Seismic data high-signal-to-noise-ratio high-resolution time-frequency spectrum generation method

Abstract

The invention relates to a seismic data high-signal-to-noise-ratio high-resolution time-frequency spectrum generation method which is realized through multi-channel weighted synthesis along a stratuminclination angle and in a mode of constructing an adaptive mask filter. The method comprises the following steps: estimating an inclination angle of each time-space position on a seismic section; constructing a multi-channel weighted synthesis channel for each time position, and calculating an instantaneous autocorrelation function of the analysis signal of the multi-channel weighted synthesis channel; calculating standard Vivigneaux time-frequency distribution and corresponding Pingyuan-imaginary Vivigneaux distribution of standard Vivigneaux time-frequency distribution; constructing a time-frequency spectrum adaptive mask filter; and realizing mask filtering of standard Weiwei time-frequency distribution and obtaining an optimized seismic trace time-frequency spectrum. The method has the characteristics of high signal-to-noise ratio and high resolution, has the capability of eliminating cross interference, and has the advantage of clearly separating the spatial distribution of the sandstone reservoir from the spatial distribution of the coal-bearing seam system when the actual three-dimensional seismic data is used for reservoir prediction.

Description

technical field [0001] The invention relates to the field of geophysical signal analysis, in particular to a generation method of seismic data with high signal-to-noise ratio and high-resolution time-frequency spectrum. Background technique [0002] Time-spectrum analysis of seismic data is a key method for reservoir geophysics research. Intuitively, time-spectrum analysis is to generate corresponding frequency spectrum point by point for any single seismic trace according to its time sampling sequence, and it is to convert a one-dimensional seismic trace that changes with time into a two-dimensional "spectrum" that changes with time and frequency. ". This two-dimensional spectrum is called the time spectrum. [0003] The Wigner-Ville time-frequency distribution method is one of the effective methods for calculating the time-frequency spectrum of seismic traces. The realization process can be divided into three basic steps: calculating the analytical signal of the seismic...

AI Technical Summary

Problems solved by technology

However, the suppression processing in both the time direction and the frequency direction is essentially a low-pass filter, and its effect is to lose high-frequency components and reduce the resolution of the time-frequency spectrum.

[0005] Since the time-spectrum calculation method above is a single-trace analysis method, the generated time-spectrum is affected by the signal-to-noise ratio of seismic data. Difficulties are caused by the application of the interpretation of the frequency spectrum during earthquakes

[0006] Based on the above analysis, the standard Weiwei time spectrum has high resolution but has serious cross-interference, while the flat-virtual Weiwei time spectrum has suppressed cross-interference but the resolution is reduced. The signal-to-noise ratio of the generated seismic time-spectrum is poor, and it is seriously affected by the noise of seismic data, which makes it difficult for the application of time-frequency spectrum and geophysical interpretation

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