利用相关域小波变换进行SWD资料预处理  

SWD data preprocessing using wavelet transform of correlation domain

作　　者：陆斌[1,2] 葛洪魁[1] 吴何珍[1] 杨微[1] 崔士波[1] 王鹏[1] 韩来聚[3] 魏茂安[3] 

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]中国地震局兰州地震研究所,兰州730000 [3]胜利石油管理局钻井工艺研究院,东营257017

出　　处：《地球物理学报》2009年第9期2349-2356,共8页Chinese Journal of Geophysics

基　　金：国家863计划项目(2006AA06A108)资助

摘　　要：随钻地震(SWD)的波场十分复杂,对钻头有效信号和地表机械干扰成分的分析是SWD重要的资料预处理步骤.本文利用有效信号和噪声带有周期性或时延差异等时间结构特征,引入相关域小波变换进行SWD信号检测和分析.有效信号在钻柱内往复多次传播,因而带有严格的周期性,泥浆泵等机械发出的噪声也是周期性的,这些成分在自相关域内可以得到很好的凸显.SWD波场的各种成分,由于到达各个接收道的时延不同,在互相关域的特定时延处也能够得到凸显,利用小波变换对这些在相关域内得到凸显的成分进行多分辨分析,能够获得优势频率范围、周期、衰减等主要特征.根据这些信息,设计出合理的SWD处理方法,初步得到了有效信号的直达波.数据试处理结果表明,相关域小波变换是随钻地震的一个有效的预处理方法.Wave fields of Seismic While Drilling （SWD） are very complex, and it is an important preprocessing to analyze the signal from bit and the noise from machines on ground. In the paper, we use temporal structures, such as periods and time-delay of signal and noise, and propose an algorithm based on wavelet transform of correlation domain to analyze SWD wave fields. Signal propagated and reflected multiply in drill-string, so it has strict periodicity. Noise from machines such as pump has periodicity too. In auto-correlation domain, these periodic components are emerged. Components of SWD wave fields have different time delays in sensors, can emerge in cross-correlation domain at certain delay. Wavelet transform is used to analyze these components emerging in correlation domain in multi-scales, and their frequency contents, periods, attenuation can be known. Based on this information, a proper SWD data processing is carried out and the direct wave of signal from bit is gained. It is indicated that the method of wavelet transform of correlation domain is a useful preprocessing.

关 键 词：随钻地震 SWD 相关域 小波变换 资料预处理 

分 类 号：P631[天文地球—地质矿产勘探]