油管腐蚀缺陷的在线检测技术

On-line Corrosion Inspection Technique for Oil Well Tubing

油管服役条件恶劣 ,为减少油管失效事故 ,实施现场探伤 ,研制了油管井口无损检测仪。采用漏磁法对腐蚀缺陷进行无损检测 ,利用计算机增强并行口设计A/D转换器 ,便于现场使用。缺陷定量分析软件能够自动完成缺陷信号的识别、特征提取和定量评价。大量的实验室和工业现场实验结果表明 ,检测仪的腐蚀坑及孔洞分辨率为0 8mm通孔 ,且腐蚀缺陷的定性检出率为 1 0 0 % ,缺陷严重程度的分类正确率大于 90 %。

An instrument for nondestructive testing of oil well tubing at wellhead is developed to reduce tubing failure. The instrument employs the magnetic flux leakage method to inspect corrosion defects. The data converter based on Enhanced Parallel Port (EPP) is designed to make the instrument portable. The methods of abnormal signals grasping, feature extraction and quantitative evaluation of defects are achieved by the computer-aided inspection technique. The complete laboratory and field tests were completed. The results show that the system′s pit resolution is 0 8 mm hole, all the defects in the tubings are successfully detected, and the classification recognition ratio of the severity of defects is better than 90 %.