A Mechanism Study of Wettability and Interfacial Tension for EOR Using Silica Nanoparticles

Abstract

Abstract Wettability alteration and interfacial tension (IFT) reduction are two important mechanisms for enhanced oil recovery (EOR). The introduction of nanotechnology from the fields of Biology and Material Science to the application in EOR is emerging because nanoparticles have the potential to alter formation factors like wettability and fluid properties like IFT and viscosity. However, a systematic literature review shows that ambiguity exists regarding whether nanoparticles can change wettability and IFT or not and which component in nanofluid plays a role. In this work, we investigated the effects of bare silica nanoparticles on wettability and IFT using a contact angle goniometer. The results showed that the contact angle measurement on quartz plates had relatively large uncertainty while those on calcite plates showed a clear trend that the smaller the nanoparticle size and the larger the nanofluid concentration, the smaller the contact angle. In addition, silica nanoparticles did not have an effect on IFT. Core flooding experiments showed an increase of 8.7% in oil recovery factor by the use of silica nanoparticles, which support the oil recovery mechanism of wettability alteration.