Calculation Of Permeability Tensor Using Boundary Element Method Provides A Unique Tool To Simulate Naturally Fractured Reservoirs

摘要

This paper presents a numerical model to calculate effectivepermeability tensor in naturally fractured reservoirs. Darcy’slaw and Navier-stoke’s equation are used to formulate fluidflow in rock matrix and fractures, respectively. Fractures ofdifferent scales based on their length are considered. Shortfractures are considered as an enhancement of matrixpermeability by applying the interface boundary condition.Long fractures intersecting more than one block are treated asa source/sink in the corresponding blocks. Fluid flow inporous matrix around the medium and long fractures ismodeled by Poisson’s equation. Periodic boundary conditionis applied on the grid-block boundaries to calculate theelements of effective permeability tensor. The model has beenvalidated against analytical results and applied to a number ofcases where arbitrary fractures of different sizes are assumedwithin the grid-blocks.