CN-122018039-A - Three-component data processing system and method for vector seismic source directivity evaluation

CN122018039ACN 122018039 ACN122018039 ACN 122018039ACN-122018039-A

Abstract

The invention discloses a three-component data processing system and method for evaluating the directivity of a vector seismic source, wherein the three-component data processing system comprises the vector seismic source, a multi-station three-component detector array, a synchronous acquisition unit and a data processing terminal, wherein the vector seismic source is used for exciting seismic waves with corresponding directions under different excitation direction working conditions, the multi-station three-component detector array is distributed around the vector seismic source according to preset directions to form an equidistant circumferential observation system, the synchronous acquisition unit is used for synchronously controlling the time sequence of acquiring data by the multi-station three-component detector array when the vector seismic source is under each working condition, and the data processing terminal is used for carrying out directivity evaluation calculation on the three-component seismic data acquired by the multi-station under different excitation direction working conditions and outputting evaluation results. Through the process, on the premise of ensuring full utilization of three-component data of multiple stations, the non-directional factor interference can be restrained, the directional intensity and the dominant excitation direction of the vector seismic source can be objectively quantized, and data support is provided for subsequent use.

Inventors

WANG BO
XU ZIQIANG
ZHU HAOTIAN
ZUO YUANBIN
WANG NAICHUAN
Bo Longfei
XIE LIUJUN
Xin Guoxu
SU YUBIN
ZENG LINFENG
Shen Sihongren
DU TAOTAO
She Zilong

Assignees

中国矿业大学
深地科学与工程云龙湖实验室

Dates

Publication Date: 20260512
Application Date: 20260123

Claims (10)

1. The three-component data processing system for vector source directivity evaluation is characterized by comprising a vector source, a multi-station three-component detector array, a synchronous acquisition unit and a data processing terminal; The vector seismic source is used for exciting seismic waves with corresponding directions under the working conditions of different excitation directions; The multi-station three-component detector array is distributed around the vector seismic source according to a preset azimuth to form an equidistant annular observation system; the synchronous acquisition unit is used for synchronously controlling the time sequence of data acquisition of the multi-station three-component detector array and outputting a unified time reference when the vector seismic source is in each excitation direction working condition; The data processing terminal is used for carrying out directivity evaluation calculation on three-component seismic data collected by a plurality of stations under different excitation direction working conditions and outputting an evaluation result.
2. The three-component data processing system for vector source directivity evaluation according to claim 1, wherein the data processing terminal comprises a preprocessing module, a coordinate rotation module, a time window determining module, a time-frequency energy analysis module, a multi-band feature extraction module, a station consistency correction module, a loop normalization module, a reference condition background suppression module, an abnormal station identification and robust statistics module, a directivity function fitting module, a directivity index and confidence assessment module and a visual output module, wherein the preprocessing module is used for preprocessing three-component waveforms, the coordinate rotation module is used for rotating three-component seismic data acquired by each station from instrument coordinates to radial-tangential-vertical coordinates, the time window determining module is used for determining an effective wave field window required by directivity evaluation, the time-frequency energy analysis module is used for performing time-frequency analysis on the three-component waveforms, the multi-band feature extraction module is used for extracting energy/amplitude features in a plurality of preset frequency bands, the station consistency correction module is used for compensating station gain and coupling differences, the loop normalization module is used for normalizing data, the reference condition background suppression module is used for introducing vertical excitation direction map and non-directional map attenuation parameters, the main directivity map is used for carrying out noise figure attenuation and the difference is used for carrying out the noise figure correction and the directivity index and the confidence map is used for carrying out the noise figure contrast and the error map is used for outputting the error map is used for evaluating the contrast map.
3. The three-component data processing system for vector source directionality assessment of claim 2, wherein the different excitation orientations comprise a first orientation excitation condition, a second orientation excitation condition, and a vertical excitation reference condition, wherein the excitation seismic wave orientations of the first and second orientation excitation conditions are different for producing a wavefield response having a directionality difference, the vertical excitation reference condition being used to excite seismic waves perpendicular to the first and second vector excitation planes twice without introducing a horizontal directionality bias, thereby providing a reference wavefield response for background compaction.
4. The three-component data processing system for vector source directivity evaluation of claim 2, wherein the time window determination module employs a fixed time window or an adaptive time window.
5. A method of evaluating a three-component data processing system according to claim 3, comprising the steps of: Firstly, laying a multi-station three-component detector array around a vector seismic source according to a preset azimuth based on a target area and laying conditions, and determining azimuth angles of all stations in the multi-station three-component detector array relative to the seismic source to form an equidistant circumferential observation system; Respectively triggering a vector seismic source to excite seismic waves under a first-orientation excitation working condition, a second-orientation excitation working condition and a vertical excitation orientation reference working condition, and controlling a multi-station three-component detector array to synchronously acquire a multi-station three-component seismic record data set through a synchronous acquisition unit; Step three, preprocessing and correcting the data set obtained in the step two to obtain three-component waveforms of each station under a unified time reference; Converting the three-component waveforms of each station to a radial-tangential-vertical coordinate system to obtain R, T, Z three-component waveforms and a synthesized vector component thereof; step five, determining a directivity evaluation time window; Step six, in the directivity evaluation time window determined in the step five, carrying out time-frequency analysis on the three-component waveforms of each station and the synthesized vector components thereof under each excitation working condition obtained in the step four so as to obtain waveform energy distribution characteristics of different excitation modes in the frequency dimension; Step seven, extracting amplitude/energy indexes of each station under a plurality of frequency bands according to the waveform energy distribution characteristics obtained in the step six, further constructing a circumferential amplitude vector and a fusion index, and correcting and circumferential normalizing the station consistency; Step eight, carrying out ratio pressing on the orientation working condition by utilizing a normalization result of vertically exciting the orientation reference working condition to obtain an effective directional annular vector; Step nine, defining a forward sector and a backward sector based on excitation orientation, removing abnormal station and carrying out steady statistics on effective directional annular vectors, constructing a directional index and calculating directional intensity; tenth, performing directional function fitting on the circumferential distribution to obtain directional main radiation azimuth and directional intensity parameters; and step eleven, outputting a directivity index, a main radiation azimuth and a visual result, and providing a basis for dominant excitation direction selection and detection scheme optimization.
6. The method according to claim 5, wherein the preprocessing in the third step includes sequentially performing a dc/trending process, a filtering process, and a denoising process.
7. The method according to claim 5, wherein the step four is characterized by converting the horizontal two components of each station azimuth determined in the step one into radial components And tangential component And with vertical component And forming a radial-tangential-vertical coordinate system together to obtain R, T, Z three-component waveforms and a synthesized vector component thereof.
8. The method according to claim 5, wherein the directivity evaluation time window in the fifth step is a fixed time window or an adaptive time window, and wherein the adaptive time window determines the start and stop time of the time window through AIC first arrival picking, envelope threshold or STA/LTA triggering.
9. The method according to claim 5, wherein in the step seven, the amplitude/energy index of each station is extracted in a plurality of frequency bands, specifically, the waveform energy distribution characteristics are divided into a plurality of frequency bands and the characteristics are extracted respectively, and the frequency band weights are determined by the signal-to-noise ratio, the energy in a window or the repetitive excitation consistency.
10. The method according to claim 5, wherein in the step nine, abnormal stations in the effective directivity characteristic are eliminated and counted in a robust manner, specifically, abnormal stations in the effective directivity characteristic are eliminated by using a MAD/bin line method, and a median, a truncated mean or a Huber estimate is used to replace a common mean.

