A review of chemical-assisted minimum miscibility pressure reduction in CO_(2) injection for enhanced oil recovery  

作　　者：Mohamed Almobarak Zangyuan Wu Daiyu Zhou Kun Fan Yongbing Liu Quan Xie 

机构地区：[1]Discipline of Petroleum Engineering,WA School of Mines:Minerals,Energy and Chemical Engineering,Curtin University,Western Australia,Australia [2]PetroChina Tarim Oilfield Company,26 Shihua Avenue,Korla,Xinjiang,841000,China [3]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan,610500,China

出　　处：《Petroleum》2021年第3期245-253,共9页油气（英文）

基　　金：by Petro China Tarim Oilfield Company(PetroChina).

摘　　要：Miscible CO_(2)injection appears to be an important enhanced oil recovery technique for improving sweep efficiency and eliminating CO_(2)-oil interfacial tension resulting in up to 10%higher oil recovery compared to immiscible flooding,in addition to the environmental benefits of reducing greenhouse gas emissions through carbon capturing utilising and storage(CCUS).Moreover,this technique could be similarly applicable to natural gas and nitrogen projects to increase oil recovery and to reduce the associated gas flaring.However,miscible displacement may not be achievable for all reservoirs,in particular,reservoirs with high temperature where high injection pressure would be needed to reach miscibility which likely exceeds the formation fracture pressure.Therefore,to further achieve reservoirs’potential,there is a pressing need to explore a viable means to decrease the miscibility pressure,and thus expand the application envelop of miscible gas injection in reservoirs with high temperatures.In this work,we aim to provide insights into minimum miscibility pressure(MMP)reduction by adding chemicals into CO_(2)phase during injection.We achieved this objective by performing a comprehensive review on chemical-assisted MMP reduction using different chemical additives(e.g.,alcohols,fatty acids,surfactants)and different experimental methodologies.Previous experimental studies have shown that a fraction of chemical additives can yield up to 22%of MMP reduction in CO_(2)-oil system.Based on results analysis,surfactant based chemicals were found to be more efficient compared to alcohol based chemicals in reducing the interfacial tension in the CO_(2)-oil system.Based on the current experimental results,adding chemicals to improve the miscibility and reduce the MMP in the CO_(2)-oil system appears to be a promising technique to increase oil recovery while reducing operating cost.Selection of the effective chemical additives may help to expand the application of miscible gas injection to shallow and high temperature reservoir

关 键 词：Enhanced oil recovery Natural gas injection CO2 injection Minimum miscibility pressure Chemical-assisted 

分 类 号：TE357[石油与天然气工程—油气田开发工程]