Borehole drilling has been progressing steadily. Yesterday evening the drillers had reached a depth of 70 metres. A thick sequence of sandstone underlies the surface, and we are now drilling into siltstones, mudstones and cementstones.
In the video below you can see the drillers changing over the core barrel after it has drilled out a core of sediment that is 3 metres long. A new core barrel is then attached and drilling of the next core continues.
In the photo below you can see the core in boxes once it has come out of the core barrel. Each box is 1.5 metres long, and contains a core of rock, with the exact depth it came from recorded. On site the team record the rock type of the core and note any changes in its properties. The core is encased in a thin plastic liner during drilling to stop the core expanding due to pressure release. Once we have finished coring we will examine the properties of the rock in situ down the hole by using petrophysics (rock physics) techniques – I will explain what these are in a future post.
I am looking forward to examining the core on site when I visit in two weeks’ time.
Keep following for further updates on the drilling!
Until next timeCarys