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 miu and transition zone chamfer radius R have significant influence on stress concentration factor Kt, which is in good agreement with the actual situation. At the same time, optimization of the miu and R based on the minimum Kt 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.