Skip to main content

Science – Society – Technology

Geothermal Energy Cover Image
Fig. 6 | Geothermal Energy

Fig. 6

From: How do the geological and geophysical signatures of permeable fractures in granitic basement evolve after long periods of natural circulation? Insights from the Rittershoffen geothermal wells (France)

Fig. 6

Wells GRT-1 and GRT-2 with geology, temperature, and gamma ray data at the same depth. The cumulative number of fractures is from acoustic images for both wells and from the caliper data for the GRT-2 well. The fracture analysis was performed using stereographic diagrams, specifically, Schmidt lower hemisphere plots realized with the Kamb method; 2 specifies the initial contouring interval and 3 specifies the number of standard deviations that define the expected count for a uniform distribution. The stereographic diagrams were constructed based on both caliper and acoustic image log data for four major fracture zones in the granitic basement of the GRT-2 well. The black areas represent zones where UBI data was not acquired, and the gray areas represent zones where fractures from the caliper log were not computed. The UBI fracture datasets are from Vidal et al. (2016). The facies are as follows: GRAN: granite, HLOW: low hydrothermal alteration grade, HMOD: moderate alteration grade, HHIG: high alteration grade, HEXT: extreme hydrothermal alteration, VEIN: quartz vein, GRAN_OX: oxidized granite, RED: reddish granite, PERM: Permian sandstone

Back to article page