1. According to the torque, push-pull force and allowable minimum curvature radius of the drilling rig, select the drill pipe of the appropriate specification and model. 2. Avoid connecting large-diameter drill pipes to small-diameter drill pipes during construction (ie, mixed use of large and small drill pipes) to prevent small drill pipes from being broken or deformed due to insufficient strength. 3. 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. 4. When attaching the drill pipe, the pre-tightening force of make-up should be controlled within 15MPa to prevent the difficulty of unloading due to excessive pressure. Avoid using fire to bake the joint, which will reduce the mechanical properties of the joint (especially the female joint) and affect the service life. Without pre-tightening the threaded connection swings, the threads grind each other and the tooth crests become sharper, resulting in ridges on the sides, resulting in the damage of the threads and the phenomenon of sticking. If there is no pre-tightening and the step of the female buckle is not pressed tightly, the thread root of the male joint may be fatigued and broken. Under the action of high-pressure liquid flow, the female joint will be pierced, resulting in puncture corrosion, which may easily lead to longitudinal cracking of the female joint. 5. 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 waste oil or inferior pressure oil) to prevent premature wear or damage of the male and female buttons . 6. 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. 7. Be careful not to forcibly buckle up. When buckling, the male buckle must not impact the shoulder and thread of the female buckle, and ensure that the male and female connectors are centered. Ensure the coaxiality of the shackle of the drilling rig and the main shaft of the power head. 8. Pay attention to check the wear of various parts 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 drill guide device. 3) When the scratch marks on the body of the drill pipe are about 1mm deep in a spiral shape for more than one circle, please use it with caution. Prevent the drill pipe from being broken during construction, resulting in greater losses. 9. 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 avoid damage to the drill pipe thread. 10. Pay attention to hoisting and avoid impact damage to the male buckle when handling the drill pipe. 11. Be careful to avoid mixing drill pipes of different buckle types, even if they are not produced by the same manufacturer, do not mix them (because the technical parameters, processing methods, props, and mechanical equipment of drill pipes manufactured by various manufacturers are different, and the tolerances of the drill pipes processed are different. , close distance, etc. must be different); 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. 12. It is found that the drill pipe buckle is damaged in a small area (about 1-2 buckles, the buckle length is 10mm), and it should be repaired in time before use. 13. Be careful not to hold any part of the drill pipe body with a vise, so as to avoid the rod body being pinched by slips and reduce the service life of the drill pipe. 14. Use qualified zinc-based rib grease. Butter is not suitable for thread oil. Insufficient thread grease will cause damage to the shoulder of the joint and produce high points, which is easy to "loose" the threaded connection and cause the thread to be damaged. Do not use thread grease or use unqualified thread grease, the surface of the thread will be glued, resulting in the phenomenon of sticking.
Drill pipe is the basic component of drill string. Its main function is to transmit torque and transport drilling fluid, and the wellbore is continuously deepened by the gradual lengthening of the drill pipe. The buying skills of drill pipes are actually very simple. As the saying goes, “snake a snake and hit seven inches”. Although this proverb is not appropriate to use here, the meaning of solving problems and grasping the key is particularly reasonable. The key issue of drill pipe purchase can be started from the reason of drill pipe fracture and failure, and then master how to distinguish the quality of drill pipe when purchasing.
Drill pipe is a rod connected with a drill bit and used to transmit power in a drilling tool. The usual components of the drill string are: drill bit, drill collar, drill pipe, stabilizer, special joint and kelly. The basic functions of the drill string are: (1) tripping the drill bit; (2) applying weight on bit; (3) transmitting power; (4) transporting drilling fluid; (5) performing special operations: squeeze cement, deal with downhole accidents, etc. The purpose of the drill pipe The drill pipe is a steel pipe with ribbing 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 together with the drill bit raise, lower or rotate the bottom hole device. Drill pipe must be able to withstand enormous internal and external pressure, twisting, bending and vibration. In the process of oil and gas extraction and refining, drill pipe can be used many times.
Inner flat type: mainly used for external thickening of drill pipe. Its characteristic is that the drill pipe has the same inner diameter, and the drilling fluid flow resistance is small; but the outer diameter is large, which is easy to wear. Through-hole type: mainly used to thicken drill pipe inside and outside. It is characterized in that the drill pipe has two inner diameters, and the flow resistance of drilling fluid is larger than that of the inner flat type, but its outer diameter is smaller than that of the regular type. Formal type: Mainly used for inner thickening of drill pipes, drill bits and fishing tools. Its characteristics are that the inner diameter of the joint inner diameter is smaller than the inner diameter of the pipe, and the drilling fluid flow resistance is large. The relative flow resistance is the largest among the three buckle types, but the outer diameter is the smallest and the strength is large. The above three types of joints all use V-type threads, but the buckle type, distance, taper and size are very different. Digital (NC) series fittings are American National Standard coarse thread series. It has been adopted as an international standard by API. NC threads are also V-threads, and some NC-type fittings have the same pitch diameter, taper, pitch and thread length as the old API standard fittings and can be used interchangeably. Oil drill pipe joints are mostly in the form of external thickening or internal and external thickening. The outer diameter of the drill pipe joint is larger than the outer diameter of the pipe. During the drilling process, it is constantly in contact and friction with the well wall or casing, resulting in wear and tear. In order to avoid the joint wear and tear, the drill will break Drilling accidents such as rods and tripping must be provided with drill pipe joint wear-resistant belts on the drill pipe female joint.