Geothermal demonstrator project in the Lusitanian layer in the Paris Basin

Abstract

In the Val-de-Marne area (South-East of Paris), the current exploitation of the Dogger aquifer (middle Jurassic, Bathonian) for heating networks (60 doublets and triplets) is going to significantly increase by the year 2016 thanks to 5 new projects aiming the Dogger aquifer (Cf. Figure 1). This leads to a density of geothermal exploitations aiming at the Dogger aquifer so high in this confined area that the question of conflict of interest acts as an incentive to explore other relevant geothermal resources. Among them, the Lusitanian reservoir (upper Jurassic, Oxfordian) is studied in this paper as an alternative to the Dogger in the Vitry-sur-Seine project whose goal is to provide the existing heating network with at least 50% of renewable energy. Despite some uncertainties about the resource tarnishing the results, the study in Vitry-sur-Seine highlights 3 main conclusions: - the top of the Lusitanian reservoir is expected to be between 1100 and 1150 meters in depth; - the expected exploitation characteristics are a flow rate of 200 m3/h, a temperature at the reservoir of 55°C and a minimum reinjection temperature of 25°C, - the power of a new doublet aiming at the Lusitanian reservoir in Vitry-sur-Seine could be 6.9 MW, which meets the heat demand of the district heating. In the framework of this innovative project and the scientific hurdles, the economic, technical and regulatory aspects are dealt with in order to demonstrate the feasibility and the reproducibility of such a project within Paris Basin.