Common reflection point data-stacking technique for converted waves

Journal Article · Sat Oct 01 04:00:00 EDT 1988 · Geophys. Prospect.; (United States)

DOI:https://doi.org/10.1111/j.1365-2478.1988.tb02186.x· OSTI ID:6530059

Tessmer, G; Behle, A

For converted waves stacking requires a true common reflection point gather which, in this case, is also a common conversion point (CCP) gather. The authors consider converted waves of the PS- and SP-type in a stack of horizontal layers. The coordinates of the conversion points for waves of PS- or SP-type, respectively, in a single homogeneous layer are calculated as a function of the offset, the reflector depth and the velocity ratio ..nu../sub p//..nu../sub s/. Knowledge of the conversion points enables us to gather the seismic traces in a common conversion point (CCP) record. Numerical tests show that the CCP coordinates in a multilayered medium can be approximated by the equations given for a single layer. In practical applications, an a priori estimate of ..nu../sub p//..nu../sub s/ is required to obtain the CCP for a given reflector depth. A series expansion for the traveltime of converted waves as a function of the offset is presented. Numerical examples have been calculated for several truncations. For small offsets, a hyperbolic approximation can be used. For this, the rms velocity of converted waves is defined. A Dix-type formula, relating the product of the interval velocities of compressional and shear waves to the rms velocity of the converted waves, is presented.

• Research Organization: Institut fur Geophysik, Universitat Hamburg, Bundesstr. 55,2000 Hamburg 13 (DE)
• OSTI ID: 6530059
• Journal Information: Geophys. Prospect.; (United States), Journal Name: Geophys. Prospect.; (United States) Vol. 36:7; ISSN GPPRA
• Country of Publication: United States
• Language: English

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