Ionic liquids as novel surfactants for potential use in enhanced oil recovery

The screening and use of benign chemicals for enhanced oil recovery (EOR) applications is important because of their properties and relationship to the embedded fluids. We investigated a special type of ionic liquids (ILs) called "Ammoeng" for potential use in surfactant EOR to replace the currently used surfactants that have many disadvantages. The interfacial tension (IFT) between a representative oil sample from Saudi reservoirs and solutions of Ammoeng (TM) ILs at different concentrations in 10 wt% NaCl aqueous solutions were measured as a function of temperature. It was found that the IFT values decreased with the increase of IL concentration. However, the effect of temperature on the IFT depended on the type of IL. Ammoeng (TM) 102 gave the lowest IFT values among the screened ILs. The comparison of the results to those resulting from TritonX100, a commercially used surfactant, showed that the IFT values using Ammoeng (TM) 102 were smaller than the corresponding values when TritonX100 was used at the same conditions. The possibility of having a synergetic effect when using a mixture of Ammoeng (TM) 102 and Triton X 100 was also investigated. The results showed that the IFT values depended on the total concentration, the surfactant to IL mass ratio, and the temperature.