钻柱振动倒谱分析及其钻头源信号提取方法研究

随钻地震参考信号处理的关键是从众多噪音成分中提取较弱的钻头源信号.钻头随机激励源信号由于其频率范围宽,持续时间短,易受钻柱和其他机器噪音的影响.倒谱分析方法是一种非线性滤波技术,该技术不但可以将时域卷积信号转变为倒时域信号的相加,而且通过窗函数的选择,还可消除结构混响,提取源信号.本文根据钻柱模拟实验数据,利用了倒谱滤波技术进行瞬态源信号的提取,并用该方法进行SWD参考信号的处理,从而达到钻头源信号强化的目的.

A research of cepstrum analysis of drill string vibration and extracting the bit source signals

Extracting the effective signals from bit among the noises from rigs and machines on ground is a key step in SWD(Seismic while drilling)pilot data preprocessing. Source signal from bit, because of the broad range of frequencies and short time duration, can be easily affected by noises from rigs and machines. Cepstrum analysis is a nonlinear filtering technique, can change the convoluted signals in time domain to a sum of signals in frequency domain. This method can remove the structural reverberation to extract the source signals by selecting a window function. In this paper, we discuss the cepstral filtering and extract the transient source signals according to the data of drill string simulated experiment. Furthermore, SWD pilot data were processed by using this method in order to realize the intensifying of bit signals.