The use of conventional pre-stack depth migration is unable to fully resolve short-wavelength velocity anomalies below rugose sea floors often causing severe imaging problems and limiting depth conversion and amplitude interpretation. Improved imaging can be achieved by initiating tomography using a velocity model built by combining geomechanics with rock physics appropriate for shallow carbonates and mudrocks.

Development of a new geomechanical PSDM approach was undertaken by Karoon Energy, in collaboration with the University of Melbourne, Gondwana Geoscience, Intrepid Geophysics and Paradigm Geophysical (link to conference paper). QIntegral are now able to offer this method as a service using our Quiacito™ software.

The method is likely to prove an important precursor for full-waveform inversion (FWI) because it has the potential to accurately model the missing low frequencies in marine seismic that are normally guessed during standard FWI. Geomechanical effects on seismic velocities should be expected along the shelf-slope break for most basins in the world, in salt-basins, and in areas where carbonate reefs exist at or near the sea floor.

 

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