A numerical model for water-oil flow in naturally fractured reservoirs

This paper describes the development of a three-dimensional, two-phase model for simulating the flow of water and oil in naturally fractured reservoirs. The model is based on the dual porosity approach. Main flow in the reservoir occurs within the fractures with local exchange of fluids between the fracture system and matrix blocks. A new formula for matrix/fracture fluid exchange rate is proposed based on an extension of the equation developed by Kazemi to account the gravity effects. This formula allows to eliminate the matrix pressure in the pressure equation for fractures and makes the solution algorithm easier.Some example calculations are presented to validate the model. These include a comparison of the results of this paper with previous results, showing the gravity effects and applicability of the model for field-scale problems.