<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "The St. Gallen Project: Development of Fault Controlled Geothermal Systems in Urban\r\nAreas"^^ . "In areas of average geothermal gradients and conduction dominated heat transport, coupled heat-power generation is the most\r\nefficient way of geothermal energy utilization. Since heat for district heating cannot get efficiently transported over large distances,\r\nviable geothermal resources should be located close to the point of end-use as it is the case in urban areas. The city of St. Gallen in\r\nnortheast Switzerland matches these requirements: St. Gallen is located in the Molasse Basin, i.e. the northern foreland basin of the\r\nAlps with viable deep geothermal resources, and has an installed and expandable district heating system.\r\nThe project in St. Gallen started in 2008 with a feasibility study considering different target horizons and different concepts of\r\nutilization including hydrothermal and petrothermal resources applying conventional and EGS technologies. An extensive 3D\r\nseismic survey in 2010 was followed by a public poll about the geothermal project in 2010. After overwhelming advocacy\r\nthroughout the voting citizens of St. Gallen, planning of the first well started in 2011. In 2013, drilling operation started and the first\r\ntarget horizon in 4 km deep Upper Jurassic carbonate rocks was successfully achieved. After an injection test and well cleaning, a\r\ngas kick and subsequent work-over operation caused a seismic event of ML 3.5. Among other approaches, stress field analysis\r\napplying the concept of limiting stress ratios, the concept of effective stresses, and the slip tendency technique helped to decide\r\nfurther steps. After a short interruption, the project continued with a 4-weeks production test, which evidenced a gas reservoir of\r\nhitherto unknown extend. One of the main conclusions drawn from the project is the existence of dormant faults, which have to be\r\nconsidered in fault-controlled regions with historic seismicity. Dormant faults may have experienced fault healing and strain\r\nhardening evolving to a strong fault with high friction coefficient as indicated from geomechanical parameters gained from the St.\r\nGallen well. A focus on dormant fault investigation and their geomechanical characterization might therefore play an important role\r\non future geothermal research topics.\r\nWith this article we demonstrate best practices of geothermal project development in urban areas, and delineate concepts and\r\ncritical data required to guide efficient decision making."^^ . "2015-04" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Michael"^^ . "Sonderegger"^^ . "Michael Sonderegger"^^ . . "Thomas"^^ . "Bloch"^^ . "Thomas Bloch"^^ . . "Stephan"^^ . "Uhlig"^^ . "Stephan Uhlig"^^ . . "Inga"^^ . "Moeck"^^ . "Inga Moeck"^^ . . "Peter"^^ . "Kuhn"^^ . "Peter Kuhn"^^ . . "Markus"^^ . "Wolfgramm"^^ . "Markus Wolfgramm"^^ . . "Stefan"^^ . "Heuberger"^^ . "Stefan Heuberger"^^ . . "Henry"^^ . "Naef"^^ . "Henry Naef"^^ . . "René"^^ . "Graf"^^ . "René Graf"^^ . . "University of Alberta, Dep. Earth and Atmospheric Sciences,Canada"^^ . . . "Sankt Galler Stadtwerke, St.Gallen, Switzerland"^^ . . . "Proseis AG, Zurich, Switzerland"^^ . . . "Proseis AG, Zurich, Switzerland"^^ . . . "Proseis AG, Zurich, Switzerland"^^ . . . "geosfer AG, St.Gallen, Switzerland"^^ . . . "Sankt Galler Stadtwerke, St.Gallen, Switzerland"^^ . . . "GeoTec Consult, Markt Schwaben, Germany"^^ . . . "Geothermie Neubrandenburg GmbH, Neubrandenburg, Germany"^^ . . . . . "Proceedings World Geothermal Congress 2015"^^ . . . . . "Melbourne, Australia"^^ . . . . . "HTML Summary of #2268 \n\nThe St. Gallen Project: Development of Fault Controlled Geothermal Systems in Urban \nAreas\n\n" . "text/html" . . . "Technology-seismicity interaction" . . . "St. Gallen" . . . "Geothermal energy production" . .