Name: United Downs Deep Geothermal Project
Location: United Downs, Cornwall (UK)
Project status: in testing
MEET Partner in contact with site: GeoT, TUDa
Number of wells: 2 wells
Drilling year: November 2018 to June 2019
The United Downs Deep Geothermal Project (UDDGP) located near Redruth in Cornwall/UK aims to use a fractured geothermal reservoir for hydrothermal district heating and power generation.
Within MEET the UDDGP will be a demonstration site for best practice enhancing reservoir permeability.
HAS Innova TI 418 rig drilling UD-1 and UD-2
The Carnmenellis granite is a sub-circular composite intrusion and forms part of the Variscan Cornubian batholith. The Porthtowan fault zone (PTF) belongs to a family of NW-SE striking structures cross-cutting SW England. The PTF is a sub-vertical strike-slip fault zone penetrating both killas and granite. Foliated and mylonitised granites give evidence for PTF being active during granite emplacement. No active movement is documented along this fault.
Mapped structures in the vicinity of the UDDGP site (geological map by BGS, sheet 352, Falmouth)
Exploitation is by two deviated wells penetrating the Porthtowan fault zone vertically above each other, the first at approx. 2 km depth for injection, and the second at approx. 4.5 km for production. Cold water being injected in the first well is expected to infiltrate the fault zone by gravity, to heat up and to be produced through the second well with up to 175 °C. MEET will help to mitigate risks concerning insufficient flow rate.
Conceptual circulation of geothermal fluid