三元复合驱采出水中存在大量驱油表面活性剂，形成了油滴破乳与乳化过程共存的溶液化学体系，破乳难度大；且油滴粒径微细，破乳后难以聚并，进一步加剧了采出水油水分离的难度。微细油滴稳定性、脱稳聚并行为与其粒径大小密切相关，揭示微细油滴由于粒径变小产生的尺寸效应是解决其脱稳聚并难题的关键。本项目拟从微观层面深入认知三元复合驱采出水油/水界面体系，运用分子动力学模拟、微量热与多种表界面测试技术，掌握油滴油/水界面膜的形成规律与微观结构特性，揭示驱油剂在油滴表面吸附行为与油滴稳定性的关系，探明微细油滴稳定性机理；分析不同粒级油滴物化特性与沉降特性变化，揭示微细油滴尺寸效应与稳定性差异；研究破乳剂在不同粒级油滴表面吸附行为差异，明确破乳剂分子结构与不同粒级油滴脱稳聚并效率之间的构效关系，阐明基于尺寸效应的微细油滴脱稳聚并机理。研究结果为高效破乳剂精准设计及三元复合驱采出水处理提供关键理论依据。

Alkali-surfactant-polymer (ASP) flooding produced water contains a large number of oil displacement surfactants leads to the coexistence of the demulsification and emulsification process in the system, which causes the produced water strong stability. Moreover, the demulsified micro-fine oil droplets are still difficult to coalesce, which further aggravates the difficulty of oil-water separation. The stability and destabilization-coalescence behavior of micro-fine oil droplet are closely related to its own particle size. It is necessary to find out the size effect of micro-fine oil droplet, so as to improve its destabilization-coalescence efficiency. This project intends to further investigate the complex oil/water interface system in the presence of oil displacement agents from the microscopic level. Molecular dynamic simulation, reaction calorimetry, and several interface characterization techniques were employed to investigate the adsorption behavior of oil displacement agents onto the oil/water interface, so as to determine the formation rules and microstructure characteristics of the interfacial film. The physicochemical properties and settlement characteristics of oil droplets with different sizes are analyzed, so as to reveal the size effect and stability differences of the micro-fine oil droplets. By studying the demulsifier adsorption behavior difference onto oil droplets with different sizes, the relationship between the demulsifier structure and demulsification efficiency was clarified, so as to further illustrate the destabilization-coalescence mechanism. The research results could provide essential theoretical support for the accurate design of novel demulsifier and effective disposal of ASP flooding produced water.