Study on seismic identification method of deformed coal based on spectral decomposition

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.