An Efficient Computational Model for Simulating Stress-dependent Flow in Three-dimensional Discrete Fracture Networks

Abstract

In-situ modelling of stress-dependent fluid flow in fractured rocks is important for various applications in rock engineering. However, precise determination of the hydraulic aperture of subsurface fractures, particularly at great depths, is often quite difficult. One of the most important parameters affecting the aperture is the stress field. Therefore, in this study, a new FEM model is proposed to study the effect of the in-situ stresses on the flow rate in fractured rocks with limited fracture lengths using a one-way hydromechanical coupling scheme and various non-linear joint constitutive models. The model is computationally efficient and of low-cost for various applications, and it provides results that are consistent with those from time-consuming two-way coupling methods. A series of sensitivity analyses have also been carried out to investigate key parameters in the model and to demonstrate how the fracture aperture and fluid flow change with variation of the in-situ stress field.