Publications

S field is a high pressure and high temperature gas field located in South Sumatra Indonesia with initial gas impurities of 30% CO2 and 100-ppm H2S. The field has been producing since April 2010, and has retrieved almost 50% of initial gas in place. utilizing initial estimated OGIP, the gas deliverability was predicted to last only until 2022. The lack of reservoir data such as pressure and SCAL (Special Core Analysis) exhibit high uncertainties in estimating accurate reserves value, therefore additional information such as SBHP (Static Bottom Hole Pressure) survey data and well optimization are essential to narrow the uncertainties in reserves estimation and gas deliverability. SBHP survey was then planned with slickline unit in 2018 during CPP shut down as preventive maintenance activity. Additional pressure data was utilized to update the OGIP (Original Gas In Place) analysis by combining several methods such as p/z analysis, flowing material balance, rate transient and history matching of dynamic model analysis . To enhance gas deliverability, the production network model was then created to evaluate existing production method. This updated system analysis showed significant bottleneck at the existing production system that limiting the production rate from the wells. As part of debottlenecking endeavor, temperature survey on the production system was employed to overcome the limited availability of pressure survey points in the system. The GIP analysis shows conclusive result that there is significant increase in the GIP and reserves, estimated 16% of additional gas reserves. Furthermore, the successful debottlenecking activity combined with temperature drop analysis resulted in 20% additional gas deliverability. This integrated evaluation and optimization also prolong the field lifetime until 2025. This paper describes some of challenges and lesson learned during the evaluation and optimization in the high pressure and high temperature sour gas field.