Method and device for extracting hybrid-phase seismic wavelets

Abstract

The embodiment of the invention provides a method and device for extracting hybrid-phase seismic wavelets, wherein the method comprises the following steps of: calculating fourth-order cumulants of seismic data; smoothing the fourth-order cumulants of the seismic data by using three-dimensional hysteretic window functions and estimating three spectrums of the seismic wavelets; and extracting the hybrid-phase seismic wavelets by using the three spectrums of the seismic wavelets. With the embodiment of the invention, the estimation precisions of high-order spectrums and wavelets can be improved.

Description

technical field [0001] The invention relates to the field of petroleum geophysical exploration, in particular to a method and a device for extracting mixed-phase seismic wavelets by using three spectra of seismic records. Background technique [0002] In seismic forward modeling, conventional inversion and seismic deconvolution methods, it is necessary to use seismic wavelets directly or indirectly. In the seismic forward modeling problem, it is necessary to use the wave equation or convolution model, combined with the seismic wavelet forward modeling to form a seismic numerical simulation record; in the inversion and deconvolution problems, it is also necessary to estimate the wavelet through seismic data, and the seismic wavelet The extraction accuracy has a great influence on the final inversion result. [0003] Seismic wavelet estimation methods can be divided into two categories, one is deterministic method and the other is statistical method. At present, the determin...

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Problems solved by technology

However, the steepest descent method has two disadvantages as a linear fitting method: the final result is greatly affected by the given initial value, and has a tendency to be similar to the initial value; the result may fall into a local extremum, if the initial value is given inappropriately , the result may have a large error

[0006] In order to reduce the error, Velis and Ulryc proposed a nonlinear fitting method, that is, the simulated annealing method, which can effectively avoid the possibility of the result falling into a local minimum, but the simulated annealing algorithm also has its own shortcomings, such as the control parameter The selection is difficult and the calculation time is long

[0007] Therefore, in the process of realizing the present invention, the inventor found that the defect of the prior art is: in the case of non-minimum phase of the seismic wavelet, the second-order statistical method is often not applicable; The phase information of the seismic wavelet is sensitive, so the high-order spectrum method can be used to realize the estimation of the mixed-phase seismic wavelet. However, the result of the wavelet estimation is often affected by the accuracy of the high-order spectrum estimation, and the accuracy of the spectrum estimation is not high.

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