%A Chrystel Dezayes
%A Albert Genter
%A Benoît Valley
%J Comptes Rendus Geoscience
%T Structure of the low permeable naturally fractured geothermal reservoir at Soultz
%X The permeability of the granite geothermal reservoir of Soultz is primarily related to major fracture zones, which, in turn, are connected to dense networks of small-scale fractures. The small-scale fractures are nearly vertical and the major direction is about N0°E. This direction differs from that of the Rhine Graben, which is about N20°E to N45°E in northern Alsace. A total of 39 fracture zones, with a general strike of N160°E, have been identified in six wells between 1400 and 5000 m depth. These fracture zones are spatially concentrated in three clusters. The upper cluster at 1800–2000 m True Vertical Depth (TVD) is highly permeable. At 3000–3400 m TVD, the intermediate cluster in composed of a dense network developed in an altered matrix and forms the upper reservoir. In the lower part of the wells, the deeper cluster appears as a fractured reservoir developed within a low permeable matrix. Fracture zones represent a key element to take into account for predicting the geothermal reservoir life time submitted to various thermo-hydromechanical and chemical processes generated by hydraulic or chemical stimulations and by hydraulic circulation tests related to long-term exploitation.
%N 7-8
%K Rhine Graben; Fractures; Fracture zones; Cores; Borehole images; Enhanced Geothermal System
%P 517-530
%V 342
%D 2010
%I Elsevier
%R doi:10.1016/j.crte.2009.10.002
%L epos1859