The CO2 Storage Resources Management System (SRMS): Toward a Common Approach to Classifying, Categorizing, and Quantifying Storage Resources

Abstract

Several international oil and gas exploration and production companies who have recognized the importance of capturing and storing CO2 identified that the global community would benefit from an accepted and recognized system in which CO2 storage resources could be quantified, categorized, and classified. In early 2016, the Society of Petroleum Engineers (SPE) agreed to sponsor and support the development of a system built from the well-established Petroleum Resources Management System (PRMS). The carbon capture, utilization, and storage technical section (CCUS-TS) of the SPE agreed to lead this effort. This group represents companies, governments, national labs, consulting firms, research institutes, and academia. To benefit from the experience in developing and using the PRMS, several individuals with recognized oil and gas classification expertise were recruited to the SRMS committee. The SRMS classification of a storage quantity is project based, which means that a higher degree of certainty of a geologic formation being used for storage is completely dependent on the certainty that the injection project will be funded through site screening, selection, and active injection. The premise is that the highest classification of confidence in an estimate of storage is from active CO2 injection. The broadest two classifications, Discovered and Undiscovered Storage Resources, are based on data available. Discovered Storage Resources require the presence of a wellbore with adequate data to assess a geologic formation for storage, which includes CO2 containment potential. Undiscovered Storage Resources are entirely exploratory and do not require a wellbore. For this reason, Undiscovered is called Prospective Storage Resource. Discovered Storage Resources are further classified as Contingent Storage Resources and Storage Capacity. The primary difference is that the project associated with the storage quantity classified as Contingent Storage Resources is temporarily not expected to move forward until one or more contingencies have been overcome. Examples of contingencies are issuance of an injection permit, final financial commitment (e.g. from a bank, government, or company), or completion of a pipeline. Each primary classification has 3-4 subclasses, which, depending on specifics of the status of the project, directly reflects the data available for estimating a range of storage. Within each of the three primary classifications, is a categorization of storage estimates: a low, best (most likely) and high estimate. These can be probability based as P10, P50, and P90. In the case of Storage Capacity, these are named: Proved, Probable, and Possible Storage Capacity. After nearly a year of development, the SPE Board approved a version to present to the public for two months of review. Several organizations and individuals provided comments that were added to the SRMS or reserved for a later guidelines document. In mid-2017, the CO2 Storage Resources Management System (SRMS) was completed, adopted, and approved by the Society of Petroleum Engineers Board of Directors. The SPE CCUS-TS agreed to continue their work by writing a supplement to the SRMS that provides guidelines to the use of the SRMS. In addition to expansion of the chapters of the SRMS, the guidelines document will have chapters with oil and gas analogues and CO2 storage quantification and classification examples. The guidelines document is planned for completion by summer 2019.