Ranking and categorizing large-scale saline aquifer formations based on optimized CO₂ storage potentials and economic factors

The process of selecting a CO₂ storage site involves evaluating many potentially suitable sites in terms of
their storage potentials as well as their associated technical and economic limitations. As such, it is useful to
apply a ranking scheme that makes use of several different criteria and weights each criterion based on its relative
importance in the overall evaluation. In this study, we demonstrate one such possible ranking workflow using
real formation datasets from CO₂ Storage Atlas of the Norwegian Continental Shelf. The workflow involves
computing practical storage potentials using a generic well placement scheme, mathematical optimization and
vertical-equilibrium modeling, and is general in the sense that it can be applied to other formation datasets.
Economic factors related to the transportation and injection of CO₂ are represented by the number of injection
wells required, depth of injection, and distance from a CO₂ point source. The purpose of this study is not to
provide formation-specific capacity estimates or efficiency factors for engineering purposes, due to the simplifying
assumptions used in this work, and the fact that our specific datasets come with their own limitations (i.e.,
homogeneous rock properties, lack of fault data). Rather, the purpose is to demonstrate a general ranking
scheme that reflects operational limitations and the economic factors likely to be involved in any commercial or
demonstration CCUS project.