应用小波分析改善随钻电阻率测量的纵向分辨率

Application of Wavelet Transform to Improving the Vertical Resolution of Logging While Drilling (LWD) Wave Propagation Resistivity

为了提高随钻电阻率测量的纵向分辨率 ,提出了一种基于小波变换的数据处理方法 ,该方法应用多尺度分析对随钻电阻率测井数据进行分析与处理 .介绍了小波变换和多尺度分析的基本概念 ,并对随钻电磁波电阻率测量数据的频谱进行了深入的研究 ;分析了影响测量纵向分辨率的主要因素 ,给出了用小波变换对信号进行多尺度分析的方法 .数值模拟结果表明 ,该方法可以有效地改善测量的纵向分辨率 ;与实际测井数据的对比说明 ,处理后的分辨率已经接近高分辨率电缆电阻率测量的水平 .现场应用表明 ,该方法对改善随钻电阻率测量的纵向分辨率是十分有效的 ,为地层评价提供了更为有利的工具 .

For improving the vertical resolution of LWD wave propagation resistivity, a data processing method based on wavelet transform is put forward. Multi-resolving analysis is applied to the data processing. Firstly, the basic concepts of wavelet transform and multi-resolving analysis are described. And then the measured wave spectrums are studied. The factors of influencing the vertical resolution are analyzed, and the method of multi-resolving analysis by means of wavelet transform is presented. Numerical simulation results show that this method can effectively improve the resolution of LWD resistivity. Compared with real logging data, the resolution of processed data by this method can compare favorably with that of the data obtained by high-resolution cable logging.