Investigating the effect of ionic liquid (1-dodecyl-3-methylimidazolium chloride ([C12mim] [Cl])) on the water/oil interfacial tension as a novel surfactant

It is estimated that two-thirds of crude oil remains in the oil reservoirs after primary and secondary (water flooding) recovery stages. The extent of residual oil trapped in the reservoir pore structure is dominated by capillary and interfacial forces. The residual oil will be mobilized if the capillary forces are reduced because of interfacial tension (IFT) reduction during surface active agents flooding into the oil reservoir. In this work, 1-dodecyl-3-methylimidazolium chloride ([C12mim] [Cl]) is proposed as the IFT reducing agent and its dynamic IFT with one of the Iranian crude oil under different conditions were examined. The obtained results revealed that the critical micelle concentration (CMC) between the crude oil and formation brine was obtained at a very low concentration of 100 ppm. Unlike to the traditional surfactants, this ionic liquid based surfactant found to be more effective for higher saline formation water. In addition, several core flooding experiments were performed to find both, tertiary oil recovery efficiency and IL adsorption on the rock surfaces which indicated promising results.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► DIFT of 1-dodecyl-3-methylimidazolium chloride solution/crude oil was measured. ► Critical micelle concentration (CMC) of water/oil system was about 100 ppm. ► DIFT of IL solution/crude oil was decreased as the NaCl concentration was increased. ► DIFT was increased as the temperature was increased from 293.15–333.15 K.