随钻测量信号中泵冲噪声对消

Adaptive Noise Canceling for Pump Noise in Measurement While Drilling Signal

泵冲噪声是噪声干扰的主要来源,其能量远远超过源信号,其频率与源信号很接近甚至重叠,在没有充足的噪声干扰信息情况下,运用固定参数数字滤波器无法将噪声干扰滤除。为此,采用最小均方算法设计了自适应噪声对消器。该自适应噪声对消器可根据信号的特点,应用噪声对消的方法抑制泵冲噪声,无需更多的噪声干扰信息和复杂的数字滤波,只要根据所需时间和精度,选取适当的滤波器长度和调整因子,就能够有效地去除钻井液脉冲信号中的泵冲噪声,从而恢复出源信号。现场应用结果表明,自适应噪声对消器有效地消除了源信号中的泵冲噪声,恢复出了源信号,在钻井液脉冲信号处理中有较高的应用价值。

The pump stroke noise is the main source of noise interference with the energy far exceeds the source signal and the frequency which is very close to or even overlaps the source signal. In the absence of sufficient noise interference information, the fixed parameter digital filter could not filter out the noise. To address the issue, the minimum mean square （LMS） algorithm is adopted to design adaptive noise canceller. Without more noise infor- mation and complex digital filter, the adaptive noise canceller could suppress the pump noise by the noise cancella- tion method according to the signal characteristics. Based on the required time and precision, the appropriate filter length and adjustment factor could be selected to effectively remove the pump stroke noise in the drilling fluid pulse signal, thereby recovering the source signal. Field application results show that the adaptive noise canceller could recover the source signal by effectively eliminating the pump noise in the original signal, providing a high applica- tion value in the mud pulse signal processing.