Title
Geochemical effects of SO2 during CO2 storage in deep saline reservoir sandstones of Permian age (Rotliegend) - A modelling approach
Author
Waldmann, S.
Rutters, H.
Publication year
2016
Abstract
tGeochemical modeling was used to assess the impact of sulfur dioxide (SO2) in impure carbon dioxide(CO2) streams on fluid–rock interaction during storage in siliciclastic rocks of Permian age (Rotliegend).We focused on the impact of SO2on the porosity evolution, as well as on the trapping of CO2as solidmineral phase. Due to the lack of a validated approach to calculate SO2solubility in highly saline brineat CO2storage conditions, different calculation approaches were tested against experimental literaturedata. Our novel approach employs a pressure and temperature adjusted Henry’s constant with salinitycorrection. Depending on the solubility calculation approach and on the consecutive reactions of dissolvedSO2, different SO2concentrations in the brine were calculated. Based on the results of these solubilitycalculations, a low and a high SO2concentration case were defined for geochemical modeling to assess theimpact of different SO2concentrations on fluid–rock interactions in a CO2storage reservoir. An exemplaryRotliegend sandstone composition was chosen reflecting compositions of potential target horizons inthe North German Basin. Short-term dissolution of carbonates and, in the presence of SO2, subsequentprecipitation of sulfur-bearing minerals results in a decrease in porosity. A precipitation of sulfates nearthe injection well may lower injectivity. With time, dissolution of alumosilicates further provides cationsto the aqueous solution for a precipitation of secondary carbonates. The presence of SO2modifies thislong-term interplay between silicate and carbonate minerals. The higher the SO2concentration in thebrine, the lower the amounts of newly formed carbonates, i.e. the mineral trapping of CO2, and thelower the overall porosity decrease. Hence, the assessment of SO2dissolution in the formation brine atsubsurface conditions is crucial for predicting mineral reactions and porosity evolution during geologicalstorage of impure CO2
Subject
Geo
SGE - Sustainable Geo Energy
ELSS - Earth, Life and Social Sciences
Geological Survey Netherlands
Geosciences
2015 Energy
CO2storage
Sulfur dioxide
SO2 solubility
Geochemical modeling
Rotliegend
Impurities
To reference this document use:
http://resolver.tudelft.nl/uuid:fe58c34e-ec2d-42b9-9e83-d8f7803878e6
TNO identifier
533234
Source
International Journal of Greenhouse Gas Control, 46, 116-135
Document type
article