Drill pipe is a steel pipe with threads at the tail end, used to connect surface equipment of drilling rigs with drilling and grinding equipment or bottom hole devices located at the bottom of the drilling rig.
Drill pipe is a steel pipe with threads at the tail end, used to connect surface equipment of drilling rigs with drilling and grinding equipment or bottom hole devices located at the bottom of the drilling rig. The purpose of drill pipe is to transport drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit. Drill pipes 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 pipes can be used multiple times.
Buckle type of drill pipe joint
Internal flat type: mainly used for external thickening of drill pipes. Its characteristic is that the inner diameter of the drill pipe is the same, and the flow resistance of the drilling fluid is small; But with a larger outer diameter, it is prone to wear and tear. Penetrating type: mainly used for thickening drill pipes inside and outside. Its characteristic is that the drill pipe has two inner diameters, and the flow resistance of the drilling fluid is greater than that of the inner flat type, but its outer diameter is smaller than that of the regular type. Formal style: mainly used for internally thickening drill rods, drill bits, and salvage tools. Its characteristic is that the inner diameter of the thickened joint is smaller than the inner diameter of the pipe body, and the flow resistance of the drilling fluid is high. Among the three types of buckles, the relative flow resistance is the highest, but the outer diameter is the smallest and the strength is relatively high. The above three types of joints all use V-shaped threads, but there are significant differences in buckle type, buckle distance, taper, and size.
The numerical (NC) series connectors are the American National Standard Coarse Thread series. It has now been adopted as an international standard by API. NC threads are also V-shaped threads, and some NC connectors have the same pitch diameter, taper, pitch, and thread length as the old API standard connectors, which can be interchanged.
Most oil drill pipe joints adopt 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 body. During the drilling process, it constantly contacts and rubs against the wellbore or casing, resulting in wear. To avoid drilling accidents such as drill pipe breakage and detachment caused by joint wear, it is necessary to install a drill pipe joint wear-resistant strip on the drill pipe female joint.
