低渗透油藏二氧化碳混相与近混相驱替规律研究

摘要

Firstly,the tubule experimental method was used to the minimum miscible pressure of CO2 under this study condition,determined value was 26 MPa.Secondly,artificial low permeability core was used to respectively carry out oil displacement experiments under 24 MPa near miscible displacement pressure condition and 28 MPa miscible displacement pressure condition.The results show that the oil displacement efficiencies change similarly,and the displacement efficiency of miscible displacement is higher than that of near miscible displacement by nearly 1.8％,which can provide theory and experimental basis for the follow-up study of CO2 flooding.%实验先利用细管实验法确定出本次试验条件下二氧化碳的最小混相压力为26 MPa,再使用人造低渗透岩心并设定驱替压力分别为24 MPa近混相驱压力条件和28 MPa混相驱替压力条件进行驱油实验.结果是二者驱油效率变化基本一致,且混相驱替比近混相驱替最终驱油效率高出1.8个百分点,以期为后续研究二氧化碳驱油提供理论和实验基础.