基于微磁的连续油管在线检测技术

连续油管作业技术已经在钻井、完井、防砂、试油、采油、修井、测井等井下作业领域得到了广泛应用，在线缺陷检测对于保证连续油管安全运行意义重大。为此，将微磁检测技术引入到连续油管管体的缺陷检测，采用电涡流检测技术来测量油管椭圆度，并建立了油管缺陷的微磁检测等效磁导率计算模型、推导了5个参数计算油管椭圆度的方法。在此基础上研制了连续油管电磁检测系统样机，通过微磁检测装置上均匀安装的6个磁通门测磁传感器和用于椭圆度测量的6个电涡流传感器，获得6个所测量油管在圆周上的距离数据，把第6个涡流传感器用于对椭圆度测量结果进行校验。实验结果表明，该检测仪器的检测速度可达1 m/s，缺陷分辨率为0.1 mm，椭圆度检测精度高达1%；可对连续油管使用过程中常见的腐蚀、裂纹缺陷和椭圆度缺陷同时进行检测，检测速度快、效率高、稳定可靠。该项成果为连续油管的快速检测应用提供了技术保障。

Mico magnetic based online testing for coiled tubing operations

Coiled tubing has been widely applied to wellsite such as drilling, completion, sand control, oil testing, production, work over, logging, etc. so its safe running will highly rely on its on line defect detection. Therefore, we introduced a micro magnetic testing technology to detect the flaws of pipe body of coiled tubings and adopted eddy current testing to measure the ellipticity of tubings. We also established a micro magnetic testing equivalent permeability model, and deduced ellipticity calculation algorithms of coiled tubings using five parameters. On this basis, we developed a coiled tubing electromagnetic testing prototype. Around a circle of the coiled tubing, there arranged one transducer of a Fluxgate Magnetometer and one eddy current sensor every 60 degrees in the instrument, from which we could obtain the data of the distance of each tubing on this circle. The sixth eddy current sensor was used to check the measurement results of ellipticity. The experimental results showed that the testing speed ran up to 1 m/s, the testing resolution of the instrument reached 0.1 mm, and the ellipticity measurement accuracy reached as high as 1%; and also this system could simultaneously test the common corrosion, crack and elliptical defects in the using process with rapid, efficient, stable and reliable performance. This study provides a technical support for the application of rapid online detection for coiled tubing assembly.