摘要
介绍了连续油管井下作业的弯曲循环方式及典型失效形式,并对连续油管作业进行了受力分析,同时采用外径38.1 mm,壁厚3.18 mm的CT80级进口连续油管进行不同内压下的疲劳试验。疲劳试验结果和失效试样的断口分析表明,内压作用下的弯曲疲劳是连续油管失效的主要原因,连续油管的疲劳失效属于典型的低周疲劳问题,疲劳裂纹都在连续油管外表面开始产生。因此,低周疲劳是连续油管工作寿命的主要影响因素。
In this article, the bending cycle mode and typical failure mode of CT downwhole operation were introduced, force analysis on CT operation was conducted,and the fatigue tests under different inside pressure on the imported CT80 Ф 38.1 mm×3.18 mm CT were earried out.The test results and the failure specimen fracture analysis showed that the bending fatigue under inside pressure is the main reason caused CT failure.CT failure belongs to typical low cycle fatigue,and fatigue crack occurred at outer surface of the coiled tubing. Therefore,low cycle fatigue is the main factor affecting CT working life.
出处
《焊管》
2012年第4期32-36,共5页
Welded Pipe and Tube
关键词
连续油管
失效形式
低周疲劳
coiled tubing（CT）
fatigue mode
low cycle fatigue
