Drilling - Geothermal probe

Hammer drilling

The drilling system is hammer drilling with a diameter of 140 mm.

After determining the drill starting point (well position), the drilling apparatus as well as the compressor and the drilling tools are placed and adjusted to the drill point.

Nach der erfolgreichen Justierung wird ein Standrohr (Verrohrung) gesetzt.

Following effective adjustment, a stand pipe (piping) is set.

Next, the drill hammer, which is positioned on a special leverage, is positioned in the borehole.

The drill hammer, or rather the bit crown (down most and first part), is fitted with industrial diamonds. Depending on soil type, different bit crowns are used.

After bolting, the compressor, which is attached to the drilling apparatus by a hose, gets activated.  

Power ratings range from 16 to 26 bar, depending on soil type.

Now, leverage and piping are rotated and compressed air is transmitted to the hole bottom.

The bit crowns have rinse ports for the compressed air. 

In the annulus between leverage and piping, the drill cuttings are conveyed to the surface.

Drilling, carried out with the hammer at the leverage, and with a hydraulic rotary table at the piping, takes place simultaneously until the ends of piping and leverage are reached. 

The leverage to which the hammer is fixed now gets unscrewed, and a new leverage and piping are attached.

This procedure gets repeated until the desired depth is reached.

During the drilling procedure the water-bearing formation is identified and recorded. In this area, the filter pipe will later be mounted.

Once the desired depth has been reached, the leverage (to which the drill hammer is attached) is dismantled.


Read more about the Construction of the Geothermal Probe.

Geothermal Drilling - Step 1Geothermal Drilling - Step 2Geothermal Drilling - Step 3Geothermal Drilling - Step 4Geothermal Drilling - Step 5