Investigating the effect of hybrid silica nanoparticles-copolymer on increasing oil recovery in a three dimensional porous media

In this work, hybrid of silica nanoparticles (NPs) with sulfonated copolymer has been prepared in order to improve the copolymer properties for Enhanced Oil Recovery (EOR). Some tests are done to find the effectiveness of injecting fluid on Recovery Factor (RF), such as Contact Angle (CA), interfacial tension (IFT), inherent viscosity, and eventually Micro-Model (MM) flooding. In CA test, wettability alteration from Oil-Wet (OW) to Water-Wet (WW) is reached by sedimentation and adsorption of NPs on the rock slice. In addition, IFT reduction is obtained by increasing the NaCl concentration. The viscosity change is investigated for the hybrid and copolymer under simulated hightemperature oil reservoir conditions. It is found that silica NPs-copolymer hybrid exhibits better inherent viscosity and thermal stability than copolymer alone does. At MM flooding, more RF and produced oil in Water (O/W) emulsion are obtained from hybrid than from polymer alone. Hybrid injection results in IFT reduction, increment in viscosity, and O/W emulsion formation that cause enhancement in capillary number (Nca) and RF, and, subsequently, reduction in residual oil saturation. Therefore, NPs-copolymer hybrid could be a much better candidate than even high-performance polymer solutions for EOR process.