The Buckle Type Of The Drill Pipe Joint

Internal flat type: mainly used for external thickening of drill pipe. It is characterized by the same inner diameter of the whole body of the drill pipe, and the flow resistance of the drilling fluid is small. But the outside diameter is large, easy to wear. Perforated type: mainly used for internal and external thickening of drill pipe. Its characteristic is that the drill pipe has two inner diameters, the drilling fluid flow resistance is greater than the inner flat type, but its outer diameter is less than the regular type. Normal type: mainly used for internal thickening drill pipe and drill, fishing tools. Its characteristics are that the inner diameter of the joint is smaller than the inner diameter of the pipe, and the drilling fluid flow resistance is large, and the relative flow resistance is the largest among the three buckle types, but the outside diameter is the smallest and the strength is larger. The above three types of joints all use V-thread, but the buckle type, buckle distance, taper and size are very different.
Digital type (NC) series connectors are the national standard coarse thread series of the United States. It has been adopted as an international standard by API. The NC thread is also a V thread, and some NC joints have the same pitch diameter, taper, pitch and thread length as the old API standard joints, and can be used interchangeably.
Most of the oil pipe joints are in the form of external thickening or internal and external thickening, and the outer diameter of the pipe joint is larger than the outer diameter of the pipe body. In the drilling process, the contact friction with the well wall or casing is constant, resulting in wear. In order to avoid drilling accidents such as broken pipe and tripping caused by joint wear, the drill pipe joint anti-wear belt must be installed on the drill pipe female joint.