Impact of anionic and cationic surfactants interfacial tension on the oil recovery enhancement

Surfactant flooding is considered as one of the efficient chemical enhanced oil recovery techniques in recent decades as it has the potential ability to alter the wettability and reduce the interfacial tension of water-oil. Addition of surfactants has caused a dramatic decrease in the interfacial of water-oil. Thereby, the capillary number has increased and has caused to enhance oil mobilization in the porous media. In this paper, a cationic surfactant of Cetyl trimethyl ammonium bromide and an anionic surfactant of linear alkylbenzene sulfonic acid were used to consider their effect on the interfacial tension and oil recovery factor. According to the results of this study, the anionic surfactant of linear alkylbenzene sulfonic acid has the highest recovery factor of 70%, and cationic surfactant of Cetyl trimethyl ammonium bromide has the second-highest oil recovery factor of about 55%. Therefore, the addition of surfactants due to its beneficial impact on the interface adsorption between oil and water would be an essential point on the oil recovery enhancement as it can increase the oil recovery factor. Moreover, the critical micelle concentration value is about 300 ppm and 250 ppm for anionic and cationic surfactants respectively where the two crosslines meet each other and anionic has the highest interfacial tension rather than cationic which has caused to have more oil recovery factor.