The drill pipe primarily consists of two components: the drill pipe body and the tool joint. The pipe body serves as the main section, while the tool joint connects multiple drill pipes to form a continuous drill string. Structurally, the connection between the tool joint and the pipe body is achieved through specific methods, with mainstream techniques including threaded connections and butt welding. Among these, threaded connections have gradually been phased out, while friction-welded butt joints have become the dominant manufacturing process in modern drill pipe production.
Function of Drill Pipe
The petroleum drill pipe, as a key equipment in oil well drilling, plays a crucial role in the drilling process due to its thin-walled and lightweight characteristics per unit length. It not only provides a smooth channel for drilling mud but also transmits tensile forces and torque. The drill pipe serves as a conduit for mud circulation and transfers axial and rotational forces during drilling, making it an essential component in petroleum drilling operations.
Manufacturing Process of Drill Pipe
This type of drill pipe is produced through a rolling process to create seamless steel tubes, with both ends undergoing upset forging to enhance the connection strength between the pipe body and joints. According to API standards, the upsetting forms include internal upset, external upset, and internal-external upset, with transition lengths typically ranging from 20–65 mm and up to 120–130 mm at maximum. The TOCT standard primarily adopts internal and external upsetting forms. The drill pipe is manufactured via seamless steel tube rolling, with upset-forged ends to strengthen connections, and the upsetting types include internal and external variations.
Additionally, the technical parameters of petroleum drill pipes are indispensable in drilling operations. These include critical dimensions such as the outer diameter, wall thickness, fixed length of the drill pipe collar, and the outer and inner diameters of the end threads. Moreover, weight per meter is another vital metric for evaluating drill pipe performance.
