THE SUBSURFACE STRUCTURE INTERPRETATION OF MUARA LABOH GEOTHERMAL FIELD USING GRAVITY

• Main Author: ASRI (NIM: 12313026), RAAFIANE
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23751
• Institution: Institut Teknologi Bandung

Geothermal energy is an eco friendly and renewable energy so its utilization if developed properly is able to reduce the impact of global warming and help reduce the dependence on fossil energy that is running low. The identification of subsurface structures is undertaken at the preliminary stage of the geothermal project to determine the heat source. In determining its heat source, a geophysical method that is sensitive to changes in subsurface density, gravity method, is applied. Sub-surface density changes affect the gravity acceleration in the area, so that subsurface structures can be detected and the result allows the geothermal system to be predicted. <br /> <br /> <br /> In this study the data used is Complete Bouguer Anomaly data of Muara Laboh geothermal field in 1992, Kab. Solok, West Sumatra Province. The data then is processed to obtain regional and residual anomalies. Forward Modeling is done with reference to geological data of the study area, SVD (Second Vertical Derivative) analysis results, and literatures. Then an analysis is made to determine the geothermal system. <br /> <br /> <br /> The result of 2.5D and 3D forward modelling shows that Muara Laboh area is a geothermal area that is controlled by graben structure, forming a normal fault as the discharge area. The heat source is predicted to be an intrusion of igneous rock, breccia as the reservoir rock, and Smectite clay as a cap rock, that is formed by hidrothermal process