Publications

Understanding production behavior is very critical in managing a producing gas field committing to deliver certain gas sales rates. Any reservoir/field performance deviation especially toward the downside from its original prediction has to be identified and captured earlier to provide sufficient time to react and develop mitigation plan. This paper presents the case history of Kambing Field that was originally thought to be completely in gas depletion mechanism without aquifer support and water production. Unfortunately, a rapid and prolific water production was observed after 50% of reserves being produced. The Kambing Field development scenario was derived based on seismically driven geo-modeling, but it did not consider potential water production from the expected major sand contributor. These were also supported by the fact that none of the exploration wells found gas-water contact nor presence of water in the major reservoirs. The wells and facility design were tailored to the pressure depletion scenario without taking into consideration of possible prolific water production. The water production was observed after 4 years of production and rapidly increased to the level beyond facility handling capability. The routine reservoir surveillance and active reservoir management have played an important role on understanding these changes and its implication to the production forecast and reserves. Consequently, adjustment to the field development scenario to ensure gas supply availability to buyer was inevitable. This paper describes the evolution of Kambing Field development scenarios from pre-development modeling, early production performance, the un-expected prolific water production, and Premier Oil Indonesia efforts to counter the unexpected performance of the major gas contributor sand to ensure sufficient deliverability of committed gas to the buyer.