Flow Properties of CO2/Crude Oil in Miscible Phase Flooding

The high-temperature and high-pressure three-dimensional (3D) device is used to study miscible flooding of CO2 and crude oil. The experiment model is a real sand plate. In oil reservoir condition, there is a large difference between production and injection volume. The complex flowing characteristics of CO2 flooding in pore media are observed in recovery, water cut, and gas-oil ratio curves. By analyzing the water saturation contour plot measured by a saturation probe, CO2 and oil can be miscible. The viscosity of miscible liquid and flowing pressure decreases. This is the important mechanism of enhanced oil recovery. When the viscosity of miscible liquid and flowing pressure decreases, miscible CO2 and oil contacted with water can make a similar three phase. This is the important mechanism of enhanced oil recovery. Based on the conclusion, the main reason for the production and injection difference is that high-density CO2 would flow into pore media in which water and oil cannot flow.