关键词:  CO₂ 驱, 最小混相压力,  , 超临界CO₂ 微乳液, 亲CO₂ 表面活性剂

Abstract: A winwin purpose of Carbon Dioxide(CO₂ ) emissions and efficient reservoir development can be achieved by injecting CO₂  into reservoir. How to effectively reduce miscibility pressure between CO₂  and crude oil, is one of the major hot and difficult problems for enhancing oil recovery by CO₂  flooding. The methods of miscibility pressure reduction using CO₂ flooding are compared, and new efficient CO₂ philic surfactants are explored. Currently, mixing cosolvent with CO₂  is limited by the price. Supercritical CO₂  micromulsion can also reduce the miscibility pressure, while the main study is focused on reducing oil/water interfacial tension of ionic surfactants. Nonionic surfactants that can reduce oil/CO₂  interfacial tension are rarely reported. Dissolving capacity of polar compounds in CO₂  is small for the poor compatibility between CO₂  and nonionic surfactant. So, the key to reduce miscibility pressure is CO₂ philic surfactant.

Key words: Carbon dioxide flooding,    , CO₂philic surfactant,    , Supercritical CO₂ micromulsion,    ,  Miscibility pressure