Wu Jianbo, Fang Hui, Li Long, Wang Jie, Huang Xiaoming, Kang Yihua, Sun Yanhua, Tang Chaoqing
School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065, China.
School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Sensors (Basel). 2017 Jan 21;17(1):201. doi: 10.3390/s17010201.
To meet the great needs for MFL (magnetic flux leakage) inspection of drill pipes at wellheads, a lift-off-tolerant MFL testing method is proposed and investigated in this paper. Firstly, a Helmholtz coil magnetization method and the whole MFL testing scheme are proposed. Then, based on the magnetic field focusing effect of ferrite cores, a lift-off-tolerant MFL sensor is developed and tested. It shows high sensitivity at a lift-off distance of 5.0 mm. Further, the follow-up high repeatability MFL probing system is designed and manufactured, which was embedded with the developed sensors. It can track the swing movement of drill pipes and allow the pipe ends to pass smoothly. Finally, the developed system is employed in a drilling field for drill pipe inspection. Test results show that the proposed method can fulfill the requirements for drill pipe inspection at wellheads, which is of great importance in drill pipe safety.
为满足井口钻杆漏磁检测的巨大需求，本文提出并研究了一种抗提离的漏磁检测方法。首先，提出了亥姆霍兹线圈磁化方法和整体漏磁检测方案。然后，基于铁氧体磁芯的磁场聚焦效应，研制并测试了一种抗提离的漏磁传感器。在提离距离为5.0 mm时，该传感器表现出高灵敏度。此外，设计并制造了后续的高重复性漏磁探测系统，该系统嵌入了所研制的传感器。它能够跟踪钻杆的摆动运动，并使管端顺利通过。最后，将所研制的系统应用于钻井现场进行钻杆检测。测试结果表明，所提出的方法能够满足井口钻杆检测的要求，这对钻杆安全具有重要意义。
