基于同步挤压小波变换的煤层强振幅抑制

Strong amplitude suppression of coal seam based on synchrosqueezed wavelet transform

在油气地震勘探中,有些含油气目标层临近煤层,会受到煤层强振幅的影响,导致储层在地震剖面的响应难以识别,地球物理参数计算不准确.为此,本文设计了基于同步挤压小波变换(Synchrosqueezed Wavelet Transform,SWT)的煤层强振幅抑制方法.利用SWT高分辨率、高精确度的时频特性准确地筛选出煤层强振幅部分,根据能量关系进行抑制,并保留其他信息,最后通过重构实现煤层强振幅抑制算法.通过对模型数据和苏里格地区实际地震数据的处理,结果表明该方法不仅能够有效地抑制煤层强振幅,且在精细程度和准确度上优于基于经验模态分解的煤层强振幅抑制方法.

In oil and gas seismic exploration,some oil and gas target layers adjacent to the coal seam will be affected by the strong amplitude of the coal seam. So the reservoir response in the seismic profile is difficult to identify,and the calculation of geophysical parameters is not accurate. Therefore, a strong amplitude suppression method of coal seam based on Synchrosqueezed Wavelet Transform（SWT） is proposed in the paper. SWT,which has the high-resolution and high-accuracy time-frequency characteristics,is used to accurately screen out the strong amplitude parts of coal seam and remain the other parts of the information. Finally the strong amplitude suppression algorithm is realized by reconstruction. Both the model test and application on the seismic data from Sulige gas field show that this method can not only suppress the strong amplitude of coal seam effectively,but also is superior to the method based on empirical mode decomposition in suppressing the strong amplitude of coal seam in fine degree and accuracy.