The geology you have to mesh
A CO₂ storage site is a saline aquifer — a porous, permeable formation deep enough to keep CO₂ supercritical — capped by a low-permeability seal, or caprock, that holds the buoyant plume down. These systems are layered and usually faulted. Injected CO₂ is lighter than brine, so it rises and spreads laterally beneath the seal, and where it goes is set by structure, dip, heterogeneity and faults.
Why conformity matters here
CO₂ storage simulation asks the grid to get several things right at once:
- Faults can seal or leak. A fault’s transmissibility decides whether the plume is stopped or channeled. If the grid does not sit on the fault, that decision is smeared. See fault-conforming grids.
- The seal is the whole point. Caprock geometry and the pressure building against it drive containment and leakage-risk assessment.
- Buoyant plumes are thin. Migration and residual trapping are sensitive to vertical resolution and to thin high-permeability layers; numerical dispersion on a poorly conforming grid blurs the plume.
- Timescales are long. Storage is simulated for centuries, so small per-step errors accumulate.
Trapping mechanisms the grid must resolve
| Mechanism | What it depends on |
|---|---|
| Structural / stratigraphic | seal and closure geometry |
| Residual (capillary) | plume footprint and saturation history |
| Solubility (dissolution) | contact area between CO₂ and brine |
| Mineral | long-term reactive contact |
Every one of these comes back to getting plume geometry right — which comes back to a grid that conforms to faults, horizons and the seal.
How AutoMesh-Geo helps
AutoMesh-Geo builds conforming Voronoi (PEBI) grids that honor faults, layers and the caprock by construction, so CO₂ migration and trapping are simulated on geometry that matches the interpreted geology. It is a core capability for CO₂ storage and subsurface work.