Structural Model Update on the Patuha geothermal system, West Java, Indonesia

Abstract

The Patuha geothermal field is a steam-dominated geothermal system lying on a quaternary volcanic unit in West Java Province, Indonesia. The existence of manifestations in this field isinterpreted from the structure control and rock deformation that generate steam production in reservoir zone. This updated study is aimed to further describe the geometry and kinematics ofthe geological structures model to estimate the permeable areas. The model also will explain the link between the larger tectonic framework and the detailed structure model scale in Patuha. The analysis consists of reassessment the LiDAR data, surface structure features measurement fromfieldwork, and review the updated subsurface data such as feed zones, new borehole images, and re-visit the geophysical data such as microearthquakes and gravity. The surface structuralinterpretation is drawn from a larger area to understand the regional tectonic framework and the relation with small detail from faults and non-tectonic features. Later, the new structural framework from surface data is correlated with subsurface data that indicates permeable features, including feed zones and conductive fractures, then coupled with the geophysical data.The latter part, which concerns validating surface fault traces using subsurface data, is currently being developed and will be included in the subsequent paper. An integrated reviewof the geological structure of the lineament found that a strike-slip system developed in the larger Patuha area with the main fault trending NE-SW, while the accompanying fault is en-echelon faults trending relatively NNE-SSW.