【摘要】 从应用效果看，聚丙烯酰胺纳米球在实际开采中已取得了令人满意的效果，可大幅提高原油采收率，然而关于纳米球提高采收率的具体机制及其粒径和驱油能力之间的相关性研究仍有不足。为了探究聚合物纳米球的驱油机制及驱油能力的尺寸效应，引入粒径为30 nm的聚丙烯酰胺纳米球，与常规的50和100 nm纳米球体系进行对比，在分析粒径、形态的基础上，通过油滴剥离实验研究结构分离压力的作用，探究结构分离压力的影响因素，建立纳米球粒径与油滴剥离能力之间的关系；并在毛细管中模拟实际油藏中的孔隙，观察纳米球作用下毛细管中的油水动态演变，为纳米驱油技术的进一步优化和应用提供理论依据。结果显示，由于纳米粒子的结构分离压力，纳米球粒径在油滴剥离过程中起到关键作用，粒径越小油滴剥离时间越短；同时在毛细管中的油水传质能力在一定范围内随尺寸减小而增强，在一定程度上可以说明纳米球的驱油能力具有尺寸效应。更多还原

【Abstract】 The application of polyacrylamide nanospheres has yielded promising outcomes in practical extraction, demonstrating the potential to markedly enhance crude oil recovery. Nevertheless, the research on the precise mechanism through which nanospheres facilitate recovery and the correlation between particle size and oil repelling ability remains limited. In order to investigate the oil repellent mechanism of polymer nanorods and the size effect on oil repellent capacity, polyacrylamide nanorods with a particle size of 30 nm were introduced and compared with conventional 50 and 100 nm nanorods. The particle size and morphology were analyzed on the basis of this comparison. The role of structural separation pressure was investigated through oil droplet stripping experiments, and the influencing factors of structural separation pressure were explored. Additionally, the relationship between nanorods′ particle size and oil droplet stripping capacity was established, and the correlation between particle size and oil droplet stripping capacity was also studied in a capillary tube. The relationship between the particle size and the oil droplet stripping ability has been established. Additionally, the pores in the capillary tube have been simulated in an actual oil reservoir, and the dynamic evolution of oil and water in the capillary tube under the action of nanorods has been observed. This provides a theoretical basis for the further optimization and application of nano oil-driving technology. The findings indicate that the structural separation pressure of nanoparticles is a crucial factor influencing the oil droplet stripping process. A reduction in particle size leads to a notable decrease in the time required for oil droplet stripping. Moreover, the oil-water mass transfer capacity in the capillary tube is enhanced with the reduction in particle size within a specific range. This suggests that nanorods may exhibit a size-dependent effect on the oil repellent capacity.更多还原