T153 Enhanced Geothermal Systems (EGS): Sustainable, Carbon-Free Energy

Tuesday, 2 November 2010
8:00 AM - 12:00 PM
Room 612

FULLY COUPLED THERMO-HYDRO-MECHANICAL MODELING FOR ENHANCED GEOTHERMAL SYSTEMS

Paper number: T153-4
Program: Technical Sessions
Time: 8:55 AM – 9:10 AM

Authors

Abstract

Enhanced Geothermal Systems (EGS) have the potential to supply a significant portion of future electricity demand worldwide. However, the advancement of EGS greatly depends on the ability to create a reservoir of sufficient volume by hydraulic fracturing, via tensile and shear failure, and also by reactivation of naturally existing fractures, to allow for commercial-scale heat transfer from the reservoir rocks to the working fluid. Our understanding of the dynamics of the coupled rock-fracture-fluid-heat system, and our ability to reliably predict how reservoirs behave under stimulation and production, are currently limited by the computational capabilities of existing simulators.

In order to advance our understanding of how reservoirs behave under these conditions, we are developing a coupled physics-based hybrid Finite Element (FE)-Discrete Element (DEM) simulator for continuum multiphase flow and heat transport (FE) and rock deformation-fracture propagation (DEM). In our approach, the continuum flow and heat transport equations are solved on an underlying finite element mesh with evolving porosity and permeability for each element that depends on the local structure of the discrete element network. Here we describe the development of the simulator, detailing the development of a parallel, fully coupled, multiphase thermo-hydro-mechanical simulation code and present results of initial code comparisons using conditions representative of EGS systems.