Residual-moveout analysis in presence of strong lateral velocity anomalies

Conclusions

Strong lateral velocity anomalies are challenging for one-parameter residual-moveout analysis. The migrated ADCIGs may display complex moveouts that are not accurately described by a a one-parameter family of curves. Furthermore, when the residual velocity error is large enough, the moveout at far angles may be larger than the dominant wavelength, and thus stack-power spectra may display local maxima. The negative effects of these phenomena can be avoided by imaging only the low-frequency components of the data, when they are available. A more general solution is to smooth the stack-power function along the residual-moveout parameter axis.