Reservoir Evaluation and Development ›› 2022, Vol. 12 ›› Issue (5): 726-733.doi: 10.13809/j.cnki.cn32-1825/te.2022.05.003

• Specialist Forum • Previous Articles     Next Articles

Research progress of assistants for reducing CO2-crude oil minimum miscible pressure

GUO Ping1(),ZHANG Wanbo1,JIA Na2,CHEN Fu3,LIU Huang1,WANG Zhouhua1,GE Xingbo3   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. Petroleum Systems Engineering Faculty of University of Regina, Regina, Saskatchewan S4S 0A2, Canada
    3. College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2021-07-13 Online:2022-10-26 Published:2022-09-27


The minimum miscible pressure (MMP) of CO2 flooding is a crucial parameter to judge whether miscible flooding is attainable. In order to reduce the application threshold of miscible flooding, the MMP between CO2 and crude oil needs to be reduced urgently. Adding miscible flooding assistants to oil reservoir is an effective means for minimum miscible pressure reduction. At present, according to the elements contained, the miscible flooding assistants can be divided into three categories including fluorocarbon, siloxane, and hydrocarbon (oxygenated). In order to reduce the cost and improve the MMP reduction performance, the hydrocarbon structure should be added to the fluorocarbon assistants to make the assistants develop in the direction of mixing type. The hydrocarbon assistants have sound MMP reduction performances and room for improvement. The key is to find a suitable CO2-phlic structure. Computer simulation is also a vital means to study micro mechanism and assist structure designing. Compared with fluorocarbon and siloxane, the cost of hydrocarbon (oxygenated) is lower, and it has the most application potential from the prospective of cost. At present, the main factor affecting the large-scale application of miscible assistants is the limitation of cost. The promotion and application in the future needs the close cooperation of petroleum and chemical practitioners. In this paper, the mechanisms of CO2 miscible flooding assistants reducing MMP are introduced. The structures of existing miscible flooding assistants, MMP reduction effectiveness are summarized, and the influencing factors on MMP reduction efficiency are analyzed. The developing directions CO2 miscible flooding assistants designing are prospected.

Key words: CO2 miscible flooding, assistants for miscible flooding, reduce MMP, surfactant, microscopic mechanism

CLC Number: 

  • TE39