Overview
ISO/TR 27926:2024 - Carbon dioxide capture, transportation and geological storage - Carbon dioxide enhanced oil recovery (CO2‑EOR) - Transitioning from EOR to storage is an ISO technical report that examines operational, technical and governance aspects of modifying CO2‑EOR and complementary hydrocarbon recovery operations to increase or convert them to CO2 geological storage. The report addresses transitions ranging from optimizing CO2 storage during ongoing EOR to engineered storage after EOR termination, and includes illustrative case studies and regulatory considerations.
Key topics and technical coverage
ISO/TR 27926:2024 focuses on practical elements that influence safe and verifiable CO2 storage during and after CO2‑EOR operations, including:
- Transition scenarios - Operational models for moving from CO2‑EOR to dedicated CO2 storage (onshore and offshore scenarios).
- Storage volume and pore‑space assessment - Methods for assessing available pore volume and current reservoir fluid saturations at the time of transition.
- Containment assurance - Evaluating long‑term containment and containment assurance when injection patterns or objectives change.
- Reservoir management - Pressure management, injection patterns, water/CO2 handling, and strategies when CO2 supply increases.
- Well operations - Well inventory, repurposing existing wellbores for CO2 injection, well abandonment and integrity considerations.
- Facility operations - Design review, integrity testing, measurement & monitoring systems, and compression/recycle capacity needs.
- Monitoring, modelling and quantification - Baseline data, monitoring design, model development, and approaches to quantify stored CO2.
- Legal, regulatory and permitting issues - Ownership of pore space, reuse of infrastructure, contractual and regulatory compliance during transition.
- Case studies - Practical examples that illustrate staged transitions, optimization of CO2 storage in active EOR fields, and conversion of gas fields.
Practical applications - who should use this standard
ISO/TR 27926:2024 is valuable for:
- Oil and gas operators planning CO2‑EOR projects that may transition to long‑term storage
- Carbon capture and storage (CCS) project developers and engineers
- Reservoir engineers and subsurface modelers working on storage capacity and containment
- Well integrity and facilities engineers evaluating repurposing or abandonment
- Regulators, permitting authorities and policy makers assessing CO2 storage projects
- Legal teams and contract managers addressing pore space, liability and infrastructure reuse
- Environmental consultants and monitoring specialists developing baseline and verification programs
Related standards
- ISO 27914 - Geological storage of carbon dioxide - General principles for storage site selection, operation and closure.
- ISO 27916 - Carbon dioxide capture, transport and storage - Specific guidance related to CO2‑EOR and storage integration (see ISO/TR 27926 for comparisons and transition scenarios).
ISO/TR 27926:2024 provides operationally focused guidance that helps bridge CO2‑EOR and engineered storage practice, supporting safe, measurable and regulatory‑compliant transition pathways for CO2 geological storage.