We present a robust nonlinear traveltime inversion procedure that enables fast iterative 3D depth velocity model reconstruction. It is based on automatic grid reflection traveltime tomography. To obtain input data necessary for inversion (traveltimes of reflected waves), we utilize conventional seismic time processing products such as normal-moveout velocities and a set of time-migrated reflection horizons picked in the final prestack time migration image. Ray-based tomographic inversion fits prestack traveltimes. They are approximated by hyperbolae using the developed effective engine of grid reflection tomography. We prove the effectiveness of the proposed approach numerically using a real-life example.
Traveltime tomography, inverse problem, time migration, depth migration, seismic exploration.
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