Calculation of effective permeability in fractured porous media using finite volume method

Abstract

This paper focuses on calculation of effective permeability in fractured porous media with blocks matrix using finite volume Computational Fluid Dynamics (CFD) method. This fractured media with blocks matrix can be found in the Enhanced Geothermal Systems (EGS). A fracture network consists of nine square (3*3) rock blocks and the fractures between the rocks. Periodic boundaries are used for four side of the domain, while zero mass flow rate is implemented in the vertical direction and a mass flow rate of 0.0092 kg/s is implemented in the horizontal direction. Effects of rock material permeability of the rock blocks on the effective permeability of the whole domain are investigated. Five cases with different rock permeability, namely, 0 m2, 0.1E-7m2, 0.1E-6m2, 0.1E-5m2, and 0.1E-5m2, are calculated based on the CFD model. It is found that the effective permeability Kx increases significantly as the increase of the rock permeability, indicating the importance of taking into consideration of rock permeability in calculating effective permeability of EGS systems.