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| Titel |
Experimental investigations and geochemical modelling of site-specific fluid-fluid and fluid-rock interactions in underground storage of CO2/H2/CH4 mixtures: the H2STORE project |
| VerfasserIn |
Marco De Lucia, Peter Pilz |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250112468
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| Publikation (Nr.) |
 EGU/EGU2015-12627.pdf |
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| Zusammenfassung |
| Underground gas storage is increasingly regarded as a technically viable option for meeting
the energy demand and environmental targets of many industrialized countries. Besides the
long-term CO2 sequestration, energy can be chemically stored in form of CO2/CH4/H2
mixtures, for example resulting from excess wind energy. A precise estimation of the impact
of such gas mixtures on the mineralogical, geochemical and petrophysical properties of
specific reservoirs and caprocks is crucial for site selection and optimization of storage
depth.
Underground gas storage is increasingly regarded as a technically viable option for
meeting environmental targets and the energy demand through storage in form of H2 or CH4,
i.e. resulting from excess wind energy. Gas storage in salt caverns is nowadays a mature
technology; in regions where favorable geologic structures such as salt diapires are not
available, however, gas storage can only be implemented in porous media such as depleted
gas and oil reservoirs or suitable saline aquifers. In such settings, a significant amount of
in-situ gas components such as CO2, CH4 (and N2) will always be present, making the
CO2/CH4/H2 system of particular interest. A precise estimation of the impact of their gas
mixtures on the mineralogical, geochemical and petrophysical properties of specific
reservoirs and caprocks is therefore crucial for site selection and optimization of storage
depth.
In the framework of the collaborative research project H2STORE, the feasibility of
industrial-scale gas storage in porous media in several potential siliciclastic depleted gas and
oil reservoirs or suitable saline aquifers is being investigated by means of experiments and
modelling on actual core materials from the evaluated sites. Among them are the Altmark
depleted gas reservoir in Saxony-Anhalt and the Ketzin pilot site for CO2 storage in
Brandenburg (Germany). Further sites are located in the Molasse basin in South Germany and
Austria. In particular, two work packages hosted at the German Research Centre for
Geosciences (GFZ) focus on the fluid-fluid and fluid-rock interactions triggered
by CO2, H2 and their mixtures. Laboratory experiments expose core samples to
hydrogen and CO2/hydrogen mixtures under site-specific conditions (temperatures
up to 200 °C and pressure up to 300 bar). The resulting qualitative and, whereas
possible, quantitative data are expected to ameliorate the precision of predictive
geochemical and reactive transport modelling, which is also performed within the
project.
The combination of experiments, chemical and mineralogical analyses and models is
needed to improve the knowledge about: (1) solubility model and mixing rule for
multicomponent gas mixtures in high saline formation fluids: no data are namely
available in literature for H2-charged gas mixtures in the conditions expected in the
potential sites; (2) chemical reactivity of different mineral assemblages and formation
fluids in a broad spectrum of P-T conditions and composition of the stored gas
mixtures; (3) thermodynamics and kinetics of relevant reactions involving mineral
dissolution or precipitation. The resulting amelioration of site characterization and
the overall enhancement in understanding the potential processes will benefit the
operational reliability, the ecological tolerance, and the economic efficiency of
future energy storing plants, crucial aspects for public acceptance and for industrial
investors. |
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