Simulation method of oil-water two-phase transient flow in dual-porosity system in tight reservoir

Abstract

The fracturing development process of tight oil reservoir has the characteristics of multiphase seepage and heterogeneity of reservoir fracture network, which makes it difficult to simulate the oil-water flow of multi-fractured horizontal well. In this paper, a novel mathematical analytical simulation method for oil-water two phase transient flow in matrix-fracture dual-porosity system of tight oil reservoirs is proposed, which considers the characteristics of oil-water two-phase seepage in matrix-hydraulic fracture-fracture network dual-porosity system. At the same time, a dynamic drainage-area is introduced to solve the fracture heterogeneity problem. The material balance equations in the three regions of matrix-hydraulic fracture-fracture network system are solved based on Newton-Raphson method. The changes of average pressure, cumulative oil-water production and daily oil-water production with time in different regions of fractured horizontal wells during production are accurately and systematically simulated and predicted. With laboratory data as constraints, this method can reduce the amount of analytical calculation, improve the understanding of oil-water two-phase transient flow in matrix-fracture dual-media system of tight oil reservoirs and guide the efficient fracturing development of tight reservoirs.