轻质油藏注空气提高采收率的影响因素研究

Sutdy on influencing factors of air injection to enhance EOR in light-oil reservoir

针对WX轻质油藏,采用数值模拟和物理模拟方法进行了轻质油藏注空气、天然气动态驱油实验,结果表明,较高的油藏温度、压力及较低的注入压差有利于注入空气与原油发生氧化反应,提高轻质油藏注入空气的采油效果。由于原油的低温氧化效应,以及气体对原油中轻质组分的抽提作用增强了空气驱的驱油能力,空气驱提高采收率幅度与天然气驱基本相当。综合提高采收率成本和经济效益等因素,注空气驱技术有助于提高WX轻质油藏的开发效果。

By means of physical modeling and numerical simulation,the dynamic oil displacement tests of air injection and natural gas injection in light-oil reservoir was conducted for WX reservoir.The influences of reservoir temperature,pressure,pressure differential and other factors on development effect have been studied in this paper.Meanwhile,the gas miscible or immiscible injection character and recovery with air drive has also been researched.Compared with those of natural gas drive,the experimental results showed that high temperature and high pressure condition could accelerate the oil oxidation reaction,which led to a better displacement effect,and the similar phenomenon could be observed by reducing pressure differential.Both air injection and natural gas injection under WX reservoir pressure had been characterized as immiscible displacement.The displacement ability of air injection was enhanced by low temperature oxidation(LTO) reaction and extraction effect on light oil component,so its recovery was close to that of natural gas injection.Considering the cost,economic benefits and other factors comprehensively,the air injection technique is more suitable to the development of WX reservoir.