去除随钻测量信号中噪声及干扰的新方法  

A nonlinear method for filtering noise and interference of pulse signal in measurement while drilling

作　　者：赵建辉[1] 王丽艳[1] 盛利民[2] 王家进[2] 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100083 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油学报》2008年第4期596-600,共5页Acta Petrolei Sinica

基　　金：国家自然科学基金(No.50674005);中国石油中青年创新基金联合资助

摘　　要：由于受到钻井特殊条件的限制,井底和地面之间的随钻测量信号难以通过有线方式进行传输,目前工程中主要采用基于钻井液脉冲位置编码调制的无线传输方式。但是,由于泥浆压力、井深、泵压等信道传输特性会对信号造成影响,随钻测量中在井口采集到的钻井液脉冲信号往往包含了各种噪声和干扰,直接影响地面信号解码结果的正确性。对钻井液脉冲脉位编码无线通信原理、噪声及干扰进行了分析,根据干扰与噪声的特点,采用线性滤波方法还原脉冲信号,又利用一种非线性"平顶消除"的方法对现场采集的信号进行了处理。与线性滤波方法处理结果的综合对比表明,该方法能更有效地去除钻井泵噪声及其他干扰。现场应用结果表明,该方法对脉冲信号位置复原误差影响小,解码过程简单实用,具有误码率低、可靠性高等特点。Limited by drilling conditions, it＇s difficult to transmit signal between ground and down-hole by wire, so at present wireless transmission style which is based on the modulation of drilling fluid pulse is used in practice. However, the channel transmission of drilling fluid pressure, well depth and pump pressure have serious effect on the sampled signal in the measurement while drilling （MWD） system. The sampled signal contains some strong noises and interference, which would affect the measurement precision and the reliability. The mode of wireless communication by drilling fluid pulse and the characteristics of noise were analyzed. The linear filtering method was used to recover the pulse signal. Considering the characteristics of the noise, a new nonlinear method based on digital filtering was applied to the sampled signal processing. The filtering result of the nonlinear method is better than that of the linear method. All the pump noise and interference can be wiped off efficiently. Field application shows that this method has little impact on position and is characterized by simple decoding process, high reliability and low error rate.

关 键 词：随钻测量 钻井液脉冲信号 非线性滤波 信号处理 解码 

分 类 号：TE24[石油与天然气工程—油气井工程]