Coupling Rock-Fracture Propagation with Thermal Stress and Fluid Flow

Abstract

AbstractThis paper describes the theory behind a recent extension of a two-dimensional (2D) boundary-element code, FRACOD, to enable simulations of either coupled fracture (F)-hydraulic (H) processes or coupled F-thermal stress (T) in rocks. This extension is the next step in the ongoing development of a three-dimensional (3D) fracture mechanics code that couples F-H-T processes and predicts fracture initiation and propagation under thermal and hydraulic loadings. The original FRACOD simulated both mode I (tensile) and mode II (shear) fracture propagation that only involved mechanical processes in rock masses. In this study, the F-T coupling in FRACOD was developed using an indirect boundary-element method based on fictitious heat sources. The F-H coupling in FRACOD focused on fluid flow in explicit rock fractures using a cubic law. An explicit iteration method is used to simulate the fluid flow process in fractures and its interaction with mechanical deformation. Several verification and application case...