钻杆失效分析中仿真模拟技术的应用

钻杆失效事故在石油勘探开发中经常发生,在对钻杆内加厚过渡区刺漏失效原因进行分析的过程中,借助大型的ANSYS有限元仿真模拟分析软件,根据钻杆结构和受力特点,建立分析模型,对钻杆受力状态进行了仿真分析。模拟结果表明:钻杆内加厚过渡区是整个钻杆的薄弱位置,内加厚过渡区长度miu和过渡区倒角圆弧半径R对该处应力集中系数Kt有直接影响,模拟结果与实际情况非常吻合,并模拟优化了内加厚过渡区应力集中系数Kt最小时对应的miu和R。仿真模拟分析技术不仅有助于钻杆失效原因分析,而且为钻杆结构优化和改进提供了有效的研究方法和手段,节约了大量的物力和财力。

Application of Simulation Technology on Failure Analysis of Drill Pipes

Drill pipe failure accidents often occur in oil exploration and development process, especially in internal upset transition area. With the help of ANSYS software, analysis model based on structure of the drill pipe was established, and stress state of the internal upset transition area was analyed. The results show that the upset transition area is the weakest position of the whole drill pipe. Length of transition zone rn~o and transition zone chamfer radius R have significant influence on stress concentration factor K~, which is in good agreement with the actual situation. At the same time, optimization of the miu and R based on the minimum K~ of upset transition zone was obtained. Simulation analysis can not only help analyze failure cause, but also prompt drill pipe structural optimization, improve research methods and save a lot of financial resources.