Imaging-based Target Response Estimation Including Multiples and Transmission Effects

Abstract

Accurate estimation of the local reservoir responses - including the AVO information - is crucial for correctly estimating the elastic parameters from the target area. In this paper the estimation of the target reflection responses
is implemented as part of the full wavefield imaging algorithm that handles multiple scattering not only by suppressing undesired overburden imprints but also by using its information for obtaining a better estimate of the responses. The newly obtained inversion problem includes the two main components — full wavefield migration (FWM) of the overburden - yielding its reflectivity properties - combined with the estimation of the local reflection impulse responses of the target area located below. Both sets of parameters are included in the forward model and should simultaneously fit the observed surface data in the least-squares manner. The main advantage of this combined approach is that multiple scattering and transmission effects in the overburden are correctly accounted for, yielding high-quality target impulse responses. It is shown that estimating the responses in this manner is also suitable for the 3D case, where sparse acquisition geometries provide an additional challenge.