Current travertines precipitation related to artificial CO2 leakages from a natural reservoir (Ganuelas-Mazarron Tertiary Basin, SE Spain)

JOURNAL OF HYDROLOGY

卷:577

Article

Rodrigo-Naharro, Julio¹  Herrero, Maria J.²  Delgado-Huertas, Antonio³  Granados, Arsenio³  Perez del Villar, Luis¹ 

[1] Ctr Invest Energet Medioambientales & Tecnol CIEM, Avda Complutense 40, Madrid 28040, Spain

[2] Univ Complutense Madrid, Fac Ciencias Geol, Dept Petrol & Geoquim, C Jose Antonio Novais 2, E-28040 Madrid, Spain

[3] CSIC UGR, IACT, Lab Biogeoquim Isotopos Estables, Avda las Palmeras 4, Granada 18100, Spain

关键词: CO2 storage;    CO2 leakage;    Travertines;    Stable isotopes;    Natural analogues;    Betic Cordillera (Spain);   

DOI  :  10.1016/j.jhydrol.2019.123997

来源: Elsevier

【 摘 要 】

In the framework of a natural CO2 reservoir with CO2 leakages as an analogue of a failed CO2 deep geological storage, the current precipitation of travertines and the associated upwelling of CO2-rich saline groundwater were analysed. This natural analogue is located in the Ganuelas-Mazarron Tertiary Basin (SE Spain). The study comprises of the chemistry of both groundwater and travertines, including stable isotopes, mineralogy and petrography of the travertines, all this performed after a review of the geology of the basin. In this sense, the basin gathers the main features of a safe natural CO2 reservoir in a deep saline aquifer sealed by a thick marl formation. The aquifer was artificially perturbed by the drilling of wells, inducing the travertines precipitation at these water discharge points. Groundwater is saline, slightly acid, oversaturated in aragonite and calcite and with significant concentrations of heavy elements, some of them toxic. From an isotopic viewpoint, the relative constant delta C-13-DIC values suggest that carbon is mainly inorganic in origin with minor organic and mantle contributions. Travertines are basically composed of aragonite or calcite, their precipitation being controlled by a sudden CO2 degassing and minor biological activity. Their delta C-13 signatures indicate that carbon mainly has an inorganic origin, although some contribution of organic carbon must be considered as well. Furthermore, these carbonate deposits did not precipitate in isotopic equilibrium, as determined by delta O-18 values. Finally, it is suggested that the appearance of travertines along with their carbon isotopic signatures represent efficient tools for detecting CO2 leakages from any CO2 storage site.

【 授权许可】

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