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 4

T logs from the granitic basement at thermal equilibrium in GRT-2 (September 2014, one month after drilling). T anomalies are associated with the permeable FZs observed in the image logs. The structural data of these FZs are presented in Table 1. Depth is expressed in Measured Depth (MD). T logs and flow logs were shifted manually to fit the anomalies with the fracture zones. Petrographic results are from Vidal et al. [44] and Glaas et al. [41]. Schmidt diagrams (lower hemisphere) and the cumulative number of fractures in the granitic basement are from Vidal et al. [36].