导向钻井下传信号Haar提升小波去噪研究

Research of Haar Lifting Wavelet Signal Denoising on Downward Communication of Steering Drilling Tool by Drilling Fluid Displacement Changes

摘要:

针对导向钻井下行通信中信号传输存在多种噪声的问题,提出了一种基于多尺度Haar小波提升变换的信号去噪方法；在分析变钻井液排量下行通信信号传输噪声特点的基础上,给出了Haar小波的提升变换方案、信号去噪的原理及实现步骤,利用Haar多尺度提升小波变换实现了对井下接收的由排量变化三降三升过程构成的下传信号的去噪处理；对比实验结果表明,该方法既能有效滤除噪声,又能保持钻井液排量三降三升变化过程构成的下传信号其脉冲沿的位置和脉宽不失真,保证了对下传信号的有效识别。

Abstract:

Considering a variety of noise problems in the downhole communication, denoising method based on Harr ascension wavelet transform is applied to process the downward command signal recognition. On the basis of analyzing of the transmission noise characteristics of drilling fluid flow signal, Haar wavelet lifting scheme, basic principle and implementation steps of signal de-noising were given. Signal denoising was achieved in the use of multi-scale Haar ascension wavelet transform in order to deal with the noises in the three down and three liters signal received on the underground. underground experiment results have proved the validity and feasibility of the method. Contrast experimental results show that the method can not only effectively filter out the noise , but can also maintain the position of pulses edge and pulse width without any distortion , to ensure the effective recognition of the downward signal.