Method and device for estimating film thickness based on even function seismic response

Abstract

The invention provides a method for estimating film thickness based on an even function seismic response. The method comprises the steps of carrying out 90-degree phase shifting on a zero-phase odd function seismic response to form the even function seismic response, carrying out matching pursuit time-frequency analysis on the even function seismic response to obtain a peak amplitude and peak frequency, and estimating the film thickness through the combination of the peak amplitude and peak frequency. A device with the method used comprises a preprocessing module used for carrying out 90-degree phase shifting on the zero-phase odd function seismic response to form the even function seismic response, a matching pursuit time-frequency analysis module used for carrying out analysis on the even function seismic response to obtain the peak amplitude and peak frequency, and a film thickness obtaining module used for estimating the film thickness through the combination of the peak amplitude and peak frequency. According to the method and device for estimating the film thickness based on the even function seismic response, the equivalence between 90-degree phase shifting and film odd-even relation conversion is verified, the advantage of an even function on film thickness estimation is determined, and prediction of the film thickness is facilitated through the combination of the peak amplitude and peak frequency.

Description

technical field [0001] The invention relates to a geophysical prospecting method, in particular to a method and a device for estimating the thickness of a thin layer based on an even function seismic response. Background technique [0002] Prediction of thin bed thickness is an important research topic in seismic exploration nowadays. At this stage, it is mainly divided into time domain estimation method, frequency domain estimation method and attribute comprehensive prediction method; the time domain estimation method is usually limited by the formation thickness less than a quarter of the wavelength; the frequency domain estimation method must know the top-to-bottom reflection coefficient ratio, It is difficult to apply in practice; the seismic attributes related to thin layers are very rare in practice, which also limits the application of attribute comprehensive prediction method. [0003] Quantitative prediction of thin bed thickness is one of the difficulties in seism...

AI Technical Summary

Problems solved by technology

Zheng Xiaodong et al. derived the theoretical relationship expression between seismic peak frequency and thickness based on the three-layer double-interface thin-layer model, but the ratio of top-to-bottom reflection coefficients needs to be known, and the template is a cluster of curves, which is difficult to apply in practice

The third category is the attribute comprehensive prediction method. The basic idea is that there is a nonlinear relationship between the seismic attribute parameters and the thickness of the thin layer, and the optimized nonlinear inversion algorithm can be used to predict the thickness of the thin layer. In practice, the seismic attributes related to the thin layer are very close Rare, which also limits the application of this method

[0004] We may not be able to completely overcome the difficulty of prediction based on thin layer thickness at this stage, but under certain conditions, it is hoped that this problem can be solved quantitatively

We know that although the widess wedge model is very ideal, it is suitable for the ubiquitous reservoir-cap configuration where sandstone or thin interbedded sandstone is separated by a large set of mudstone

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