Carbon dioxide injection in deep saline aquifers is a key method for permanently sequestering anthropogenic CO₂. This study employs a reactive transport model to explore mineral precipitation/dissolution and its impact on reservoir properties in deep saline aquifers. We also assess capillary pressure and relative permeability hysteresis on various CO₂ trapping mechanisms. Results from this study reveal the significant influence of initial brine composition on mineral precipitation/dissolution. The dissolution and precipitation of minerals have different effects around the wellbores compared to the overall reservoir. Additionally, salt concentration (Ca⁺⁺ and Mg⁺⁺) and quartz surface area affect CO₂ mineralization, while Na⁺ impacts halite precipitation, altering reservoir flow properties. The effect of capillary pressure is significant, as including the capillary pressure in the simulation case resulted in significantly improved CO₂ trapping, achieving almost total dissolution of the injected CO₂ in around 300 years. This study offers novel insights into the interactions of reservoir minerals, brine properties, and the injected CO₂.