Numerical simulation method of multi-fracture fracturing coupling proppant transport

Hydraulic fracturing is a critical technology for the efficient development of unconventional reservoirs. It involves multi-physics coupling, making its numerical simulation an extremely challenging task. In this paper, an efficient hydraulic fracturing simulator is developed by integrating a simplified proppant transport model into the multi-fracture fracturing framework. In the fracture propagation model, the finite volume method is used to solve fluid flow, while the displacement discontinuity method is employed rock deformation. Proppant transport is realized by the simplified Eulerian–Eulerian method, which only needs to consider the one-dimensional fluid flow. The high-precision weighted essentially non-oscillatory scheme is used to solve the nonlinear proppant transport equation. Compared with the Eulerian–Lagrangian method, the proposed method enhances simulation efficiency by 2–3 orders of magnitude. The numerical model is verified through physical experiments and fracture analytical solutions. The fracture propagation and proppant transport models are implemented via a unidirectional coupling strategy. First, the fully coupled model calculates the fracture morphology, followed by the computation of proppant distribution at each time step. Four cases were established to analyze the effects of fracturing fluid injection time, injection rate, fracture cluster spacing, and the number of fracture clusters on the industrial-scale proppant distribution in fractures. This method can be applied to large-scale fracturing simulation, optimization of fracturing parameters and other fields requiring high computational efficiency.