Solubility of CO_2 in oil,water and their mixture and density of the saturated CO_2 fluids

The solubility of CO2 in the Daqing crude oil and formation water was measured under high pressure using PVT method.The density and swelling factor of the saturated CO2 oil and water phase were calculated.The experimental results show that under the experimental condition,the solubility of CO2 in the crude oil and formation water increases with the increase of pressure.The density of the saturated CO2 oil and formation water increases linearly with the increase of the solubility of CO2.The swelling factor of the saturated CO2 fluids depends on the equilibrium pressure and the solubility of CO2,but it has almost nothing to do with the liquid composition.The solubility of CO2 in the oil-water mixture of different oil-water volume ratios was also measured,and it is found that the solubility of CO2 in the oil-water mixture is related to the pressure and liquid composition at constant temperature.The experimental results could be used as a reference for the program design of CO2 geological sequestration and CO2 flooding.