Prediction of Transport Properties of Deformed Natural Fracture Through Micro-scale Hydro-mechanical Modeling

Abstract

To study the effect of fracture properties on mechanical and fluid flow behavior of fractured rocks, we developed a micro-scale hydro-mechanical model. Modeling grains and studying their interactions are used to predict the mechanical response of digital rock samples. Fluid flow behavior is obtained through a realistic network model of the pore space in the compacted assembly. As a result of grain deformation and micro-crack development in a rock sample, the geometric description of the complex pore structure is regenerated to predict fluid flow performance of the rock sample using a dynamic pore network model. In our numerical model, the first step consisted of constructing a Berea sandstone sample. Then, fractures with different properties such as orientation, dilation angle, roughness, and cementing materials are introduced. Mechanical properties of the fractured sample are measured as functions of deformation by performing numerical triaxial tests. Applying a dynamic pore network provides a tool to investigate the important role of fracture parameters on transport behavior. Our results show that shearing along the fracture dilates the sample, and increases its permeability, which is a complex function of fracture mechanical properties.