In order to realize high-precision offline detection of corrosion desects on inner wall of in-service production tubing in oil well strings,a method based on dual magnetic field sensing for external detection of pulsed eddy current and depth quantitative evaluation is proposed. In the experimental study,the slope of the logarithmic curve of the falling edge of the detection signal is used as the signal feature. Based on the mapping relationship between the signal feature and the remaining wall thickness of the tubing,by analyzing cross-correlation relationship between the distribution range of induced eddy current in the tubing and the corrosion defects area identified by imaging detection,and the corrosion defects depth evaluation compensation coefficient β is introduced. Combined with the established mapping relationship,an efficient visual quantitative evaluation method for the depth of corrosions defects on the inner wall of oil pipes is formed. Through comparative analysis of defects imaging and depth quantitative evaluation results with the real situation,it is found that the proposed method can not only achieve three-dimensional morphology remerge of corrosion defects on the inner wall of the tubing,but also has high precision in quantitative evaluation of the corrosion depth,meeting the precision requirements of the detection of in-service oil tube in engineering practice.
关键词
电磁无损检测/脉冲涡流检测/在役油管/内壁腐蚀缺陷/定量评估
Key words
electromagnetic nondestructive detection/pulsed eddy current testing/in-service oil tube/corrosion defects on the inner wall/quantitative evaluation
维普
万方数据