Description

Three-component data processing system and method for vector seismic source directivity evaluation Technical Field The invention belongs to the technical field of geophysical exploration, and particularly relates to a three-component data processing system and method for vector seismic source directivity evaluation. Background Seismic exploration is a key technique used in geology and geophysics to detect subsurface structures. By generating seismic waves at the surface or underground and recording the propagation response of the seismic waves in the underground medium, the nature, the structural morphology and the abnormal body distribution of the underground rock stratum are deduced. Traditional seismic exploration methods generally rely on active excitation of an artificial seismic source such as explosives, ramming, and the like to acquire seismic data. However, in engineering scenes such as mine tunnels, chambers, strong heterogeneous media and the like, abnormal body characteristic signals are easily aliased due to the influence of factors such as wave field scattering, multiple wave and noise background and the like, so that exploration interpretation uncertainty is increased, and imaging precision and target recognition capability are limited. In order to improve the detection effect in a complex environment, novel seismic source forms with directional excitation capability such as vector seismic sources are recently developed. The vector seismic source can enable energy to be concentrated in a specific direction by controlling the excitation direction, so that the effective illumination capacity of a side or deep target is enhanced, and the potential of improving response characteristics and detection distance of an abnormal body is provided. The actual application effect of the vector seismic source is highly dependent on the radiation directivity characteristics, on one hand, the energy distribution difference in different excitation directions is obvious, and on the other hand, the observed amplitude change is influenced by site conditions, propagation path differences, station coupling, installation conditions and the like, often contains both the seismic source directivity and non-directivity factors, and directivity judgment deviation is easy to cause, so that the selection of the dominant excitation directions and the optimization of a detection scheme are influenced. At present, the vector seismic source directivity is evaluated by adopting a single station or a small number of measuring points for amplitude comparison or an experience-based qualitative interpretation method, so that stable and repeatable quantitative evaluation is difficult to realize under the three-component observation condition of multiple stations, and meanwhile, the unified processing flow capable of effectively weakening the influence of field effect and system difference is lacked, so that the directivity results among different working conditions or different test batches are insufficient in comparability. Therefore, how to provide a new directional quantitative evaluation method, on the premise of ensuring full utilization of three-component data of multiple stations, the method can inhibit the interference of non-directional factors and objectively quantify the directional intensity and the dominant excitation direction of the vector seismic source, and is the direction of research required by the invention. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a three-component data processing system and method for evaluating the directivity of a vector seismic source, which can inhibit the interference of nondirectional factors and objectively quantify the directivity intensity and the dominant excitation direction of the vector seismic source on the premise of ensuring the full utilization of three-component data of a plurality of stations, and provide data support for subsequent use. In order to achieve the purpose, the technical scheme adopted by the invention is that the three-component data processing system for evaluating the directivity of the vector seismic source comprises the vector seismic source, a multi-station three-component detector array, a synchronous acquisition unit and a data processing terminal. The vector seismic source is used for exciting seismic waves with corresponding directions under the working conditions with different excitation directions. The multi-station three-component detector array is distributed around the vector seismic source according to a preset azimuth, so that an equidistant circumferential observation system is formed. The synchronous acquisition unit is used for synchronously controlling the time sequence of the data acquisition of the multi-station three-component detector array and outputting a unified time reference when the vector seismic source is in each excitation direction working condition. The data processing terminal i