Interfacial tension of smart water and various crude oils

The utilization of smart water in EOR (enhanced oi l recovery) operations has drawn increased attention in recent years. Nevertheless, the variety and complexity of mechanisms during smart water injection require more research endeavors. In this study, interfacial tension (IFT) for the smart water/crude oi l interacting system has been investigated. The investigated parameters included various salts with different salinity, pH, asphaltene type, and aged smart water with two crude oi l samples. The results showed that the hydration of ions in smart water would play a key role to discer n the prima r y mechanism of smart water. The interaction of acidic and basic asphaltene with hydration shel l of different ions can be considered as prima r y mechanism for efficacy of smart water. Acidic and basic asphaltenes serve as intrinsic surfactants due to their interaction with OH � in the anion hydration she l l and H+ in the cation hydration shel l , respectively. The propensity of acidic asphaltene to interact with anions with high hydration energy and the tendency of basic asphaltene to interact with cations with high hydration energy led to an IFT of 0.2 mN/m and 11.3 mN/m for acidic and basic oils, respectively. The impact of pH also revealed that acidic and basic asphaltenes would have lower IFT in alkaline and acidic environments. Finally, it was found that changes in IFT for the aged smart water with crude oi l depend on the asphaltene type as wel l as salt and salinity.

Automated summary

The utilization of smart water in EOR operations has gained attention, but more research is needed to understand the complex mechanisms involved. This study investigated the interfacial tension between smart water and crude oil, considering factors such as salt, pH, asphaltene type, and aged smart water. The results revealed that the hydration of ions in smart water plays a key role in its efficacy, with acidic and basic asphaltene acting as intrinsic surfactants. The pH also influenced the interfacial tension, and the aged smart water's interaction with crude oil depended on asphaltene type, salt, and salinity.