Research on Cepstrum Analysis of Drill String Vibration and Extraction of Bit Source Signals

Abstract

AbstractExtracting effective signals from bit in noises from rigs and machines on ground is a key step in SWD (Seismic while drilling) pilot data preprocessing. Source signals from bit, because of the broad range of frequencies and short time duration, can be easily affected by the noises from rigs and machines. Cepstrum analysis is a nonlinear filtering technology, which can change the convoluted signals in time domain into added 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 simulation data of drill string. Furthermore, SWD pilot data are processed by using this method in order to realize the intensifying of bit signals.