Welcome to

Wilhelm Fenners Baugesellschaft mbH
in Neukirchen-Vluyn
Weserstraße 15-17
47506 Neukirchen-Vluyn

Email: info@fenners-bau.de

Tel.: +49 (0) 2845 - 96 60 - 0
Fax: +49 (0) 2845 - 96 60 - 60


Geothermal drilling/ geothermics

Stollenbau - die Lösung für den innerstädtischen Kanalisationstiefbau (Download PDF)

A new field of application for the construction firm Wilhelm Fenners is the creation of boreholes for geothermal probes.

The geothermal probes are needed for operating brine/water heat pumps. As opposed to horizontal surface collectors, vertical geothermal probes need less space and optimally use the energy available in the ground.

Besides pure drilling work, further ground work for laying lines to the building is carried out. The boreholes for the geothermal probes are created using a double-head drilling process with water flushing in a closed cycle without drilling fluid. This drilling method makes it possible to reach depths far in excess of 100m.

The entire length of the boreholes can be covered with pipes so that there is no problem with reaching the necessary final depth for the geothermal borehole and the geothermal probe can be integrated according to plan.

Even the most difficult geological conditions, such as rough gravel and rocks, can be broken through using special boring tools. The work is carried out in accordance with the W 120 certification of the German Association for Gas and Water (DVGW), VDI directive 4640 and other valid standards. Only factory-made and quality-controlled probes are used.

Once the probe is integrated, the annular space between the wall of the borehole and the geothermal probe is grouted with a filling compound with good heat conductivity. Once the geothermal probe is integrated and the grouting is finished, the probe is subjected to a final pressure test.

The operational procedure for installing the geothermal probe is

  • creation of the pipefitted borehole
  • integration of the probe
  • disassembly of the piping while grouting the borehole.



Doublehead drilling          
equipment for----------- geothermal drilling

Integration of the
geothermal probe


Waterproof drill cuttings

Geothermal energy      geothermal probe -----drilling before -----------integration