Investigating injection of low salinity brine in carbonate rock with the assist of works of cohesion and adhesion and spreading coefficient calculations

Low salinity (LS) and smart water (SW) flooding processes which receive a great interest as cost-effective and environmental friendly techniques are relatively new enhanced oil recovery methods. Although shifting carbonate surfaces towards a water-wet state is the main mechanism behind these methods, effects of controlling factors (for instance: ion type or salinity) are already remained unsettled. In this regard, the effects of sulfate ion types (i.e. Na2SO4, MgSO4 and CaSO4) and their concentrations (i.e. 0-45,000 ppm) on wettability alteration are investigated using contact angle (CA) measurement technique. In addition, work of cohesion, work of adhesion and spreading coefficient of all examined salts are calculated based on the experimental interfacial tension (IFT) and CA measurements. The results reveal that reduction of salinity of the aqueous solution and presence of sulfate anion at high salinity conditions (15,000-45000 ppm) are two important parameters for wettability alteration.