Corchero Morais, RaquelRodríguez Escontrela, IriaRodríguez Figueiras, ÓscarSoto Campos, Ana María2020-09-292020-11-122019Fluid Phase Equilibria, 483 (2019), 144-152, https://doi.org/10.1016/j.fluid.2018.11.0100378-3812http://hdl.handle.net/10347/23311Ionic liquids have increased the possibilities of Enhanced Oil Recovery (EOR) with surfactants. However, results obtained with only one of these salts as surfactant are not particularly promising. Best results are obtained with blends of these salts or blends with traditional surfactants. This work aims to break new ground regarding the role of ionic liquids in this application. Many traditional surfactants in EOR fail because they are not sufficiently soluble at optimal salinity in water. The possibilities of design of ionic liquids must also be considered to use them as co-surfactants in optimal formulations for oil recovery. In this work, the phase behaviour of the ionic liquid 1-hexyl-3-methylimidazolium acetate with water and different model oils (n-octane, cyclohexane and toluene) was determined at 298.15 K and 323.15 K. The complete miscibility of the ionic liquid with water and its low miscibility with the different oils, point to the use of 1-hexyl-3-methylimidazolium acetate as co-surfactant with surfactants with high oil solubilising capacityeng© 2018 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license (http://creativecommons.org/licenses/by-nc-nd/4.0)http://creativecommons.org/licenses/by-nc-nd/4.0/Ionic liquidWaterOilEquilibriumEORjournal article10.1016/j.fluid.2018.11.010open access