Enhanced Oil Recovery in Low-Permeability Reservoirs Utilizing Dispersions of Monodisperse Crumpled SiO₂ Nanoparticle

Abstract

Nanomaterials have great potential as novel materials for enhancing oil recovery in low-permeability reservoirs. Spontaneous aggregation hampers their application effectiveness and may lead to irreversible reservoir damage. In this study, monodisperse crumpled SiO 2 nanoparticles (C-SiO 2 ) with central radial pore channels were synthesized by using the spherical micelle selfassembly method. After hydrophobic modification, modified C-SiO 2 formed a highly stable nanodispersion with the assistance of sodium dodecyl sulfate and octadecanol. Results showed that C-SiO 2 exhibited reduced external surface area, increased active sites, and excellent dispersibility. The C-SiO 2 dispersion demonstrated excellent temperature tolerance (90 °C) and salt resistance (20000 mg/L, including 4000 mg/L Ca 2+ ), outstanding enhanced oil recovery performance, and negligible reservoir damage. Injecting 0.5 pore volume of the C-SiO 2 dispersion at a concentration of 0.025 wt % enhanced oil recovery by 14.25%. The C-SiO 2 dispersion effectively mobilized residual oil through the combined action of multiple mechanisms. This study provides an effective approach to enhancing the development of low-permeability reservoirs. It also advances the understanding of C-SiO 2 synthesis and stable nanodispersion design, which is crucial for future oil recovery applications.