Seismic source wavelet estimation and the random reflectivity assumption

Ayon Kumar Dey, Laurence R. Lines

In the February 1991 issue of GEOPHYSICS, Anton Ziolkowski gives a scathing criticism of statistical wavelet estimation methods. Among other points, Ziolkowski questions the validity of the randomness assumption. This assumption allows statistical methods to estimate the seismic source wavelet autocorrelation from the seismic trace autocorrelation. In this study, we examine this traditional assumption of a random reflectivity sequence. The validity of this assumption is examined by using well-log synthetic seismograms and by using a procedure for evaluating the resulting deconvolutions. With real data, we compare our wavelet estimations with the in-situ recording of the wavelet from a vertical seismic profile (VSP). As a result of our examination of the randomness assumption, we present a fairly simple test that can be used to evaluate the validity of a randomness assumption.