Fully coupled fluid-solid numerical simulation of stimulated reservoir volume (SRV)-fractured horizontal well with multi-porosity media in tight oil reservoirs

A mutual coupling effect exists between the flow and stress fields in tight oil reservoir development. In terms of the characteristics of multi-porosity media (the matrix, natural fractures and network fractures) for stimulated reservoir volume (SRV)-fractured horizontal wells in tight oil reservoirs, considering the dual porosities of matrix and natural fractures, and based on the flowing feature of a discrete-fracture mode (DFM) fracture network stimulated system, a numerical simulation method based on fully coupled fluid-solid is introduced. According to the effective stress principle and regional flow characteristics, the fully coupled fluid-solid mathematical model considering the multi-porosity media characteristics of complex fracture networks is presented. The fully coupling numerical solution for the stress and flow fields is solved by the finite element method. The accuracy of this model is verified by comparing the finite differential model, non-coupled model and actual production data, respectively. And analyzing the computational time needed to solve the model under different solution methods and complexity levels. The variation of stress-strain and reservoir physical property parameters is revealed. For the non-coupled and fully coupled model, the productivity and formation pressure differences are compared and analysed. The results show that when considering the stress field, the initial production rate of an SRV-fractured horizontal well is large but declines quickly, and it has fundamentally different characteristics from the traditional flow model. Our research provides theoretical and technical guidance for the efficient development of unconventional resources.