Effect of different families (imidazolium and pyridinium) of ionic liquids-based surfactants on interfacial tension of water/crude oil system

Interfacial tension between crude oil and water plays a significant role in enhanced oil recovery. Many researchers seek surfactants to reduce the interfacial tension of crude oil and water that can be applicable in reservoir conditions of high salinity and temperature. The current study introduces the results of using two different families of ionic liquids (ILs) including imidazolium (1-dodecyl-3-methylimidazolium chloride ([C12mim][Cl]) and 1-octyl-3-methylimidazolium chloride ([C8mim][Cl])) and pyridinium (1-dodecyl pyridinium chloride ([C12Py][Cl]) and 1-octyl pyridinium chloride ([C8Py][Cl])) for this purpose. Measured IFT values between solutions of ILs and a southern Iranian crude oil reveal that these ILs are successful in reducing the IFT. Unlike traditional surfactants, these ILs are more effective as the salinity increases. Also the measurements revealed that there is a correlation of the IFT of the solutions with salinity and temperature.