Prestack V(z) f-k migration for P-P and P-S data

Xinxiang Li, Gary F. Margrave

Prestack V(z) f-k migration for P-P and P-S data

Xinxiang Li and Gary F. Margrave

V(z) f-k migration is a new f-k migration method based on non-stationary filter theory, which can handle the vertical velocity variation with at least the same accuracy as the phase-shift method. It retains the global wavefield mapping advantage of Stolt's method and properly accommodates the velocity variation. Instead of using a Fourier-domain complex-valued interpolation (as in Stolt's f-k method), V(z) f-k migration is formulated as a nonstationary filter, where the input for the filter is the f-k spectrum of the unmigrated seismic traces and the output is the spectrum of the migrated traces.

In this paper, the V(z) f-k migration is formulated for both P-P wave and P-S wave seismic data as a pre-stack migration method. In addition to some theory of the algorithm, the implementation detail is also presented.

The current implementation performs Fourier transform in CDP and offset dimensions. It only includes the migration up to 90 degrees, and the evanescent energy is ignored. Some application results of this new method to synthetic data and field data are shown.