Composite wave separation method for moveout correction

Abstract

The invention discloses a moveout correction-oriented superposed wave separating method. The moveout correction-oriented superposed wave separating method comprises steps that seismic data is analyzed, and a standard channel is selected reasonably; a cross correlation coefficient of a to-be-separated channel and the standard channel is calculated, and at the same time, a time window slides, and the waveform of the to-be-separated channel and the waveform of the standard channel are basically identical to each other, and the amplitude ratio of the to-be-separated channel and the standard channel is calculated; the product of the standard and the amplitude ratio is subtracted from the to-be-separated channel, and therefore influences of waveform data in a first time window are stripped; by adopting the same idea, other seismic waves are stripped iteratively, and then the superposed wave separation is realized, and the separated waves are combined together according to the corresponding moveout; and finally the seismic data after the waveform separation is output. Defects of conventional moveout correction methods are overcome, and the superposed wave separation is realized, and therefore dynamic correction tension effect is eliminated, and event flattening quality is high.

Description

technical field [0001] The invention relates to the field of seismic data processing, in particular to a composite wave separation method capable of realizing seismic wave time difference correction. Background technique [0002] The time difference correction of seismic data, also known as motion correction, is one of the basic contents of seismic data processing. Its function is to eliminate the influence of offset on the propagation time of reflected seismic waves and to alias together far offsets. Waveforms are separated to level the reflected wave events in the CMP gather. Whether the aliasing waves can be separated correctly will directly affect the quality of subsequent processing such as migration imaging. Conventional correction methods have problems such as unbalanced events and large offset stretching distortion, and the effect is particularly poor for seismic traces where waveforms are aliased and interfered together. [0003] The time-distance equation of the ...

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Problems solved by technology

[0010] The method of dynamic correction or eliminating the residual time difference of dynamic correction can make the event axis level, but still can not eliminate the waveform distortion

This kind of waveform distortion caused by time difference correction usually occurs in shallow layers and large offsets. The specific performance is that the waveform is elongated, the frequency is lowered, and when the events interfere with each other, the waveforms are mixed together, and the correction quality is more difficult to guarantee.

In conventional seismic data processing, the data stretched beyond a certain ratio is usually cut off, so that the seismic data at the shallow and far-offset distances are mostly cut off due to severe stretching, resulting in a reduction in the number of coverages and cannot be well utilized

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