ASME Gas Lift Workshop Spring 2004 Dual Gas Lift Breakout Session Dual Gas Lift Breakout Session February 10, 2004

Dual Gas Lift n Problems n Successes n Gas Lift Design

Dual Gas Lift Problems n Surveillance n Upper / Lower string communication n Wire line work more risky on dual wells n Interference between strings – gas robbing n Need more detailed accurate information for better design n Heading problems – fluctuating casing pressure – general instability n Generally restricted to using 1” valves.

Dual Gas Lift Successes n Use of PPO unloading valves on both strings – operate best string on an orifice and the other on an IPO valve. n Use of venturi valve n Use of shear orifice valve – enables packer test and ability to later to kick-off flowing well if needed. n Minimize back pressure, maximize gas lift injection pressure n Maximize design effectiveness with good data to start with n Properly trained well operators – troubleshooting – need written procedures for testing/optimizing wells n Willingness of the Operator to spend the money and time to get measured data (accurate meters, flowing surveys, etc.) n Improved monitoring and control via automation/SCADA.

Dual Gas Lift Design n Design each string independently of the other. n Use PPO mandrel spacing to ensure close mandrel spacing in both strings – don’t “skimp” on mandrels. n A re-design of valve placement and set pressures may be required after well is unloaded and well performance is better understood. n Verify design performance after well is stabilized – Use the tools: –2 pen or multi-pen pressure recorder –Flowing pressure/temp surveys with coinciding well test n Evaluate the well test, design and flowing survey data n Do not oversize valve port sizes n Use dynamic valve flow testing data if available.