一种超声石油固井质量检测回波信号识别的新方法

A novel approach to identify the ultrasonic echoes in inspecting well cementing quality

本文提出一种基于连续小波变换和傅里叶交换相结合的超声固井质量检测回波信号的识别方法。根据超声固并质量检测回波信号的非平稳特性，该方法先对回波信号进行连续小波变换；然后利用博里叶变换，计算其在特定刻度时间段的幅度谱作为模式特征对回波信号进行识别。分析研究表明：理论和实际回波信号的处理结果基本一致，该方法相对于仅基于频谱特征和仅基于离散小波变换的识别方法而言具有分析刻度精细、受回波信号的时间错位影响很小、识别率高的优点，非常适合对具有时变谱特性的超声回波信号的识别。

This paper presents an approach based on the Continuous Wavelet Transform(CWT) and the Fourier transform(FT) to identny the ultrasonic echoes in inspecting oil well cementing quality.First ) CWT is used to process echo signals. Then the spectra of the results in some specific scale-time segments are calculated as pattern features. The research results show that the theoretical calculations basically agree with experimental results.. Compared with the approach based only on the spectra or Discrete Wavelet transform, our approach has the adVantages of fine analyzing scales, stable features and high recognition rate. It is very suitable to identify the echo signals whose spectra vary with time.