Plume Dynamics: Influence of Geological Heterogeneity, Solubility and Grid Resolution on CO2 Storage Efficiency and Trapping

This study explores the role of geological heterogeneity in carbon storage, with a particular focus on the controls governing vertical CO2 plume migration. It challenges the conventional reliance on laterally extensive, impermeable primary seals, typical of petroleum systems and re-evaluates their necessity in the context of CO2 storage. Unlike hydrocarbons, CO2 differs in physical properties, injection volumes, and timescales, and these factors influence the capillary thresholds that govern containment.

Key parameters such as barrier frequency, correlation length, capillary pressure contrast, and continuity were varied to assess the conditions under which composite confining systems effectively restrict CO2 movement. The findings aim to elucidate the role of such systems in enhancing containment security.

CO2 migration behaviour is governed not only by geological architecture but also by fluid and aquifer properties. Accordingly, the study incorporates sensitivity analyses of pore structure, wettability, and brine composition across a range of salinity levels. This integrated approach enables a comprehensive evaluation of the coupled influence of rock and fluid properties on multiphase flow behaviour and trapping efficiency. Simulation results were analysed to identify key trends and derive generalised relationships applicable to field-scale storage scenarios.