Among the successful methods in enhanced oil recovery (EOR) is the chemical EOR. The surfactant-based chemical techniques are highly recommended. However, some drawbacks remained unsolved such as surfactant selection and application in the reservoirs. Surfactants are particularly applied in sandstone reservoirs, so paving the path to expand the implementation to limestone reservoirs is required. Recently, alkaline surfactant polymer (ASP) was suggested for limestone reservoirs in Malaysia. However, limited studies discussed the effect of surfactant screening on the process. Thus, this study investigates the influence of sulfosuccinate and extended sulfated sodium surfactants in improving ASP performance. The evaluation considered the interfacial tension, wettability and recovery factor. The approach used was two-stage experiments of surfactant analysis and ASP core flooding. The first step used the drop Kruss spinning drop tensiometer, and data physics equipment drop shape analyzer to analyze the IFT and the contact angle. The second stage included the limestone sandpack preparation and characterization, followed by ASP flooding. The results showed that single surfactant has low IFT between 0.005 and 0.05 mN/m, while significantly, the synergy of surfactant mixtures has ultra-low IFT of 0.0006–0.001 mN/m. The contact angle results showed a drastic alteration of 65–81% reduction. The cationic surfactants achieved complete water-wet on limestone. The sandpack preparation confirmed acceptable uniformity by the histogram identification. The oil recovery proved additional recovery between 22 and 40%. The results of this research are a step forward to attain the technical feasibility of ASP in limestone reservoirs.

化学强化采收率是提高采收率（EOR）的成功方法之一。强烈推荐使用基于表面活性剂的化学技术。但是，一些缺点仍未解决，例如表面活性剂的选择和在储层中的应用。表面活性剂特别适用于砂岩储层，因此需要为将实施扩展到石灰岩储层铺平道路。最近，碱性表面活性剂聚合物（ASP）被建议用于马来西亚的石灰岩储层。然而，有限的研究讨论了表面活性剂筛选对工艺的影响。因此，本研究调查了磺基琥珀酸酯和扩展的硫酸钠表面活性剂对改善ASP性能的影响。评估考虑了界面张力，润湿性和恢复因子。使用的方法是表面活性剂分析和ASP岩心驱油的两阶段实验。第一步使用液滴Kruss纺丝液滴张力计和数据物理设备的液滴形状分析仪来分析IFT和接触角。第二阶段包括石灰岩沙袋的制备和表征，然后是ASP驱。结果表明，单一表面活性剂的IFT在0.005至0.05 mN / m之间，而显着地，表面活性剂混合物的协同作用具有0.0006–0.001 mN / m的超低IFT。接触角的结果表明减少了65-81％。阳离子表面活性剂可在石灰石上完全润湿。通过直方图识别，沙袋制备确认了可接受的均匀性。石油采收率证明了22％至40％的额外采收率。