Theoretical storage capacity of unstructured aquifers can be calculated estimated easily. However, the potential for safe CO2 storage largely depends on the propagation the injection plume, and is generally much more limited (per area or volume) than for structured aquifers.
Slab
In Ariane for Carbon Storage, the reference volume for the unstructured aquifer is a simple “slab model“.
This is where reservoir parameters are defined, and theoretical storage capacity is calculated.
Plume
The injection plume is described based on geometrical parameters and injection mass, and is inserted into the slab with an injection point.
Effective storage capacity is derived from the plume volume.
The spill and leak masses as well as the calculated 3D sweep efficiency and storage efficiency uses both the slab and the plume volumes.
See how we deal with structured aquifers.