Hilbert-Huang变换在提取阵列声波信号动力特性中的应用

Application of Hilbert-Huang transform in extracting dynamic properties of array acoustic signals

阵列声波信号是典型的非线性、非平稳信号,其动力特性的量化提取对于进行地层结构构造分析提供了必要的基础资料.而Hilbert-Huang变换(HHT)是一种处理非线性、非平稳信号的新方法.它通过经验模态分解(EMD)将信号分解为有限个固有模态函数(IMF),并对每个固有模态函数进行Hilbert变换得到Hilbert谱.本文将这种方法应用于阵列声波信号动力特性的提取,有效地获得了信号能量的时频分布,瞬时能量、Hilbert能量、最大振幅对应的时频分布等动力特性,显示了HHT的优势以及对于进一步实现地层结构构造分析的重要意义.

Array acoustic logging data is a non-linear and non-stationary signal, and its dynamic properties extracting can provided a basic background data for analyzing reservoir formation structural and textural characteristics. Hilbert- Huang transform （HHT） is a new method for dealing with non-linear and non-stationary data. By using this method, any signals can be decomposed into a finite number of intrinsic mode functions （IMF） and then Hilbert spectrum is obtained by Hilbert transform, In this paper, the new method is introduced in extracting dynamic properties of array acoustic signals. The,energy time-frequency distribution can be effectively acquired. Several dynamic properties such as instantaneous energy, Hilbert energy and time-frequency distribution are extracted. And the advantage of HHT and its considerable significance for formation structural and textural analysis are shown.