Seismic surveys
3D seismic surveys in autumn 2025
Before a final decision can be made about establishing a geological CO2 storage site in the Greenstore area, we need to collect much more detailed knowledge about the many layers of subsurface in the region
During the autumn of 2025, we will therefore carry out a comprehensive survey to produce detailed, three-dimensional images of the many geological layers down to a depth of 3,000 metres. Data from the surveys will show us whether the subsurface is as suitable for geological CO2 storage as GEUS and our own experienced geologists and geophysicists expect.
Detailed images of the many layers of the subsurface
Seismic surveying is a geophysical method used to map the structure of the subsurface by sending pressure waves into the ground – primarily using specialised vibration trucks. These trucks follow a planned route along public roads and, in some cases, on private land.
The pressure waves travel down through the ground and are reflected back at the boundaries between the individual geological layers. As the waves are reflected differently by layers such as clay, sandstone and limestone, we get a very accurate picture of the subsurface.
All data is collected and recorded by small wireless receiving devices, also called geophones, which are placed around the landscape in agreement with authorities and landowners. The purpose of the study is to get an accurate picture of the many different layers in the subsurface, which will be used to decide whether a safe geological CO2 storage facility can eventually be established in the area
Drilling three exploration wells
If the seismic surveys show promising results, the next step will be to establish three exploration wells over the next few years. The exploration wells will collect samples deep underground. The final location of the wells will be determined based on seismic data and in close co-operation with the authorities. First, a so-called drilling rig – a mobile structure – is set up to drill the first well. When the wells are no longer in use, they are securely closed and sealed.
Close dialogue with the authorities and the local community
We reamin in contact with the authorities throughout the entire project. It is the authorities who grant the permits and approve the underground investigations and test drilling work. We will also be in dialogue with the local community, inviting them to information meetings and open house events.
Frequently asked questions
A three-dimensional (3D) seismic survey maps the geological structures underground by sending vibrations into the ground, in this case from a truck with a vibrator attached. Small sensors, called geophones, are placed in the landscape and pick up the reflected signals from the subsurface. This signal is then converted into a detailed, three-dimensional image of the geological structures and the thickness of the layers. This allows us to assess whether the area is suitable for CO2 storage.
Data is analysed to identify the thickness, extent and geometry of porous sandstone layers where CO2 can be stored, as well as the overlying dense clay layers that will act as sealing layers. In addition, the study also maps the position and depth of any fractures
We have planned the routes carefully to minimise inconvenience to residents in the area. Buildings, infrastructure and sensitive areas are taken into account and work is only carried out during daylight hours to avoid unnecessary disturbance. During seismic surveys, low-frequency vibrations and some noise may occur, especially when the vibration trucks are in operation. If a vibration truck passes close to your home, you will briefly feel mild vibrations - typically only for 10-20 minutes. Before and during data collection, we will demonstrate the vehicles to citizens. Stay tuned to this page, where we will announce where and when this will take place.