Reactivation of Fractures in Subsurface Reservoirs - a Numerical Approach using a Static-Dynamic Friction Model

TL;DR

This paper introduces a numerical approach to model fracture reactivation in subsurface reservoirs by coupling fluid flow, rock deformation, and fracture slip using a static-dynamic friction model, with an iterative solution scheme.

Contribution

It develops a coupled multiphysics model for fracture reactivation incorporating a static-dynamic friction law and proposes an iterative solution scheme considering shear modulus and mesh size.

Findings

Effective iterative scheme for non-linear equations

Coupled model capturing fluid, deformation, and slip dynamics

Guidelines for step parameter based on material and mesh properties

Abstract

Fluid-induced slip of fractures is characterized by strong multiphysics couplings. Three physical processes are considered: Flow, rock deformation and fracture deformation. The fractures are represented as lower-dimensional objects embedded in a three-dimensional domain. Fluid is modeled as slightly compressible, and flow in both fractures and matrix is accounted for. The deformation of rock is inherently different from the deformation of fractures; thus, two different models are needed to describe the mechanical deformation of the rock. The medium surrounding the fractures is modeled as a linear elastic material, while the slip of fractures is modeled as a contact problem, governed by a static-dynamic friction model. We present an iterative scheme for solving the non-linear set of equations that arise from the models, and suggest how the step parameter in this scheme should depend on the shear modulus and mesh size.