小波变换域地震资料瞬时频率分析方法

Instantaneous frequency analysis of seismic data in wavelet transform domain

(1.西安交通大学波动与信息研究所，陕西西安710049；2.大庆石油管理局物探公司，黑龙江大庆163357)

Institute of Wave and Information, School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China

小波变换域瞬时频率分析方法是地震资料分析的重要工具。分析了在小波变换域提取瞬时频率的原理及优点，讨论了选择不同的小波函数对计算结果的影响。利用Ricker子波和薄互层模型数据，分析了以Morlet小波、匹配地震子波的小波及三参数小波为基本小波计算的瞬时频率，结果表明：基于三参数小波的瞬时频率分析方法具有良好的抗噪性能及较高的时间分辨率。将该方法用于地下薄互层结构的地震响应分析,不仅可以刻画地层的整体变化特征，而且可以刻画薄互层内部结构。在大庆油田三维数据体瞬时频率分析中，将该方法与常用的Hilbert变换属性提取方法进行了对比，结果表明，该方法可以更清晰地刻画出火山岩的空间展布。

Instantaneous frequency analysis in wavelet transform domain is an important tool for seismic data analysis. The principles and advantages of extracting instantaneous frequency in wavelet domain are briefly discussed. The paper focuses on the effect of different wavelet function on computation result. By using the Ricker wavelet and thin inter-beds model data, taking Morlet wavelet, MSW wavelet (A mother wavelet which can match seismic wavelet) and three-parameters wavelet as mother wavelet respectively, the calculated instantaneous frequency is analyzed. Results show that the instantaneous frequency analysis based on three-parameter wavelet (called IFETPW method) has good anti-noise ability and higher temporal resolution. When the method is applied to the instantaneous frequency analysis of seismic data from thin inter-bed structure, IFETPW method can describe the overall characters of layers and the internal structure of thin inter-beds. The IFETPW method was applied in the 3D data analysis for a certain oilfield, showing that the IFETPW method can describe the spatial distribution of volcanic rocks more clearly than the conventional Hilbert transform method.