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Prediction of Shallow Gas from Seismic Data

  • Reidar Kanestrøm
  • Åshild Skålnes
  • Per Riste
  • Trond Eide
  • Sverre Strandenes
Conference paper
Part of the Advances in Underwater Technology, Ocean Science and Offshore Engineering book series (AUTOO, volume 25)

Abstract

Since prediction of shallow gas is essentially a prediction of pore fill, we have chosed to focus on seismic parameters which are significantly affected by a change in pore fill. These parameters are: Seismic velocity, attenuation, amplitude versus offset and seismic response. To study these parameters, different techniques are required, and in this paper we apply the techniques on real data for shallow gas prediction. If all the techniques described could be applied at the same site, the result should be a reliable prediction.

The attenuation of seismic energy is a promising parameter, but it requires that refracted waves are recorded.

The amplitude versus offset is expected to be a powerful prediction technique in the future, but at the present time more development is needed. This technique also has the potential of estimating the saturation under favourable conditions.

Single trace inversion is also a promising technique, and with further development and linked to velocity modelling it will become a powerful tool in shallow gas prediction.

Direct use of seismic velocities in shallow gas prediction requires refracted arrivals. These data are of special importance where no borehole data are available.

All techniques will benefit from borehole data, and they are absolutely necessary for a quantitative estimation of relevant parameters.

Keywords

Seismic Data Seismic Response Seismic Velocity Acoustic Impedance Seismic Energy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Berge, A.M., and Beskow, B. (1985). A method to determine the velocities in the seafloor and near-surface sediments, Geophysical Prospecting 33, 377–399.CrossRefGoogle Scholar
  2. Berge, A.M., Kanestreem, R. and Pedersen, L.M. (1983). Detailed seismic velocities in sediments along a 250 km profile in the Barents Sea, First Break 1, 8, 9–17.Google Scholar
  3. Frisillo, A.L. and Stewart, T.J.,(1980). Effect of partial gas/ brine saturations on ultrasonic absorption in sandstone, J.Geophys.Res. 85, 5209–5211.CrossRefGoogle Scholar
  4. Spencer, J.W.,Jr. (1979). Bulk and shear attenuation in Berea sandstone: The effects of pore fluids, J.Geophys. Res. 84, 7521–7523.Google Scholar
  5. Winkler, K., and Nur, A., (1979). Pore fluids and seismic attenuation in rocks, Geophys. Res. Litt. 6, 1–4.CrossRefGoogle Scholar

Copyright information

© Society for Underwater Technology 1990

Authors and Affiliations

  • Reidar Kanestrøm
    • 1
  • Åshild Skålnes
    • 1
  • Per Riste
    • 1
  • Trond Eide
    • 1
  • Sverre Strandenes
    • 1
  1. 1.Research CentreNorsk Hydro A/SBergenNorway

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