Surfactant mixtures used during chemical enhanced oil recovery and methods of use thereof

Surfactant mixtures include a cationic surfactant, an anionic surfactant, and a nonionic surfactant in a brine solution. The cationic surfactant may include at least one quaternary ammonium, at least one brominated trimethylammonium, or combinations thereof. The anionic surfactant may include at least one organosulfate. The nonionic surfactant may include the nonionic surfactant comprised of a polyoxyethylene fatty acid ester, a phenylated ethoxylate, or combinations thereof. The surfactant mixtures may be incorporated into methods for reducing the interfacial tension between the surfactant mixture and oily fluids during chemical enhanced oil recovery. The methods for reducing the interfacial tension may include introducing the surfactant mixture comprising a cationic surfactant, an anionic surfactant, and a nonionic surfactant in a brine solution to a hydrocarbon-bearing reservoir, thereby reducing the interfacial tension at a liquid-liquid interface of the surfactant mixture and the fluid.