Smart water flooding, as a popular method to change the wettability of carbonate rocks, is one of the interesting and challenging issues in reservoir engineering. In addition, the recent studies show that nanoparticles have a great potential for application in EOR processes. However, little research has been conducted on the use of smart water with nanoparticles in enhanced oil recovery. In this study, stability, contact angle and IFT measurements and multi-step core flooding tests were designed to investigate the effect of the ionic composition of smart water containing SO₄²⁻ and Ca²⁺ ions in the presence of nanofluid on EOR processes. The amine/organosiloxane@Al₂O₃/SiO₂ (AOAS) nanocomposite previously synthesized using co-precipitation-hydrothermal method has been used here. However, for the first time the application of this nanocomposite along with smart water has been studied in this research. Results show that by increasing the concentrations of calcium and sulfate ions in smart water, oil recovery is improved by 9% and 10%, respectively, compared to seawater. In addition, the use of smart water and nanofluids simultaneously is very effective on increasing oil recovery. Finally, the best performance was observed in smart water containing two times of sulfate ions concentration (SW2S) with nanofluids, showing increased efficiency of about 7.5%.

中文翻译：

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智能水/新型功能化纳米复合材料的润湿性变化分析，可提高采油率

智能水驱是改变碳酸盐岩润湿性的一种流行方法，是储层工程中有趣且具有挑战性的问题之一。此外，最近的研究表明，纳米颗粒具有在EOR工艺中应用的巨大潜力。但是，关于将智能水与纳米颗粒结合使用以提高采油率的研究很少。在这项研究中，设计了稳定性，接触角和IFT测量以及多步堆芯驱油测试，以研究在纳米流体存在下含SO ₄ ^2-和Ca ²⁺离子的智能水的离子组成对EOR过程的影响。胺/有机硅氧烷@Al ₂ O ₃ / SiO ₂（AOAS）纳米复合材料以前使用共沉淀-水热法合成。但是，这项研究首次研究了这种纳米复合材料与智能水的应用。结果表明，与海水相比，通过增加智能水中钙和硫酸根离子的浓度，石油采收率分别提高了9％和10％。此外，同时使用智能水和纳米流体对提高石油采收率非常有效。最后，在含有两倍硫酸盐离子浓度（SW2S）和纳米流体的智能水中观察到最佳性能，显示出约7.5％的效率提高。