Observational evidence confirms modelling of the long-term integrity of CO2-reservoir caprocks
- Shell Global Solutions International, Rijswijk (Netherlands); Univ. of Cambridge (United Kingdom)
- Shell Global Solutions International, Rijswijk (Netherlands)
- RWTH Aachen Univ. (Germany)
- Univ. of Utrecht (Netherlands)
- Julich Research Centre (Germany)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- British Geological Survey, Nottingham (United Kingdom)
- Utah State Univ., Logan, UT (United States)
- Univ. of Cambridge (United Kingdom)
Storage of anthropogenic CO2 in geological formations relies on a caprock as the primary seal preventing buoyant super-critical CO2 escaping. Although natural CO2 reservoirs demonstrate that CO2 may be stored safely for millions of years, uncertainty remains in predicting how caprocks will react with CO2-bearing brines. The resulting uncertainty poses a significant challenge to the risk assessment of geological carbon storage. We describe mineral reaction fronts in a CO2 reservoir-caprock system exposed to CO2 over a timescale comparable with that needed for geological carbon storage. Moreover, the propagation of the reaction front is retarded by redox-sensitive mineral dissolution reactions and carbonate precipitation, which reduces its penetration into the caprock to ~7 cm in ~105 years. This distance is an order-of-magnitude smaller than previous predictions. The results attest to the significance of transport-limited reactions to the long-term integrity of sealing behaviour in caprocks exposed to CO2.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Nanoscale Control of Geologic CO2 (NCGC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC05-00OR22725; NE/F004699/1; AC02-05CH11231
- OSTI ID:
- 1279389
- Journal Information:
- Nature Communications, Vol. 7; ISSN 2041-1723
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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