Multiple wave matching attenuation method based on optimized phase axis tracking

Abstract

A multiple wave matching attenuation method based on optimized phase axis tracking belongs to the field of seismic multiple wave attenuation. The method comprises the following steps: firstly, giving the phase axis density Nm and the spectrum energy threshold E0; then applying a surface-related multiple prediction (SRMP) method to an original record to obtain a multiple wave record as an initial record; using optimized phase axis tracking technology and a short time window FK fan filtering method to iteratively extract and attenuate a multiple wave phase axis until the amplitude maximum of a residual multiple wave stacking velocity spectrum is less than E0; and thereby obtaining a primary wave record after multiple wave attenuation. The method carries out matching attenuation according to the direction of the multiple wave phase axis, is not affected by the predicted multiple wave signal amplitude difference and waveform change, can more or less overcome the defect that Wiener filtering methods are likely to damage a primary signal, and can significantly improve the attenuation effect of far-offset channel multiple wave signals.

Description

technical field [0001] The invention belongs to the field of seismic multiple wave suppression, in particular to a multiple wave matching attenuation method based on event optimization tracking. Background technique [0002] Most of the multiples in marine seismic data are free interface multiples related to the sea surface, and the accuracy of their elimination determines the authenticity and reliability of subsequent seismic imaging. Since multiple wave components in seismic records can be effectively eliminated without any prior information, the surface-related multiple wave attenuation method (Surface-related Multiple Elimination, SRME) has become the mainstream technology for multiple wave suppression in current production means. The SRME method includes two steps: multiple wave prediction and multiple wave matching attenuation. First, the multiple wave components in the seismic record are predicted based on the "feedback loop" theory, and then various multiple wave co...

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Problems solved by technology

[0004] However, in the actual data processing, due to the limitation of the Kirchhoff integral aperture, the two-dimensional side reflection effect, the field observation error and the inability to obtain the accurate free interface factor, the predicted multiples exist in the propagation time and signal waveform. certain difference (especially in the long-offset trace), which leads to the failure of the traditional multiple wave matching attenuation method

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