Combined effect of silica nanoparticles and binary surfactants in enhancing oil recovery: An experimental investigation

Abstract

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.