Developing and circulating a fault system in the crystalline rock for geothermal power generation in Insheim, Germany.
Abstract
Pfalzwerke geofuture GmbH together with its general contractor BESTEC GmbH intend to build a geothermal power plant in Insheim using a single fault system in the crystalline rock for geothermal heat extraction. The Insheim site is located in the Upper Rhine Graben, about 4 km South of the geothermal power plant in Landau, Germany, and about 30 km North of the European EGS site at Soultz-sous-Forêts, France. In 2008 and 2009 two wells were successfully drilled to a depth of about 3,800 meters targeting the same fault system in the crystalline basement. The geothermal reservoir was tapped with a temperature of more than 165 degrees Celsius. In order to improve well properties and prepare both wells for safe, clean and viable power generation, circulation tests and hydraulic injections with gradually increasing flowrate were conducted in late 2009 and early 2010. Seismic monitoring networks, recording also ground velocities, along with an alarm plan ensured the success of the operations. The recorded peak ground velocities stayed far below the reference values of 3 and 5 millimeters per second, specified in the DIN 4150, while seismic activity obviously decreased during the hydraulic operations. In autumn 2010 a lateral well was drilled out of the injection well at approximately 2,500 meters, aiming to better distribute the fluid volume between the two injection branches and thus further minimize microseismic activity. During subsequent hydraulic injection tests no more seismicity was registered. The geothermal power plant in Insheim will have a capacity of 4 to 5 megawatts, capable of supplying about 8,000 homes with electrical energy. The beginning of electric power production is planned for summer 2012.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.S44B..03T
- Keywords:
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- 0450 BIOGEOSCIENCES / Hydrothermal systems;
- 8010 STRUCTURAL GEOLOGY / Fractures and faults