Extraction And Enhancement Technology Of Channel Wave Energy And Its Application

In-seam seismic exploration mainly uses reflected channel wave and transmitted channel wave to detect and image the structure in coal seam.At present,it has become an important method of mining seismic exploration in coal mines.When the coal seam and its top and bottom formations are well developed,the coal seam is a good waveguide layer,which is conducive to the development and propagation of channel waves,with clear waveforms and obvious dispersion characteristics.Due to the complex geological conditions of Chinese coal seams and the large variation of the top and bottom layers of the seams,in many areas of actual detection,the channel waves are poorly developed and weak in energy,which seriously affects the identification and imaging accuracy of the channel waves.At the same time,the channel wave field is complex,including not only direct P-waves,direct S-waves and channel waves,but also transmitted channel waves,reflected channel waves,scattered waves and random noise,etc.How to enhance and extract the slot waves from the complex wave field is the key link to carry out slot wave exploration.Aiming at the problems of low signal-to-noise ratio,weak reflected energy and complex twocomponent recording processing of channel wave data,this thesis studies the energy extraction technology for transmitted and reflected acquired by In-seam seismic exploration.The methods are applied on synthetic data and field data,which provides a guidance in In-seam seismic data processing.Firstly,this thesis systematically describes the research status of In-seam seismic exploration and seismic data noise suppression at home and abroad.And difficulties in In-seam seismic data processing are analyzed.Then the significance of study in in-seam seismic data energy extraction and enhancement technology are proposed.The formation mechanism of channel wave are summarized.We also clarify the basic principles and imaging methods of reflection and transmission channel wave exploration,determine the theoretical equation and basic method of numerical simulation of channel wave.In the extraction and enhancement of channel wave energy,the F-X domain spatial predictive filtering algorithm and continuous wavelet transform algorithm are studied to improve the signal-to-noise ratio of channel wave seismic records and enhance the continuity of channel wave event through random noise suppression and dominant band record extraction,respectively.In order to solve the cumbersome processing of two-component recording data,polarization analysis,rotation,Hilbert transform and other methods are introduced to extraction of channel wave field.Finally,application of channel wave energy extraction and enhancement technology are applied on two simulated data and four field data.After processing,geological anomalies are imaged.Application results indicate that F-X predictive filtering technology can suppress random noise in channel wave recording effectively.The frequency division processing technology using continuous wavelet transform can extract the dominant frequency band record of channel wave and improve the continuity of channel wave event effectively.Polarization analysis can rotate the two-component transmitted channel wave record to the polarization direction so as to obtain highquality channel wave single component record and reduce the complexity of two-component processing.Extraction method for two-component reflected channel wave field can effectively separate the reflected channel wave from the direct channel wave and enhance the continuity of the reflected channel wave event.