Changing the salinity and ionic composition of the injected water and designing “engineered water” (EW) is an enhanced oil recovery approach which affects the wettability of carbonate reservoirs and improves the oil recovery in many cases. Application of nanoparticles also affects oil production by various mechanisms such as altering the wettability, changing the viscosity of the oil and the injected fluid, and changing the interfacial tension. The benefits of combining these two approaches and developing a hybrid method are investigated in this paper.

Experiments and measurements of different characteristics such as contact angle, zeta potential, particle size, ATR (attenuated total reflectance) analysis, ESEM (environmental scanning electron microscope) imaging, ion/nanoparticle deposition, and microemulsion formation were completed to analyze the influence of the hybrid method on rock/oil/brine interactions. Core flooding tests were also conducted to study the performance of the method to improve oil recovery.

The most effective EW was selected by adjusting the concentrations of magnesium, calcium, and sulfate ions of Persian Gulf water. Nanoparticles such as SiO₂, CaCO₃, TiO₂, and gamma Al₂O₃ were also studied to achieve the longest stability. Finally, the effect of combining the optimum states of engineered brine and nanoparticles on different mechanisms was investigated.

Our results showed that spiking the injection brine with sulfate ions and using a hybrid method with silica nanoparticles at a concentration of 0.1 wt% provided the best effect on the enhanced oil recovery. This combination altered the wettability more than standalone methods. Also, there was a decrease in adsorption of nanoparticles on the rock surface, which controls the retention mechanism. Therefore, the presence of more nanoparticles in the fluid flow leads to the formation of microemulsions and increases in the viscosity of the injected fluid, which affects the sweep efficiency in porous media.

改变注入水的盐度和离子组成并设计“工程水”（EW）是一种提高采油率的方法，它会影响碳酸盐岩储层的润湿性并在许多情况下提高采油率。纳米颗粒的应用还通过各种机制影响产油，例如改变润湿性，改变油和注入的流体的粘度以及改变界面张力。本文研究了结合这两种方法并开发混合方法的好处。

完成了不同特性的实验和测量，例如接触角，ζ电位，粒度，ATR（衰减全反射率）分析，ESEM（环境扫描电子显微镜）成像，离子/纳米颗粒沉积和微乳液形成，以分析离子对纳米粒子的影响。岩石/石油/盐水相互作用的混合方法。还进行了岩心驱油测试，以研究该方法改善石油采收率的性能。

通过调节波斯湾水域中镁，钙和硫酸根离子的浓度来选择最有效的电子战。还研究了诸如SiO ₂，CaCO ₃，TiO ₂和γAl ₂ O _3的纳米颗粒，以实现最长的稳定性。最后，研究了结合工程盐水和纳米颗粒的最佳状态对不同机理的影响。

我们的结果表明，向注入盐水中添加硫酸根离子并与二氧化硅纳米粒子以0.1 wt％的浓度混合使用混合方法，对提高采油率具有最佳效果。这种组合比独立方法更能改变润湿性。同样，纳米颗粒在岩石表面的吸附减少，这控制了固位机理。因此，在流体流中存在更多的纳米颗粒会导致形成微乳状液并增加所注入流体的粘度，从而影响多孔介质的吹扫效率。