Sensitivity-Based Framework Developed for Predicting CO2 Storage Performance

Abstract This study investigated the influence of reservoir and geomechanical properties on CO2 storage performance, focusing on trapping mechanisms, pressure evolution, displacement, and plume migration in saline aquifers of the Gulf Coast region. We conducted a numerical simulation and sensitivity analysis to evaluate how key parameters—such as permeability, porosity, Young's Modulus (YM), Poisson's Ratio (PR), and injection rates—affect CO2 containment and long-term storage security. We created a synthetic saline aquifer model simulating multiple cases using a compositional model to assess the impact of reservoir and geomechanical variability. Our sensitivity analysis examined multiple permeabilities, porosities, and different injection rates to evaluate their effects on pressure build-up, CO2 trapping efficiency, and geomechanical deformation. We used tornado charts to rank the relative influence of each parameter on key storage performance indicators. The results showed that permeability and porosity are primary controls on plume extent, pressure distribution, and residual trapping efficiency. Higher permeability cases led to greater CO2 migration and injection capacity, while lower permeability cases resulted in more localized containment and reduced injectivity. Geomechanical properties, particularly YM and PR, played a significant role in subsurface deformation, with softer formations exhibiting greater displacement. Pressure build-up was strongly influenced by porosity and stress anisotropy, though all cases remained within safe operating limits. This study provides a comprehensive framework to characterize reservoir-geomechanical interactions in CCS projects and should help to optimize injection strategies and improve long-term CO2 containment assessment. The findings contribute to enhancing storage security and minimizing leakage risks, offering valuable insights for future site development and monitoring strategies.