Water-Dispersible Reactive Nanosilica and Poly(2-acrylamido-2-methyl-1-propanesulfonic acid sodium) Nanohybrid as Potential Oil Displacement Agent for Enhanced Oil Recovery

2-acrylamido-2-methyl-1-propanesulfonic acid sodium (AMPS) was grafted onto the surface of reactive nanosilica (RNS-D) by free radical polymerization to afford RNR-D/PAMPS inorganic–polymer nanohybrid with good water dispersibility, which can serve as a potential oil displacement agent for enhanced oil recovery. The RNS-D/PAMPS nanoparticles were characterized by transmission electron microscopy and Fourier transform infrared spectrometry, and the oil displacement performance of the RNS-D/PAMPS nanohybrid solution was evaluated by static and dynamic oil displacement tests. Results showed that the RNS-D/PAMPS nanohybrid as the potential oil displacement agent could obviously reduce the interfacial tension between crude oil and water, increase the hydrophilicity of rock surface, and dramatically decrease the adhesion work of crude oil and rock. When the RNS-D/PAMPS solution is introduced at a mass fraction of 5.0% under static and dynamic oil displacement tests, the tested crude oil can be recovered at a total rate of up to 87.67% and 92.86%, respectively, showing promising potential in enhanced oil recovery.