eprintid: 1859 rev_number: 10 eprint_status: archive userid: 6 dir: disk0/00/00/18/59 datestamp: 2017-03-02 11:24:25 lastmod: 2017-03-02 11:24:25 status_changed: 2017-03-02 11:24:25 type: article metadata_visibility: show creators_name: Dezayes, Chrystel creators_name: Genter, Albert creators_name: Valley, Benoît corp_creators: BRGM, Geothermal Department, France corp_creators: GEIE exploitation minière de la chaleur,France corp_creators: ETH Zürich, Engineering Geology,Switzerland title: Structure of the low permeable naturally fractured geothermal reservoir at Soultz subjects: MP2 subjects: RF1 subjects: SG divisions: IP4 full_text_status: none keywords: Rhine Graben; Fractures; Fracture zones; Cores; Borehole images; Enhanced Geothermal System abstract: 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. date: 2010 date_type: published publication: Comptes Rendus Geoscience volume: 342 number: 7-8 publisher: Elsevier pagerange: 517-530 id_number: doi:10.1016/j.crte.2009.10.002 issn: 1631-0713 official_url: http://doi.org/10.1016/j.crte.2009.10.002 access_IS-EPOS: limited owner: Publisher citation: Dezayes, Chrystel and Genter, Albert and Valley, Benoît (2010) Structure of the low permeable naturally fractured geothermal reservoir at Soultz. Comptes Rendus Geoscience, 342 (7-8). pp. 517-530. DOI: https://doi.org/10.1016/j.crte.2009.10.002