Spontaneous imbibition and core flooding investigations were carried out on limestone core plug samples using different low salinity water (LSW) and smart brines at temperatures of 110 and 50℃, respectively. To demonstrate further the potential of low salinity water injection (LSWI) as an agent for enhanced oil recovery (EOR) studies, the interfacial tension (IFT), contact angle (CA), and zeta potential (ZP) were measured. The recovery factor values provided from spontaneous imbibition experiments investigated by formation water (FW), seawater (SW), dilution versions of SW (i.e., 1/2SW, 1/10SW) were 10.07, 15.11, 18.05, and 16.04%, respectively. However, the secondary LSW flooding produced more oil, i.e., a higher recovery factor (37.3, 55, and 61% for FW, SW, and 1/10SW, respectively). The recovery factor obtained from LSW flooding at the tertiary state for SW, 1/2SW, and 1/10SW brines increased up to 11.86, 12.67, and zero, respectively. The main conclusions of the work were as follows. (1) The results of secondary spontaneous imbibition tests showed that LSWI had a significant potential to mobilize the trapped oil. (2) During secondary and tertiary core flooding, the maximum oil recovery (78% of OOIP) was achieved during smart water flooding when the amount of \({\text{SO}}_{4}^{2 - }\) ion was increased and inactive ions (\({\text{Na}}^{ + }\) and \({\text{Cl}}^{ - }\)) were eliminated. (3) LSWI and smart water showed significant effects on relative permeability curves, which are indicative of wettability alteration. (4) The main driving mechanism for oil mobilization was found to be wettability alteration, which was supported by the analyses of CA and ZP.

分别使用不同的低盐度水 (LSW) 和智能盐水在 110 和 50 ℃ 温度下对石灰岩岩心塞样品进行了自吸和岩心驱研究。为了进一步证明低盐度注水 (LSWI) 作为提高石油采收率 (EOR) 研究试剂的潜力，测量了界面张力 (IFT)、接触角 (CA) 和 zeta 电位 (ZP)。通过地层水 (FW)、海水 (SW)、SW 稀释版本（即 1/2SW、1/10SW）研究的自吸试验提供的采收率值分别为 10.07、15.11、18.05 和 16.04%。然而，二次 LSW 驱采油更多，即采收率更高（FW、SW 和 1/10SW 分别为 37.3、55 和 61%）。SW、1/2SW 和 1/10SW 卤水在第三级 LSW 驱中获得的采收率分别增加到 11.86、12.67 和 0。工作的主要结论如下。(1) 二次自吸试验结果表明，LSWI 具有显着调动被困油的潜力。(2) 在二次和三次岩心驱过程中，当\({\text{SO}}_{4}^{2 - }\)离子增加和非活性离子 ( \({\text{Na}}^{ + }\)和\({\text{Cl }}^{ - }\)）被淘汰。(3) LSWI和smart water对相对渗透率曲线有显着影响，表明润湿性发生变化。(4) 发现油流动的主要驱动机制是润湿性改变，这得到了 CA 和 ZP 分析的支持。