| Title | Seismic Monitoring at the United Downs Deep Geothermal Power Project, Cornwall, UK |
|---|---|
| Authors | Andrew JUPE, Ryan LAW, Jane CHARMAN |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Deep geothermal, microseismic monitoring, EGS, Cornwall, UK |
| Abstract | The United Downs Deep Geothermal Power project is the first development of its kind in the UK. It is located near Redruth in west Cornwall and is part-funded by the European Regional Development Fund (ERDF) and Cornwall Council. Two wells have been drilled to intersect a target fault structure that, it is hoped, will provide enough natural permeability to allow circulation between the wells at flow rates between 20 and 60l/s. The wells intersect the fault at vertical depths of approximately 2,200m (injection well) and 4,500m (production well). The bottom-hole temperature is expected to be in the region of 190OC which should support electricity generation of between 1 and 3WMe (net). Drilling began in November 2018 and was completed at the end of April 2019. The production well reached a depth of 5,275m (MD) and the injection well 2,393m (MD). During post-drilling well testing and long-term circulation of the system it is expected that low level seismicity will be induced by pressure changes in the fracture system. In order to serve both as an engineering tool and to address public concerns over induced seismicity, a comprehensive seismic monitoring system has been installed and the project will operate a monitoring and control protocol in order to protect the surrounding community from disturbance. Background monitoring started in May 2018, approximately 6 months before the start of drilling. The real-time monitoring has detected and located a number of small natural events ranging in magnitude from 0.5 to 2.3 and four induced events with magnitudes less than 0, associated with drilling mud losses. |