In seismic reflection surveying, by recording both pressure and shear-wave reflections, one can increase the amount of information obtained about the subsurface rather than by re-cording pressure waves alone. Geologic structures that are not visible by using conventional pressure-data may possibly be imaged using shear waves, thus mitigating the risk in oil and gas exploration and production. Horizontally layered sedimentary rocks exhibit anisotropy that can be approximat-ed by an effective transverse isotropic medium with a vertical axis of symmetry. Taking into account a vertically transverse isotropic earth, we derive phase-slowness expressions for quasi-P and quasi-SV waves that are used in a one-way wave-equation migration scheme. We derive simplified slowness-expressions that are useful for processing of conventional pressure data. Numerical examples demonstrate that the slowness approximations are valid for wide-angle propaga-tion, and the resulting one-way propagators are validated on a series of synthetic tests and applied on a field ocean-bottom seismic data set. The results show that the method accurately images both compressional and converted waves in OBS data over a vertically transverse isotropic medium.
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