Monitoring Workshop – Inaugural Meeting

Publication Overview

The objective of the workshop was to get a common understanding of the current state of the art, to identify the techniques available, and to assess their limitations. This was achieved by using the results available from projects that are currently monitoring injected CO₂. The aim was then to develop a view of where the technology needs to go from here, in order to develop stakeholder confidence that injected CO₂ can be monitored and verified and any leakage quickly detected

Publication Summary

• There is a substantial tool box of monitoring techniques already available for use. This tool box includes techniques for monitoring in situ CO₂ movement and monitoring for surface and well-bore leakage. Actual experience of their use provides additional confidence in their applicability and the particular limitations of the techniques available have been identified.
• Seismic surveying has proven itself capable of monitoring CO₂ movement in the subsurface at Sleipner and Weyburn. Seismic surveying of the overburden should also identify if leakage is occurring from a CO₂ storage formation.
• Monitoring of pilot projects can provide valuable information on the advantages and limitations of particular monitoring techniques and allows comparison to modelling results. Even monitoring experiences at small projects like the Frio and Nagaoka projects can provide enormous amounts of information.
• Monitoring costs will not add substantially to the operational costs of an injection project.
• For successful monitoring of an injection site it was essential to have detailed baseline conditions at the surface and in the subsurface prior to injection; to know as much about the reservoir as possible at the beginning. For oil fields, there will be information already available from exploration and production activities and this could result in lower overall costs of monitoring at these sites. However, for deep saline aquifers, characterization and monitoring will be most probably required from scratch. One of the benefits of a baseline study is the ability to identify naturally occurring fluxes of CO₂, distinguishing such CO₂ from what is injected and identifying other noise around the site that may mask a leakage or seepage signal.