Regular Article
Geochemical modeling of changes in caprock permeability caused by CO2–brine–rock interactions under the diffusion mechanism
1
Center for Hydrogeology and Environmental Geology Survey, CGS, Baoding 071051, China
2
Key Laboratory of Carbon Dioxide Geological Storage of China Geological Survey, Baoding 071051, China
3
School of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
4
School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
5
Chengdu Hydrogeology and Engineering Geology Center, Sichuan Bureau of Geology and Mineral Resources, Chengdu 610081, China
* Corresponding author: ygdguodong@126.com
Received:
19
May
2019
Accepted:
11
October
2019
Geologic Carbon Sequestration (GCS) has been widely considered as a significant means for reducing CO2 emissions to address global climate change. The caprock sealing plays a key role in determining permanence and security of carbon dioxide (CO2) storage in geologic formations. This study presents geochemical modeling of CO2–brine–rock interactions in a deep saline aquifer in the Jianghan Basin, which is a potential target for CO2 injection and geological storage. A one-dimensional model was developed to investigate the changes in caprock permeability caused by CO2–brine–rock interactions under the diffusion mechanism. The results show that the dissolution of K-feldspar and albite plays a key role in the variation of caprock permeability, which makes permeability increased by 60% at the bottom of caprock. The caprock permeability is increased with temperature by enhancing the minerals dissolution of caprocks. In addition, the common-ion effect generated by the increased salinity inhibits the minerals dissolution in caprock.
© X. Ma et al., published by IFP Energies nouvelles, 2019
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
