2025/01/10 by Marco De Paoli, Francesco Zonta, De Paoli, Marco +7 · 1 citation
Earth and Planetary Sciences · Environmental Science · #CO2 Sequestration and Geologic Interactions #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Geological Modeling and Analysis #Geophysics (physics.geo-ph) #Methane Hydrates and Related Phenomena
paper · pdf · doi:10.48550/arxiv.2501.06090
openalex publication_date 2025/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We perform large-scale numerical simulations of convection in 3D porous media at Rayleigh-Darcy numbers up to Ra=8×104. To investigate the convective mixing of carbon dioxide (CO2) in geological formations, we consider a semi-infinite domain, where the CO2 concentration is constant at the top and no flux is prescribed at bottom. Convection begins with a diffusion-dominated phase, transitions to convection-driven solute finger growth, and ends with a shutdown stage as fingers reach the bottom boundary and the concentration in the system increases. For Ra ≥ 5×103, we observe a constant-flux regime with dissolution flux stabilizing at 0.019, approximately 13% higher than in 2D estimates. Finally, we provide a simple and yet accurate physical model describing the mass of solute entering the system throughout the whole mixing process. These findings extend solutal convection insights to 3D and high-Ra, improving the reliability of tools predicting the long-term CO2 dynamics in the subsurface.