Permanent shallow subsoil CO 2 flux chambers for monitoring of onshore CO 2 geological storage sites

Abstract

Public concern over the possibility of migration of stored CO 2 to the surface with resulting damage to vegetation or hazard to humans and animals is a matter which will need to be addressed to be able to satisfy likely regulatory requirements for onshore CO 2 storage in a number of jurisdictions. While soil CO 2 concentration is readily measured continuously and in situ with current technology, the measurement of CO 2 flux at depths below the soil A horizon may be a more sensitive and meaningful technique for early detection of a near surface CO 2 plume. We describe a system for the continuous measurement of soil CO 2 flux at a depth of approximately 1.3 m and present results from three instruments deployed at the Otway Basin Pilot Project in Victoria, Australia and one development system deployed at Sutton, near the Australian Capital Canberra.