Failure Of The Drill Pipe Rotary Drilling Rig

The drill pipe of rotary drilling rig is the main tool for delivering torque and increasing pressure. In the case of alternating force, the pipe often cracked, tape stuck and suffered other faults. A company, the rate of failure had reached to 50%in 2009. Therefore, a great deal of customers complaints had been caused, but many factors affected the quality of the drill pipe, so the buck-passing between all the departments often taken place, resulting in a very bad influence.This thesis absorbed the analysis of oil drill pipe which based on experiments.It managed to discuss the issue on the drill pipe failure. Hoping to find out and control the factors that affect the quality of it. Details are as follows:1. To establish drill static and dynamic mechanical model of the mechanical model, and analyze the drill pipe load2. The number of drill pipe for statistical analysis, to classify the fault of drill pipe. According to find the same point, remove the small probability and merge factor in the same failure. Finally, we can draw up the methods and procedures about the analysis of failure.3. Inspecting the drill pipe through the metal material properties and mechanical properties to determine whether the material substandard caused the drill pipe failure.4. Used the macro-analysis by a representative cracking failure to obtain the drill pipe failure because of fatigue failure.5. Used the macro-micro analysis of the drill pipe to found that inclusion content and microstructure are very different in cracking occurring the same drill site and non-cracking site.6. founding the stress concentration and residual stresses existed in this part, through the analysis of drill pipe about finite element and welding stress...