The promising properties of surface-active ionic liquids (SAILs) make these salts interesting candidates for the optimization of surfactant-enhanced oil recovery (EOR) methods. The tests that should be performed at the laboratory scale before a SAIL is proposed for EOR were carried out with tributyl(tetradecyl)phosphonium chloride ([P-44414]Cl). The phase diagrams with water and n-dodecane showed that the affinity of the surfactant for water is greater than that for oil, even in the presence of a high salt content. The advantage of the use of Winsor type I micro emulsions in EOR is the low phase trapping/adsorption. A formulation consisting of 4000 ppm [P-44414]Cl, 4 wt % NaCl, and 5000 ppm NaOH was able to reduce the interfacial tension between water and Saharan crude oil from 19.2 to 0.1 mN.m(-1). Core-flooding experiments were carried out at room temperature and an injection rate of 2 mL/min, mimicking enhanced oil recovery with brine solutions of SAIL, NaOH, and the optimized formulation combining the two chemicals. The injection of the proposed formulation, after flooding with brine, led to an additional recovery of about 8% of the original oil in place.