A New Family of Anionic Surfactants for Enhanced-Oil-Recovery Applications

A new family of anionic surfactants that has great potential for enhanced-oil-recovery (EOR) applications was synthesized and characterized in our laboratory. The unique and versatile structure of these surfactants has endowed them with properties that are attractive for BOR. A detailed experimental study was carried out and is presented here on the oil/water and solid/water interfacial properties of seven novel molecules. The interfacial properties of this series of seven anionic surfactants with different lengths of hydrophobic tail and linking spacer group show systematic trends in interfacial tension (IFT) and static adsorption density with changes in solution conditions. These molecules showed excellent aqueous stability even in high-salinity and hard brines. Ultra low IFT (ULIFT) values were measured at low surfactant concentrations. The synthesized Gemini surfactants also showed lower maximal adsorption densities than the conventional single-chain surfactants. The results from this study showed the potential of using these surfactants at low concentrations and in harsh reservoir conditions.