MEET associated partner United Downs Deep Geothermal Power (UDDGP) project successfully finished drilling the deepest wells onshore Great Britain
The two deep wells of the UDDGP project were finished this year in April (UD-1, 5057 m TVD) and June (UD-2, 2214 m TVD) both successfully intersecting the targeted Porthtowan Fault Zone.
Preliminary results from investigation of the drill cuttings (, which were obtained every ten meter in both wells and every five meters in the fault zone), as well as from the borehole geophysical logging and mud losses during drilling are promising. Both wells intersected the fault at the predicted depth. Tand the temperature at the bottom of the deepester well is around 190° C, which is also as expected. Results from borehole imaging have confirmed that there are plenty of natural fractures. and mMud losses and geothermal gradients indicate that the permeability is promising. MEET associated partner Geothermal Engineering Ltd. (GEL, owner of the project), provided drill cuttings and full access to the drilling, logging and test data to the MEET partners TUDa, GeoT, ESG and Vermilion for further investigation and interpretation.
The next steps will include a series of downhole measurements and hydraulic tests, which need to be carried out to evaluate the fault structure, make sure that the wells are in good condition, and evaluate how much geothermal energy can sustainably be harnessed from the system. This phase is expected to take from November 2019 to March 2020.
The first part of this work will be to remove a temporary downhole packer from UD-1, and, in cooperation with the MEET partners, carry out some more downhole ‘logging’ measurements and attempt to collect about 30 sidewall cores. The cores and the additional data will be used for detailed investigation and to assess whether the systems needs to be enhanced by an innovative approach developed as part of the MEET project.