Building Knowledge for Environmental Assessment of CO₂ Storage: Controlled Releases of CO₂ and Natural Releases Workshop

Publication Overview

The main focus of this workshop was on controlled release projects with other sessions on environmental impact assessments and Regulations, monitoring, overburden/ mechanisms of migration from deep to shallow subsurface, leakage scenarios and communication of leakage. The third day of the meeting was spent at Yellowstone National Park, with part of the day observing formations created from natural CO₂ seepage.

Publication Summary

• EIA regulations are not a barrier to projects
• There are now a good number of controlled release projects, providing useful knowledge
• CO₂ release behaviour in the near-subsurface can be unpredictable
• Marine work – very good progress on monitoring and on baselines
• Electro-magnetic remote monitoring of brine appears very useful for ‘early’ leakage detection
• Environmental Assessments will be substantially different for offshore to onshore, we don’t have offshore examples yet
• If leakage does occurs –it will be ‘patchy’ and in small localised areas, not over a large area
• The Process-based technique is an example of monitoring moving in right direction – able to provide important information where there are no baselines. This technique uses ratios of gases present to determine source of CO₂
• Still need baselines for leakage detection and impact assessment
• Indicator species are being identified, especially benthic and terrestrial plants
• Seasonality and timing can effect leakage impact
• Broader acceptance of near-surface monitoring then in 2008