MODELING OF SUBSURFACE PERMEABILITY ZONE BASEDON THE SPATIAL CORRELATION BETWEENFRACTURE INTENSITY, PRESSURE AND TEMPERATUREDATA IN WAYANG WINDUGEOTHERMAL FIELD, WESTJAVA PROVINCE

• Main Author: Azmi, Khairul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53300
• Institution: Institut Teknologi Bandung

The permeable zone is an important variable in the development of a geothermalfield. Some parameters that can be used to identify the permeable zone are fracture zone and feed zone. Fracture intensity is used to identify the fracture zone and Pressure-Temperature (P-T) curve slopes from the result of Pressure-Temperature-Spinner (PTS) tests to identify the feed zone. In this study, the fracture intensity data was composited into 10 m,then pressure and temperature data of the LPA and LPB well consisting of LPA1, LPA2, LPA3, LPA4, LPB1, LPB2, LPB3 and LPB6 located in the northern part of Wayang Windu geothermal field. The model was generated using the Sequential Gaussian Simulation (SGS) method for fracture intensity and P-T, then the Sequential Indicator Simulation (SIS) method for fracture direction and lithology. From the SGS results off racture intensity model, it was found that the zone which has a high fracture intensity is in the elevation of 1215 to 765 m.a.s.l with the major direction of Northeast–Southwest. From the analysis of P-T curve slope, it was indicated that the feed zone is at elevation (in m.a.s.l.) 1120 to 1036 in LPB1, 1211 to 1188 and 862 to 835 in LPB3, 1320 to 1306 in LPB6, 1156 to1132 and 859 to 826 in LPA1, 1218 to 835 1195 and 1151 to 1138 in LPA2, 967 to954 and 722 and 715 in LPA3, 1278 to 1260 and 988 to 980 in LPA4. Then the permeable zone was identified based on the high fracture and feed zones. Although not all high fracture intensity zones are the feed zone, but almost each feed zone has a high fracture intensity. The major direction of the fracture in the high fracture intensity area from the simulation result gave a similar direction to the fracture of hard data.This study produced the permeable zone based on the spatial correlation of high fracture density and feed zones as well as the relationship between subsurface and near surface permeable zone parameters.