为实现在役抽油管表面和近表面缺陷的高精度检测，基于漏磁检测机理，结合多通道数据同步采集技术，设计了一款可检测不同类型抽油管缺陷的检测系统。该系统采用阵列差分式传感器布局及相应的信号调理电路，首先通过变步长LMS （最小均方算法）自适应滤波与双传感器差分结合算法对漏磁信号进行优化，然后使用自适应阈值缺陷识别与定位算法对抽油管杆体的缺陷进行识别和定位，最后基于QT程序开发框架设计上位机系统并将计算结果展现在上位机中。试验结果表明，该系统可有效检测出油管缺陷位置及数量，其缺陷检测平均误差在5%以内。

In order to achieve high-precision detection of surface and near surface defects in in-service oil well tubing, a detection system that can detect different types of oil well tubing defects was designed based on magnetic flux leakage detection mechanism and multi-channel data synchronization acquisition technology. The system adopted an array differential sensor layout and corresponding signal conditioning circuit. Firstly, the magnetic flux leakage signal was optimized through variable step size LMS (minimum mean square algorithm) adaptive filtering and dual sensor differential combination algorithm. Then, the adaptive threshold defect recognition and positioning algorithm was used to identify and locate the defects of the oil well rod body. Finally, the upper computer system was designed based on QT and the calculation results were presented in the upper computer. The experimental results showed that the system can effectively detect the location and quantity of oil pipe defects, and the average error of defect detection was within 5%.