Exploratory drilling for the Haute-Sorne geothermal project began on 21 May.

The end of the first section was reached at a depth of 500 metres on 27 May. The work proceeded according to plan and no problems were encountered during the drilling of this section, with no loss of drilling mud or water ingress.

It took a week to carry out the measurements (logs), casing and cementing of this section in order to isolate it from the surrounding rock and the next section. The seal was verified by means of hydraulic tests.

During the first week of drilling, neighbours reported being intermittently disturbed by a low-frequency rumble. Adjustments were made immediately and additional noise barriers were installed. Although compliance with standards has been demonstrated, investigations are continuing to further reduce noise emissions.

Drilling of the second section resumed on 3 June. In the space of a week, the drilling penetrated all the sedimentary rock layers of the Secondary (Mesozoic) era to a depth of approximately 1,500 metres. No geological difficulties were encountered and drilling is currently continuing through older sediments (Permian) down to the crystalline basement. Drilling will then be suspended for around ten days to carry out logging operations, followed by casing and cementing the section.

The final depth of the borehole is 4,000 metres, with the project expected to take a total of three to four months.

Regular updates on the progress of the work will be published on this blog.