Towards Targeting Geothermal Reservoir : Guide From Survey Design To Processing Through Seismic Acquisition In Urban Context In Alsace

Abstract

Based on the geothermal expertise gathered from the soultz project which was successfully demonstrated with the recent geothermal doublet of rittershoffen, new targets in the upper rhine valley are under development by the groupe es (Genter et al., 2015a). Thus, as part of a geothermal project in alsace (France), a preliminary survey of seismic reflection was acquired during summer 2015 at illkirch in the suburb of strasbourg area. The deep geothermal target is a fractured/Faulted zone at the interface between the deep clastic sediments and the top crystalline basement. This seismic survey was designed in order to qualify a potential deep geothermal target for an egs (« enhanced geothermal systems ») Exploitation of the resource (Genter et al., 2015b). Obtaining a structural and hydrogeological model of this kind of deep fractured reservoir is a key point for a successful project (Dezayes et al., 2010). So geometry design and acquisition parameters have been discussed to provide a suitable and valuable image of the sub-surface. Furthermore within a complex structural model, a seismic processing sequence dedicated to enhance fault direction should be implemented. Beyond technical considerations, being environmentally concerned and scientifically transparent the “groupe es” is willing to develop local energy for local purpose to ensure the acceptability by people to the project.