High pressure gas lift optimization

A method for controlling a High Pressure Gas Lift (HPGL) system based on a gas utilization factor, comprising:

• operating a compressor of the HPGL system at three gas injection set points for predetermined time periods, wherein the three gas injection set points each correspond to one of three gas injection rates of the compressor, respectively;
• identifying three discharge pressures corresponding to the three gas injection set points;
• performing a non-linear regression with the values of the three discharge pressures relative to the three gas injection set points to generate a bottom hole pressure verses injection pressure function;
• converting the bottom hole pressure function to a gas utilization factor versus injection rate function based on a preselected well productivity index;
• and
• identifying an updated gas injection set point for the compressor using the gas utilization factor versus injection rate function for a predetermined gas lift utilization factor;
• and
• operating the compressor at the updated gas injection set point for a predetermined run-time.

A High Pressure Gas Lift (HPGL) system, comprising:

• at least one HPGL compressor configured to selectively inject gas into one of production tubing and an annulus of a well;
• at least one pressure sensor configured to measure a discharge pressure of the at least one HPGL compressor;
• and
• a controller configured to:
• operate the compressor of the at least one HPGL compressor at three gas injection set points for predetermined time periods, wherein the three gas injection set points each correspond to one of three gas injection rates of the compressor, respectively;
• identify three discharge pressures corresponding to the three gas injection set points;
• performing a non-linear regression with the three discharge pressures relative to the three gas injection set points and identifying a minimum of the non-linear regression;
• identify a gas injection rate associated with the minimum of the non-linear regression;
• generate an updated gas injection set point for the at least one HPGL compressor based on the gas injection rate associated with the vertex of the quadratic equation;
• and
• operate the at least one HPGL compressor at the updated gas injection set point for a predetermined run-time.