Klauder wavelet removal before vibroseis deconvolution

Abstract

The spiking deconvolution of a field seismic trace requires that the seismic wavelet on the trace be minimum phase. On a dynamite trace, the component wavelets due to the effects of recording instruments, coupling, attenuation, ghosts, reverberations and other types of multiple reflection are minimum phase. The seismic wavelet is the convolution of the component wavelets. As a result, the seismic wavelet on a dynamite trace is minimum phase and thus can be removed by spiking deconvolution. However, on a correlated vibroseis trace, the seismic wavelet is the convolution of the zero‐phase Klauder wavelet with the component minimum‐phase wavelets. Thus the seismic wavelet occurring on a correlated vibroseis trace does not meet the minimum‐phase requirement necessary for spiking deconvolution, and the final result of deconvolution is less than optimal. Over the years, this problem has been investigated and various methods of correction have been introduced. In essence, the existing methods of vibroseis deconvolution make use of a correction that converts (on the correlated trace) the Klauder wavelet into its minimum‐phase counterpart. The seismic wavelet, which is the convolution of the minimum‐phase counterpart with the component minimum‐phase wavelets, is then removed by spiking deconvolution. This means that spiking deconvolution removes both the constructed minimum‐phase Klauder counterpart and the component minimum‐phase wavelets. Here, a new method is proposed: instead of being converted to minimum phase, the Klauder wavelet is removed directly. The spiking deconvolution can then proceed unimpeded as in the case of a dynamite record. These results also hold for gap predictive deconvolution because gap deconvolution is a special case of spiking deconvolution in which the deconvolved trace is smoothed by the front part of the minimum‐phase wavelet that was removed.