Glossary of terms
Discovered Storage Resources: The estimated quantity of Total Storage Resources, as of a given date, in which the potential for storage has been ascertained within an assessed geologic formation.
Stored: The quantity of Discovered Storage Resources that has been exploited by a given date: This equates to the cumulative quantity of CO2 injected and stored. While all storage resources are estimated, and Stored is measured in terms of CO2 metering specifications, the total injected quantities (CO2 plus associated injectants) are also measured, as required in support of engineering analyses.
Storage Capacity: Those quantities of Total Storage Resources anticipated to be commercially accessible in the characterized geologic formation by application of development projects from a given date forward under defined conditions. Commercial Storage Resources must further satisfy four criteria: The target geologic formation must be discovered and characterized (including containment); it must be possible to inject at the required rates; the development project must be commercial; and the storage resource must remain, as of the evaluation date (i.e., not previously used for storage), on the development project(s) applied.
Contingent Storage Resources: Those quantities of Total Storage Resources estimated, as of a given date, to be potentially accessible in known geologic formations, but the applied project(s) are not yet considered mature enough for commercial development, as a result of one or more contingencies. Contingent Storage Resources must be discovered (characterized) and may include projects, for example, for which there are currently no viable CO2 sources, and in which project value is insufficient to support development, permitting is still incomplete, commercial storage is dependent on technology under development, management is not committed, or evaluation of the geologic formation is insufficient to clearly assess commerciality. Contingent Storage Resources are further categorized in accordance with the level of certainty associated with the estimates and may be subclassified on the basis of the project maturity and/or characterized by their economic status and permitting/stakeholder status.
Prospective Storage Resources: The quantity of Undiscovered Storage Resources estimated, as of a given date, to be potentially accessible within undiscovered geologic formations or uncharacterized parts of discovered geologic formations by application of future exploration/development projects. Prospective Storage Resources have both an associated chance of discovery and a chance of development. Prospective Storage Resources are further subdivided in accordance with the level of certainty associated with accessible estimates, assuming their discovery and development, and may be subclassified on the basis of project maturity.
Undiscovered Storage Resources: The estimated quantity of Total Storage Resources, as of a given date, in which the suitability for storage has not been ascertained within the target geologic formation.
Inaccessible Storage Resources: The estimated portion of Discovered or Undiscovered Storage Resources, as of a given date (i.e., the time of the evaluation), that are not usable by future storage development projects. A portion of these Inaccessible Storage Resources may be used for storage in the future as commercial or regulatory circumstances change or technological developments occur; the remaining portion may never be used for storage resulting from physical/societal constraints of the storage location, both surface and subsurface.
Sum of Storage Resources: Is not part of the SPE-SRMS but is used to show all the known quantities of storage resources estimated in a geologic formation