eprintid: 1861 rev_number: 11 eprint_status: archive userid: 6 dir: disk0/00/00/18/61 datestamp: 2017-01-25 07:58:02 lastmod: 2019-02-06 10:38:45 status_changed: 2017-01-25 07:58:02 type: article metadata_visibility: show creators_name: Dorbath, Louis creators_name: Evans, Keith F. creators_name: Cuenot, Nicolas creators_name: Valley, Benoît creators_name: Charléty, Jean creators_name: Frogneux, Michel creators_id: creators_id: keith.evans@erdw.ethz.ch creators_id: cuenot@soultz.net creators_id: creators_id: creators_id: corp_creators: EOST, University Louis Pasteur, France corp_creators: Department of Earth Sciences, Swiss Federal Institute of Technology (ETH), Switzerland; corp_creators: GEIE Exploitation minière de la chaleur,France corp_creators: Department of Earth Sciences, Swiss Federal Institute of Technology (ETH), Switzerland; MIRACO/Laurentian University, Sudbury, Canada corp_creators: GeoscienceAzur, France corp_creators: EOST, University Louis Pasteur, France title: The stress field at Soultz-sous-Forêts from focal mechanisms of induced seismic events: Cases of the wells GPK2 and GPK3 subjects: MP6_1 subjects: RF1 subjects: SG divisions: IP4 full_text_status: none keywords: Soultz-sous-Forêts; Focal mechanisms; Stress field; France abstract: The stress field at the EGS geothermal site of Soultz-sous-Forêts has been the subject of many studies, because it largely controls the response of the reservoir to fluid injection. The analysis of borehole logging data, especially breakouts and drilling-induced tension fractures, in the four geothermal wells define an average SHmax orientation ranging between 170° and 180° down to 5 km depth. It also reveals strong heterogeneities in several depth intervals. In this paper, the inversion of double-couple source mechanisms of seismic events induced during GPK2 and GPK3 stimulation tests is performed to retrieve the orientation and shape factor of the stress tensor, using the Slickenside Analysis Package of Michael, 1984, Michael, 1987a and Michael, 1987b. The results indicate a well-determined orientation of Shmin in GPK2 and in GPK3; in GPK3 Shmin is clockwise rotated by about 10°. The stress tensor defines an uniaxial extension. The results from both methods, analysis of borehole logging data and inversion of focal mechanisms, are only slightly different; the discrepancy may be due to the larger reservoir volume covered by the focal mechanisms, which can include strong stress heterogeneities. date: 2010 date_type: published publication: Comptes Rendus Geoscience volume: 342 number: 7-8 publisher: Elsevier pagerange: 600-606 id_number: doi:10.1016/j.crte.2009.12.003 issn: 1631-0713 official_url: http://doi.org/10.1016/j.crte.2009.12.003 access_IS-EPOS: limited owner: Publisher citation: Dorbath, Louis and Evans, Keith F. and Cuenot, Nicolas and Valley, Benoît and Charléty, Jean and Frogneux, Michel (2010) The stress field at Soultz-sous-Forêts from focal mechanisms of induced seismic events: Cases of the wells GPK2 and GPK3. Comptes Rendus Geoscience, 342 (7-8). pp. 600-606. DOI: https://doi.org/10.1016/j.crte.2009.12.003