Near-surface seismic experiments as part of an integrated approach were carried out in October 2010 and in June 2012 on Bornholm, Denmark, with the aim to study seismic properties of gas shales. Several combined reflection and refraction seismic profiles were conducted in the range of borehole locations. Downhole logging data was used to calibrate the seismic data. Additionally, geoelectric measurements at selected profiles, ambient noise seismic recordings covering a larger area, and laboratory analyses of core material were carried out. We applied tomographic methods to determine basic seismic properties including P-wave velocities, P-wave/S-wave velocity ratios, and attenuation. We will investigate the influence of reservoir and rock physical parameter variations on different seismic attributes at different scales and the relation to other geophysical parameters.

Time Frame

• 10/2010 - 06/2012

Funding

• Industry

Personnel

• Maria Baumann-Wilke (GFZ Potsdam)

Cooperations

• Geological Survey of Denmark and Greenland GEUS
• Niels Schovsbo (GEUS)
• Erik Spangenberg (GFZ Potsdam)

Methods & Equipment

• Geometrics Geodes, DSS-Cubes, accelerated weight drop, GEOSYM mini-vibrator ElViS, GEOTOM multi-electrode system
• Traveltime tomography, reflection seismics, surface wave inversion, electrical resistance tomography

Publications/Results

• Baumann-Wilke, M., Bauer, K., Schovsbo, N. H., Stiller, M. (2012): P-wave traveltime tomography for a seismic characterization of black shales at shallow depth on Bornholm, Denmark. Geophysics, Vol. 77, No. 5

Acknowledgement

The project is funded by the GASH consortium. Seismic instruments were provided by the Geophysical Instrument Pool Potsdam (GIPP). Communication with land owners, permitting and other logistic tasks were kindly organized by Niels Schovsbo and Arne T. Nielsen (GEUS Copenhagen). Furthermore we could rely on the extensive geological background knowledge of our GEUS partners. Special thanks goes to all colleagues who were involved in the field campaigns in 2010 and 2012:

• Karl Otto
• Kevin Bogott
• Klaus Bauer
• Manfred Stiller
• Manuel Amberger
• Maria Baumann-Wilke
• Mike Hönig
• Thomas Haberlau