A practical field test was carried out by the Institute of Drilling Technology and Fluid Mining (IBF) behind the Otto Meißer Building at TU Bergakademie Freiberg. The aim was to operate a scientific drilling rig under real operating conditions and to test new sensor and measurement technologies. The data obtained in the field test is now being analysed. The trial was carried out in cooperation with Bohrmaus GmbH from Bobritzsch-Hilbersdorf, a long-standing industrial partner of the university, which contributes its practical experience from the drilling and geothermal environment.
As part of the field test, two boreholes were drilled to a depth of around 50 metres for the Institute of Hydrogeology. They are part of a scientific measuring field in which temperature and other environmental sensors will be installed in the future. At the same time, the IBF used the deployment to test new measurement systems for recording vibrations, oscillations and dynamic process variables on the drilling rig.
Dr Thomas Zinke, research associate at the institute, explained:
"We are using this deployment to test our sensor technology in the ERDF/SAB SMART-Drilling project under real conditions - especially during percussive drilling in Freiberg gneiss. This creates vibrations, the propagation of which we analyse in detail in the soil and on construction elements."
The measurements are also connected to the BMBF project ThermoSENS, which is coordinated by TUBAF. At the hydrogeological test site, a team led by Prof. Dr Traugott Scheytt is researching the use of thermosensitive tracers to characterise geothermal reservoirs more precisely in future.
3D acceleration sensors were installed on the drilling rig for this purpose; geophones were also used in the surrounding area to record wave propagation underground. The data obtained will help to develop algorithms that will recognise critical vibration conditions at an early stage in the future. "Especially in the field of near-surface geothermal energy, it is important to be able to carry out drilling safely - even in built-up areas," says Zinke. The further development of such sensor and control systems is seen as a key contribution to the future viability of geothermal energy. While drilling work in new-build areas is usually uncritical, retrofitted heat pumps in existing residential areas place higher demands on process monitoring.
