电磁随钻信号传输技术研究  

Study on the signal transmission of EM MWD

作　　者：姚爱国[1] 张萌[1] 吴来杰[1] 李运升[1] 

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《探矿工程（岩土钻掘工程）》2009年第S1期115-119,共5页Exploration Engineering:Rock & Soil Drilling and Tunneling

基　　金：国家"863"项目"电磁随钻遥测式自动垂钻系统关键技术研究;"(编号:2006AA06Z208)

摘　　要：电磁波随钻测量系统信号传输速率高,可有效应用于欠平衡钻井,国外近年来发展很快。本文介绍了电磁波随钻测量发展的历史与现状,讨论了电磁波发射方式与传输深度。采用自制的样机进行了实验室与浅孔试验,证明方波信号传输比正弦波更易受干扰,小信号孔内有泥浆时方波传输误码率高。电磁波双向信号能够实现正常传输,但下传信号衰减较大。The system of electromagnetic measurement while drilling(EM MWD) has the advantage of high rate of data transmission and suitable for underbalance drilling,so it is developed fast abroad in recent years.This paper introduces the history and advancement of EM MWD,and discus transmitting mode and skin depth of electromagnetic waves.Some experiments have done in lab and shallow borehole with the EM MWD and the apparatus for two ways transmission made by authors.Results demonstrate that compared with sine waves,square waveform is liable to be interfered by noise from formations.Under the condition of drilling fluid in borehole,error rate is much higher for weak signals in square than that in sine waveform.Two ways transmission works effectively,but the attenuation of downward signals is 2-3 times greater than that upward.

关 键 词：电磁随钻测量系统 信号传输 影响因素 双向传输 

分 类 号：P634.5[天文地球—地质矿产勘探]