Small scale experiment design to study CO2 leakage through a shallow subsurface system
2012 (English)Conference paper, Abstract (Refereed)
CO2 leakage to the ground surface is one of the main concerns associated with geological carbon storage. A solid understanding of how CO2 which has leaked from a storage reservoir behaves in the shallow subsurface is critical for developing effective leakage-monitoring programs. CO2 may reach the unsaturated zone by different leakage mechanisms such as exsolution from CO2-supersaturated water, continuous bubbling or gas flow along a leakage path. In the unsaturated zone, the CO2 is heavier than air and may accumulate below the ground surface and move laterally. In this study, a small scale experimental setup is designed and applied for measuring CO2 distribution in time and space through a near-surface soil. The CO2 concentrations are measured using sensitive gas sensors at several locations in the soil. To interpret the experimental results and develop better understanding of the near-surface CO2 migration processes, the experiments are modeled with the TOUGH2/EOS7CA numerical simulator, including multiphase flow of CO2, water and air. The combination of experiments and modeling is used to investigate the influence of the leakage rates on CO2 concentrations in unsaturated zone and emissions to the atmosphere. The effects of soil water content and depth of the water table on the migration of the leaked CO2 are also investigated.
Place, publisher, year, edition, pages
Research subject Earth Science with specialization in Environmental Analysis
IdentifiersURN: urn:nbn:se:uu:diva-198355OAI: oai:DiVA.org:uu-198355DiVA: diva2:615926
AGU Fall Meeting, San Francisco, CA