Various approaches are used to evaluate the resources of saline aquifers to store CO2 at preliminary stage (before flow modeling studies). The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches which provide endmembers of the resources of a given aquifer store. We propose a novel approach based on extending the analytical aquifer methods, routinely used for decades in the oil and gas industry, to CO2 saline aquifer storage. The CO2 storage resource is derived from the pore volume liberated by pressurization to accommodate CO2 in the store, which is the sum of (i) the volume of the store obtained by compression and (ii) the volume of water outflow towards the regional aquifer. It enables to estimate CO2 storage resources and storage efficiencies for pressure-limited stores (meaning when resource is not even more limited by CO2 migration issues). Formalism is presented as well as implications and limitations of the method. With this method, storage efficiencies are directly connected to closed store efficiencies that are corrected for the water outflux and pressure dissipation from the CO2 store into the regional aquifer, reconciling “closed” and “open” approaches.

We present an application to Havnsø saline aquifer structure in order to highlight consequences for CO2 storage resource evaluation and also for appraisal and development phases.

This content is PDF only. Please click on the PDF icon to access.
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.