An improved multiple sub-region method for flow simulation of fractured reservoirs

Key words:  fractured reservoir  discrete fracture model  oversampling technique  double media model  mimetic finite difference method

Abstract:

An improved multiple sub-region method (MSR) for flow simulation of a fractured reservoir was proposed by using an over-sampling technique and a volume averaging method. The improved MSR method can reflect the strong anisotropy in fractures and can effectively simulate the effects of nearby sub-region on the transmissibility of the fractures. A mimetic finite difference method (MFD) was used for the numerical solution, which has excellent local conservation features and good applicability for the complex unstructured grid and permeability tensors. Several case studies were conducted to verify the accuracy and applicability of the improved method. The results obtained using the improved model agree well with those obtained using a conventional discrete fracture model, and the calculation efficiency of the improved model is higher than that of the discrete fracture model.