Mechanistic study of nanoparticles-assisted xanthan gum polymer flooding for enhanced oil recovery: a comparative study

Recently, nanoparticle additives have been used to improve stability and hence efficiency of chemicals during enhanced oil recovery. Herein, a comparative analysis of the application of nanoparticle-stabilized xanthan gum for oil recovery applications was investigated. The nanoparticles used as additives are silicon oxide (SiO₂), metallic aluminium oxide (Al₂O₃), and titanium oxide (TiO₂). Rheological measurements were carried out to examine the shear viscosity of the polymeric nanofluids under a range of salinity typical of reservoir conditions. Interfacial tension (IFT) experiment was conducted using Kruss tensiometer. Oil displacement studies were carried out to examine the incremental recovery factor of the polymeric nanofluids. The polymeric nanofluids exhibited better rheological behaviour compared to bare xanthan gum (XG) polymer. At 0.5 wt.% nanoparticle concentration, 0.5 wt.% polymer concentration, shearing rate of 10 s⁻¹, and 3 wt.% NaCl concentration, rheology result shows that the shear viscosity of SiO₂-XG, Al₂O₃-XG, and TiO₂-XG is 423 mPa.s, 299 mPa.s, and 293 mPa.s, respectively. Moreover, the polymeric nanofluids lowered the IFT of the oil/brine interface due to adsorption at the nanoparticles at the interface. Finally, oil displacement result confirms that the incremental oil recovery after water flooding by Al₂O₃-XG, TiO₂-XG, and SiO₂-XG is 28.4%, 27.6%, and 25.2%, respectively.