Numerical Model of A Vapor Core System of Tangkuban Perahu Geothermal Field

Abstract

The Tangkuban Perahu geothermal field, represents a high-temperature volcanic geothermal system with potential characteristics of a vapor core. This study aims to construct a numerical reservoir simulation for the Tangkuban Perahu Geothermal Working Area (GWA) using available geoscientific data from the Pre-Feasibility Study by PT PLN (Persero). The objective is to simulate the natural-state behavior of the system, assess subsurface temperature and pressure distributions, and update the conceptual model for future development planning.

Geological, geochemical, and geophysical datasets were integrated to construct a conceptual model. A numerical simulation was then performed using the VOLSUNG simulator. Model calibration focused on reproducing observed thermal gradients and matching fluid flow patterns with manifestation zones such as Kawah Ratu, Domas, Baru and Upas.

According to the simulation results, the updated conceptual model of Tangkuban Perahu has been created. The reservoir could attain temperatures up to 270 °C, with high steam content concentrated in the upflow zone. Multiple drilling targets have been identified, each assessed in terms of their potential benefits and associated challenges. The recommendations presented in this study are expected to support future exploration efforts and well placement strategies in the Tangkuban Perahu area, aiming to achieve both operational reliability and long-term sustainability of geothermal energy production.