微乳液驱油技术的研究进展

Research Progress of Micro-emulsion Flooding Technology

张志超 柏明星 王勇 聂剑峰 刘敬源 邵军

ZHANG Zhichao BAI Mingxing WANG Yong NIE Jianfeng LIU Jingyuan SHAO Jun

针对低渗特低渗等非常规油藏注水开发存在水注不进液采不出的难题，系统论述了微乳液驱对低渗油藏 降压增注、调剖堵水、储层保护等提高采收率的驱油机理，注入油藏中微乳液黏度高于水，相比水驱能够改善油 水流度比，减小驱替液的黏性指进，微乳液与油接触也会产生超低界面张力，降低毛管阻力，改变岩石润湿性，扩 大油藏宏观波及体积。另外，微乳液在流经油藏的孔吼通道时，也会通过对原油增溶、黏弹性拖拽等协同作用， 提高油藏洗油效率。同时，也对几种对低渗油藏驱油适用性较好的微乳液（超临界CO2微乳液、纳米微乳液、原 位乳化微乳液和微乳液泡沫）的类型和性质进行了论述。并论述了不同类型微乳液在实际现场低渗透油藏降压 增注提高采收率中的应用效果，微乳液驱能普遍使低渗油藏中注水井注入压力降压35%以上，油井的增油效果 也较好。通过该论述旨在为当前低渗透等非常规油藏应用微乳液驱油提高采收率技术提供一定的理论借鉴。

Because of the difficult problem of water injection and liquid production in unconventional reservoirs such as low-permeability and ultra-low permeability reservoirs，this paper systematically discussed the oil displacement mechanism of micro-emulsion flooding for improving oil recovery in low-permeability reservoirs，such as injection pressure reduction and injection ability increase，profile control and water plugging，and reservoir protection. Compared with water flooding，the viscosity of injected micro-emulsion into the reservoir is higher than that of water. Thus，it can improve the oil-water mobility ratio，reduce the viscous fingering of displacement fluids，and reduce interfacial tension（IFT）between the micro-emulsion system and oil phase，which reduces capillary resistance，changes wettability of reservoir rock，and expands the macroscopic sweep volume in the reservoir. In addition，when the micro-emulsion flows through the pore and throat channel of the reservoir，it will also improve the oil-washing efficiency of the reservoir through the synergistic effect of oil solubilization，viscoelastic drag，etc. At the same time， various types and properties of microemulsions（supercritical CO2 micro-emulsion，nano micro-emulsion，in-situ micro-emulsion， and micro-emulsion foam）with good applicability of oil displacement for low permeability reservoirs were also discussed. The application effect of different types of micro-emulsion in actual low permeability fields was also discussed in this paper. It was found that micro-emulsion flooding can generally reduce the injection pressure of water injection wells in low permeability reservoirs by more than 35%，and the oil increase effect of oil wells was also good. The purpose of this review is to provide a certain theoretical reference for the application of micro-emulsion flooding to enhance oil recovery in low permeability and other unconventional reservoirs.

10.19346/j.cnki.1000-4092.2023.04.028