Numerical study of fractured reservoirs: Hydromechanical analysis of the permeability tensor

Fractures in the rock mass localize flow and deformations. Consequently, they play a critical role in the hydromechanical evolution of the reservoir. Continuum models are preferred over discontinuous approaches to simulate fractured rock masses as they fully capture the set of governing equations at the element level and coupled processes are easier to implement. This study builds on the implicit joint-continuum model to advance the understanding of flow through stress-sensitive fractured rock masses. The proposed formulation assumes persistent, quasi-planar, and regularly spaced fracture sets and the model can simulate several different sets. Benchmarking examples illustrate the capabilities of the model and highlight the importance of a fracture transmissivity asymptotic state for the evolution of the rock mass permeability. The stress-induced anisotropy is limited as fracture transmissivity reaches a constant value with both normal stress and shear displacement.