气溶性表面活性剂降低CO2/原油混相压力发展现状

Progress of Reducing Miscibility Pressure between CO2 and Crude Oil by CO2-soluble Surfactant

李兆敏 席玲慧 张超 王美佳

LI Zhaomin，XI Linghui，ZHANG Chao，WANG Meijia

为降低CO2与原油间的混相压力、提高CO2混相驱的驱油效率，介绍了混相溶剂法、超临界CO2微乳液法和 气溶性表面活性剂法3 种降低混相压力的方法，着重分析了气溶性表面活性剂的结构特征及其降低CO2混相压 力的作用机理。混相溶剂法所需烃类气体量较大，成本较高；超临界CO2微乳液法在一定程度上可以降低混相 压力，但降幅较低；气溶性表面活性剂在CO2中有一定的溶解度，可作用于油气界面、降低油气界面张力，实现混 相压力的降低。然而，目前气溶性表面活性剂种类较少，亟需开发新型的气溶性表面活性剂，提高CO2与原油的 混相能力，实现原油CO2混相驱的高效开发。图4 参54

In order to reduce the miscibility pressure between CO2 and crude oil and improve the oil displacement efficiency of CO2 miscible flooding，three methods to reduce the miscibility pressure were summarized，including miscible solvent，supercritical CO2 microemulsion and CO2-soluble surfactant. The structure characteristics of CO2-soluble surfactant and its mechanism of reducing the miscibility pressure of CO2 were analyzed. The miscible solvent method required a large amount of hydrocarbon gas and the cost was high. Supercritical CO2 microemulsion method could reduce the miscibility pressure to a certain extent，but the degree of reduction was relatively low. CO2-soluble surfactant could dissolve in CO2 so that CO2-soluble surfactant could act on the oil and gas interface，reduce the interfacial tension of oil and gas，and reduce the miscibility pressure. However，there were few kinds of CO2-soluble surfactants at present. Therefore，it was urgent to develop new CO2-soluble surfactant to improve the miscibility of CO2 and crude oil，and achieve high efficiency development of CO2 miscible flooding for crude oil.