GEOTHERMAL SYSTEM MODELING BASED ON THE GRAVITY DATA OF LOKOP’S GEOTHERMAL FIELD, EAST ACEH, NANGGROE ACEH DARUSSALAM

• Main Author: Graciano Vladislav K., Ezekiel
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67337
• Institution: Institut Teknologi Bandung

Indonesia is one of the countries with the highest potential for geothermal resources, making it the fourth largest in the world. One of the geothermal areas in Indonesia is the Lokop Geothermal Field, East Aceh, Nanggroe Aceh Darussalam. The purpose of this study is to create a conceptual model of the geothermal system from the Lokop Geothermal Field. In this study, the data used are Complete Bouguer Anomaly (CBA) data and topographic data obtained from the PSDMBP research results in 2013 in the Lokop Geothermal Field. With Complete Bouguer Anomaly (CBA) data and PSDMBP topographic data, corrections were made, corrections made were latitude, free air, and Bouger corrections, after which the gravity data processing resulted in a Complete Bouguer Anomaly Map with a value range of -2 to -26 mGal. Then the regional and residual anomalies are separated using the Moving Average and Order-2 Polynomial methods, where the window width is determined by performing a 1-dimensional spectral analysis. The anomaly results using the Moving Average method show moderate anomaly values seen in the eastern area on the map and high anomaly in the center of the map, which is thought to be due to magma intrusion so that this method is considered to have a correlation with the geology of the study area. 2.5D modeling shows that high anomalous values can be indicated as magma intrusion with a density contrast of +0.83 gr/cc. Estimated geothermal system based on the integration of gravity data from processing, TDEM and Geology from PSDMBP research in 2013 the presence of magma intrusion is estimated as a heat source. Slate-Dolomite unit as reservoir and slate (?) unit as caprock.