| Abstract |
Geothermal System and Conceptual Model of Sorik Marapi - Roburan - Sampuraga, North Sumatera, Indonesia Yuanno Rezky, Dudi Hermawan Center for Geological Resource - Geological Agency, jln. Soekarno-Hatta No.444 Bandung, Indonesia yuanno@gmail.com; doeday@gmail.com Keywords : Sorik Marapi - Roburan - Sampuraga, Geothermal system. Abstract This paper comprises the study of prospect condition representation, reservoir characteristic and constraint possibility. Study approach is carried out by applying qualitative method and quantitative analysis. The study result shows there are 3 geothermal prospect areas in Sorik Marapi - Roburan – Sampuraga Working Area (WKP), they are : Sibangor prospect, Roburan prospect and Sampuraga prospect. Sibangor prospect is related to volcanic system and considered at risk to develop, considering the volcanic hazard potency of Gunung Sorik Marapi. Meanwhile Roburan prospect area of about 15 km2 (upflow) and Sampuraga 14 km2 (outflow) are related to the geothermal system, therefore these two areas are good potential areas to develop. Reservoir of geothermal system in Sorik Marapi area is interpreted formed in undifferentiated volcanic which bordered by footwall of Gadis fault which has NW - SE strike direction. Reservoir of Roburan prospect Area is estimated to have two phase system with temperature of 270 - 290°C thickness of 1000 m where its top at 900 to 1000 m and shallow reservoir at depth of 600 m. Reservoir of Sampuraga prospect area is estimated to have water dominated system with temperature of 220 - 230°C thickness of 800 m where its top at 1200 m. Heat sources is interpreted as cooling magma which probably associated to the young volcano of Sorik Marapi. |