Hu Yingxue, Dong Kai, Zhang Dan, Wu Tianjiang, Xu Wei, Gu Zhaolin
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China.
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, China.
Front Chem. 2025 May 19;13:1601086. doi: 10.3389/fchem.2025.1601086. eCollection 2025.
microemulsion has emerged as an advanced tertiary oil recovery technique that utilizes the injection of surfactant solutions to improve displacement efficiency through spontaneous microemulsification. This study presents a novel pore-scale numerical model to simulate the dynamic process of microemulsion formation during surfactant-cosolvent-salt flooding in complex porous media. Through comprehensive numerical simulations based on realistic rock geometries, we systematically investigated the spatiotemporal evolution of phase distributions and identified critical mechanisms governing oil mobilization. The developed model incorporates four fundamental characteristics of microemulsion systems: interfacial tension reduction, viscosity modification, wettability alteration, and enhanced solubilization capacity. During the microemulsion-forming surfactant flooding in a realistic rock medium, the formed microemulsion was observed at the interface between oil and aqueous. The microemulsion flooding can significantly improve the recovery rate under the combined effect of multiple factors. Increasing the viscosity of the formed microemulsion can enhance the oil recovery during the microemulsion-forming surfactant flooding in the complex porous media. Under water-wet conditions, the oil-water interface stays at the junction of the throat and the pore space, which contributes to the formation of microemulsions and thus to the enhancement of recovery. This study provides a better understanding of the microemulsion formation and the mechanisms of enhanced oil recovery in complex porous media.
微乳液已成为一种先进的三次采油技术，该技术通过注入表面活性剂溶液，利用自发微乳化作用提高驱替效率。本研究提出了一种新颖的孔隙尺度数值模型，用于模拟复杂多孔介质中表面活性剂-助溶剂-盐驱油过程中微乳液形成的动态过程。通过基于真实岩石几何形状的综合数值模拟，我们系统地研究了相分布的时空演化，并确定了控制原油运移的关键机制。所建立的模型包含了微乳液体系的四个基本特征：降低界面张力、改变粘度、改变润湿性和增强增溶能力。在真实岩石介质中形成微乳液的表面活性剂驱油过程中，在油相和水相的界面处观察到了形成的微乳液。在多种因素的综合作用下，微乳液驱油可显著提高采收率。提高形成的微乳液的粘度可以提高复杂多孔介质中形成微乳液的表面活性剂驱油过程中的原油采收率。在水湿条件下，油水界面位于喉道和孔隙空间的交界处，这有助于微乳液的形成，从而提高采收率。本研究有助于更好地理解复杂多孔介质中微乳液的形成及提高原油采收率的机制。
