微乳液泡沫驱油技术原理、挑战和研究进展

微乳液驱和泡沫驱是强化采油领域中的两个重要技术。前者利用表面活性剂形成油-水微乳液提高增溶能力，降低油水界面张力和毛细管阻力，从而提高驱替效率和微观采收率；后者利用泡沫剂将气体稳定地分散在水相中，在油藏孔隙中形成泡沫，封堵优势通道和已驱替区域，从而扩大波及体积并提高宏观采收率。通过综述两个技术的国内外发展历史和研究进展，阐明了其优势和局限性。近年来提出的微乳液泡沫驱油技术，又称为低张力泡沫驱，其既可以保留两个独立技术的优势，又可以克服他们的缺点，最终同时提高微观和宏观采收率。但是在实际研究中，微乳液泡沫驱技术却面临理论和应用上的双重挑战。通过调查国内外相关研究进展，详细阐述了微乳液泡沫驱技术目前面临的挑战、研发思路和研究建议。

Mechanisms, challenges and research advances in microemulsion-foam EOR

Microemulsion and foam floodings are two important technics in enhanced oil recovery (EOR). The former one enhances the microscopic oil recovery efficiency, i.e., displacement efficiency, by using surfactant to increase solubilization ratio and decrease oil-water interfacial tension and capillary pressure; the latter one enhances the macroscopic oil recovery efficiency, i.e., sweep efficiency, by using foaming agent to generate foam in reservoir pores for blocking preferential flowing channels and swept zones. The advantages and limitations of two technics are illustrated here through the review of their developments and research advances. Microemulsion-foam flooding, also known as low-tension-foam flooding, that is a novel EOR technic proposed recently, can combine the advantages of the individual method, meanwhile overcome their limitations, ultimately enhance both microscopic and macroscopic oil recovery efficiency. However, there are theoretical and practical challenges for the microemulsion-foam EOR. By reviewing the research advances of this EOR method, the current challenges, potential solutions and research suggestions are discussed in details.