阅读说明：本技术 一种地震原始数据信噪比定量分析评价方法 (Quantitative analysis and evaluation method for signal-to-noise ratio of seismic original data ) 是由 吴吉忠 柳波 谢奋全 赵小青 贾文娟 吴吉厚 于 2019-10-13 设计创作，主要内容包括：本发明涉及的是一种地震原始数据信噪比定量分析评价方法,它包括:一是求取炮域地震原始数据20-40Hz频带范围内的信息能量；二是求取炮域地震原始数据0-10Hz频带范围内的信息能量；三是求取炮域地震原始数据150Hz以上频带范围内的信息能量；四是定量求取低频信噪比与高频信噪比,并计算相应的数学期望与离散度；五是基于上述数据开展地震原始数据信噪比定量分析评价。本发明能够在空间平面上描述地震原始数据有效信号与噪声的分布及发育情况,可以定量的对地震原始数据信噪比开展分析与评价,为后续地震数据去噪处理提供参考,为地震原始数据品质评价提供了一种定量手段,本发明对油气、矿产资源勘探具有重要应用价值。(The invention relates to a quantitative analysis and evaluation method for the signal-to-noise ratio of seismic original data, which comprises the following steps of firstly, obtaining the information energy of the seismic original data in a shot domain within the frequency band range of 20-40 Hz; secondly, information energy in the frequency band range of 0-10Hz of the original seismic data of the shot domain is obtained; thirdly, solving the information energy in the frequency band range of the original seismic data of the shot domain above 150 Hz; fourthly, quantitatively calculating a low-frequency signal-to-noise ratio and a high-frequency signal-to-noise ratio, and calculating corresponding mathematical expectation and dispersion; fifthly, carrying out signal-to-noise ratio quantitative analysis and evaluation on the seismic original data based on the data. The method can describe the distribution and development conditions of effective signals and noise of the seismic original data on a spatial plane, can quantitatively analyze and evaluate the signal-to-noise ratio of the seismic original data, provides a reference for the subsequent denoising processing of the seismic data, provides a quantitative means for the quality evaluation of the seismic original data, and has important application value for the exploration of oil gas and mineral resources.)

1. A quantitative analysis and evaluation method for the signal-to-noise ratio of seismic raw data is characterized by comprising the following steps:

acquiring full-work area shot region data, and solving calculation parameters;

step two, solving the information energy in the frequency band range of 20-40Hz from the original seismic data of the shot domain;

① for shot coordinates (x, y)Recording shot gathers, calculating the root mean square amplitude value of all seismic data in the frequency band range of 20-40Hz in the energy calculation time window range, accumulating and summing, and recording the final sum value as E₀Then the information energy recorded in the 20-40Hz frequency band by the shot gather at the shot point coordinate of (x, y) is E₀/N_xy；

② repeating step ① for other shot sets in the work area to obtain the information energy plane distribution map (x, y, E) recorded in the 20-40Hz frequency band by the shot set in the work area₀/N_xy)；

Thirdly, solving information energy in a frequency band range of 0-10Hz from the original seismic data of the shot domain;

① for shot gather record with shot point coordinate of (x, y), calculating the root mean square amplitude of all seismic data in the frequency band of 0-10Hz in the energy calculation time window range, accumulating and summing, and recording the final sum as E₁Then the information energy recorded in the frequency band range of 0-10Hz by the shot gather at the shot point coordinate of (x, y) is E₁/N_xy；

② repeating step ① for other shot sets in the work area to obtain the information energy plane distribution map (x, y, E) recorded in the frequency band range of 0-10Hz in the shot set of the whole work area₁/N_xy)；

Step four, solving the information energy of the frequency band range above 150Hz from the original seismic data of the shot domain;

① for shot gather record with shot point coordinate of (x, y), calculating root mean square amplitude value of all seismic data in frequency band range above 150Hz in energy calculation time window range, accumulating and summing, and recording the final sum value as E₂Then the information energy recorded in the frequency band range above 150Hz by the shot gather at the shot point coordinate of (x, y) is E₂/N_xy；

② repeating step ① for other shot sets in the work area to obtain information energy plane distribution diagram (x, y, E) of the shot set in the work area recorded in the frequency band range above 150Hz₂/N_xy)；

Step five, quantitatively solving a low-frequency signal-to-noise ratio and a high-frequency signal-to-noise ratio, and calculating corresponding mathematical expectation and dispersion;

① low frequency SNR sn_low(x,y)＝(x,y,E₀/N_xy)/(x,y,E₁/N_xy)；

② high frequency SNR sn_high(x,y,)＝(x,y,E₀/N_xy)/(x,y,E₂/N_xy)；

Mathematical expectation and dispersion for low frequency signal to noise ratio:

① mathematical expectation

② dispersion

Mathematical expectation and dispersion for high frequency signal to noise ratio:

① mathematical expectation

② dispersion

And sixthly, carrying out signal-to-noise ratio quantitative analysis and evaluation on the seismic original data based on the data.

2. The method for quantitative analysis and evaluation of signal-to-noise ratio of seismic raw data according to claim 1, characterized in that: the first step is specifically as follows:

① for shot gather records with shot point coordinate of (x, y), the number of the records is N_xy；

② selecting energy calculation time window, wherein the start time of the time window should be later than the occurrence time of first arrival wave of shot gather, and the end time of the time window is set to 3 s;

③ statistics of the total work area cannon collection number N_shot。

The technical field is as follows:

the invention relates to the technical field of reflection seismic data processing in seismic exploration, in particular to a quantitative analysis and evaluation method for a signal-to-noise ratio of seismic raw data.

