Elyas Golabi - Chemical engineering Dept., University of Isfahan, Isfahan, Iran.
Fakhri Seyedayn Azad - Chemical engineering Dept., University of Isfahan, Isfahan, Iran.
Ayatollahi Shahab - Chemical engineering Dept., University of Shiraz, Shiraz, Iran
Majid Dastanian - Chemical engineering Dept., University of Isfahan, Isfahan, Iran.

Oil recovery by water flooding of carbonate reservoir is usually not effective because of capillary forces in fractured oil-wet carbonate formations. Alkaline/surfactant solution is used to enhance spontaneous imbibition between the fractures and matrix by both wettability alteration and ultra-low interfacial tensions. In this study the effects of anionic surfactant, from sulfate family, and a cationic surfactant, from C TAB family, on the interfacial tension (IFT), wettability alteration and spontaneous imbibition of oil and outcrop rock samples obtained from Aghajari reservoir were investigated. The experimental results show that these surfactants could be suitable candidates for EOR as they are effective in creating low interfacial tensions at dilute concentrations.

interfacial tension, wettability, spontaneous imbibition, surfactant