Duration - 01/05/2021 - 30/04/2022
Research Fellow & Co-PI - Srikumar Roy
Co-Principal Investigator - John Walsh
Funding - iCRAG (Irish Centre for Research in Applied Geosciences) project funded by Science Foundation Ireland (SFI),
and cofunded by the European Regional Development Fund and iCRAG industry partners.
Project description
For CO2 storage in geological media to be successful, confinement /integrity of the reservoir (with effectively no migration and/or leakage of CO2 from the storage zone)
is essential because CO2 leakage poses local risks to other resources, vegetation and marine life, and to human health. Pathways for CO2 leakage could be natural (e.g.,
via active or reactivated faults, open fractures, interruptions and breaches through the confining strata) or they can be wells drilled through the low permeability caprock
(shale, mud and anhydrite) that would otherwise ensure that the storage zone remains as a ‘sealed aquifer’ for long term safe CO2 retention. The potential for CO2 leakage
through wells is particularly important for depleted oil and gas reservoirs with a high density of existing wells. An additional trapping mechanism has been proposed
recently for the long-term storage of CO2 that benefits from the CO2 gas hydrate formation under favourable pressure-temperature conditions (Gauteplass et al., 2020).
Thermodynamic calculations show that CO2 gas hydrates are stable at relatively low pressures (i.e., shallow water depths ~ 200-250m) at typical seabed temperatures
(Tohidi et al., 2010). Other studies suggest that CO2 hydrate formation is quite fast (< hours), with the kinetics controlled by the ready availability of water and CO2 gas
molecules, and the thermal conductivity of the base rock (Kvamme et al., 2007; Palodkar and Jana, 2017), irrespective of the storage scheme (Zatsepina and Pooladi-Darvish,
2011). These processes supports a potential model in which CO2 leakage from deeper aquifers/reservoirs will follow an upward migration pathway (e.g., permeable pore space,
along the well bore, faults), eventually migrating into the CO2 gas hydrate stability zone where it forms a secondary hydrate-seal above the CO2 storage zone. This project
will investigate potential of the CO2 gas hydrate layer to act as a secondary seal for CO2 storage, a model which has recently been advocated one of the Co-PIS (i.e. Srikumar
Roy) and his collaborators (Almenningen et al., 2019).
Contact: Srikumar Roy
Tel: +353 89 4310191
EMAIL