Analytical path-summation imaging of seismic diffractions

Reflection/diffraction separation

Diffraction amplitudes can be several orders of magnitude lower than those of reflections (Klem-Musatov, 1994). In order to highlight subtle diffractivity features a reflection/diffraction separation procedure has to be applied to the data. There is a variety of methods based on different separation techniques. Dell and Gajewski (2011); Tsingas et al. (2011); Bauer et al. (2015); Kanasewich and Phadke (1988); Landa and Keydar (1998); Berkovitch et al. (2009); Rad et al. (2014) employed optimal stacking of diffracted energy along diffraction travel-time curves. Papziner and Nick (1998); Taner et al. (2006); Reshef and Landa (2009); Fomel et al. (2007); Harlan et al. (1984); Klokov and Fomel (2012) decompose full-waveform seismic records into diffracted and reflected components, Kozlov et al. (2004); Koren and Ravve (2011); Popovici et al. (2015); Klokov and Fomel (2013); Sturzu et al. (2013); Moser and Howard (2008) modify a Kirchhoff migration kernel to eliminate specular energy coming from the first Fresnel zone and image diffractions only.

To perform reflection/diffraction separation we used plane-wave destruction filter (Fomel, 2002; Fomel et al., 2007) for both field data examples. For both examples reflections appear to be continuous and laterally consistent. This behavior aids PWD reflection's prediction along estimated local slopes followed by their subtraction from the stack.