ISO 27917:2017

Overview

ISO 27917:2017 - "Carbon dioxide capture, transportation and geological storage - Vocabulary - Cross cutting terms" is an ISO vocabulary standard that defines common terms and acronyms used across the carbon dioxide capture, transportation and geological sub‑surface storage (CCS) sector. The document focuses exclusively on CO2 geological sub‑surface storage (including storage associated with enhanced oil recovery, EOR) and provides a harmonized lexicon to improve clarity and interoperability among standards, regulators, operators and stakeholders.

Key topics

ISO 27917:2017 organizes cross‑cutting terminology into concise categories and includes an informative list of acronyms (Annex A) and a CCS project life‑cycle illustration (Annex B). Key technical topics and definitions covered include:

• CCS and lifecycle concepts

  • Definition of CCS and CCS project life cycle (concept through post‑closure).
  • Life cycle assessment (LCA) adapted for CCS projects.

• CO2 physical and stream characteristics

  • Terms for supercritical CO2, dense phase CO2, critical point, critical temperature (304.1282 K) and critical pressure (7.3773 MPa).
  • Definitions for CO2 stream, impurities, additives, and CO2 stream phase state.

• Operational and safety terms

  • Pressure limit, closure period, post‑closure period, geological storage complex.
  • Intermittency, energy consumption of CCS components.

• Monitoring, measurement and performance

  • Monitoring, baseline, detection limit, threshold, verification, validation, uncertainty and uncertainty analysis.

• Risk and stakeholder relations

  • Standardized vocabulary for risk, CO2 leakage, relationships with stakeholders and value chain concepts.

Note: ISO 27917 is a vocabulary standard - it defines terms rather than prescribing technical specifications or procedures.

Practical applications and users

ISO 27917:2017 is used to ensure consistent language across documents, projects and regulatory frameworks. Typical users include:

• CCS standard developers and technical committees
• Project developers and engineering teams designing capture, transport and storage systems
• Regulators, permitting authorities and auditors evaluating compliance
• Environmental consultants and LCA practitioners
• Researchers, educators and industry stakeholders involved in EOR and subsurface storage
• Policy makers and financial analysts needing consistent terminology for contracts and risk assessments

Related standards

ISO 27917 references and aligns with established standards such as ISO 14040 (LCA), ISO 14064‑2 (GHG project accounting), ISO 26000 (social responsibility terminology) and ISO 20988 (measurement uncertainty), helping users integrate vocabulary across environmental and quality frameworks.

Using ISO 27917:2017 promotes clearer communication, reduces ambiguity in CCS documentation, and supports safer, more transparent deployment of CO2 capture, transportation and geological storage projects.