Comparison of Shot-based Image-domain Tomography Approaches - DSO, Penalized Image Local-correlations, and Image-warping
F. Perrone and P. Sava
Event name: 76th EAGE Conference and Exhibition 2014
Session: Tomography - Theory
Publication date: 16 June 2014
Info: Extended abstract, PDF ( 766.78Kb )
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Imaging changes of physical parameters in the subsurface requires an estimate of the long wavelength component of the same parameters in order to reconstruct the kinematics of the waves propagating in the subsurface. The model is unknown and must be estimated from the same data. One can try to reconstruct the model by matching the recorded data with simulated waveforms extrapolated in a trial model. Alternatively, also assuming a trial model, one can obtain a set of images of the reflectors from a number of seismic experiments and match the locations of the imaged interfaces. Apparent displacements between migrated images contain information about the velocity model and can be used for velocity analysis. We derive an image-domain wavefield tomography procedure using the displacement vectors obtained by image warping. Our objective function is related to the known image difference objective function by a Taylor series expansion of the warped images with respect to the warping vectors. Image warping allows us to effectively perform phase unwrapping in the image domain, thus making shot-based migration velocity analysis more robust against cycle skipping.