Spontaneous imbibition of amphoteric-anionic surfactant and Fe₃O₄ nanoparticles colloidal mixture for enhanced oil recovery

This study investigates the effects of individual and combined systems on interfacial tension (IFT) and wettability alteration characteristics of a combination mixture of colloidal Fe₃O₄ nanoparticles and amphoteric-anionic surfactant. Combining a binary of amphoteric-anionic surfactants has resulted in an IFT reduction compared to brine alone. Furthermore, the addition of Fe₃O₄ nanoparticles at concentrations lower than the critical micelle concentration (CMC) of binary surfactant mixes (<0.15 wt%) resulted in an observed increase in IFT values. However, there is no significant change in IFT around or above the CMC (≥0.15 wt%). The alteration in wettability can be observed through a reduction in contact angle when amphoteric-anionic surfactants and Fe₃O₄ nanoparticles are combined, resulting in a change from water-wet to strongly water-wet conditions. The findings of the imbibition test also demonstrated that adding 0.01 wt% Fe₃O₄ colloidal nanoparticles in the surfactant mixture provided an optimal recovery efficiency of 63.17%. The results of this study indicate that a notable improvement in recovery can be observed when the primary mechanism of wettability alteration is achieved and simultaneously supported by IFT reduction.