The procedural framework developed mirrors best practices within the oil & gas industry, reflects existing and emerging regulations, standards and directives relevant for geological storage of CO2, and draws on learnings from CCS projects around the world.

Leading engineering, oil & gas companies and government bodies were brought together by DNV to develop the CO2QUALSTORE guideline. This guideline introduces a generic procedural framework which will contribute to enhanced transparency and streamlined implementation.

Activities and deliverables associated with each leg are explained and defined, from initial site screening, through tailored site assessment and storage permit application, through responsible operation based on tailored monitoring and verification, to preparation for site closure and transfer of responsibility from the operating entity to national or state authority. The framework is based on a risk-based approach to selection and qualification of potential storage sites that takes into account the need to evaluate each site based on its unique characteristics.

Screen – The screening process identifies potential storage sites in a given region that, based on a preliminary high-level evaluation, are anticipated to serve as secure sites for long-term storage of CO₂. The output from this stage is a list of identified sites that are considered eligible for further characterization based on geological, environmental and commercial considerations.

Assess & select - The objective of this stage is to characterize a storage site in sufficient detail to enable site and engineering concept selection and storage permit application. This will be achieved by obtaining the geological evidence needed to provide confidence that the site has sufficient accessible storage capacity and can provide long-term effective storage containment.

Operate/permit – The objective of the outlined workflow for this stage is to facilitate verification that the CO₂ storage project has been operated in compliance with regulations and permit conditions, and that the storage site provides and will continue to provide safe long-term storage of CO₂.

Close - This stage defines a workflow to guide the process of providing evidence to support transfer of responsibility and liability from the project developer to a national or state authority. This stage also guides communication between project developers and regulators to establish confidence that the conditions for transfer of responsibility have been met.

With the world of CCS developing rapidly, the CO2QUALSTORE guideline will be updated periodically to keep pace of changes.