Numerical Studies of Coupled Flow and Heat Transfer Processes in Hydraulically Fractured Geothermal Reservoirs

Abstract

Prediction and modeling of coupled fluid flow and heat transfer processes in naturally and hydraulically fractured rock systems represent a critical component for energy recovery analysis and lifetime performance evaluation of enhanced geothermal systems (EGS). In this study we applied a fracture continuum model, which enables accurate and efficient description of discrete fracture network systems, to simulate the thermal-hydrologic (TH) behaviors of geothermal reservoirs in response to two common hydraulic stimulation scenarios, hydro-fracturing and hydro-shearing. Numerical heat transfer results demonstrate that the heat transfer/ production efficiency of an EGS system can be greatly improved by the application of hydraulic stimulation. The numerical heat transfer models developed in this study, in conjunction with hydro-geomechanical models simulating hydraulic stimulation, will provide a useful and effective modeling framework for EGS operation and performance assessment/evaluation.