Risk management of induced seismicity in the life cycle of a hydro-geothermal heating plant in an urban area

Due to the constantly increasing menace of global climate change, Stadtwerke München (SWM) has set the ambitious goal of supplying Munich with 100% district heating from CO2 -neutral sources by 2040 at the latest. Hydrothermal geothermal energy, which needs to be extracted for an efficient supply directly in urban areas, accounts for a large part of the projects. A fractured and karstified carbonate reservoir, buried 2–3 km below Munich, offers the best conditions for the extraction of 90–120 °C hot thermal water. However, the injection of chilled thermal water carries the risk of triggering small seismic events caused by changes in the local stress field. Therefore, SWM has implemented a comprehensive life-cycle risk management system to investigate, prevent, and, if necessary, mitigate any seismic events during the operation of hydro-geothermal heating plants. A variety of innovative techniques and installations (e.g., fiber optic cables) will provide information for the development of a safe strategy already in the planning and construction phase. In addition, permanent seismic monitoring mechanisms and a sophisticated risk management system will ensure early detection of potential hazards during the test/operation phase and enable the prevention or mitigation of seismic events through a holistic reservoir management system.