Operation of Gas Lift Compressor Without Discharge Cooler in Handil Field – Pertamina Hulu Mahakam

Handil is a mature oil field in Mahakam Block which has been producing for more than 45 years. Following its depletion challenge, more than 90% of Handil’s oil production relies mainly on gas lift, which is circulated from Compressor in the process area. The HEOR (Handil Enhanced Oil Recovery) Compressor is one of the compressors used to supply gas lift in Handil field. HEOR is equipped with two air coolers, namely the interstage cooler (E-5550) and discharge cooler (E-5530). Based on inspection findings, the discharge cooler E-5530 is leaking and out of service. Consequently, HEOR compressor cannot be operated, thereby reducing the rate of gas lift to field and resulting to lower oil production from Handil field. Further study was then carried out to review the feasibility of running the HEOR compressor without its discharge cooler (discharge cooler operation by-passed). Several efforts were performed to ensure the process safety condition as follows: Jumper line size to ensure the deliverability of gas lift rate. The existing 6” jumper line with a rating 1500# is capable to deliver 48 MMscfd with potential debottlenecking to 8” line with a capacity of 86 MMscfd; Stress analysis on piping & pipeline is performed to review the impact of increasing temperature; Water condensation study along the pipeline discharge cooler to check the Top of Line Corrosion (ToLC) issue; Corrosion mitigations with sampling liquid (e.g. pH analysis) and corrosion monitoring requirement (e.g. routine UT measurement at critical sections and chemical injection on critical points as per sampling result); Field trial of the by-pass discharge cooler by utilizing existing configuration were carried out to examine the temperature profile along the pipeline and its impact on the performance of HEOR compressor. The new philosophy of running HEOR compressor without discharge cooler was successfully implemented in the Handil field. The modification is succeeded to boost oil production up to 2,000 bopd thanks to great collaboration among engineering, production method, and site Operation team. All efforts from engineering studies up to implementation in the field are a good lesson learns that can be implemented to other oil and gas field.