CO_2在油水混合物中的溶解度及饱和CO_2油水的密度

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

采用PVT法,在高压条件下测定了CO2在大庆原油和地层水中的溶解度,并计算了饱和CO2油、水相的密度和膨胀系数.实验结果表明:在实验条件下,CO2在原油和地层水中的溶解度随压力的升高而增大,饱和CO2油、水相的密度随CO2溶解度的增大而线性增大.饱和CO2液相的膨胀系数受实验压力和CO2溶解度的影响较大,受液相组成的影响很小.实验还测定了CO2在不同油水体积比混合物中的溶解度,发现恒定温度下CO2在油水混合物中的溶解度只与压力和液相组成有关,而不受其他条件影响.

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.