Abstract:Tight oil formation is commonly tight with a low formation pressure coefficient, which makes the development of tight oil very difficult. As an alternative, water huff and puff has great advantages on maintaining reservoir pressure and oil production. In this paper, based on the embedded discrete fracture model, a mathematical model with threshold pressure gradient and stress sensitivity for tow phase flow in volumetric fracturing tight oil reservoir is developed, and the numerical schemes are established. Then 12 huff-puff cycles of production process in a one-stage fractured tight oil reservoir model is simulated with the established numerical simulation method, and the effects of matrix and fracture properties are investigated. The results show that with the increase of matrix permeability, micro-fracture permeability and micro-fracture density, the water-spreading area increases, and the cumulative oil production also greatly increases. The hydraulic fracture permeability has little impact on water-spreading area, while greatly increases the cumulative oil production. However, the cumulative oil production increases little when the hydraulic fracture permeability increases to a certain value. It can be seen that the properties of matrix and fractures have great effects on water huff and puff EOR in tight oil reservoirs.