Analysis of Test Method for Oil and Water Relative Permeability Curve in Tight Reservoirs

Abstract With the development of the international economy, the global demand for oil and gas resources has continued to increase in recent years. The development of high-permeability reservoirs has reached the middle and late stages, and resources are depleting. With the large-scale successful exploitation of tight oils in North America, low-permeability tight reservoirs have gradually become the main object of development. Compared with conventional reservoirs, tight reservoirs mainly develop nano- scale pore systems. It causes poor reservoir properties, high interlayer heterogeneity, low porosity and permeability, and generally no natural productivity in reservoirs. In tight reservoirs, the flow of oil-water phases is not affected by the scale, but also the wettability, they make the oil and water phases seepage more complicated. In this paper, the natural core of a tight reservoir in Daqing was selected. Experiments were carried out using two experimental methods: steady-state method and non-steady-state method. The characteristics of oil and water phases percolation in tight reservoirs were analyzed. The results by comparing the two experimental methods showed the steady state method is suitable for measuring the oil and water relative permeability curve of tight reservoirs.