The drill pipe is a steel pipe with a thread at the tai […]
The drill pipe is a steel pipe with a thread at the tail, which is used to connect the surface equipment of the drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the well. The purpose of the drill pipe is to transport the drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit.
Regarding the common causes of drill pipe fracture, there may be the following points:
1. After long-term use of drill pipes, there are many surface damages, which are close to or exceed the fatigue life;
2. During operation, the drill bit encounters a hard object to produce a strong impact force, and the torque increases, causing the drill pipe to break or twist;
3. The reamer model selection is unreasonable, and the matching model cannot be selected according to the actual geological conditions, which increases the drilling torque and increases the wear of the drill pipe and breaks;
4. The deviation control of the guide hole is unreasonable. If the deviation is too large, the actual curve will be unreasonable in the later correction process, and the bending moment of the drill pipe will be too large, which will easily cause the drill pipe to break;
5. Due to unsatisfactory geological conditions, the tunnel is broken and collapsed, and the drill cuttings are too much, which increases the risk of drilling tool lockup and causes drill pipe fracture;
6. The material and thickness of the drill rod body do not meet the technical specifications.