Now that drilling has finished we are 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 190˚C, 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.
But we need to carry out a series of measurements and hydraulic tests 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.
We expect this work to be carried out during the first half of 2020.
Between December and February we will be constructing a water storage pond that will allow us to carry out further tests on our deep well UD-1. We need this facility to store water that we produce from the well so that it can be allowed to cool and analysed before either being reinjected or disposed of offsite.
Once the pond is complete we will mobilise a ‘workover’ drilling rig to the site in March to remove a temporary downhole packer from UD-1, carry out some more downhole ‘logging’ measurements, attempt to collect sidewall cores and carry out the production test.
The workover rig is much smaller than the one we used for drilling the wells; about half the mast height and less equipment on the ground, but it will still be worth seeing and we will hold a public drop-in session while it is here.
We will put further details on the website as our plans are developed.
The UDDGP team
The diagram above shows how deep the wells are after completion compared with the tallest building in the world and the deepest mine in Cornwall