Microfluidic Evaluation of Oil Recovery Efficiency Using Magnesium Oxide Nanoparticle Suspensions Synthesized by Sol–Gel Method

For the first time, a systematic study was conducted on the properties and colloidal stability of suspensions containing synthesized MgO nanoparticles. The nanoparticles were synthesized using hydroquinone as a chelating agent. This approach ensured the formation of an ultradispersed system with an average size of 14 nm and also prevented the formation of stable micrometer-sized agglomerates, as confirmed by acoustic spectroscopy data. The suspensions were characterized for colloidal stability, rheological properties, and surface properties. Light transmission profiles along the height of the sample remained virtually unchanged. Rheological measurements demonstrated Newtonian flow patterns across the entire concentration range studied. The surface tension of the suspensions at the air interface remained at the level of distilled water (72–73 mN/m), indicating the absence of pronounced particle surface activity. A microfluidic study was conducted to evaluate the efficiency of oil displacement from a model pore space using suspensions of synthesized nanoparticles stabilized with hydroquinone. The displacement efficiency consistently increased with increasing MgO concentration. For water, it was 44.15%, reaching 55% at 2 wt.% nanoparticles. The results demonstrate the potential of MgO suspensions synthesized with hydroquinone for enhanced oil recovery technologies.