A new family of anionic surfactants that has great potential forenhanced-oil-recovery (EOR) applications was synthesized and characterized inour laboratory. The unique and versatile structure of these surfactants hasendowed them with properties that are attractive for EOR. A detailedexperimental study was carried out and is presented here on the oil/water andsolid/water interfacial properties of seven novel molecules.

The interfacial properties of this series of seven anionic surfactants withdifferent lengths of hydrophobic tail and linking spacer group show systematictrends in interfacial tension (IFT) and static adsorption density with changesin solution conditions. These molecules showed excellent aqueous stability evenin high-salinity and hard brines. Ultralow IFT (ULIFT) values were measured atlow surfactant concentrations. The synthesized Gemini surfactants also showedlower maximal adsorption densities than the conventional single-chainsurfactants. The results from this study showed the potential of using thesesurfactants at low concentrations and in harsh reservoir conditions.