3D Model of Bora Pulu Non-Volcanic Geothermal Prospect, Central Sulawesi, Indonesia

Abstract

Geothermal 3D geological modeling provides an integrated database, detailed visualization, and representation that could improve geothermal prospecting. This approach also facilitates new perspectives related to geothermal system conditions that may not be represented properly through 2D conceptual models. The 3D model development is an important step for geothermal prospecting not only for mature and well-surveyed areas but also for greenfield areas or areas in the exploration phase. Bora Pulu is a geothermal prospect located in Sigi Regency, Central Sulawesi, Indonesia.  It is estimated to hold a potential capacity of 123 MW in possible reserves and is classified as a medium enthalpy system. Bora Pulu is associated with extensional tectonic activities of the NW-SE trending Palu-Koro fault and plutonism instead of the volcanic controlled systems mainly preferred for utilization in Indonesia. Geologically, Bora Pulu is hosted by granitic and metamorphic rocks. These characteristics are also similar to other geothermal potentials formed along the Palu-Koro segment. This research has objectives to develop a 3D geological model of the Bora Pulu geothermal prospect through several published data related to stratigraphy, structural geology, hydrogeologic condition, and conceptual model. Authors perform 3D geological modeling using Leapfrog geothermal to visualize geological unit boundary, fault geometry and manifestation location in the prospective area. This model would enrich the recent perspective from the prospect to gain a better understanding of the non-volcanic geothermal system in Indonesia.