Causes and treatment methods of drill pipe failure
Nov 15, 2023| 1. The drill pipe breaks along the threads of the male and female buckles
1) The torque of the drilling rig exceeds the torque that the drill pipe inclination can bear
2) The radius of curvature of the construction hole exceeds the minimum radius of curvature of the drill pipe
3) When enlarging the hole (especially when enlarging the hole) or drilling a pilot hole over a long distance, the drill bit suddenly hits a hard object and generates a strong impact force. This causes a sudden increase in torque, causing the drill pipe to break or twist.
4) The operator should reasonably control the rotation speed and propulsion force when operating the drilling rig to avoid such situations.
2. The drill pipe body is broken
1) The torque of the drilling rig exceeds the torque that the drill pipe inclination can bear
2) The radius of curvature of the construction hole exceeds the minimum radius of curvature of the drill pipe
3) When enlarging the hole (especially when enlarging the hole) or drilling a pilot hole over a long distance, the drill bit suddenly hits a hard object and generates a strong impact force. This causes a sudden increase in torque, causing the drill pipe to break or twist.
4) The material and thickness of the drill pipe body do not meet the requirements of the technical specifications.
5) The surface of the drill pipe body is seriously scratched (more than 1mm deep and in a spiral shape)
6) The drill pipe has been used for too long, the surface is damaged, and the fatigue life is close to or beyond.
3. The drill pipe friction welding joint is cracked or broken
1) Welding quality issues
2) Questions in Article 1 and Article 2 shall be handled in the same way.
4. The drill pipe body is bent or twisted
1) The thrust force is too large and too strong when drilling the guide hole.
2) The curvature radius of the guide hole during construction is too small
5. Drill pipe female buckle end expansion
1) Different buckle types, different manufacturers, old and new drill pipes are mixed, resulting in the tight distance exceeding the standard when the drill pipes are connected, and the female buckle expands.
2) The buckle type of the protection sub-joint of the drilling rig power head does not match the drill pipe buckle type or is too severely worn, and the tightness tolerance is large.
3) The lengths of the male and female ports are not accurate, and the main and auxiliary step surfaces of the joint cannot be double-topped.
4) The radius of curvature of the hole exceeds the allowable radius of curvature of the drill pipe, causing the female button to expand.
6. Deformation of end face of drill pipe female buckle
1) The vise slip is clamped on the female port
2) When the buckle cannot be removed due to too much torque, it may be deformed by hitting it with a sledgehammer or roasting it with fire.
7. The drill pipe buckle is damaged
1) Qualified thread oil is not used.
2) The thread surface is not cleaned
8. The surface of the male and female joints of the drill pipe is seriously damaged.
1) The vise slips are too hard and may be pinched by the vise slips.
2) Joint heat treatment, nitriding hardness issues or material issues.
3) The joint was hit with a sledgehammer or roasted by fire due to difficulty in unfastening.
Please avoid or replace if possible.