García-Ríos, M.

Cama Jordi

Luquot, Linda

Soler J.

English

Digital.CSIC

Geophysical Research AbstractsVol. 16, EGU2014-329, 2014EGU General Assembly 2014© Author(s) 2013. CC Attribution 3.0 License.Laboratory-scale interaction between CO2-rich brine and limestone andsandstone under supercritical CO2 conditionsMaria Garcia-Rios, Jordi Cama, Linda Luquot, and Josep SolerIDAEA-CSIC, Barcelona, Spain (mgrios3@gmail.com)A test site for a prospective CO2 geological storage is situated in Hontomín (Burgos, northern Spain) with areservoir rock that is composed of limestone (calcite) and sandstone (66 wt.% calcite, 28 wt.% quartz and 6 wt.%microcline). During and after CO2 injection, the resulting CO2-rich acid brine will likely promote the dissolutionof carbonate minerals (calcite) and aluminosilicates (microcline). Since the reservoir Hontomín brine containssulfate, gypsum (or anhydrite at depth) may precipitate. These coupled dissolution and precipitation reactions mayinduce changes in porosity and pore structure of the repository rocks. Percolations experiments with mechanicallyfractured cores (8.6 mm in diameter and 18 mm length) were performed under CO2 supercritical conditions (Pfluid= 150 bar; pCO2 ≈ 90 bar and T = 60 ºC) in order to evaluate and quantify variations in fracture permeability,preferential path formation and fracture volume. The brine sulfate content and the flow rate were varied.Regarding limestone, as the synthetic brines circulated through the fracture, the fracture permeability ini-tially increased slowly, to thereafter increase rapidly. This change was due to a localized dissolution process(wormhole formation) along the core that occurred regardless gypsum precipitation. Nonetheless, the originatedfracture volume in the sulfate-rich brine experiments was a factor of two smaller than that in sulfate-free brineexperiments. Also, an increase in flow rate from 0.2 to 60 mL/h increased the volume of both dissolved calcite andprecipitated gypsum. Regarding sandstone, permeability increased gradually with time. Nonetheless, this increasewas not always continuous due to eventual fracture clogging. Formation of wormholes was observed.AcknowledgementsThis study was financed by CIUDEN (Ciudad de la Energía), the Compostilla OXYCFB300 project andthe PANACEA project (European Community’s Seventh Framework Programme FP7/2007-2013 under grantagreement number 282900).

Laboratory-scale interaction between CO2-rich brine and limestone and sandstone under supercritical CO2 conditions.

https://digital.csic.es/bitstream/10261/214975/1/747756.pdf

Laboratory-scale interaction between CO2-rich brine and limestone and sandstone under supercritical CO2 conditions.

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