ASME Gas Lift Workshop ASME Gas Lift Workshop Spring 2004Spring 2004

Dual Gas Lift Breakout SessionDual Gas Lift Breakout Session

February 10, 2004February 10, 2004

Dual Gas LiftDual Gas Lift

ProblemsProblems

SuccessesSuccesses

Gas Lift DesignGas Lift Design

Dual Gas Lift ProblemsDual Gas Lift Problems

SurveillanceSurveillance Upper / Lower string communicationUpper / Lower string communication Wire line work more risky on dual wellsWire line work more risky on dual wells Interference between strings – gas robbingInterference between strings – gas robbing Need more detailed accurate information Need more detailed accurate information

for better designfor better design Heading problems – fluctuating casing Heading problems – fluctuating casing

pressure – general instabilitypressure – general instability Generally restricted to using 1” valves.Generally restricted to using 1” valves.

Dual Gas Lift SuccessesDual Gas Lift Successes

Use of PPO unloading valves on both strings – operate Use of PPO unloading valves on both strings – operate best string on an orifice and the other on an IPO valve.best string on an orifice and the other on an IPO valve.

Use of venturi valve Use of venturi valve Use of shear orifice valve – enables packer test and Use of shear orifice valve – enables packer test and

ability to later to kick-off flowing well if needed.ability to later to kick-off flowing well if needed. Minimize back pressure, maximize gas lift injection Minimize back pressure, maximize gas lift injection

pressurepressure Maximize design effectiveness with good data to start Maximize design effectiveness with good data to start

withwith Properly trained well operators – troubleshooting – Properly trained well operators – troubleshooting –

need written procedures for testing/optimizing wellsneed written procedures for testing/optimizing wells Willingness of the Operator to spend the money and Willingness of the Operator to spend the money and

time to get measured data (accurate meters, flowing time to get measured data (accurate meters, flowing surveys, etc.)surveys, etc.)

Improved monitoring and control via Improved monitoring and control via automation/SCADA.automation/SCADA.

Dual Gas Lift DesignDual Gas Lift Design

Design each string independently of the other.Design each string independently of the other. Use PPO mandrel spacing to ensure close mandrel Use PPO mandrel spacing to ensure close mandrel

spacing in both strings – don’t “skimp” on mandrels.spacing in both strings – don’t “skimp” on mandrels. A re-design of valve placement and set pressures may A re-design of valve placement and set pressures may

be required after well is unloaded and well performance be required after well is unloaded and well performance is better understood.is better understood.

Verify design performance after well is stabilized – Use Verify design performance after well is stabilized – Use the tools:the tools:– 2 pen or multi-pen pressure recorder2 pen or multi-pen pressure recorder– Flowing pressure/temp surveys with coinciding well testFlowing pressure/temp surveys with coinciding well test

Evaluate the well test, design and flowing survey dataEvaluate the well test, design and flowing survey data Do not oversize valve port sizesDo not oversize valve port sizes Use dynamic valve flow testing data if available.Use dynamic valve flow testing data if available.