Anthropogenic carbon dioxide (CO₂) emissions are widely recognized as a principal driver of global climate change, contributing to rising atmospheric temperatures and increasing environmental instability. Among various mitigation strategies, carbon capture and storage (CCS) has emerged as a vital approach to reducing emissions by injecting captured CO₂ into deep geological formations such as saline aquifers. However, maintaining injectivity during CO₂ storage remains a key challenge, particularly in sandstone formations with high clay content. Two major mechanisms responsible for injectivity decline are fines migration and salt precipitation. Fines migration involves the detachment and transport of clay minerals (e.g., kaolinite) from pore walls under the influence of viscous and capillary forces. The mobilized particles tend to accumulate at pore throats, leading to permeability reduction and impaired CO₂ injectivity.

This study investigates the potential of a commercial silica-based nanoparticles (NPs) to mitigate fines migration and enhance formation stability during CO₂ injection. A series of core flooding experiments were conducted using high-clay-content sandstone samples to evaluate the effect of nanoparticle treatment on fines stabilization. Results show that, in the absence of nanoparticles, fines migration led to at least 1.5-fold reduction in permeability. In contrast, cores pre-treated with silica nanoparticles exhibited stable permeability throughout the CO₂ injection process, indicating effective fines stabilization by NPs. Effluent analyses further confirmed a high concentration of detached particles in the untreated case, while negligible fines production was observed in the nanoparticle-treated samples.

These findings suggest that nanoparticle pre-treatment can effectively mitigate fines migration during CO₂ storage in saline aquifers, enhancing formation stability and maintaining injectivity. The outcomes of this research provide valuable insights for improving the efficiency and reliability of geological CO₂ storage operations.