Design of ions for injection water may change the wettability of oil-brine-rock (OBR) system, which has very important applications in enhanced oil recovery. Though ion-tuned wettability has been verified by various experiments, the mechanism is still not clear. In this review paper, we first present a comprehensive summarization of possible wettability alteration mechanisms, including fines migration or dissolution, multicomponent ion-exchange (MIE), electrical double layer (EDL) interaction between rock and oil, and repulsive hydration force. To clarify the key mechanism, we introduce a complete frame of theories to calculate attribution of EDL repulsion to wettability alteration by assuming constant binding forces (no MIE) and rigid smooth surface (no fines migration or dissolution). The frame consists of three parts: the classical Gouy-Chapman model coupled with interface charging mechanisms to describe EDL in oil-brine-rock systems, three methods with different boundary assumptions to evaluate EDL interaction energy, and the modified Young-Dupré equation to link EDL interaction energy with contact angle. The quantitative analysis for two typical oil-brine-rock systems provides two physical maps that show how the EDL interaction influences contact angle at different ionic composition. The result indicates that the contribution of EDL interaction to ion-tuned wettability for the studied system is not quite significant. The classical and advanced experimental work using microfabrication is reviewed briefly on the contribution of EDL repulsion to wettability alteration and compared with the theoretical results. It is indicated that the roughness of real rock surface may enhance EDL interaction. Finally we discuss some pending questions, perspectives and promising applications based on the mechanism.

注入水离子的设计可能会改变油盐岩（OBR）系统的润湿性，这在提高采油率方面具有非常重要的应用。尽管已通过各种实验验证了离子调谐的润湿性，但机理尚不清楚。在这篇综述文章中，我们首先对可能的润湿性改变机制进行了全面总结，包括细粉迁移或溶解，多组分离子交换（MIE），岩石与石油之间的双电层（EDL）相互作用以及排斥水合作用力。为了阐明关键机理，我们引入了完整的理论框架，通过假设恒定的结合力（没有MIE）和刚性光滑的表面（没有细粉迁移或溶解）来计算EDL排斥力对润湿性变化的影响。框架包括三个部分：经典的Gouy-Chapman模型结合界面电荷机制来描述油-盐水-岩石系统中的EDL，三种具有不同边界假设的方法来评估EDL相互作用能，以及改进的Young-Dupré方程将EDL相互作用能与接触角联系起来。对两个典型的油-盐水-岩石系统的定量分析提供了两个物理图，显示了EDL相互作用如何影响不同离子组成下的接触角。结果表明，EDL相互作用对所研究体系的离子调节润湿性的贡献不是很显着。简要回顾了使用微细加工的经典和高级实验工作，探讨了EDL排斥对润湿性变化的贡献，并与理论结果进行了比较。结果表明，真实岩石表面的粗糙度可以增强EDL的相互作用。最后，我们基于该机制讨论了一些悬而未决的问题，观点和有希望的应用。