Coupled Simulation of Flow and Geomechanics in Fractured Reservoirs Using an Integrally Embedded Discrete Fracture Model

Abstract Fluid flow in fractured reservoirs is significantly affected by the effect of geomechanics since fractures can be more stress-sensitive than rock matrix. In this work, we present a flow and geomechanics coupled model for the simulation of fractured reservoirs. The flow model uses the integrally embedded discrete fracture model (IEDFM). This model considers a more improved pressure distribution assumption in the vicinity of fractures compared to traditional EDFM and calculates the matrix-fracture transmissibility semi-analytically. Another advantage of the IEDFM is the capability of modeling flow between matrix and fractures in anisotropic reservoirs. The geomechanical model uses the equivalent continuum approach, which introduces an equivalent material to capture the deformation of both rock matrix and fractures. Constitutive models are established for both natural fractures and hydraulic fractures to capture the stress-dependent fracture stiffness. The force balance equation is discretized by the finite element method (FEM) and coupled with IEDFM to form an iterative coupling simulation approach. A water flooding example in a naturally fractured reservoir and a depletion example from a horizontal well with hydraulic fractures in a tight oil reservoir are investigated to demonstrate the feasibility of the proposed model in coupled flow and geomechanics simulation of fractured reservoirs.