在役石油长输管道缺陷是严重的安全生产隐患，由于输送介质特殊又处于埋地或深海等特殊环境，一旦因缺陷导致事故，不仅影响正常生产，还会对环境造成严重污染，甚至危及生命财产安全。传统的管道缺陷检测技术方法和功能单一，对检测条件要求高，无法实现状态预测评估。项目针对埋地或海底管道的特殊服役环境，研究管道腐蚀、焊缝、裂纹等局部应力集中区域的磁场、自激声场特性；融合管道缺陷磁记忆和自激声发射等多种传感信息，建立新的在役管道缺陷内检测方法；研究设计可进行现场试验的在役管道缺陷内检测实验装置，对管道缺陷内检测方法及其性能进行验证和评价；研究在役管道状态分析评估方法及实现状态评价和发展趋势预测的可行性。

The defects of Long-distance oil pipeline in service are serious hazards of safe production. Owing to special transmission medium and its harsh environment such as underground and deep-sea, once the defect causes the accident, it not only affects normal production, but also causes serious environment pollution, and even endangers people's life and property safety. The method and function of traditional pipeline defect detection technology is too simple, which has high requirements on the detection conditions, cannot achieve the state prognosis evaluation. Considering the special underground or undersea environment in service, the magnetic field and the self-excited acoustic field characteristics are studied in the local stress concentration area of pipeline corrosion, weld, cracks and other defects. All sorts of sensing information are integrated such as magnetic pipeline defect memory and self-excited acoustic emission, and new defect detection methods of the pipelines in service are established. The internal defect detection experimental facilities are studied and designed in the field trials of pipelines in service，and the method and performance of pipeline internal defect detection are verified and evaluated. The state analysis and evaluation methods of pipeline in service are studied, together with the realization feasibilities of the state evaluation and the development trend prediction.