Conclusions

Multiple reflections often occur in land data, in particular in areas with layer-cake geology and strong acoustic impedance contrast between adjacent layers in the subsurface. The fact that these multiples tend not to be periodic makes them difficult to identify in the stacked section and can lead to the erroneous conclusion that there are no multiples. The Parabolic Radon Transform can be used to suppress the multiples if their difference in moveout with respect to the primaries is large enough (as usually happens). Suppressing the multiples is a requirement for any faithful interpretation of the seismic data.

The suppression of the multiples not only helps to identify the primaries, but also allows a better selection of the stacking velocities for the primaries, in that way improving the quality of the primary reflections themselves.

Multiples are a problem not limited to marine data. Multiples can be as severe a problem with land data, especially since they are more difficult to identify and hence are more likely to be mistaken as primaries.