1. Soft stimulation treatment of geothermal well RV-43 to meet the growing heat demand of Reykjavik
- Author
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Torsten Dahm, Hannes Hofmann, Rögnvaldur Magnússon, Claus Milkereit, Gylfi Páll Hersir, Dimitrios Karvounis, Simona Regenspurg, Vala Hjörleifsdóttir, Francesco Grigoli, Ragnheiður St. Ásgeirsdóttir, Stefan Wiemer, Ernst Huenges, Arno Zang, Santiago Aldaz, Sigurveig Árnadóttir, Günter Zimmermann, Bjarni Reyr Kristjánsson, Sebastian Heimann, and Marco Broccardo
- Subjects
Multiple stages ,Zonal isolation ,0211 other engineering and technologies ,Multi-stage hydraulic stimulation ,Adaptive traffic light system ,Capital region ,02 engineering and technology ,Induced seismicity ,010502 geochemistry & geophysics ,Cyclic soft stimulation ,Fluid injection induced seismicity ,01 natural sciences ,enhanced geothermal systems (EGS) ,Realtime seismic monitoring ,021108 energy ,Energy supply ,Seismic risk ,Geothermal gradient ,0105 earth and related environmental sciences ,Microseism ,Petroleum engineering ,Renewable Energy, Sustainability and the Environment ,business.industry ,Geothermal energy ,Geology ,Geotechnical Engineering and Engineering Geology ,Environmental science ,business - Abstract
Reykjavik is almost entirely heated by geothermal energy. Yet, recent growth of the city significantly increased the heat demand. Past experiences in Iceland's capital region showed that hydraulic stimulation of existing geothermal wells is suited to improve hydraulic performance and energy supply. However, fluid injection may also trigger felt or even damaging earthquakes, which are of concern in populated areas and pose a significant risk to stimulation operations. Consequently, soft stimulation concepts have been developed to increase geothermal well performance while minimizing environmental effects such as induced seismicity. In a demonstration project of hydraulic soft stimulation in October 2019, more than 20.000 m³ of water were injected into well RV-43 in Reykjavik in multiple stages and with different injection schemes. The hydraulic performance of the well was improved without inducing felt seismicity. An a priori seismic risk assessment was conducted and for the first time the risk was continuously updated by an adaptive traffic light system supported by a sophisticated realtime microseismic monitoring. Our results confirm that it is possible to improve the performance of geothermal wells in Reykjavik and worldwide with acceptable technical, economic, and environmental risks. Here we provide an overview of the entire stimulation project including site description, stimulation design, zonal isolation, logging, seismic risk assessment and mitigation measures, realtime seismic, hydraulic and chemical monitoring, and stimulation results and challenges., Geothermics, 96, ISSN:0375-6505
- Published
- 2021
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