Background art:

the signal-to-noise ratio of the seismic data is an important evaluation index in the seismic data processing process, and the quality of the seismic data is directly influenced by the level of the signal-to-noise ratio. At present, a plurality of methods for solving the signal-to-noise ratio of seismic data are available in the industry, but the methods are developed based on two-dimensional seismic section data, so that the effective information of seismic data in a whole work area and the distribution and development conditions of high and low frequency noise cannot be macroscopically provided, and the research on the signal-to-noise ratio quantitative analysis and evaluation method based on three-dimensional seismic original data is less.

The invention content is as follows:

the invention aims to provide a quantitative analysis and evaluation method for the signal-to-noise ratio of seismic original data, which is used for solving the problem that effective information of seismic data in a whole work area and distribution and development conditions of high and low frequency noise cannot be macroscopically given based on the signal-to-noise ratio of the seismic data obtained by two-dimensional seismic profile data.

The technical scheme adopted by the invention for solving the technical problems is as follows: the method for quantitatively analyzing and evaluating the signal-to-noise ratio of the seismic original data comprises the following steps:

acquiring full-work area shot region data, and solving calculation parameters;

step two, solving the information energy in the frequency band range of 20-40Hz from the original seismic data of the shot domain;

① for shot gather record with shot point coordinate of (x, y), calculating the root mean square amplitude of all seismic data in the frequency band of 20-40Hz in the energy calculation time window range, accumulating and summing, and recording the final sum as E₀Then the information energy recorded in the 20-40Hz frequency band by the shot gather at the shot point coordinate of (x, y) is E₀/N_xy；

② pairsRepeating the step ① for other shot gathers in the work area to obtain the information energy plane distribution diagram (x, y, E) recorded in the 20-40Hz frequency band range of the shot gather in the whole work area₀/N_xy)；

Thirdly, solving information energy in a frequency band range of 0-10Hz from the original seismic data of the shot domain;

① for shot gather record with shot point coordinate of (x, y), calculating the root mean square amplitude of all seismic data in the frequency band of 0-10Hz in the energy calculation time window range, accumulating and summing, and recording the final sum as E₁Then the information energy recorded in the frequency band range of 0-10Hz by the shot gather at the shot point coordinate of (x, y) is E₁/N_xy；

② repeating step ① for other shot sets in the work area to obtain the information energy plane distribution map (x, y, E) recorded in the frequency band range of 0-10Hz in the shot set of the whole work area₁/N_xy)；

Step four, solving the information energy of the frequency band range above 150Hz from the original seismic data of the shot domain;

① for shot gather record with shot point coordinate of (x, y), calculating root mean square amplitude value of all seismic data in frequency band range above 150Hz in energy calculation time window range, accumulating and summing, and recording the final sum value as E₂Then the information energy recorded in the frequency band range above 150Hz by the shot gather at the shot point coordinate of (x, y) is E₂/N_xy；

② repeating step ① for other shot sets in the work area to obtain information energy plane distribution diagram (x, y, E) of the shot set in the work area recorded in the frequency band range above 150Hz₂/N_xy)；

Step five, quantitatively solving a low-frequency signal-to-noise ratio and a high-frequency signal-to-noise ratio, and calculating corresponding mathematical expectation and dispersion;

① low frequency SNR sn_low(x,y)＝(x,y,E₀/N_xy)/(x,y,E₁/N_xy)；

② high frequency SNR sn_high(x,y,)＝(x,y,E₀/N_xy)/(x,y,E₂/N_xy)；

Mathematical expectation and dispersion for low frequency signal to noise ratio:

① mathematical expectation

② dispersion

Mathematical expectation and dispersion for high frequency signal to noise ratio:

① mathematical expectation

② dispersion

And sixthly, carrying out signal-to-noise ratio quantitative analysis and evaluation on the seismic original data based on the data.

The first step in the scheme is specifically as follows:

① for shot gather records with shot point coordinate of (x, y), the number of the records is N_xy；

② selecting energy calculation time window, wherein the start time of the time window should be later than the occurrence time of first arrival wave of shot gather, and the end time of the time window is set to 3 s;

③ statistics of the total work area cannon collection number N_shot。

The invention has the following beneficial effects:

1. the method can describe the distribution and development conditions of effective signals and noise of the seismic original data on a spatial plane;

2. the method can quantitatively analyze and evaluate the signal-to-noise ratio of the seismic original data;

3. the method provides reference for subsequent denoising processing of seismic data, and provides a quantitative means for quality evaluation of seismic original data.

Drawings

FIG. 1 is a 20-40Hz frequency band range information energy plane diagram of seismic raw data.

FIG. 2 is a 0-10Hz frequency band range information energy plane diagram of seismic raw data.

FIG. 3 is a diagram of an energy plane of seismic raw data over a frequency band of 150 Hz.

Fig. 4 is a plan view of a low frequency signal-to-noise ratio.

Fig. 5 is a high frequency signal-to-noise ratio plan.

Detailed Description

The invention is further illustrated below: