Publications

The Baturaja Limestone is the main productive formation with a depletion drive mechanism in the Kaji Semoga field. At present it is undergoing a peripheral waterflood which has recovered oil at about 4.2 MMBO. The two-year evaluation period highlights that the peripheral waterflood method has recovered inadequate amounts of oil as described in the original waterflood Plan of Development (POD). This paper focuses on the implementation of the waterflood project from the perspective of reservoir management. The utilization of limited data, particularly the modeling of the static and dynamic properties of this reservoir, has led to flawed geological and reservoir assumptions. Therefore, the results derived from the reservoir simulation have meant poor decision making occurred, specifically with respect to matters such as waterflood pattern selection, drilling and conversion schedule, and injection rate targets, among others. However, other factors, like the delay of the installation of a new artificial lift method, facility modification, drilling and conversion activities, also contributed to the underperformance of the waterflood project. The most recent activities with respect to future plans include a waterflood design and operational improvements that take advantage of a new strategy hat is designed to optimize oil recovery. Production and reservoir data will be analyzed using reservoir characterization techniques and by updating the existing reservoir simulation. The analyses of the results will be utilized to then optimize the waterflood plan and flooding techniques in order to maximize secondary oil recovery in this reservoir. Simulating sensitivities of Electric Submersible Pump (ESP) implementation strategy, injection rate optimization, infill drilling opportunity, have shown significant oil increment of initial waterflood design.