摘要
对随钻系统地面遥测信号及测量环境进行了分析,讨论了一种用数字信号处理技术从频率不固定的多频强噪声背景下提取有用信号的方法。主要噪声源——泵的干扰在一般情况下是多频干扰,频率随泵的转速而变化,其幅度为信号的10倍以上。在信号编码为分相码的传输中,需要进行信号幅度检测,以识别码元序列传递的数据。讨论了用多权的数字自适应滤波器消除泵噪声及用匹配滤波器提取有用信号的波形实现解码的原理,并给出仿真结果。
The characteristics of downhole signals and noises are analyzed in details.Anew corresponding digital filtering method is compared with other methods, including digitaladaptive noise cancellor(DANC)and digital matched filter(DMF) methods. DANC is for theelimination of large-amplitude, multi-frequency, frequency-shifting pump noise and DMF forthe improvement of SNR。 The properties of two methods are analyzed quantitatively。Theresults of simulation on a PC/AT show the robutness of the algorithm which can be trustedwhen SNR is as low as-24dB and stroke rate of mudpump as low as 80 r/min。A high dataacquisition rate and more ANC weights can be achieved on a faster computer。
出处
《石油大学学报(自然科学版)》
CSCD
1994年第2期96-101,共6页
Journal of the University of Petroleum,China(Edition of Natural Science)
关键词
随钻测量
滤波器
钻井
Measurement while drilling
Adaptive filter
Adaptive noise cancellor
Matched filter