How Can Temperature Logs Help Identify Permeable Fractures and Define a Conceptual Model of Fluid Circulation? An Example from Deep Geothermal Wells in the Upper Rhine Graben

Figure 1

Structural map of the center of the Upper Rhine Graben with isotherms at a 2 km depth from the geoportal GeORG [55]. The geothermal anomaly in the Strasbourg area is from the dataset of Baillieux et al. [1]. Geothermal power plants in operation are represented by green stars, and the geothermal projects under drilling operations are represented by blue stars. On the left: N-S section through the geothermal wells of the Soultz-sous-Forêts power plant with a simplified geology. On the right: N-S section through the geothermal wells of the Rittershoffen power plant with a simplified geology. The thick line represents the casing section of the well, whereas the thin one represents the open hole. Production wells are in red, and injection wells are in blue. The GPK-1 well is represented in black because it is now used as an observation well.