Interaction between a fractured marl caprock and CO2-rich sulfate solution under supercritical CO2 conditions
Geological CO2 sequestration at pilot-plant scale will be developed at Hontomin (Spain). CO2 will be injected into a limestone reservoir that contains a NaCl- and sulfate-rich groundwater in equilibrium with calcite and gypsum. The caprock site is composed of marl. The present study seeks to evaluat...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/99076 |
| Acceso en línea: | https://hdl.handle.net/2117/99076 https://dx.doi.org/10.1016/j.ijggc.2015.11.005 |
| Access Level: | acceso abierto |
| Palabra clave: | Geological carbon sequestration CO2 sequestration Caprock Fracture permeability Calcite Gypsum Sealing FLUID-ROCK INTERACTION DISSOLUTION KINETICS CARBON-DIOXIDE RESERVOIR CONDITIONS COUPLED DISSOLUTION SEDIMENTARY BASINS AQUEOUS-SOLUTIONS SALINE AQUIFERS PORE-SCALE STORAGE Anhídrid carbònic -- Segrest Àrees temàtiques de la UPC::Enginyeria química::Química del medi ambient::Química atmosfèrica |
| Sumario: | Geological CO2 sequestration at pilot-plant scale will be developed at Hontomin (Spain). CO2 will be injected into a limestone reservoir that contains a NaCl- and sulfate-rich groundwater in equilibrium with calcite and gypsum. The caprock site is composed of marl. The present study seeks to evaluate the interaction between the Hontomin marl and CO2-rich sulfate solutions under supercritical CO2 conditions (P-Total = 150 bar, pCO(2) = 61 bar and T = 60 degrees C).; Flow-through percolation experiments were performed using artificially fractured cores to elucidate (i) the role of the composition of the injected solutions (S-free and S-rich solutions) and (ii) the effect of the flow rate (0.2, 1 and 60 mLh(-1)) on fracture permeability. Major dissolution of calcite (S-free and S-rich solutions) and precipitation of gypsum (S-rich solution) together with minor dissolution of the silicate minerals contributed to the formation of an altered skeleton-like zone (mainly made up of unreacted clays) along the fracture walls. Dissolution patterns changed from face dissolution to wormhole formation and uniform dissolution with increasing Peclet numbers.; In S-free experiments, fracture permeability did not significantly change regardless of the flow rate despite the fact that a large amount of calcite dissolved. In S-rich solution experiments, fracture permeability decreased under slow flow rates (0.2 and 1 mLh(-1)) because of gypsum precipitation that sealed the fracture. At the highest flow rate (60 mLh(-1)), fracture permeability increased because calcite dissolution predominated over gypsum precipitation. |
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