利用漣波及傅立葉轉換技術偵測地層分層界面之研究

Identification of Stratigraphic Formation Interfaces Using Combined Wavelet and Fourier Transforms

潘時瑜(S.Y. Pan) ； 謝秉志(B.Z. Hsieh) ； 呂明達(M.T. Lu) ； 林再興(Z.S. Lin)

《鑛冶：中國鑛冶工程學會會刊》 51卷2期 (2007/06) Pp. 50-57

https://doi.org/10.30069/MM.200706_51(2).0006

摘要

本研究的目的是利用漣波轉換及傅立葉－漣波轉換濾波處理技術，過濾電測資料之信號並擷取地層岩性變化之信號特性，由滲透性地層指示電測資料偵測地層界面，以獲得更客觀且快速的地層分層結果。本研究使用（1）漣波轉換之漣波係數分析自然電位差電測（Spontaneous potential log, sp）及伽瑪電測（Gamma ray log, GR），建立連接漣波係數正負相反且絕對值大小一致之斜線而辨認分層之基本原則，並突顯地層分層之不連續點。（2）使用漣波轉換、傅立葉轉換及Logarithm轉換之綜合濾波技術，可分離或過濾自然電位差電測及伽瑪電測中特定頻帶信號，並建立特定頻譜模式，而求得更為清晰的信號判別地層分層界面，改進使用單一漣波轉換係數地層分層方法。使用本文之技術應用於現地電測資料，與岩樣資料的分層結果相當一致。

關鍵字

地層界面 ； 漣波轉換 ； 傅立葉轉換 ； 地球物理電測

並列摘要

The purpose of this study was to identify the formation interfaces from geophysical well log data using wavelet transform and wavelet-Fourier transform methods. In the wavelet transform method, the identification of formation interfaces is based on the wavelet coefficients from the wavelet transform of the Spontaneous Potential log (SP) and the Gamma Ray log (GR) data. In the wavelet-Fourier transform method, the wavelet transform, spectrum analysis, and logarithmic transform of well logs are applied to the SP and GR log data in series to obtain clear signals for identifying the stratigraphic formation interface. In analyzing the SP and GR logs from a field, both the wavelet transform method and the conventional well log analysis showed similar results. However the results from the wavelet-Fourier transform method were better than those from the wavelet transform method and the conventional well log analysis.

並列關鍵字

Formation interface ； Wavelet transform ； Fourier transform ； Geophysical well log