基于Hilbert-Huang变换的阵列声波测井信号时频分析

Time-Frequency Analysis of Array Acoustic Logging Waveform Signal Based on Hilbert-Huang Transform

针对目前阵列声波测井信号的信息提取主要集中在纵波、横波、斯通利波等组分波的速度、衰减的处理分析上,对频率特征的分析还缺少足够的重视的不足,引入了Hilbert-Huang变换(HHT)时频分析方法及瞬时频率的概念,给出了阵列声波信号的经验模态分解及其时频分布,并对实际阵列声波的波形信号进行了HHT时频处理与剖析.把这种方法用于区分和识别岩石构造破碎带取得了理想的效果.从阵列声波测井信号处理和构造异常的地球物理意义两方面表明,IMF序列能更好反映原始数据固有的物理特性,所使用的EMD分解是有效和易行的,为HHT分析在阵列声波测井信号处理中的应用,进行了有益的探索.

The array acoustic logging information extraction had been focused on processing the velocities and attenuations of the primary wave, shear wave and stoneley wave, and people have not still paid enough attention to the analysis on the frequency characteristics of waveform. In order to make up for this defect, the time-frequency analysis method of Hilbert- Huang transform （HHT） and the conception of transient frequency were introduced, and the empirical mode decomposition （EMD） and its time-frequency distribution about digital array acoustic logging waveform signals were given. This method was provided with the abilities to distinguish and identify the different kinds of structural fracture zones responses. The application of Hilbert-Huang transform on array acoustic logging waveform yields ideal results. Therefore, in terms of signal processing and geophysics theory, the intrinsic mode function （IMF） reflected properly the intrinsic physical properties in waveform and the method of EMD was effective and feasible. All these researches have contributed a lot to confirming the HHT in array acoustic logging waveform processing by providing effective and feasible methods.