The assessment of geothermal energy reserves within the Sibayak Geothermal Field employs both the volumetric method and Monte Carlo probability simulation. This approach hinges on reservoir physical parameters to derive meaningful insights. The simulation results yield a probability distribution for the comprehensive system value, thereby establishing a range of probability values that encompass proven (P90), probable (P50), and suspected (P10) geothermal reserves classifications. Executing the intricate Monte Carlo calculation process manually is notably timeintensive. Thus, this study pioneers the development of a specialized software using Visual Basic Application, amplifying calculation efficiency and efficacy. Parameters pivotal to these calculations are derived from assumptions rooted in SNI 13-6482- 2000 standards, along with geoscience data and production test analyses from preliminary survey activities. Through the input of P10, P50, and P90 values for each parameter, encompassing factors like area (4.5, 7, and 19 km²), reservoir thickness (1074, 1190, and 1275m), rock density (2400, 2500, and 2600 kg/m²), porosity (0.1, 0.125, and 0.15), reservoir temperatures (226, 270, and 300 °C), recovery factors (0.1, 0.2, and 0.3), initial saturations (0.9, 0.95, and 0.99), and estimated final saturations (50%, 80%, and 90%), a comprehensive analysis emerges. The envisioned operational lifespan is set at 30 years, while the rock's heat capacity is acknowledged as 1 kJ/kg °C, culminating in a final temperature of 180°C. Through this comprehensive approach, pessimistic (P10), optimistic (P90), and most likely (P50) estimates of geothermal energy yield from the Sibayak geothermal field stand at 34 MW, 60 MW, and 101 MW, respectively.

Link publikasi : https://www.apcore-inc.org/_files/ugd/183efc_5dba257a9e744d4db5749eac5bc499de.pdf