Feasibility of Monitoring Tools

Publication Overview

This report sets out to identify and evaluate appropriate monitoring tools for substances mobilised by the actions/reactions caused by CO₂ injection during CCS operations and includes a brief description of the types of physical, chemical and biological parameters that might be affected. Monitoring these is important for verifying predicted migration pathways and characterising changes in the physical and chemical properties of associated sedimentary formations and groundwater. Understanding these processes and mapping their distribution aids in the identification of potential monitoring tools and facilitates an assessment of their utility in a particular monitoring domain. Matching the appropriate monitoring tool with the monitoring environment is therefore critical to designing an effective monitoring and verification program

Publication Summary

CO₂ release might have on the subsurface have been identified and discussed in this study:

• Flow effects (including pressure, density, viscosity, temperature)
• Biological effects or changes (including changes to plant species, bacteria and general ecology, much of which has been drawn from the microbial ecology and mineral exploration literature as well as a few CCS studies where recent testing of these approaches has taken place)
• Geochemical effects (including the oxidation/reduction state of fluids and minerals, and the monitoring of changes to the metals, metalloids and anions. Species entrained in the capture gas are also considered)
• Hydrocarbons and Organics (including compounds that might be found in depleted oil and gas fields, or in EOR [enhanced oil recovery] environments, mobilisation of hydrocarbons removed by the solvent effects of supercritical CO₂ from organic matter [source rocks, coals or hydrocarbon reservoirs], organics entrained in the capture gases from fossil fuel processing or burning.
• CO₂ itself (where the Ross et al. (2007) report has been updated to include a review of potential monitoring tools for CO₂)