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IEA Greenhouse Gas R&D Programme

Background to the Study


The work aims to summarise and synthesise the two ISO Standards relevant to the geological storage of CO2: – ISO 27914:2017 (‘Carbon dioxide capture, transportation and geological storage - Geological storage’) and ISO 27916:2019 (‘Carbon dioxide capture, transportation and geological storage - Carbon dioxide storage using enhanced oil recovery (CO2-EOR)’) – to provide a high-level understanding of the content into an easily digestible format.

By comparison with international regulatory frameworks, and providing case studies of how applicable the standards are to real CO2 storage projects, the study provides a comprehensive overview and concludes on the usefulness of the documents in supporting the implementation of CCUS projects. For the purposes of this overview, the standards will hereafter be referred to as ISO 27914 and ISO 27916.


Key Messages


  • Both standards relevant to the geological storage of CO2, ISO 27914 and ISO 27916, are complementary with minimal overlap, as was intended by stakeholders.
    • ISO 27914 is intended for projects with the sole purpose of CO2 storage:
              The objective being ‘to commercial, safe, long-term containment of carbon dioxide in geological systems in a way that minimises risk to the environment, natural resources, and human health’.
      • ISO 27916 is intended to apply to CO2-EOR projects:
                With the objective of promoting ‘the use of geologic storage associated with CO2-EOR by providing a common process for assuring safe, long-term containment and for quantifying and documenting the amount of CO2 that is stored in association with CO2-EOR’.
  • Both standards can be used to evaluate and guide key technical areas of storage projects, including site feasibility, well re-qualification and developing risk-based monitoring and verification programmes.
  • Both standards provide limited specific support for requirements related to approval processes, ownership, government roles, subsurface ownership regime, and transport.
  • Both standards support (in general) CO2 stream definition, leakage accounting, MMV, storage and siting, closure, public engagement and risk assessments.
  • Elements of ISO 27914 can provide guidance for CO2-EOR projects, even though it is not explicitly intended for such use.
  • There is a similarity between regulatory regimes for oil and gas projects and CO2 storage projects and therefore existing petroleum regimes, complemented by the ISO standards, could be combined to form a specific regulatory regime for the geological storage of CO2.
  • Five examples are provided from developing economies with an oil and gas industry to show that regulations pertinent to CO2 storage are either established or require refinement from pre-existing oil and gas regulations or need to be fully developed.
  • The ISO standards are an evolving entity and subject to refinement and continuous updating where deemed necessary by an independent panel (ISO operate a 5-year review cycle on all published standards). Experts have recognised that ISO standard 27914:2017 may be difficult to actually implement for real projects due to the large number of non-technical requirements, and perhaps this standard could be seen as more of a best practice guide.

This report is available to download.