eprintid: 2270 rev_number: 12 eprint_status: archive userid: 6 dir: disk0/00/00/22/70 datestamp: 2020-07-13 07:40:28 lastmod: 2020-07-13 07:40:28 status_changed: 2020-07-13 07:40:28 type: article metadata_visibility: show creators_name: Altwegg, Pierrick creators_name: Schill, Eva creators_name: Abdelfettah, Yassine creators_name: Radogna, Pier-Vittorio creators_name: Mauri, Guillaume corp_creators: Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel,Switzerland corp_creators: Institute of Nuclear Waste Disposal INE, Karlsruhe Institute of Technology KIT, Hermann-von-Helmholtz-Platz 1, Germany corp_creators: Institute of Nuclear Waste Disposal INE, Karlsruhe Institute of Technology KIT, Hermann-von-Helmholtz-Platz 1, Germany corp_creators: RBR Geophysics GmbH, CH-6340 Baar, Switzerland corp_creators: Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel, Emile-Argand 11, CH-2000 Neuchâtel, Switzerland title: Toward fracture porosity assessment by gravity forward modeling for geothermal exploration (Sankt Gallen, Switzerland). subjects: O subjects: RS2 subjects: SG divisions: S4CE-1 full_text_status: none keywords: Fracture porosity, Gravity, Stripping, Reservoir characterization, Fractured reservoir abstract: Fracture porosity is a crucial parameter in hydrocarbon and geothermal reservoir exploration and a major challenge in the absence of nearby exploration wells. The Sankt Gallen geothermal project targets a fault zone that affects Mesozoic sediments at a depth of about 4500 m. Spatial extension of these sediments, a major fault zone and indication for graben structures in the crystalline basement are observed in 3D seismic. Both the graben and the fault zone coincide with negative gravity anomalies acquired and analyzed during this study. Forward modeling of gravity anomalies based on a 3D seismic survey is used to estimate possible fracture porosity. After stripping gravity effects of geothermally irrelevant geological units from the residual anomaly, most likely only local structures related to the fault zone account for remaining anomalies. Synthetic case study on the effect of density variation and considerable gas content in the well support possible fracture porosity between about 4% and 8%. date: 2015-09 date_type: published publication: Geothermics volume: 57 publisher: Elsevier Science pagerange: 26-38 id_number: 10.1016/j.geothermics.2015.05.006 issn: 0375-6505 official_url: https://doi.org/10.1016/j.geothermics.2015.05.006 access_IS-EPOS: limited owner: Publisher citation: Altwegg, Pierrick and Schill, Eva and Abdelfettah, Yassine and Radogna, Pier-Vittorio and Mauri, Guillaume (2015) Toward fracture porosity assessment by gravity forward modeling for geothermal exploration (Sankt Gallen, Switzerland). Geothermics, 57. pp. 26-38. DOI: https://doi.org/10.1016/j.geothermics.2015.05.006