基于磁悬浮天平的超临界CO2-癸烷溶液密度特性研究

摘要

The capacity of supercritical carbon dioxide (sc-CO2 ) to dissolve crude-oil is mainly determined by the density of supercritical fluid . Using decane instead of crude-oil , magnetic suspension balance (MSB) is applied to the measurement of CO 2-decane solution density of different CO2 mass fractions (0 ,8% ,20% ,43% ,67% ) at different temperatures (313-353 K) and pressures (12-18 M Pa) .And the effects of the three parameters on CO 2-decane solution density are analyzed . The experimental results show that the CO 2-decane solution density increases with the pressure increasing and decreases with the temperature increasing at the certain CO 2 mass fraction .The CO2 mass fraction plays a decisive role in CO 2-decane solution properties .During CO2 flooding processes , CO2 injection rate has a relative effective region .In addition ,the optimal region of CO 2 injection rate is determined by the reservoir temperature and pressure .%　　超临界CO2溶解原油的能力主要取决于超临界流体的密度．基于高精度磁悬浮天平实验系统，利用癸烷模拟原油，系统测量了不同温度（313～353 K）和压力（12～18 MPa）下，不同CO2质量分数（0、8％、20％、43％、67％）CO2-癸烷溶液的密度，并分析了各参数对CO2-癸烷溶液密度的影响．研究发现在CO2质量分数一定的情况下，CO2-癸烷溶液密度随着压力的增加而增加，随温度的升高而降低．CO2溶解质量分数对溶液的性质有显著影响，CO2的注入量对驱油存在一个有效的区间，可以根据井下温度、压力来决定注入量，从而达到最佳的驱油效果．