Numerical simulation of multiphase fluid flow in naturally fractured reservoirs.

A new mathematical flow model is derived for characterizing the multiphase fluid flow phenomenon in naturally fractured reservoirs. This model treats the reservoir as a double porosity medium consisting of a heterogeneous, isotropic primary rock matrix and an anisotropic, heterogeneous fracture. The statistical distribution in space and orientation of the fracture is manifest in terms of the fracture permeability tensor. The model permits flow through the rock matrix and the fractures to be described simultaneously. The fluid interaction terms coupling flow between the rock matrix and fractures, the gravity effects, the capillary forces and the fracture velocity of fluids are all taken into consideration.