift Workshop
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AVT Computer Control
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2001 ASME/API Gas-Lift Workshop
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Preparing to Test a Valve
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2001 ASME/API Gas-Lift Workshop
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Close Fixture, Connect Hose
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
How the Tester Works
Quick, simple test of each gas-lift valve (con't)
• Entire test of one valve takes about 3 minutes
• Produces a report
– Actual test results vs. operator-entered test criteria
– A Pass or Fail is declared for each test
• Produces a gas-lift valve performance plot
– Actual performance plot of the tested valve vs.
– Plot based on VPC (or standard) characteristics
• Exports a file
– Test results and actual valve characteristics can be exported
to any gas-lift program
– For example, Shell inputs results into WinGLUE
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2001 ASME/API Gas-Lift Workshop
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AVT Test Results Screen
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Intended Operational Process
Routine testing of every gas-lift valve
• Test every valve before it is run
– If valve "passes" all tests, run it
– If valve "fails" one or more tests, return it
– Have one or more spares on hand
• Store every test result in a gas-lift program and a
database
– Use in program for routine analysis
– Use in database to learn, evaluate
• Test every valve when it is pulled
– Store results in database
– Compare "after" performance with "before"
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Initial Field Experience
Use of the AVT has….
 Increased accuracy of pressure and port
leak measurements.
 Extended the practice of testing gaslift
valves to individuals who may not be
familiar with typical shop practices.
 Insures a consistently applied testing
standard. The technician cannot “help” the
valve pass a test.
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Initial Field Experience
Use of the AVT has…
 Found that good valves re-test
consistently.
 Provided the technician, engineer, and
wireline operator with a “certificate”
indicating the valve has passed all tests.
 Provided a link from the gaslift shop to the
engineers desk.
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Initial Field Experience
Camco BKR-5 valves were tested for Brunei
Shell Petroleum in Seria, Brunei
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The tested R ratio was MUCH larger than
the manufacturer’s published R ratio.
Valves with 3/16” TC ports tested with R
ratios of .154. The printed R ratio is .118.
This means the valve will have
approximately 30% more casing
sensitivity than expected.
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Chamfered TC Port
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Routine Valve Testing
Initial Field Experience
Camco BKR-5 valves were tested for Brunei
Shell Petroleum in Seria, Brunei
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Back checks do not seal leak tight.
The AVT found several valves with bad Orings on the seat.
The AVT found 1 valve with a leaking tail
plug.
The AVT found several valves with leaking
O-rings at the valve body joints.
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Initial Field Experience
Camco BKR-5 valves were tested for Brunei
Shell Petroleum in Seria, Brunei
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The loadrate was generally less than 1300
psig/inch. This is expected for valves set
at pressures less than 1000 psig.
The effective stem travel was generally
less than 0.100 inch. This is less than
expected but enough for a 3/16” ported
valve with an 8 or 10 choke.
Feb. 6, 2001
2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Outstanding Issues
There is more work to be done
• Initial valve tester is a prototype
– Needs to be re-packaged into a fully field-worthy device
• It may be possible to use the tester to help
conduct some VPC tests
– Needs to be evaluated
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2001 ASME/API Gas-Lift Workshop
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Routine Valve Testing
Conclusions
This is one more step forward for gas-lift
• There is now a cost-effective way to test every
gas-lift valve
– Before it is run
– After it has been pulled
• This should greatly improve quality assurance
and reduce "infant mortality" that comes from
running valves that are not properly suited:
– Manufacturing faults
– Handling problems
– Setting problems
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