| Title | 3D NATURAL STATE MODEL OF KARAHA-TALAGA BODAS GEOTHERMAL FIELD, WEST JAVA, INDONESIA |
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| Authors | W. Prabata, Sutopo and H. Berian |
| Year | 2017 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Karaha-Talaga Bodas geothermal field, natural state matching, TOUGH2 |
| Abstract | Karaha-Talaga Bodas (KTB) Geothermal Field is classified as one of the vapor dominated systems located in Western Java, Indonesia. The KTB field is divided into two areas, Karaha (northern) and Talaga Bodas (southern). The KTB geothermal field has steam zone underlain by deep brine reservoir. The steam cap in KTB field formed due to liquid reservoir evolution and it extends from south to north where the southern area has the thickest steam cap. The understanding of the actual reservoir performance of the KTB field in an early stage of development, it is important to build a numerical model. It was built based on an existing conceptual model which is obtained from Geological, Geochemical and Geophysical (G-G-G) survey results and wells data. The natural state model of the KTB geothermal field was developed using TOUGH2 and was built using non-isothermal-pure water equation of state (EOS1). The surface of the model follows the topographic contour so that the water table in shallow zone can be represented. The output of the natural state model was validated by seven wells of the actual measurement data also heat and mass flow from the conceptual model. The additional of the heat source in the northern area below Karaha Crater shows a good match of the validation and it will update the existing conceptual model. The southern area has a moderate to high permeability with the range of 10 to 100 mD and the northern area has a low to moderate permeability with the range of 1 to 20 mD. This is the first generation of the KTB numerical model with a good result. |