United Downs geothermal project concluded drilling and prepares for next steps
Set up of drilling rig on site in Cornwall, UK (source: UDDGP)
Alexander Richter
16 Jul 2019
With the dismantling of the the drilling rig, the United Downs Deep Geothermal Project is entering the next phase of development that is to evaluate drilling results and implications for next steps.
In its updates on the website of the United Downs Deep Geothermal Project it is reported that the team has now removed the top section of the mast using a 500t crane; the top section is the lightest weighing in at a mere 29 tons!
The transport process is the same as when the rig was mobilised last October. There will be about 80 truckloads leaving the site over the next two weeks using the route agreed with the Local Planning Authority as part of the planning consent for the site; through Crofthandy, Vicarage Hill and Scorrier to the A30 at Avers roundabout. This route has been agreed on the basis of minimising impact and traffic disruption to the local community.
?The project has been able to use the raceway car park of the United Downs Raceway operators, for the trucks to minimise congestion on the industrial estate and nearby roads.
?Everything should be off the site by about 20th July.
Now that drilling has finished the project is entering the third phase of the programme; evaluation.
Preliminary results from the drilling are promising. Both wells intersected the fault at the predicted depth and the temperature at the bottom of the deeper well is around 190C, which is also as expected. Downhole measurements have confirmed that there are lots of natural fractures and early indications are that the permeability is promising.
There now needs a series of measurements and hydraulic tests to be carried out to evaluate the fault structure, make sure the wells are in good condition, and evaluate the amount of geothermal energy we can sustainably harness from the system.
?This phase is expected to take from August until the end of March 2020.?
The first part of this work will be to remove a temporary downhole packer from UD-1, carry out some more downhole ‘logging’ measurements and attempt to collect some sidewall cores. It is expected that this happens in September.
Some of this work will require a small ‘workover’ drilling rig to be on site for 2 to 3 weeks to run equipment in and out of the well. This would be on a much smaller scale than the rig used for drilling and would only operate during the daytime.
Source: UDDGP
