纳米乳液渗吸驱油剂性能评价与应用

Performance Evaluation and Application of Nanoemulsion Imbibition Oil-displacing Agent

丁小惠 周丹 吴凯 李栓 贺勇 余波 陈丽

DING Xiaohui ZHOU Dan WU Kai LI Shuan HE Yong YU Bo CHEN Li

为适应低渗透油藏提高采收率的需求，以双子表面活性剂双烷基酚酮聚氧乙烯醚为主要原料制备了一种 新型纳米乳液作为驱油剂。室内评价了其界面性能、润湿性能、耐温抗盐性能等，并通过核磁共振、相渗实验及 自发渗吸实验考察了该纳米乳液驱油剂的驱油效果，同时与常规驱油剂磺酸盐表面活性剂进行了对比。结果表 明，该纳米驱油剂乳液的平均粒径为60 nm。随纳米驱油剂加量增加，溶液表面张力和油水界面张力逐渐下降。 驱油剂加量为0.2%时，油水界面张力可达2.94×10-3mN/m，界面活性良好。纳米驱油剂可使岩心表面由亲油性 转变为亲水性，实现润湿反转。纳米驱油剂加量为0.2%时，对原油的乳化效率为98%，其耐温抗盐性能良好，静 态渗吸驱油可提高采收率30 百分点。在新疆油田压裂驱油和老井注水吞吐的应用表明，纳米渗吸驱油技术的增 产效果好于常规驱油技术，在产液量相差不大的情况下，返排率更低，产油量更高，驱油置换增油效果更好。

In order to meet the needs of enhanced oil recovery in low-permeability reservoir，a new type of nanoemulsion was developed as an oil-displacing agent. Its interfacial property，wettability，temperature and salt resistance were evaluated. The oil displacement efficiency of the nanoemulsion oil-displacing agent was investigated by magnetic resonance，relative permeability experiment and spontaneous imbibition experiment. At the same time，the performance of oil-displacing agent was compared with that of conventional sulfonate surfactant. The results showed that the average particle size of the nanoemulsion oil-displacing agent was 60 nm. When the mass fraction of the nanoemulsion oil-displacing agent increased，the surface tension of solution and oil-water interfacial tension gradually decreased. When the dosage of oil-displacing agent was 0.2%，the oil-water interfacial tension could reach 2.94×10-3 mN/m，showing good interfacial activity. At the same time，it could change the core surface from lipophilicity to hydrophilicity，realizing wetting reversal. When the dosage of nanoemulsion oil-displacing agent was 0.2%，the emulsification efficiency to crude oil could reach 98% . The nanoemulsion oil-displacing agent had excellent temperature resistance and salt resistance. The static imbibition could increase oil recovery by more than 30 percentage points. The application of fracturing flooding in Xinjiang oilfield and water injection huff and puff in old wells showed that the nano imbibition flooding technology had better stimulation effect than conventional flooding technology. When the liquid production was not much different，the flowback rate was lower，while the oil production was higher. The oil displacement replacement effect was better.

10.19346/j.cnki.1000-4092.2022.04.013