Simulating Horizontal CO₂ Plume Migration in a Saline Aquifer: The Effect of Injection Depth

This study investigates the impact of injection depth on CO₂ plume migration dynamics in saline aquifers, a critical aspect of secure and efficient carbon capture, utilization, and storage (CCUS). While CCUS offers a vital pathway for mitigating greenhouse gas emissions, challenges such as buoyancy-driven flow, salinity effects, and potential leakage threaten long-term CO₂ containment. Using compositional reservoir simulation (CMG GEM 2021.10, Calgary, Canada) and Illinois Basin Decatur Project (IBDP) data, we modeled CO₂ injection into a 10,000 ppm salinity aquifer, evaluating the effects of single- and multi-depth injection (5370 to 5385 ft). The results demonstrate that multi-depth injection significantly enhances CO₂–brine contact area, promoting dissolution trapping and mitigating buoyancy-driven migration. This enhanced dissolution and residual trapping improves horizontal containment and overall storage security in the modeled salinity environment. The work provides valuable insights for optimizing injection strategies to maximize CO₂ storage efficiency and minimize leakage risks.