Diffuse soil CO2 flux to assess the reliability of CO2 storage in the Mazarrón–Gañuelas Tertiary Basin (Spain)

Abstract

Geological storage of CO 2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store the CO 2 in deep saline aquifers at more than 800 m depth, because it achieves its supercritical state. Among the most important aspects concerning the performance assessment of a deep CO 2 geological repository is the evaluation of the CO 2 leakage rate from the chosen storage geological formation. Therefore, it is absolutely necessary to increase the knowledge on the interaction among CO 2 , storage and sealing formations, as well as on the flow paths for CO 2 and the physico-mechanical resistance of the sealing formation. Furthermore, the quantification of the CO 2 leakage rate is essential to evaluate its effects on the environment. One way to achieve this objective is to study of CO 2 leakage on natural analogue systems, because they can provide useful information about the natural performance of the CO 2 , which can be applied to an artificial CO 2 geological storage.This work is focused on the retention capacity of the cap-rock by measuring the diffuse soil CO 2 flux in a site selected based on: i) the presence of a natural and deep CO 2 accumulation; ii) its structural geological characteristics; and iii) the nature of the cap- The results obtained allow to conclude that the geological sealing formation of the basin seems to be appropriate to avoid CO 2 leakages from the storage formation.

The Syabru‐Bensi hydrothermal system in central Nepal: 1. Characterization of carbon dioxide and radon fluxes

“…The SBHS value appears smaller than most CO 2 discharges of volcanic, geothermal, and hydrothermal sites. Nevertheless, the SBHS value is similar to some volcanic sites, such as La Fossa (Italy) [ Carapezza et al , ] and White Island (New Zealand) [ Wardell et al , ]; some geothermal sites, such as Dixie Valley (USA) [ Bergfeld et al , ] and Mazarrón‐Gañuelas Tertiary Basin (Spain) [ Rodrigo‐Naharro et al , ]; and some hydrothermal sites, such as Long Valley (USA) [ Bergfeld et al , ]. In general, the CO 2 discharge of the SBHS is compatible with the majority of mofette sites, such as Selvena (Italy) [ Rogie et al , ], Stavešinci (Slovenia) [ Vodnik et al , ], and Hartoušov (Czech Republic) [ Kämpf et al , ], but appears orders of magnitude higher than estimated values of fault‐related sites, such as Peloritani Monts (Italy) [ Giammanco et al , ], San Andreas and Calaveras faults (USA) [ Lewicki et al , ], and Kunlun fault (China) [ Richon et al , ].…”

“…More generally, studies that have dealt with the spatial distribution of CO 2 fluxes at the Earth's surface were carried out primarily near volcanoes [e.g., Baubron et al , ; Farrar et al , ; Giammanco et al , ; Chiodini et al , ; Hernández et al , ]. Recently, many studies have focused on various natural systems, e.g., volcanic [e.g., Chiodini et al , ; Toutain et al , ; Viveiros et al , ; Finizola et al , ; Granieri et al , ; Di Napoli et al , ; Federico et al , ; Mazot et al , , ; Carapezza et al , ; Inguaggiato et al , ; Hernández et al , , ; Rinaldi et al , ; Tassi et al , ], geothermal [e.g., D'Alessandro et al , ; Fridriksson et al , ; Werner and Cardellini , ; Annunziatellis et al , ; Rodrigo‐Naharro et al , ], and hydrothermal geosystems [e.g., Gerlach et al , ; Lewicki et al , , , ; Werner et al , ; Rissmann et al , ]. However, only a few studies were performed in low temperature (<50°C) CO 2 degassing areas [e.g., Mörner and Etiope , ], such as mofette sites [e.g., Italiano et al , ; Rogie et al , ; Vodnik et al , ; Chiodini et al , ; Kämpf et al , ; Bräuer et al , ], as well as in fault‐related areas [e.g., Etiope , ; Lewicki and Brantley , ; Lewicki et al , ; Ciotoli et al , ] and, more rarely, in the largest orogens [ Perrier et al , ; Richon et al , ].…”

The impact of heterogeneous anisotropy of porous media on density-driven convection

“…First, the CO 2 is injected into the saline aquifers in a supercritical state under the condition of high temperature and enormous pressure (Zhou et al , 2019). As the supercritical CO 2 is significantly less dense (200-700 kg/m 3 ) than the ambient brine (900-1200 kg/m 3 ) and oil (about 800 kg/m 3 ; Huppert and Neufeld, 2014; Abedini and Torabi, 2014), the injected supercritical CO 2 will keep rising and leaking (Rodrigo-Naharro et al , 2013) owing to the buoyance until stopped by a cap rock. As a result, the supercritical CO 2 will reside above brine water (Talebian et al , 2013).…”

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

“…In the framework of a large project on Carbon Capture and Storage (CCS) technologies, the Gañuelas-Mazarrón Tertiary Basin (GMTB), SE Spain, was studied as an analogue of a natural CO 2 reservoir affected by leakages (Pérez del Villar et al, 2008;Nisi et al, 2010a,b;Rodrigo-Naharro et al, 2011, Rodrigo-Naharro et al, 2013aRodrigo-Naharro, 2014;Rodrigo-Naharro et al, 2017, 2018. CO 2 -rich saline groundwater from deep and thermal aquifers are currently upwelling through geothermal wells, precipitating travertines at the water discharge points.…”