油管原有标记的丢失导致不同级别可再用油管的混杂，因而造成巨大的经济损失和安全隐患。基于涡流检测方法，采用磁敏探头，对油田大量使用的J55和N80型再用油管开展材质识别试验。结果表明，响应电压大小受到提离、磁敏探头方向和激励频率等的影响。在磁敏探头与油管方向垂直时，施加100~260 Hz正弦激励频率的电流，两种油管的响应电压具有较好的线性关系；在150 Hz激励频率下，两种油管的响应电压差别明显，现场识别准确率高于97%。

Losses of the original marker result in a confusion of oil pipelines that can be recycled, which lead to huge security risks and great economic losses. In this paper, material identification tests of commonly used J55 and N80 oil tubes are conducted by eddy current method. Results show the size of response voltage is affected by lift-off, the direction of magnetic probe, the excitation frequency, etc. When magnetic probe is perpendicular to tubing, response voltage of two kinds of pipelines has good linear relationship with the 100~260 Hz sinusoidal excitation frequency, and response voltage of J55 is significantly different from that of N80 at the sinusoidal excitation frequency of 150 Hz. As a result, the recognition accuracy of these two kinds of pipeline is higher than 97%.