Clay minerals are usually regarded as an important factor affecting the results of low salinity water (LSW) flooding. However, experiments on clay minerals are mainly in qualitative stage, the mechanism of clay minerals has not been studied completely. In this paper, Zeta potential of four kinds of clay minerals (montmorillonite; chlorite; illite; kaolinite) in different brine was measured, microscopic models of these clay minerals were made to measured wetting angle in different brine, and montmorillonite and kaolinite were chosen to conduct microscopic displacement experiments through customized micro-glass etching models. From experiment results, the following conclusions can be get: 1). With the decrease of salinity of injected water, the negative zeta potential of clay minerals increases and the wetting angle decreases. 2). Clay minerals are more sensitive to monovalent Na⁺ than bivalent Ca²⁺. 3). The results of microscopic experiments show that LSW can effectively improve oil recovery, whether kaolinite or montmorillonite. The recovery of montmorillonite is better with a relatively high salinity of LSW and kaolinite is better with a relatively low salinity of LSW. The mechanism of LSW improves kaolinite recovery factor is the change of wettability while that of montmorillonite is the increase of water phase wettability. However, a lot of droplet-like residual oil cannot be displaced in the montmorillonite throat. In filed production, both kaolinite-rich and montmorillonite-rich reservoirs are suitable for LSW flooding to improve oil recovery. However, for kaolinite reservoirs, a lower salinity of injected water would produce a better result, while for montmorillonite reservoirs, residual oil droplets in the throat are noteworthy.

通常认为粘土矿物是影响低盐度水（LSW）洪水结果的重要因素。但是，粘土矿物的实验主要处于定性阶段，对粘土矿物的机理还没有完全研究。本文测量了四种黏土矿物（蒙脱石，绿泥石，伊利石，高岭石）在不同盐水中的ζ电势，并建立了微观模型以测量不同盐水中的润湿角，并选择了蒙脱土和高岭土。通过定制的微玻璃蚀刻模型进行微观位移实验。从实验结果可以得出以下结论：1）。随着注入水盐度的降低，粘土矿物的负ζ电势增加，润湿角减小。2）。⁺比二价Ca ²⁺。3）。微观实验结果表明，无论是高岭石还是蒙脱石，LSW都能有效提高采收率。LSW的盐度较高时，蒙脱土的回收效果更好，而LSW的盐度较低时，高岭石的回收效果更好。LSW提高高岭石采收率的机理是润湿性的变化，而蒙脱土提高水相润湿性的机理。但是，许多液滴状的残留油不能在蒙脱土的喉道中被置换。在油田生产中，富含高岭石和富含蒙脱石的油藏均适合于LSW驱油，以提高采油率。但是，对于高岭石储层，注入水的较低盐度会产生更好的结果，而对于蒙脱石储层，喉中的残留油滴是值得注意的。