【摘要】 油管的各种失效事故严重影响了油田正常生产,并带来了重大经济损失,而大多数油管失效事故都是由油管缺陷处微小裂纹缓慢扩展到一定深度后发生快速扩展导致的,因此对油管裂纹发生快速扩展的临界深度进行研究具有重要意义。选用油田常用的73 mm×5.51 mm的N80、J55材质油管加工成标准3点弯曲试样,通过3点弯曲试验,模拟研究了含缺陷油管的裂纹扩展规律,确定了2种材质油管裂纹发生快速扩展时的临界深度,为制定合理的油管判废标准提供了参考。结果表明,N80和J55油管裂纹发生快速扩展时的临界深度分别为其壁厚的41.0%和37.0%。更多还原

【Abstract】 Various failure accidents of oil tubings have severely influenced normal oilfield production and have brought severe economic loss.And most of such accidents of oil tubings were caused by the rapid propagation of tiny cracks on the defects of the oil tubings as the cracks slowly grew further depth.Thus studying on the limit depth at which the crack on oil tubings propagated rapidly was of great importance.Oil tubings of J55,N80 material with the specification of 73 mm×5.51 mm commonly used in oilfields were chosen to be the source of standard three-point bending specimens.Crack propagation regularity of oil tubings with different defects was studied through three-point bending tests.The limit depths were determined.And thus reference for making rational criterion for discarding oil tubings was provided.The results showed that the limit depths of the crack extension of N80 material and J55 material were respectively 41.0% and 37.0% of the wall thickness.更多还原