Integrated Well-Logging and Numerical Simulation for Geothermal Resource Assessment in Eastern Taiwan

Taiwan, situated along the Pacific Ring of Fire, possesses substantial high-enthalpy geothermal resources, particularly within its subduction zone regions. Consequently, the deployment of geothermal energy has become a pivotal component of the national energy-transition policy. Focusing on a tectonically active field in eastern Taiwan, this study evaluates geothermal development potential by integrating advanced well-logging analysis with numerical reservoir simulation. To characterize stratigraphy, structural layers, and fracture networks, we utilize natural gamma ray, resistivity, sonic, and Formation Micro-Resistivity Imager (FMI) logs, integrated with High-resolution Sonic Scanner data. The inclusion of the Far Field Sonic Scanner specifically allows for imaging fracture systems and formation heterogeneities beyond the detection range of conventional acoustic tools. These geophysical datasets support the construction of a three-dimensional geomechanical model that captures in-situ lithological variations and geothermal reservoir properties. Subsequently, thermal–hydraulic behavior is simulated using the TOUGH3 code via the PetraSim interface, allowing for efficient model calibration and post-processing. Model parameters are constrained by in-situ logging measurements to refine estimates of temperature distribution, fracture pathways, and structural orientation. Ultimately, this study aims to deliver a robust conceptual model and a 3D numerical representation of the geothermal system, providing quantitative estimates of recoverable thermal reserves and power generation potential. The proposed workflow enhances the accuracy of geothermal resource evaluation in Taiwan and offers a transferable methodological framework for similar metamorphic tectonic environments.