Edgefield Delineation Resource Assessment Method, Case Study of North Patuha Exploration Project

Patuha geothermal field is one of the geothermal working areas (WKP) managed by PT Geo Dipa Energi. The Patuha geothermal potential resources have been explored from 1982 to 1989 through geoscientific surveys and shallow drilling. The exploration continues in 2019, 2020, and 2022. Recently, GDE conducted a LiDAR survey, an additional Geophysical and a detailed geological study, and two temperature core hole wells. These studies aim to delineate resources and build conceptual models and well-targeting in the Cimanggu area (Patuha Extension).

Cimanggu area is located in the northern part of Mt Patuhua, extending to the Northeast from the current Patuha prospect. The heat source is interpreted beneath Mt Patuha. Based on the additional data, the possible geological structure has been analyzed from LiDAR data and has been field-checked. There is two possible structure that might control permeability, the NW (Babakan and Ciwidey fault) and the NE structure (Munding fault). Still, it is also possible that the Cimanggu permeability is controlled by lithology. The MT data shows that the conductive clay existence spread out in the northern part of Mount Patuha (Cimanggu Area). The BoC is found at the elevation of 500-800 masl. The geothermal reservoir possibility is supported by a shallow temperature well with a temperature of 218oC in 820 meters. The fluid temperature in the reservoir is estimated to reach 230oC. In this study, P10, P50, and 90 areas have been defined to calculate the resource estimation that is 10 km2, is 6 km2, and 4km2, respectively.