基于改进Morlet小波的MP算法在地震频谱分析中的应用

MP Algorithm Based on Improved Morlet Wavelet in the Seismic Spectrum Analysis

对地震信号的时频分析,Morlet小波是在时频联合域内具有最好分辨率的解析小波。介绍了基于Morlet小波的匹配追踪算法的原理,在此基础上改进了时频原子库,并增加了参数k来调节Morlet小波的带宽。对比了基于Morlet小波的匹配追踪(MP)算法与传统STFT时频分析方法,理论模型表明,该算法具有更高的时频分辨率;对某油田实际碳酸盐岩地震资料进行处理的结果表明,改进的Morlet小波匹配追踪时频算法对储层的刻画明显优于传统STFT方法。

In the analysis of the instantaneous frequency of seismic signals,Morlet wavelet provides the best resolution ratio in symphysial area.This paper introduces the theory of matching pursuit algorithm on the basis of Morlet wavelet,and further improves the time frequency atom dictionary.Besides,the parameter is added to adjust the bandwidth of Morlet wavelet.The comparison of the theory of matching pursuit algorithm on the basis of morlet wavelet with the traditional STFT method with a theory model indicates that the former has a higher resolution ratio for the instantaneous frequency.The actual seismic data processing of carbonate rocks in southern Tahe Oilfield confirms that the modified Morlet wavelet method of matching pursuit time-frequency characterization of the reservoir is prominently better than STFT method.