利用伪随机信号系统辨识钻柱系统

IDENTIFICATION OF DRILL-STRING SYSTEM BY MEANS OF PSEUDO-RANDOM SIGNALS

用白噪声信号作为输入信号对钻柱系统脉冲响应进行辨识。研究了伪随机信号的特征及伪随机信号产生的方法 ,得出了用伪随机信号代替白噪声信号辨识钻柱系统脉冲响应的结论。结合输入信号和输出信号 ,利用钻柱系统的脉冲响应 ,讨论了钻柱的临界转速、钻柱共振、钻柱与井壁之间的相互作用、所钻地层岩性等钻井工程问题。

Following a previous article in which identification of drill-string system with white noise as input signals was discussed, this work investigated the characteristics of pseudo-random signals and ways of generating pseudo-random signals. The results show that the input white noise can be substitute by pseudo-random signals in identifying the impulse response of a drill-string system. Using input signals, and output signal, the impulse response of drill-string is obtained. Some important aspects of drilling engineering, such as critical rotation speed of drill-string, drill-string resonance, interactions between the drill string and the borehole wall and lithology of the formation drilled, are discussed.