Precautions for the use of double wall drill pipe & reverse circulation drill pipe
1. Avoid connecting large-diameter drill pipes to small-diameter drill pipes during construction (that is, mixed use of large and small drill pipes) to prevent small drill pipes from being broken or deformed due to insufficient strength.
2. When clamping the drill rod with a vise, do not clamp the female part of the female connector to prevent the female buckle from being clamped and deformed.
3. When attaching the drill pipe, the pre-tightening force of the make-up should be controlled within 15Mpa to prevent the difficulty of unloading due to excessive pressure. Avoid using fire joints to reduce the mechanical properties of the joints (especially the female joints) and affect the service life. Without pre-tightening, the threaded connection oscillates, causing the threads to grind each other and the crests to become sharper, resulting in ridges on the sides, resulting in thread damage or sticking. Without pre-tightening, the step of the female buckle is not compressed, which can cause fatigue and fracture of the thread root of the male joint; under the action of high-pressure liquid flow, the female joint is pierced, resulting in puncture corrosion, which is easy to cause longitudinal cracking of the female joint.
4. Pay attention to clean the male and female buttons before attaching the drill pipe, and apply thread oil (thread oil cannot be replaced by other expensive oil or inferior pressure oil) to prevent the male and female buttons from premature wear or tear. damage.
5. Pay attention to cleaning the water channel holes before installing the drill pipe to prevent the debris from blocking the channel and causing the mud system to hold back pressure.
6. Be careful not to forcibly buckle up. When buckling, the male buckle cannot punch the shoulder and thread of the female buckle, and ensure that the male and female joints are centered. Ensure the coaxiality of the shackle of the drilling rig and the main shaft of the power head.
7. Pay attention to check the wear of each part of the drill pipe. If abnormal wear occurs, the cause should be found in time:
(1) Determine whether the drill pipe is scratched by sharp and hard substances in the hole;
(2) Determine whether the drill rod is scratched by the drilling rig guide device.
When the scratch marks on the body of the drill pipe are about 1mm deep and in a spiral state for more than one turn, please use it with caution. Prevent the drill pipe from being broken during construction, resulting in greater losses.
8. Pay attention to the damage of the short connection of the drill collar (wrong buckle, serious wear of the random buckle, etc.), and it should be replaced in time to damage the drill pipe thread.
9. Pay attention to hoisting and avoid impact damage to the male buckle when handling the drill pipe.
10. Be careful to avoid mixing drill pipes with different buckle types; even if they are not from the same manufacturer, do not mix them (because the technical parameters, processing methods, tools, and mechanical equipment used by various manufacturers of drill pipes are different, and the drill pipe tolerances, The tight distances must be different); if the difference between the old and the new is too large, and the drill pipes with too much wear and tear should not be mixed to avoid construction hazards.
11. It is found that the drill pipe buckle type has local small-scale damage (about 1-2 buckles, the buckle length is 10mm), and it should be repaired in time before use.
12. Be careful not to clamp any part of the drill rod body with a vise clamp, so as to avoid the rod body being pinched by slips and reduce the service life of the drill rod.
13. Use qualified zinc-based rib grease. Butter is not suitable for thread oil. Insufficient rib grease will damage the shoulder of the joint, which will easily make the threaded connection loose and cause the thread to be damaged. If the thread grease is not used or the thread grease used is unqualified, the surface of the thread will be glued, resulting in the phenomenon of sticking.
