Stanford Geothermal WorkshopFebruary 9-11, 2026

The Salak Geothermal Field is currently the largest operating geothermal field in Indonesia and has been continuously operating since 1994, with an installed capacity of 405.4 MWe, comprising of 388.8 MWe flash plant and 16.6 MWe binary plant. As one of the country’s most mature geothermal fields, Salak has drilled more than 115 wells and accumulated an extensive dataset through drilling and reservoir monitoring programs. Leveraging this dataset, Salak’s Earth Science team has updated the static model by incorporating the latest drilling result, monitoring data, new reservoir studies, including new insights from the Naturally Fractured Reservoir (NFR) study. This updated static model served as the foundation for updating the Salak numerical model, with the objective of making the numerical model to have consistent reservoir property distributions. In addition to updating the static property distributions, the dynamic boundary conditions were also revised to align with the updated conceptual model of the field. These improvements made the NFR-based numerical model more effective during the calibration process and demonstrated high calibration quality during the pre-exploitation condition and reservoir response throughout commercial production, including recent major injection strategy change, namely the Salak Injection Realignment Program (SIRP). The quality result from the calibration process indicates that the model is reliable to predict the evolution of key dynamic reservoir parameters observed from surveillance activities during the first few years of the SIRP. Overall, the model update using the NFR-based data has improved the calibration results and enhanced confidence in the model as a reliable predictive tool for evaluating various long-term exploitation strategies, which ultimately improve decision-making quality for Salak’s key strategic projects.

Topic: Modeling