Integrated Numerical Simulation Method for Fracturing and Production of Fractured Tight Oil Reservoirs Based on Embedded Mesh

Efficiently integrated simulation of the fracturing production process of fractured tight oil reservoirs is one of keys to evaluate fracturing design. In this paper, a full-space hydro-geomechanics coupling numerical simulation method of matrix fractures based on embedded grids is adopted. We further consider the dynamic fracture propagation under the influence of natural fractures, low-velocity nonlinear flow, and the stress sensitivity effect of matrix and fractures. The integrated multi-mechanism simulation of fracturing production in fractured tight oil reservoirs is achieved. Then the integrated influence of natural fractures and nonlinear flow on fracture propagation and production performance is analyzed. The research results show that our model can simulate fracturing at any time during production, providing an effective tool for the design and analysis of refracturing and infill wells. When the tensile strength of the matrix rock decreases from 10.2 MPa to 2.3 MPa, the damage zone gradually increases and the fluid leak-off increases, resulting in a decrease of the main fracture length by 8%~9%. However, it can increase the cumulative oil production by 17.5% to 61.1%. The impact is significant and mainly affects the early daily oil production. Low-velocity nonlinear flow can better predict tight oil production performance than the threshold pressure gradient model. Our proposed method provides an efficient tool for integrated dynamic prediction, effect analysis, and optimization of fracturing production in fractured tight oil reservoir.