Geothermal Anomaly Identified Under a Dense Urban Area in the Metropolitan Region of Barcelona, Spain

Abstract

During the drilling of the Barcelona Metro L9 line, at the Fondo station of Santa Coloma de Gramanet (Barcelona) a geothermal anomaly was detected, in which groundwater temperature was found to be up to 55°C. This anomaly was attributed to a rise of deep groundwater through some tectonic structures, in a similar way to other geothermal zones of Catalonia (Spain). This geothermal area is located under a dense urban area where the information of its hydrogeological and geothermal features is limited. Due to the economic benefits of geothermal energy to society, studying and understanding the dynamics of the geothermal system, as well as, assessing its potential for future exploitation of the resource in this dense urban area, are of great interest. In order to study the feasibility of a future energy exploitation of the geothermal resource, a study is being undertaken at local and regional scale. In the regional study, whose first results are presented in this work, the objective is to understand the hydrothermal operation of the system. To achieve this, different works have been performed as are: geological review, borehole drilling, petrology, borehole logging, hydrochemical and isotopic assessment, thermography images, etc. This information has been integrated in numerical models of flow and heat transport.