INTEGRATION OF GEOGRAPHIC INFORMATION SYSTEM MODELING IN DETERMINING THE PRIORITY DRILLING AREA OF THE SOUTHERN MOUNT KABA GEOTHERMAL FIELD, BENGKULU

• Main Author: Deo Prambudi, Teguh
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/53540
• Institution: Institut Teknologi Bandung

Kepahiang geothermal field is planned to be operated in 2025 with an installed capacity of 110 MWe. Among the three main prospects comprised in this field, the Southern Mount Kaba prospect area is recommended to be first developed to achieve the power development plan considering it has a bigger hypothetical resource than other prospect areas which around 113 MWe. Nevertheless, the well targeting for this area has not already been determined specifically. Analysis on the boundary system of this area needs to be conducted by considering the difference in fluid origin between manifestation of APSE, APBB1 and APBB2. Determination of priority drilling area is carried out by considering the upflow zone, permeable zone and landslide safe zone factors. This study is dedicated to determine the high priority drilling area using the integrated models of geographic information system applied to the Southern Mount Kaba geothermal field. The methods used in this study include volcanostratigraphy for determining the boundary system, geographic information system modeling using fuzzy tools for identifying the upflow zone, the permeable zone, and the high priority drilling area. Southern Mount Kaba geothermal system is inferred to be constrained by Bukit 1960 crown and Babakan Bogor fault in the southwest of the field. The upflow zone is concentrated on the APSE manifestation based on the fact that APSE is the only surface manifestation located in the Southern Mount Kaba area and its characteristics are resembling as a typical manifestation usually found in the upflow zone. The permeable zone is estimated to be around the intersection between the Northern Sempiang fault and the upflow zone of the Southern Mount Kaba geothermal system. The other identified permeable zone is located on the east side of the Southern Sempiang fault based on the evidence of the Sempiang fault zone, the high content of soil CO2 gas and soil Hg distribution. The high priority drilling area is subdivided into two priorities which are for well targeting and for recommended well pad areas. The well targeting area in the Southern Kaba Mountain system with very high priority are estimated to be around the upflow zone or the manifestation of Sempiang (APSE). Meanwhile, the well pad area is recommended to be in a landslide safe zone within a radius of 500 m from the predetermined priority drilling target.