Modern oil fields extensively utilize enhanced oil recovery (EOR) techniques to optimize production. This investigation evaluates the potential of silica (SiO2) nanoparticles (NPs) when combined with the SDS-TX100/xanthan gum (XG) binary surfactant/polymer mixture for enhancing oil recovery. The study focuses on examining the synergistic effects of the SDS-TX100 + XG combination and SiO2 NPs on reducing interfacial tension (IFT), altering wettability, and improving viscosity. Core flooding experiments were conducted on low-permeability San Saba sandstone cores. The dispersion and stability of SiO2 NPs in the SDS-TX100 surfactant mixture were evaluated through stability analysis, dynamic light scattering (DLS), Ultraviolet–visible spectroscopy (UV–VIS), and turbidity meter. Notably, the NPs exhibited a significant reduction in IFT between the SDS-TX100 surfactant mixture and crude oil, while the addition of the SDS-TX100 surfactant mixture improved the stability of nanofluids. Core flooding experiments revealed a synergistic effect of SiO2 NPs with the SDS-TX100 + XG mixture, leading to higher incremental oil recovery compared to the SDS-TX100 + XG mixture alone. The study elucidates various mechanisms contributing to oil recovery, including wettability alteration and IFT reduction. The flooding outcomes indicate that injecting SiO2 NPs with the SDS-TX100 + XG mixture increases oil recovery by up to 16% of the original oil in place (OIIP) after conventional water flooding. This research contributes to a comprehensive understanding of the application of SiO2 NPs with binary surfactant and polymer as a chemical-EOR (CEOR) agent and assists in identifying sandstone reservoirs where nanofluids could be effectively deployed.