Seismic Time-frequency Spectral Decomposition by Matching Pursuit to Detect Channels
Seismic Time-frequency Spectral Decomposition by Matching Pursuit to Detect Channels
复制标题
通过匹配追踪检测通道进行地震时频谱分解
DOI：
10.3997/2214-4609.20149369
复制
发表时间：
2011
期刊：
影响因子：
3.3
通讯作者：
M. Vanaki
中科院分区：
文献类型：
--
作者：
R. Mohebian;M. Yari;M. Riahi;M. Vanaki
地震数据本质上是非平稳的，具有随时间变化的频率内容。地震信号的时频分解旨在表征地下岩石和储层的时变频率响应。有多种频谱分解方法;这些方法包括短时傅立叶变换（STFT）、连续小波变换（CWT）和匹配追踪分解（MPD）。在STFT中，通过预先选择窗口长度，时间-频率分辨率在整个时间-频率空间上是固定的。因此，地震数据分析中的分辨率变得依赖于用户指定的窗口长度。连续小波变换对小波进行膨胀和压缩，以提供时间尺度谱而不是时间-频率谱。使用尺度的中心频率将尺度图转换为时间-频率谱给出了谱中的错误衰减。与STFT和连续小波变换（CWT）相比，MPD不涉及地震数据的加窗，因此具有时间和谱分辨率的最佳组合。Castagna等人（2003年）使用匹配追踪分解进行瞬时频谱分析，以检测油气藏下方的低频阴影。本文分析了匹配追踪法在伊朗西南油田河道沉积物测绘中的应用效果。
Seismic data, being non-stationary in nature, have varying frequency content in time. Time-frequency decomposition of a seismic signal aims to characterize the time-dependent frequency response of subsurface rocks and reservoirs. There are a variety of spectral decomposition methods; these include the Short Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT) and Matching Pursuit Decomposition (MPD). In STFT, time-frequency resolution is fixed over the entire time-frequency space by preselecting a window length. Therefore, resolution in seismic data analysis becomes dependent on a user specified window length. The CWT dilates and compresses wavelets to provide a time-scale spectrum instead of a time-frequency spectrum. Converting a scalogram into a time-frequency spectrum using the center frequency of a scale gives an erroneous attenuation in the spectrum. Decomposition (MPD) do not involve windowing of the seismic data and thus have the best combination of temporal and spectral resolution as compared to STFT and the continuous wavelet transform (CWT). Castagna et al, 2003, used matching-pursuit decomposition for instantaneous spectral analysis to detect low-frequency shadows beneath hydrocarbon reservoirs. In this paper we analyze performance of matching pursuit method in mapping channel sediments at one of the south-west oil- field in Iran.