An Improved Grid Generation Approach for Discrete Fracture Network Modelling Using Line Fracture Concept for Two-Phase Flow Simulation

摘要: In traditional Discrete Fracture Network (DFN) method for fractured porous media simulation, fractures are modelled in different scales and orientations using single computational grid. However, a large number of small grids near both ends fracture generated, which substantially reduce the computation efficiency. this paper, new line approach is presented to avoid generation grids. Combined with Multi-Point Flux Approximation (MPFA) algorithm, simulation efficiency highly improved without losing accuracy. We present modified mesh algorithm volume set zero by neglecting width. The aperture (very short line) treated as node during paving method. Therefore, around significantly decreased. quadrilateral unstructured grid system generated proposed Then, taking median dual control volume, all properties such permeability accounted independent parameters discrete fractures. governing equations DFN model derived solved MPFA oil-water two-phase flow. A network developed. To show accuracy model, applied case study two separated crossed fractures, domain scale 50 meters. Compared standard including width (by 2.5 times), due reduction numbers (20%). Good agreement water oil saturation distributions resulted from models validates newly developed Simulation naturally reservoirs has been challenge decades. modelling promising approach. an efficient method, not feasible practical amount time. novelty work coupled multi-point flux approximation flow system. High readily reservoir simulation. Sponsored NSFC (Natural Science Fund China - "the numerical natural based on hexahedral concurrent computation") (No. 51474179)