The use of smart nanofluids has become an interesting alternative to control and modify the interfacial and wetting properties of liquid-liquid and liquid-solid interfaces. The understanding of how these properties can be modified at the nanoscale and how affects the fluid behavior at the microscale is essential to the development of smart nanofluids for enhanced oil recovery (EOR) techniques. Although the recent experimental advances, the determination of these interfacial properties at nanoscale continues to be a challenge. We proposed an integrated multiscale computational protocol ranging from first principles calculations, molecular dynamics and Lattice Boltzmann method (LBM) to explore the potential applications of smart nanofluids in EOR processes. More specifically, we study the role of dispersed functionalized SiO2 nanoparticles in brine to the oil displacement process in clay pore structures. At first, the montmorillonite surfaces with functionalized Si probe tip model were investigated within density functional theory (DFT) with the generalized gradient approximation revPBE functional with van der Waals density functional (vdW-DF). These results were benchmarked with classical MD calculations. Those previous calculations indicate that the addition of nanoparticles to the brine solution considerably reduces the interfacial tension between oil and brine. Also, a small reduction in oil viscosity and an increase of the contact angle is observed. Here, by mapping the MD results into LBM parameters and simulating the oil extraction process by a nanoparticle solution at the microscale, we observed that the inclusion of nanoparticles indeed improve the oil displacement process in realistic pore network models. The improvement in oil recovery was evaluated for different rock geometries, porosity and permeability. The proposed multiscale approach can be a useful tool to explore potential chemical additives for EOR and investigate the effects of the interfacial and wetting properties on fluid behavior at both nano and micro scales.

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