β-Cyclodextrin modified SiO2 nanofluid for enhanced oil recovery

Recently, with the deterioration of oil storage conditions, the extraction of oil has been limited. In this experiment, β-cyclodextrin (β-CD) was grafted onto the surface of SiO2 nanoparticles. The structure and morphology of nanoparticles were analyzed by various characterization tools to effectively validate the synthesis of nanomaterials. In addition, it was experimentally demonstrated that the developed β-CD-SiO2 nanofluid has excellent stability and salt resistance. Finally, the comparative studies of the nanofluids were carried out by wettability, interfacial tension (IFT), Pickering emulsion, viscosity, and core flooding experiments. The results showed that β-CD-SiO2 nanofluid exhibited better performance: β-CD-SiO2 nanofluid changed the contact angle (CTA) of carbonate plate from 131.5º to 90.1º; the IFT was significantly reduced from about 35 mN/m to 22.5 mN/m; the emulsion droplets formed were fine and dense; the viscosity increased and viscosity not changed with shear rate; and total crude oil recovery up to 59.2%, 23.9% higher than using water drives. Overall, these results showed the great potential of β-CD-SiO2 nanofluid in ultra-low permeability reservoirs.