Surfactant flooding, a chemical enhanced oil recovery (EOR) technique, boosts oil production mainly through lowering oil–water interfacial tension (IFT) and altering reservoir rock wettability. In the current study, the performance of pure saponin, a non-ionic surfactant, was evaluated for EOR in sandstone and carbonate reservoirs. The performance evaluation experiments were IFT by pendant drop method, wettability through the use of sessile drop technique, and core flood to discover the oil recovery improvement. According to IFT experiments, the surfactant had a critical micelle concentration (CMC) of 5 g/L, and which it decreased the oil–water IFT by 66.98% at CMC, for the system free from salt. Moreover, after increasing the salinity by sodium chloride up to 100 g/L, it not only was salt-tolerant but also lowered oil–water IFT up to 77.31%. Depending on salt concentration, the surfactant decreased the sessile drop contact angle by 4.49–27.84° and 5.62–16.98° for the sandstone and carbonate slices, respectively. From the core flood experiments, the oil recovery was improved by 8.4% and 6.23% for the surfactant flooding in the sandstone and carbonate cores, respectively. All in all, the non-ionic surfactant saponin performed best in improving oil recovery from both sandstone and carbonate reservoirs.

表面活性剂驱油是一种化学增强油采收率（EOR）技术，主要通过降低油水界面张力（IFT）和改变储层岩石润湿性来提高石油产量。在当前的研究中，评估了非离子表面活性剂纯皂苷在砂岩和碳酸盐岩储层中的EOR性能。性能评价实验是采用悬滴法进行IFT试验，通过无柄滴技术进行润湿性试验，并进行岩心驱油以发现采收率的提高。根据IFT实验，该表面活性剂的临界胶束浓度（CMC）为5 g / L，对于不含盐的系统，该表面活性剂在CMC处的油水IFT降低了66.98％。此外，在通过氯化钠将盐度提高到100 g / L之后，它不仅耐盐，而且将油水IFT降低了77.31％。根据盐浓度的不同，表面活性剂分别使砂岩和碳酸盐片的固着液滴接触角分别降低了4.49–27.84°和5.62–16.98°。通过岩心驱油实验，砂岩岩心和碳酸盐岩心中的表面活性剂驱油分别提高了8.4％和6.23％的采收率。总而言之，非离子表面活性剂皂苷在改善砂岩和碳酸盐岩油藏的采收率方面表现最佳。