Dynamic Modeling of Darajat Field Using Numerical Simulation

A preliminary comparison study of simple vapor dominated reservoir models using TOUGH2 and CHEARS ® (ChevronTexaco Extended Application Reservoir Simulator) reservoir simulators was conducted. The purpose of the study was to verify the ability of CHEARS ® to simulate a vapor dominated reservoir. CHEARS ® was designed to simulate the recovery processes for oil and gas reservoirs. The result showed that both simulators generate similar and consistent responses. Based on this preliminary comparative study, a full field model of the Darajat vapor dominated field in Indonesia has been built. The numerical model of the Darajat field was constructed based on the detailed reservoir characterization work using earth modeling gOcad ® software. A CHEARS ® reservoir model was used to simulate the natural state and 10 years of production history from the field. The good agreement between the CHEARS ® simulated results and the field data obtained prior to and during the field production, demonstrates the simulator’s ability to simulate a vapor dominated geothermal reservoir. The model was used to forecast the field’s potential responses based on different field development scenarios.