Unforeseen variances encountered in the operation of two Norwegian gas projects, Sleipner and Snøhvit, that store carbon dioxide under the seabed call into question the long-term viability of carbon capture and storage (CCS), possibly creating financial and environmental risks, according to a new report from the Institute for Energy Economics and Financial Analysis (IEEFA).
Key points of the report:
- Sleipner and Snøhvit demonstrate the CCS is not without material ongoing risks that may ultimately negate some or all the benefits it seeks to create.
- Every project site has unique geology, so field operators must expect the unexpected, make detailed plans, update the plans and prepare for contingencies.
- Ensuring storage is securely maintained implies a high level of proactive regulatory oversight, activities for which governments may not be adequately equipped.
- Sleipner and Snøhvit cast doubt on whether the world has the technical prowess, strength of regulatory oversight, and unwavering multi-decade commitment of capital and resources needed to keep carbon dioxide sequestered below the sea – as would be needed – permanently.
Grant Hauber, IEEFA’s Strategic Energy Finance advisor and author of the report, says the Sleipner and Snøhvit subsea fields may have been globally cited as success stories of how to store the CO2 by-product of gas production; however, due to the unpredictability of the subsurface conditions, the pair cannot be used as definitive models for the future of CCS.
Hauber’s literature review of technical studies and academic papers from the 1990s to the 2020s demonstrates that even with the most advanced data, science, and monitoring, subsurface unknowns can arise at any point. The findings raise ominous implications for the scores of CCS projects planned globally, with field operators and the governments that regulate them needing to expect the unexpected, make detailed contingency plans, and ensure funding is at the ready to address materialised risks.
“Every project site has unique geology,” he says. “Subsurface conditions which exist at a given point on the Earth are specific to that place; even then, any information obtained about that place is only a snapshot in time. The Earth moves and strata can change.”
Observed changes
Storage conditions at Snøhvit began deviating dramatically from design plans only about 18 months into CO2 injections, necessitating major interventions and investments. In the case of Sleipner, CO2 moved into an area previously unidentified by engineers despite extensive study of the subsurface geology.
“While the oil and gas industry is used to dealing with uncertainty in exploration and production, the risks multiply when trying to place something like CO2 back in the ground,” Hauber says.
More than 200 CCS and carbon capture, utilisation and storage (CCUS) proposals are under consideration worldwide. Their proponents have held up Sleipner and Snøhvit as proof that large-scale offshore CO2 storage is a viable means to help meet net-zero carbon emissions mandates.
But Hauber notes that proposed CCS projects seek to deposit CO2 underground at rates exceeding 10 times those of Sleipner and Snøhvit. As his report indicates, there is no way the two Norwegian sites can be proxies for projects of that scale.
Rather than being models for CCS, the two fields raise a cautionary tale about the technical and financial viability of the concept in the long run, he says.
“Their subsurface performance deviations cast doubt on whether the world has sufficient technical prowess, strength of regulatory oversight, and unwavering multi-decade commitment of capital and resources needed to keep CO2 sequestered below the sea, as intended, permanently” he says.
• IEEFA has released studies that assess the overall costs, benefits and challenges of CCS projects, including prospects for CCS in the power sector, a global compendium of CCS projects, and CCS in Southeast Asian markets.
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