Nanofluids for enhanced oil recovery offer a breakthrough solution towards tertiary recovery and consequently higher oil production. Their ability to reduce interfacial tension, alteration of formation’s wettability, higher adsorption capacity, and acceleration of disjoining pressure makes them excellent candidates for enhanced oil recovery. The main objective of this paper is to investigate the effect of polymers on zinc oxide (ZnO) nanofluids for enhanced oil recovery (EOR) and the role played by chemical modification using polymer stabilizers on nanoparticle stability in nanofluids. Nanoparticles with an average particle size of 34 nm were synthesized and used to prepare nanofluids of different concentrations and their stability was evaluated using sedimentation and UV–vis spectrophotometry tests. ZnO-synthesized nanofluids were used solely and in addition to Polyvinylpyrrolidone (PVP) and Polyvinyl alcohol (PVA) as stabilizing agents. It was noted that ZnO nanofluids with PVA stabilizer recorded the highest oil recovery of 82%. In contrast, the ZnO nanofluids without stabilizing agents registered the lowest recovery rate during the flooding experiment. The results revealed that a higher injection rate increases the oil recovery and reduces the viscous fingering effect with a better displacement front. Furthermore, nanofluids containing polymeric stabilizing agents achieved better recovery factors compared to ZnO nanofluids without stabilizing agents. This phenomenon was also observed in the interfacial tension test where nanofluids with PVA and PVP stabilizers reduced the IFT by 59% and 61% respectively.

中文翻译：

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氧化锌纳米流体提高采收率的稳定性和功能性评价

用于提高石油采收率的纳米流体为三次采油从而提高石油产量提供了突破性的解决方案。它们降低界面张力、改变地层润湿性、更高的吸附能力和加速分离压力的能力使它们成为提高石油采收率的优秀候选者。本文的主要目的是研究聚合物对氧化锌（ZnO）纳米流体提高石油采收率（EOR）的影响，以及使用聚合物稳定剂进行化学改性对纳米流体中纳米颗粒稳定性的作用。合成了平均粒径为34 nm的纳米粒子，并用于制备不同浓度的纳米流体，并通过沉降和紫外可见分光光度法测试评估其稳定性。ZnO 合成的纳米流体单独使用，另外还使用聚乙烯吡咯烷酮 (PVP) 和聚乙烯醇 (PVA) 作为稳定剂。值得注意的是，含有 PVA 稳定剂的 ZnO 纳米流体录得最高采收率 82%。相比之下，不含稳定剂的 ZnO 纳米流体在驱替实验中的回收率最低。结果表明，较高的注入速度可提高采收率并减少粘性指进效应，并具有更好的驱替前沿。此外，与不含稳定剂的 ZnO 纳米流体相比，含有聚合物稳定剂的纳米流体实现了更好的回收因子。在界面张力测试中也观察到了这种现象，其中含有 PVA 和 PVP 稳定剂的纳米流体的 IFT 分别降低了 59% 和 61%。