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| Titel |
Experimental study of the caprock / cement interface under CO2 geological storage conditions |
| VerfasserIn |
Emmanuel Jobard, Jérôme Sterpenich, Jacques Pironon, Aurélien Randi, Marie-Camille Caumon |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076603
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| Zusammenfassung |
| In the framework of CO2 geological storage, one of the critical point leading to possible
massive CO2 leakages is the behavior of the interfaces crossed by the injection well. The lack
of relevant data on the behavior of these interfaces (rock/well materials) in the presence of
CO2 under high pressure and temperature conditions led to the development of a new
experimental model called "Sandwich". These batch experiments consisted in putting a
caprock (Callovo-Oxfordian claystone of the Paris Basin) in contact with cement (Portland
class G) in the presence of supercritical CO2 with or without aqueous solution.
The new experimental device was designed in order to follow the evolution of a
clayey caprock, a Portland cement and their interface submitted to the acidic attack
of carbonic acid through a study of the initial and final states. This model should
help to document the behavior of interfaces in the proximal zone at the injection
site.
After one month of ageing at 80Ë C under 100 bar of CO2 pressure, the caprock, the
cement and the interface between caprock and cement are investigated thanks to SEM,
cathodoluminescence and Raman spectrometry. The main results reveal i) the influence of the
presence of an aqueous solution since the carbonation mechanisms are quite different under
dry and wet atmospheres, ii) the good cohesion of the different interfaces despite the
carbonation of the cement, iii) the precipitation of different carbonate phases, which relates
the changes in the chemistry of the solution to time, iv) the enrichment of silica in the cement
phase submitted to the action of CO2 putting into evidence new mechanisms of in situ silica
re-condensation, v) the very good behavior of the caprock despite the alkaline flux from
cement and the acidic attack from the dissolved CO2. These experimental results
will be compared to those obtained by geochemical simulations performed with
PHREEQC.
This study was financially supported by the French agency ANR (ANR-08-PCO2-006). |
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