Interfacial Regulation of Hybrid Nanoparticles via Silane Modification and Corresponding Pore-Scale Flow Simulation

Abstract High-temperature and high-salinity porous reservoirs impose severe challenges on nanofluid-based enhanced oil recovery (EOR), mainly including poor colloidal stability, excessive particle retention, and limited deep migration. To tackle these limitations, silane coupling agent 3-glycidoxypropyltrimethoxysilane (KH560) was adopted to regulate the intermolecular interactions of hybrid nanoparticles (HNPs). Colloidal probe atomic force microscopy (AFM) and quartz crystal microbalance with dissipation (QCM-D) were combined to quantitatively characterize the short-range adhesion and long-range steric repulsion, as well as mineral interfacial adsorption behaviors of HNP/KH560 blended systems with varied mass ratios. The results demonstrate that the optimal HNP-to-KH560 mass ratio of 2:1 effectively suppresses short-range interfacial attraction and strengthens long-range steric repulsion. This yields rigid and uniform adsorbed layers, which contribute to wettability alteration and the reduction of oil–water interfacial tension. Pore-scale multiphysics simulation was further performed. All interfacial boundary-setting parameters, including wettability state, interfacial tension, and particle-deposition kinetics, were derived from AFM and QCM-D measurements on the optimized silane-modified HNP sample. Simulation results show that regulated intermolecular forces induce uniform particle adsorption, neutralize pore wettability, and mitigate pore blockage, suggesting potential sweep-efficiency gains under simulated pore-scale conditions. Different from pore-blocking microspheres and single silica nanofluids, this silane-modified HNP system achieves favorable EOR performance via synergistic interfacial modification and controllable particle deposition. A multiscale quantitative correlation is established between microscopic intermolecular interactions and pore-scale transport properties. This work provides fundamental guidance for designing high-performance nanofluids adapted to harsh subsurface porous media.