多元检测线圈在石油拼接套管的远场涡流检测中的应用

在基于远场涡流的拼接套管检测中，拼接套管各管道分析的复杂性会因为远场涡流两次穿透套管壁的特性而增加.当发射线圈处于缺陷位置时，作者已提出基于双接收线圈的伪峰移除方法.当发射线圈处于正常管道位置时，伪峰移除方法并不能移除检测信号中发射线圈处管道的信息，所以本文提出弥补该不足点的方法.该方法首先通过去伪峰方法将检测信号中发射线圈附近的管道情况统一转化为无缺陷的情况；然后，采用维纳去卷积滤波器获取拼接套管上缺陷（接箍可视为缺陷）的位置信息，并根据缺陷位置反向定位拼接套管正常位置.最后，统一移除检测信号中发射线圈处管道的信息.该方法通过仪器测试科索#1井得到验证，有利于提高远场涡流在拼接套管检测分析中的实用性.

The Applications of Dual Pick-up Coils in RFEC Testing of Casings in Oil Wells

In the Remote Field Eddy Current Testing (RFECT) of joint casings,the two penetrations of eddy current will enhance the complicacy of analyzing joint casings.Based on our previous studies,the secondary peaks that caused by transmitter passing defects can be removed by employing two pick-up coils in remote field.However,when transmitter at normal pipe locations,there are not any secondary peaks,and nothing will be removed.The pipe information near transmitter is still contained in testing signals.In order to overcome this shortcoming,based on the pick-up coils,this paper deduced the method for removing Normal Pipe Value (NPV) caused by transmitter from testing signals.Firstly,the Wiener deconvolution filter is adopted to identify the signal that can be used to indicate defects.Secondly,based on the signal obtained by Wiener filter,the self-adapting acquisition of NPV is achieved.The correctness and feasibility of proposed method are validated by testing tool and Kesuo #1 well.