-
oa Dependency of Enhanced Geothermal System Performance on Fractures with Different Working Fluids (Water and sCO2)
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, World CCUS Conference 2025, Sep 2025, Volume 2025, p.1 - 5
Abstract
This study compares the performance of Enhanced Geothermal Systems (EGS) using Supercritical CO2 (sCO2) and water, focusing on how each fluid’s efficiency depends on fracture geometry. While sCO2 offers many advantages for geothermal applications, the impact of fracture network properties on its performance is not yet fully understood compared to water. Using a fully coupled Thermo-Hydraulic model in COMSOL Multiphysics, the study simulates fluid flow and heat transfer in a 2D EGS domain with three fracture scenarios: discrete fractures, a connected fracture network, and a combination of both. Results show that water is more sensitive to fracture geometry, with greater variations in output temperature and thermal power across different fracture configurations. In contrast, sCO2 maintains more stable output temperature and thermal power due to its lower dynamic viscosity and higher mobility. The study highlights the importance of optimizing fracture network design differently for water- and sCO2-based EGS, given their distinct behaviors within fracture networks.