Pemanfaatan Sumur Uji Sintetis Pada Simulasi Numerik Untuk Studi Awal Potensi Penyimpanan Karbon di Sistem Panas Bumi Gunung Rajabasa

Abstrak

Geothermal exploration at Mount Rajabasa has progressed through various stages, however, the absence of deep exploration well remains a constraint for reservoir characterization in preliminary carbon storage studies. This study aims to determine the geothermal reservoir characteristics based on synthetic test wells in numerical simulations and to estimate the initial carbon storage potential of the Mount Rajabasa geothermal system. Numerical modeling was performed using HYDROTHERM software, applying the finite-difference method and the Newton-Raphson algorithm until a steady-state condition was achieved, which was validated against shallow exploration well data (RJB-1A). Three synthetic test wells (DWR-1, DWR-2, DWR-3) were placed in the model to analyze temperature and pressure profiles in order to delineate the steam cap zone and reservoir boundaries. The modeling results indicate that the Mount Rajabasa geothermal reservoir has a lateral extent of approximately 4 km and a thickness of 2 km, with the reservoir top at depths of 700–1200 m and reservoir fluid temperatures ranging from 286°C to 337°C. An initial volumetric estimate of carbon storage capacity yielded a CO₂ mass capacity of 1.185 million metric tons (Mt CO₂e), assuming injection in the dissolved phase at 155°C and 20 bar. These findings suggest that the Mount Rajabasa geothermal system holds initial potential for carbon storage, although further development of models on other transects and additional studies on injection rates and CO₂ fluid behavior within the reservoir are still required.

Kata kunci

• Gunung Rajabasa
• penyimpanan karbon
• reservoar panas bumi
• simulasi numerik
• sumur uji sintetis