IEEFA Presentation Challenges CCS Success Narrative of Norwegian Offshore Projects

An IEEFA presentation reviewing decades of technical literature on Norway's Sleipner and Snohvit carbon capture and storage projects concludes that both facilities experienced major unexpected deviations in subsurface CO2 behaviour that placed their containment integrity at risk, undermining their use as universal models for the technology. The findings are drawn from a literature review spanning academic papers and technical studies from the 1990s through the early 2020s.

Sleipner, operational since 1996, and Snohvit, operational since 2008, are routinely cited by CCS proponents in the oil and gas industry and by governments as definitive evidence that offshore carbon storage works at scale. The IEEFA presentation challenges this characterisation, documenting that both projects experienced geological surprises that were not predicted despite extensive pre-operational field assessment. At Sleipner, CO2 migrated into an unidentified shallow geological layer within three years of injection. At Snohvit, the primary storage site began rejecting injected CO2 within 18 months, with a formation originally assessed as having 18 years of storage capacity showing less than six months of further usability.

The presentation notes that despite Sleipner and Snohvit accounting for fewer than 200 academic papers and extensive seismic monitoring, their subsurface storage behaviour proved consistently difficult to predict. This finding has direct relevance to the approximately 200 offshore CCS projects proposed globally, many of which are far larger in scope and involve storage fields covering thousands of square kilometres. The monitoring intensity applied to the two Norwegian projects would be difficult to replicate at scale without significantly expanding both technical capacity and regulatory infrastructure.

The presentation concludes that field operators in any proposed CCS project must systematically plan for geological contingencies, maintain detailed monitoring throughout the operational life of the project, and prepare emergency remediation plans that extend well beyond project closure. Regulatory frameworks governing CCS vary widely — and in most of the world are entirely absent — leaving communities and governments exposed to long-term storage failure risks. The companion IEEFA report in full text form is available separately.

Key figure — 18 months — time elapsed at Snohvit before its primary CO2 storage site began rejecting injected carbon dioxide