摘要
针对油田连续管实际作业工况,研制开发出了基于塑性变形下的连续管低周疲劳试验机。通过CT80钢级连续管疲劳试验表明,随着连续管管径减小或壁厚增加,疲劳寿命明显增加;管内压力增加时,疲劳寿命明显降低;同钢级连续管屈服强度越高,疲劳寿命越高。同时表明,连续管表面缺陷和内部夹杂物会对其疲劳寿命产生极大影响,缺陷和夹杂物尺寸越大,疲劳寿命越低;带有环焊缝对接接头的连续管疲劳寿命明显低于管体寿命。
According to the practical oilfield operation condition of coiled tubing, a low cycle fatigue testing machine based on plastic deformation was developed. The fatigue test result of CT80 coiled tubing indicated that with diameter decreasing or wall thickness increasing, the fatigue life is obviously increased, with internal pressure increasing, the fatigue life is obviously reduced ; the higher the yield strength of coiled tubing with the same steel grade is, the longer fatigue life is. Meanwhile, it showed that surface defects on coiled tubing and inside inclusions will greatly affect its fatigue life, the bigger size of defect and inclusion is, the shorter fatigue life is . Moreover, the fatigue life of coiled tubing with circumferential butt welded joint is obviously lower than that of pipe body.
出处
《焊管》
2012年第6期5-8,共4页
Welded Pipe and Tube
关键词
连续管
疲劳寿命
屈服强度
表面缺陷
coiled tubing（CT）
fatigue life
yield strength
surface defect
