SmartWater, through tailoring of injection water salinity and ionic composition, is gaining positive attention in the petroleum industry to synergize with several enhanced oil mobilization agents, such as chemicals and nanoparticles. The SmartWater assisted oil mobilization methods are currently considered as potential optimization routes to improve the efficiency and economics of different processes. In this study, we investigated the synergy of SmartWater in surfactant-polymer flooding for efficient oil mobilization in carbonates. The interfacial tension (IFT) data showed that SmartWater retained almost similar performance when compared to using a conventional high salinity water (HSW) with surfactant. The streaming potential tests demonstrated surface charge alterations to more negative due to SmartWater when compared to using high salinity water in carbonate reservoir cores. SmartWater also displayed favorable reductions in contact angle on carbonate surfaces towards a desired wettability condition in comparison to HSW. Oil displacement experiments conducted with a small surfactantpolymer (SP) slug followed by chase polymer and SmartWater/HSW flooding revealed the enhanced performance with SmartWater in SP flooding. Only half the dosage of polymer was used in SmartWater compared to that used in HSW, while around 70% of polymer solution viscosity was reached. The results showed that SP flooding with SmartWater can increase the oil mobilization by more than 5% in comparison to that obtained from SP flooding with HSW, and most of this oil mobilization gain was observed within one pore volume of injection. The different experimental findings from this work clearly established the potential synergy between SmartWater and surfactant-polymer flooding as a promising hybrid method for carbonates. The combined use of SmartWater with surfactant and polymer has yielded additional oil mobilization when compared to using HSW in surfactant polymer flooding, besides resulting in reduced polymer consumption and accelerated oil production. This favorable synergy will improve the efficiency, practicality and economics of chemical flooding projects in the field.

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