Silica Nanoparticle Assisted Polymer Flooding of Heavy Crude Oil: Emulsification, Rheology, and Wettability Alteration Characteristics

Polymer flooding based enhanced oil recovery (EOR) has been proven to be effective and successful for heavy crude oil systems due to its ability to achieve favorable mobility ratios driven by viscosity alterations. Nanoparticles have the potential to intensify favorable mobility ratios as well as various other mechanisms responsible for EOR. This work addresses the interfacial tension (IFT), emulsification, and rheological and wettability alteration characteristics of silica nanoparticle (SNP) assisted polymer flooding. The stability of the xanthan gum–SNP system was evaluated by a particle size analyzer and zeta potential method. The rheological behavior of the system in addition to IFT and the emulsification mechanism at variant temperatures were also investigated. Wettability alteration studies involved contact angle measurements for oil drops with respect to a nanoparticle saturated rock surface. SNP assisted polymer flooding enabled higher oil recovery of 20.82% at 30 °C and 18.44% at 80 °C due to IFT reduction, higher viscosity, better emulsion stability, and wettability alteration.