生产井瞬变电磁响应特征研究  

Response Characteristics of Transient Electromagnetic in Production Wells

作　　者：任志平[1] 党瑞荣[1] 宋汐瑾[1] 

机构地区：[1]光电油气测井与检测教育部重点实验室(西安石油大学),陕西西安710065

出　　处：《石油天然气学报》2011年第9期100-104,168,共5页Journal of Oil and Gas Technology

基　　金：国家"863"计划项目(2007AA06Z217);国家自然科学基金项目(50974103);陕西省教育厅专项(09JK694)

摘　　要：研究了生产井环境下井中瞬变电磁的响应特征,建立了柱状分层介质的电磁响应模型,推导出了生产井井中瞬变电磁响应的一般表达式,结合数值计算讨论了套管电导率、厚度、磁导率、发射线圈、接收线圈的几何参数以及收发距对井中电磁响应信号的影响规律。研究表明:生产井中接收线圈上的感应电动势随时间的增大而减小,套管电导率越大,响应信号衰减得越慢;套管厚度的增加将降低响应信号的幅度;在不同磁导率的套管中,弱磁性套管的电磁响应强度较大;在其他参数一定时,增加发射线圈和接收线圈的匝数有助于提高响应信号强度,扩大探测范围,并且电磁响应强度随发射线圈半径的增大而增大,随收发距的增大而减小。The transient electromagnetic response characteristics in production wells were studied.An electromagnetic response model for multi-cylindrical-layer media was established,and the general formula for expressing the transient electromagnetic response in production wells was deduced.The influence of casing conductivity,thickness,magnetic permeability,the parameters of emission coil,receiving coil and transmitter-receiver distance were analyzed through numerical calculations.The result shows that the voltage of response electromotive force(EMF) decreases with time increase,the higher the casing conductivity is,the more slowly the response voltage attenuates.The thicker the casing is,the lower the voltage of the early signal is.The weaker of casing magnetism intensity is,the higher the amplitude of received signal is.The voltage of response signal decreases with the increase of transmitter-receiver distance,Moreover the increase of coil number of and the radius of transmitter can improve signal strength and enlarge detective ranges.

关 键 词：生产井 瞬变电磁响应 柱状分层介质 套管 线圈系 

分 类 号：P631.325[天文地球—地质矿产勘探]