The contribution of "NMO stretch" to the resolution of a formation image

What is it about?

For a given angular frequency, wave-number vector for the incoming and outgoing waves, taking the ratio of these two extrapolated wave fields gives a measure of the scattering potential at the scatterer at one single wave-number vector that is equal to the difference in the wavenumber between the two wavefields. This is the "kick" the wave field receive from the formation. To make estimates over a larger section of the 3D wavenumber space, one would need to increase the spatial range as well as the frequency range over which the data are acquired. The large scattering angle associated with forward scattering results in a low value for the wavenumber. This paper gives a practical discussion of these issues. Most commonly, the low-frequency effects associated with small wavenumber differences are referred to as "NMO stretch" and the "artifacts" reduced by applying far-offset mute to the data, thereby removing potentially valuable information about the low-frequency formation trends.

Featured Image