Background to the Study

Key Messages

• Monitoring technologies in CO2 storage provide options to address site-specific risks which
• may affect project performance, storage security, human health, the environment and surface
• features.
• Monitoring provides accountability for injected CO2, ensures regulatory requirements are met,
• provides detection of leakages and assesses CO2 migration; key criteria in a risk assessment
• plan.
• There are opportunities to reduce costs in monitoring, and projects may benefit from doing such
• analyses when planning their monitoring programmes
• There is a confidence in the range of monitoring technologies available for large-scale CO2
• storage (on the scale of ~1 Mt CO2 per year).
• There is a large range in monitoring costs, therefore it can be hard to interpret the cost-benefit
• ratio.
• Commercial scale projects storing on the order of 1 Mt CO2/year usually incur costs on
• monitoring alone of around US $1-4 million (per year).
• Economies of scale do exist; so the higher the volume of CO2 to be stored, the costs per tonne
• do decrease.
• Monitoring costs in construction, well drilling, characterisation, administrative and technical
• support are fairly consistent. Monitoring costs are generally a small fraction of the whole project
• (less than 5% of the total costs which is significant in comparison to capital and operating costs
• of capture facilities), and many monitoring methods are reasonably priced.
• Pilot projects focussed on research had high costs to validate a range of technologies.
• Earlier pilot projects (i.e. those that became operational in the 1990’s and early 2000’s) were
• not subject to the same regulations as new projects, meaning simpler monitoring programmes
• were undertaken and therefore costs were lower.
• Analogues for CO2 storage (such as natural CO2 fields, offshore oil and gas operations and
• natural gas storage) provide monitoring examples for the evaluation of long-term monitoring.
• There is an overall confidence in the range of technologies for monitoring CO2 storage and
• current operational projects have made their monitoring programmes more efficient, focussing
• on the most useful methods to address specific project risks and better control costs.
• The path forward for implementing the safe storage of carbon dioxide seems stable.