EVALUATION, REDESIGN OF GAS LIFT VALVE, AND OPTIMIZATION OF GAS INJECTION ON WELLS K-18 AND S-15 IN KS FIELD PERTAMINA DOH JBB

PROCEEDINGS, INDONESIAN PETROLEUM ASSOCIATION
Thirtieth Annual Convention & Exhibition, August 2005

EVALUATION, REDESIGN OF GAS LIFT VALVE, AND OPTIMIZATION OF GAS INJECTION ON WELLS K-18 AND S-15 IN KS FIELD PERTAMINA DOH JBB

Kurniawan Febrianto*

ABSTRACT

Gas Lift System has been installed as artificial lift method for wells K- 18 and S-15 at KS field. Based on production data, well K-18 produces 236 BFPD with 547 MSCFD of gas injection rate at pressure of 2241 psi. When gas injection rate is increased up to 1.1 MMSCFD, liquid rate will increase up to 240 BFPD or 2% at optimum condition. Well S-15 produces 1524 BFPD with gas injection rate of 500 MMSCFD at pressure of 2094 psi. Optimum point will be obtained by injecting 0.4 MMSCFD of gas and it will produce 1524 BFPD of liquid.

However, redesign of Gas Lift Valve (GLV) is one of alternative effort to increase liquid rate from well. Redesign GLV on K-18 shows operating pressure (Pso) is designed at 710 psi which is 3% lower than existing condition of 735 psi. New design of GLV suggests to add valve from 5 to 6. GLRt condition does not change before and after redesigning, but volume of gas injection will decrease by 57% from 600 MSCFD to 260 MSCFD.

GLV redesign on well S-15 shows that _Pso is designed at 850 psi that is 21% higher than 700 psi as the existing condition. New GLV design suggests to use only 4 valves which is less one valve from the existing one. GLRt in redesign of well S-15 will change from 500^SCF/BBL to 2000^SCF/BBL and it will result of increasing gas injection from 500 MSCFD in existing condition become 2700 MSCFD for the new design.

Gas injection performance can be optimized by using Pipesim-2000. At well K-18, existing gas injection rate optimum of 1.1 MMSCFD and pressure 2241 psi will produce liquid at rate of 240 BFPD. After redesigning the GLV, the volume of liquid production will increase by 13% to 271 BFPD with only 0.5 MMSCFD of gas injection as optimum condition. While GLV redesign at well S-15 indicates that optimum injection gas rate is 0.25 MMSCFD at pressure 2094 psi and it will give optimum point at 1576 BFPD. The liquid rate is 3% higher than optimum condition before redesigning which is 1524 BFPD with 0.4 MMSCFD of gas injection rate.

Based on this evaluation, redesign of GLV, and optimization of gas injection on wells K- 18 and S-15 will give result of increasing liquid production and injection gas rate can be managed efficiently.

* Trisakti University