| Abstract |
Since the last decade, geothermal exploitation activity in the Upper Rhine Graben (URG) has been on-going with several German, Swiss and French deep geothermal sites such as Bruchsal, Bruhl, Groβ Gerau, Insheim, Landau for Germany, Basel, Riehen for Switzerland and Soultz-sous-Forêts, Rittershoffen for France, which are active from exploration to exploitation. All these projects deal with deep fractured geothermal reservoirs located within Triassic-sediments and/or crystalline basement. Since 2011, Electricity of Strasbourg is the holder or co-holder of several exclusive lease for the exploration of high temperature geothermal fields (>150°C) in the Northern Alsace (France). This paper is part of an exploration phase, where we attempt to combine different stratigraphic models realized for four exclusive licenses (Soultz-sous-Forêts, Rittershoffen, Wissembourg, and Lauterbourg) using a modeling software. In a first step, this paper aims to harmonize reprocessed seismic sections interpretation derived from several acquisitions through time within a unique model in order to compile each unique interpretation of the four licenses within a same Northern Upper Rhine Graben 3D model. In a second step, velocity data acquired during drilling campaigns have been used to estimate the local interval velocity of major interpreted geological formations. This time-depth relationships data allowing a conversion from a time based model to a depth based model. Such an outcome has various geothermal applications. For example, it allows the location of induced seismicity in 3D structures representing a significant improvement of events location or it can be used to constrain interpretation of results obtained by other geophysical methods, such as potential methods. |