基于谱分解的构造煤地震识别方法研究
Study on seismic identification method of deformed coal based on spectral decomposition
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摘要: 为了研究构造煤的地震响应特征,提高应用三维地震预测构造煤的精度,以芦岭煤矿Ⅲ102采区为例,利用地震正演模拟对不同厚度原生煤、构造煤的振幅特征及其在不同调谐频率段的振幅吸收衰减特征进行了研究,提出了基于三维地震谱分解的构造煤识别方法。研究结果表明:原生煤、构造煤在地震低频段振幅吸收衰减基本一致,随着调谐频率升高,原生煤、构造煤的振幅吸收衰减差异在某一频率段达到最大后,缓慢减小,煤层厚越小,振幅吸收衰减差异达到最大的调谐频率段越高,在芦岭煤矿应用谱分方法识别的构造煤发育范围与钻井吻合度为93%,而传统方法与钻井吻合度为76%,基于谱分解的构造煤地震识别方法有效的提高了构造煤识别精度。Abstract: In order to study the seismic response characteristics of deformed coal and improve the accuracy of using 3D seismic to predict deformed coal, the No.Ⅲ102 mining area of Luling Coal Mine was taken as an example. The amplitude characteristics of undeformed coal and deformed coal with different thickness and the characteristics of amplitude absorption attenuation in different tuning frequency were studied by using seismic forward modeling. A method of deformed coal identification based on three-dimensional seismic spectrum decomposition was proposed. The results showed that the amplitude absorption attenuation of undeformed coal and deformed coal was basically the same in the low frequency range of seismic. With the increase of tuning frequency, the difference of amplitude absorption attenuation between undeformed coal and deformed coal increased, at a certain frequency reaches the maximum and then decreased slowly. The smaller the thickness of coal, the higher tuning frequency when the amplitude absorption attenuation difference reached the maximum. In Luling Coal Mine, the conformity between the range of deformed coal development identified by spectral division method and drilling was 93%, and the conformity between conventional method and drilling was 76%. The deformed coal seismic recognition method based on spectral decomposition effectively improved the recognition accuracy of deformed coal.