The Approach to the Inversion Process in Reflection Seismics

Abstract

The seismogram generated by plane waves falling vertically on a stack of plane parallel layers can be expressed in terms of the sequence of the reflection coefficients corresponding to the interfaces between individual layers. The reflection coefficients can be expressed through the wave impedances, which are parameters characterizing the layers and are related to the elastic constants and the density (and thus also to the velocity) of the layers. A first approximation to the synthetic seismogram is the convolution of the input pulse with the sequence of reflection coefficients. In this approximation, only the simple wave path (surface — reflector — surface) is taken into account. Internal multiples (“reverberants”) can be taken into account by algorithms such as that described by the “Burg ladder”.