Study on the synergy between silica nanoparticles and surfactants for enhanced oil recovery during spontaneous imbibition

Silica nanofluid with silica nanoparticles and surfactants was prepared and used to enhance oil recovery through spontaneous imbibition. Nonionic surfactant (TX-100) as dispersant and synergistic enhancement agent was used to disperse silica nanoparticles into water. The silica nanofluid showed excellent anti-temperature and anti-salinity property. Because of synergistic effect, silica nanofluid has much better ability of oil detachment and wettability alteration than surfactant. The imbibition tests showed that silica nanofluid can improve oil recovery to about 16%, comparing with about 8% oil recovery of TX-100 solution, which improved the synergistic effect mechanism. The silica nanofluid has good application foreground for EOR. (C) 2018 Elsevier B.V. All rights reserved.