Updating Fault Model with Using Borehole Image Data on Patuha Geothermal System, West Java, Indonesia

Abstract

Patuha geothermal field is a steam-dominated geothermal system lying on a quaternary volcanic unit in West Java Province, Indonesia. The fault structure and rock deformation in Patuha may strongly control the permeability and being a media to generate the steam production in the wellbore. Geodipa has conducted a structure study prior to the drilling campaign and the updated one will be presented through this paper which aimed to reevaluate the surface geological structure framework from the interpretation from borehole image data to improving well targeting. The geological structure framework analysis from LiDAR data, fieldwork measurement, and review some of the subsurface data such as feedzones and MeQ were done on 2023. The result was showing a strike-slip system developed in the larger Patuha area with the main fault trending NE-SW, while the accompanying fault is en-echelon faults trending relatively NNE-SSW The model also will explain the link between the larger tectonic framework and the detailed structure model scale in Patuha. Later, when the interpretation from borehole image data was done, it shows the comprehensive fracture trend in detail scale. The result so far confirming the presence of NW-SE trend on 2 wells but also show NNE-SSW trends that is parallel with our current stress interpretation. The data also confirming the high dip angle fault that align with strike slip system fault model that been developed earlier. In conclusion, these result so far has been contributed and improved the geological structure interpretation's confidence for well targeting and provide a confirmation of general fracture trend associated with surface fault to predict permeable zone area.