One property of attenuation and estimation of seismic attenuation from field data

Abstract

Estimation of attenuation of seismic waves is of practical importance because of two main reasons. The first, attenuation parameters of rocks may be used in geophysical interpretation. The other reason is that attenuation changes shape of seismic wavelet. To obtain a spike reflection trace this change should be eliminated, (e.g., by Q-deconvolution). Q-filters require an estimation of the attenuation. Attenuation can be accurately measured in the laboratory, but field estimations contain significant error (Tonn, 1991). High levels of noise, unknown velocity structure of a medium and non exact divergence correction are usually given as reasons for low quality of the field measurements. Investigation of one internal property of seismic attenuation, namely a value of a constant component of the attenuation coefficient, is a subject of this paper, It is shown that this value may be significant and, so, may result in considerable estimation error when spectral ratio technique, the most spread method to estimate seismic attenuation, is used.