Publications

To arrest the natural decline of oil production in mature fields, one option is to drill new wells. Drilling a new well in a mature field will have challenges such as the already high recovery factor of the reservoir target, the new well’s placement distance to existing wells, etc. One other option is to conduct integrated reservoir management to support an aggressive workover and well intervention (WOWI) program of existing wells for delivering potential candidates with good oil gains. Field "A" is a mature field located in the WK Rokan block of the Central Sumatra Basin which has produced more than 50 years from five main reservoirs. To prolong the life of Field “A”, breakthrough ideas and comprehensive programs are needed with the aim of finding potential bypassed oil. Integrated reservoir management begins by applying high resolution stratigraphy to deliver better subsurface understanding such as finding stratigraphic traps, unperforated zones, etc. The combination of study and reservoir surveillance provides current reservoir data to identify remaining oil potential, including additional reservoir data from new wells drilled in 2022. History matching analysis from existing wells show high quality reservoirs dominating production compared to low quality reservoirs. The recommended production strategy is to upsize high quality reservoirs and produce individually or comingle with low quality reservoirs as an effort to increase oil performance by reducing water production. The integrated reservoir management process has been implemented in 32 wells with success rate of 80% and pay out time of less than 3 months. Field “A” production is stable at approximately 1700 BOPD within three years with additional reserves of 209 MBO. Additional remaining opportunities have been documented and catalogued for future WOWI jobs. This paper discusses the successful collaboration of multidisciplinary team members from asset optimization in providing a high number of aggressive WOWI candidates by integrating reservoir management from geological concepts, well data, and production data. The success of the WOWI campaign in the last 3 years has delivered a total initial production 3250 BOPD and extended the life of field “A”.