地面集输用柔性复合管开裂失效原因分析

近年来,柔性复合管由于其优异的耐腐蚀性和可盘卷性能,在国内油田被大规模推广应用。随着应用范围的进一步扩大,出现了部分失效事故。通过对国内某油田集输管道用柔性复合管现场截取的泄漏管段开展的外观尺寸、化学成分及物理性能检测等,分析引起其开裂失效的原因。结果表明该柔性复合管失效原因主要有两个方面:1)内衬层材料的维卡软化温度远低于实际使用温度和设计温度,在运行中将导致内衬层发生软化而使其强度明显下降;2)增强层纤维缠绕间隙较大且不均匀,由此导致该柔性复合管承载能力不足而发生了断裂失效。

Cracking Failure of Reinforced Thermoplastic Pipe Used in Ground Gathering and Transportation

Due to the excellent corrosion resistance and coiling performance,the reinforced thermoplastic pipes have been widely used in domestic oilfields recently.With the further expansion of the application scope,some failure events have occurred.In this study,the leakage section cut from flexible composite pipe line was tested.According to the inspection of appearance and size,chemical composition and physical properties,the causes of cracking and failure were analyzed.The results show that there are two main reasons for the failure of the pipe:1)the vicat softening temperature of the liner material is much lower than the actual service temperature and the design temperature,which causes the liner to soften and the strength to decrease obviously;2)the filament winding gap of the reinforcing layer is large and uneven,which leads to insufficiency of the compressive capacity of the pipe,and fracture failure occurs ultimately.