Seismic survey completed to assess the geothermal potential of the NRW region, Germany

Vibro trucks used for seismic survey of North Rhine Westphalia (source: DG NRW)

After 13 days of measurements, the seismic survey being conducted in the North Rhine-Westphalia (NRW) region in western Germany has been completed. Conducted by the Geological Survey of NRW and commissioned by the Ministry of Economic Affairs, the seismic survey was done to characterize the subsurface and identify formations that could be hosting geothermal resources.

For the past weeks, special trucks or “vibrotrucks” that emit sound waves underground drove around the study area. These sound waves were then reflected in varying values of intensity and speed depending on the characteristics of the subsurface. Geophones located on the surface collected data from the reflected waves. Measurements were made for every 40 meters over a total distance of 70 kilometers spanning across Viersen, Krefel, Dusseldorf, and Duisburg.

Along the route, the approximately 50-meter-long convoy was met with great interest. Private individuals came to see the measurements live and representatives from politics and business sector got an impression of how the investigation is conducted.

Project manager Ingo Schafer said that they are looking for two very specific layers of limestone that are likely to host hot water. It is yet unclear what depth these layers can be found, but they are assumed to be somewhere around 3500 meters. If the limestone layers are thick enough, they can be targets for test drilling and potentially provide geothermal energy for district heating networks.

More than 15 TB of geodata were collected from 1735 measurement points and 6948 geophone stations. This data will now be evaluated by geophysicists of the Geological Survey of NRW over the next ten months.

“Our results are then freely available to the public. If we find suitable rock formations for geothermal use, Municipalities or energy supply companies can build on it.” said Geological Survey of NRW Director Ulrich Pahlke.

Earlier this year, an “Alliance for Geothermal Energy” was formed by five municipal utility companies in NRW and Fraunhofer IEG. Part of the agenda of the alliance is to secure investments for geothermal plants and deal with the uncertainty of geothermal exploration.

Source: RP Online and WDR