LEAPFROG 3D TEMPERATURE DISTRIBUTION BASED ON TOUGH2 NUMERICAL MODELLING: A NEW APPROACH

Abstract

Atadei geothermal prospect area is located in Lembata Regency, East Nusa Tenggara, Indonesia. The estimated reservoir temperature based on ammonia geothermometer is about 221oC, with the upflow zone in three separate locations, namely: Watuwawer, Lewo Kebingin, and Lewokeba. The earlier exploration stage produced minimal subsurface data. Nevertheless, an interpretation of subsurface conditions and the lateral extent of the geothermal area was developed by previous researchers. This includes an interpretation of reservoir geometry; the fluid contained (i.e., steam caps formation), fluids flow pattern, and some structural geology that may control permeability and reservoir depth. Based on these published data, we have created a TOUGH2 numerical model of Atadei geothermal field to add substantial information regarding the reservoir characterization and to avoid inaccurate interpretation during the early exploration stage. This paper aims to explore a new approach regarding integration between TOUGH2 and Leapfrog Geothermal. Reservoir simulation results using TOUGH2 numerical modeling are then integrated into the Leapfrog Geothermal in order to get a more robust 3D model of the temperature distribution of the Atadei geothermal field.