Feb 6, 20012001 ASME/API Gas-Lift Workshop1 Erosion Testing of Standard Monel Gaslift Valve Seats Informal Presentation by Shauna Noonan, Chevron Petroleum

Feb 6, 2001 2001 ASME/API Gas-Lift Workshop

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2001 ASME/API Gas-Lift Workshop2001 ASME/API Gas-Lift Workshop

Erosion Testing of Standard Monel Erosion Testing of Standard Monel Gaslift Valve SeatsGaslift Valve Seats

Informal PresentationInformal Presentation

bybyShauna Noonan, Chevron PetroleumShauna Noonan, Chevron Petroleum

Ken Decker, Decker TechnologyKen Decker, Decker Technology


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Erosion Testing of Standard Monel Erosion Testing of Standard Monel SeatsSeats

• OutlineOutline– Brief historyBrief history– Testing MethodologyTesting Methodology– Testing ProgramTesting Program– Summary of Test ResultsSummary of Test Results– Conclusions and ConsequencesConclusions and Consequences– The Way ForwardThe Way Forward


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• Brief HistoryBrief History– No quantitative test had been performed to No quantitative test had been performed to

determine the erosion rate of standard determine the erosion rate of standard monel seats in gaslift valves.monel seats in gaslift valves.

– API recommends an unloading rate based on API recommends an unloading rate based on experience.experience.

– Erosion continues to occur even with Erosion continues to occur even with admonitions to unload slowly.admonitions to unload slowly.


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• Brief HistoryBrief History– This Erosion Testing program was conducted This Erosion Testing program was conducted

as a special project of the VPC.as a special project of the VPC.– Participating members were…Participating members were…

• Chevron Petroleum TechnologyChevron Petroleum Technology• Shell International Exploration and Shell International Exploration and

ProductionProduction• Weatherford Artificial Lift SystemsWeatherford Artificial Lift Systems


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• Testing MethodologyTesting Methodology– Typical erosion testing measures the rate of Typical erosion testing measures the rate of

loss of material from a sample by carefully loss of material from a sample by carefully measuring the weight of the sample both measuring the weight of the sample both before and after the test.before and after the test.

– In gaslift valves, the loss of material is less In gaslift valves, the loss of material is less important than the rate of gas leakage important than the rate of gas leakage through the valve.through the valve.

– The rate of erosion was correlated to the The rate of erosion was correlated to the amount of leakage through the port when a amount of leakage through the port when a standard TC ball was placed over the port.standard TC ball was placed over the port.


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• Testing MethodologyTesting Methodology– A 1-1/2” orifice valve was chosen as the A 1-1/2” orifice valve was chosen as the

carrier for the seat.carrier for the seat.– The seat was leak tested prior to running the The seat was leak tested prior to running the

erosion test.erosion test.– The seat leak rate was rechecked after 1 hr, The seat leak rate was rechecked after 1 hr,

2 hrs, 4 hrs, and 6 hrs.2 hrs, 4 hrs, and 6 hrs.


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• Testing MethodologyTesting Methodology– The valve was installed in a modified The valve was installed in a modified

pocket. The pocket was enclosed in a pocket. The pocket was enclosed in a fixture which was plumbed to a triplex fixture which was plumbed to a triplex pump.pump.

– The plumbing allowed control of pressure The plumbing allowed control of pressure upstream and downstream of the test upstream and downstream of the test fixture.fixture.

– Fresh water from a rusty holding tank was Fresh water from a rusty holding tank was used as the test media.used as the test media.


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• Testing Program #1Testing Program #1– Seat sizes of 1/8”, 3/16”, ¼”, 5/16”, and 3/8” Seat sizes of 1/8”, 3/16”, ¼”, 5/16”, and 3/8”

were erosion tested.were erosion tested.– Tests were performed at flow rates of 40-50 Tests were performed at flow rates of 40-50

gallons per minute.gallons per minute.– The downstream pressure leaving the test The downstream pressure leaving the test

fixture was maintained at 100 psig or fixture was maintained at 100 psig or greater.greater.


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• Testing Program #2Testing Program #2– Seat sizes of 1/8”, 3/16”, ¼”, 5/16”, and 3/8” Seat sizes of 1/8”, 3/16”, ¼”, 5/16”, and 3/8”

were erosion tested.were erosion tested.– Tests were performed at flow rates of 90-100 Tests were performed at flow rates of 90-100

gallons per minute.gallons per minute.– The downstream pressure leaving the test The downstream pressure leaving the test

fixture was maintained at 100 psig or fixture was maintained at 100 psig or greater.greater.


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• Summary of Test ResultsSummary of Test Results– Results are not consistent with expected Results are not consistent with expected

erosion patterns. Wire drawing and cutting erosion patterns. Wire drawing and cutting was not evident, rather the erosion occurred was not evident, rather the erosion occurred very uniformly.very uniformly.

– The leak rate increased after 1 hr, then The leak rate increased after 1 hr, then decreased after 2 hrs, and then increased decreased after 2 hrs, and then increased after 4 and 6 hrs.after 4 and 6 hrs.

– Highest leak rates occurred with largest port Highest leak rates occurred with largest port sizes.sizes.


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• Summary of Test ResultsSummary of Test Results– The erosion did not appear to extend down The erosion did not appear to extend down

into the barrel of the seat. Thus when these into the barrel of the seat. Thus when these seats are used in an orifice valve, the size of seats are used in an orifice valve, the size of the port does not change.the port does not change.

– The original backcheck was repeatedly used The original backcheck was repeatedly used and after 30 hrs at 2 bbl/min was and after 30 hrs at 2 bbl/min was significantly eroded to the point of being significantly eroded to the point of being useless as a reverse flow check.useless as a reverse flow check.


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• Conclusions and ConsequencesConclusions and Consequences– Unloading at rates up to 2 bbl/min will lead Unloading at rates up to 2 bbl/min will lead

to moderate leak rates generally less than 1 to moderate leak rates generally less than 1 Mscfd.Mscfd.

– Erosion occurred at the sealing surface and Erosion occurred at the sealing surface and was very uniform.was very uniform.

– The biggest effect of the erosion will be the The biggest effect of the erosion will be the change in R ratio. The seat sealing area will change in R ratio. The seat sealing area will be significantly larger then the port area.be significantly larger then the port area.


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• The Way ForwardThe Way Forward– The erosion testing program needs to be The erosion testing program needs to be

extended to include…extended to include…• erosive fluidserosive fluids• TC seatsTC seats• effects on backcheckseffects on backchecks• continued erosion of leaking seatscontinued erosion of leaking seats• erosion of cross-over ported seatserosion of cross-over ported seats• erosion with downstream chokeserosion with downstream chokes


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• The Way ForwardThe Way Forward– The VPC will continue the erosion testing The VPC will continue the erosion testing

program in 2001 to determine the erosion of program in 2001 to determine the erosion of TC seats.TC seats.

– The VPC program is open to other interested The VPC program is open to other interested parties.parties.

– Contact Decker Technology, Inc.Contact Decker Technology, Inc.

Documents

Feb 6, 20012001 ASME/API Gas-Lift Workshop1 Erosion Testing of Standard Monel Gaslift Valve Seats Informal Presentation by Shauna Noonan, Chevron Petroleum