Nanocomposite of binary colloids in effective CO₂ utilization in porous media for enhanced oil production and wettability alteration

Carbon dioxide injection is a renowned enhanced oil recovery method, where the inclusion of a novel material is appreciated via mobility control of injected CO₂ during flow through porous and permeable oil reservoirs. Therefore, the combination of nanoparticles and their associated additives is recommended for foam flooding schemes. Thus, this study reports the use of nanocomposites of SiO₂ (0.1 – 2 wt%) and TiO₂ (0.1 wt%) in promoting CO₂ utilization in oil recovery projects. The assessment of a foam emulsion is a crucial and interesting task to understand the basic fundamental of three-phase interactions viz., Crude oil (oil phase), nanocomposites (aqueous phase), and CO₂ (gas phase) in the context of foam-emulsion, and was examined via microscopic and rheological characterization. CO₂ foam showed temperature tolerance capability and a shear-thinning viscoelastic nature due to the inclusion of nanocomposites. Furthermore, wettability alteration was understood via contact angle measurements between CO₂ and nanocomposite. Interestingly, the contact angle was reduced to 39° after the inclusion of 0.1 wt% TiO₂ and CO₂ in the system. Finally, nanocomposite stabilized CO₂ foam demonstrated a total cumulative oil recovery of 78 % at (40 °C), higher than the cumulative oil recovery (70 %) associated with nanocomposite without CO₂. The results of this study suggest that CO₂ utilization for oil recovery can be enhanced by developing its viscous foam, stabilized by a nanocomposite of SiO₂ and TiO₂ nanoparticles.