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Silica (SiO2) nanoparticles were synthesized from rice husk (RH) via wet milling method and evaluated for enhanced oil recovery (EOR) applications. Physical properties of RH-SiO2 nanoparticles (RH-SNP) with its size distribution were explored through field emission scanning electron microscopy (FESEM) and dynamic light scattering (DLS). Stability, functional groups and purity of RH-SNP were determined by zeta potential, Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), respectively. Effect of RH-SNP on the precipitation and thermal degradation of oilfield polyacrylamide (HPAM) was studied using Brookfield RST rheometer. Interfacial tension (IFT) properties of RH-SiO2 polymeric nanofluid (RH-SPNF) at interface of oil and water (O/W) were investigated using Easy-Dyne KRUSS tensiometer. Subsequently, oil displacement efficiency of RH-SPNF was determined and compared with oilfield HPAM at reservoir conditions using Fars EOR high-pressure high-temperature (HPHT) core flooding equipment. The wet milling method was effective in producing RH-SNP of size ranges 43.9–59.5 nm with a purity of 98% through the mechanism of nucleation, Brownian motion and coalescence. Rheological results show that RH-SNP inhibited the precipitation and thermal degradation of oilfield HPAM. IFT of RH-SPNF showed a monotonic tendency as temperature increased. HPAM and RH-SPNF flooding showed an incremental oil recovery of approximately 10% and 24%, respectively. Emulsion generated using RH-SPNF shows higher stability and resistance to coalescence. Finally, mobility ratio of water flooding approaches unity faster, compared to HPAM and RH-SPNF. Overall, the low energy utilization, use of low-cost and benign raw material make RH-SNP and the extraction method an appropriate substitute to commercially available SiO2 nanoparticles.