Drill pipe is a steel pipe with threaded ends used to connect surface drilling equipment to the drilling or bottom-hole assembly located at the bottom of the well. Its functions include conveying drilling mud to the bit and-in conjunction with the bit-raising, lowering, or rotating the bottom-hole assembly. Drill pipe must withstand immense internal and external pressures, as well as torsion, bending, and vibration. It can be reused multiple times during oil and gas exploration and extraction operations.
Drill pipe is manufactured from plain-end steel pipe through a series of processing steps. First, the pipe undergoes an upsetting process, where the outer surface at the ends is folded inward to thicken the pipe wall. Next, threading is performed, and the threads are copper-plated to enhance strength. Non-destructive quality control inspections follow, after which the pipe body is welded to the tool joints. The assembly then undergoes weld heat treatment and final weld processing to relieve residual welding stresses. Before the finished drill pipe is painted and packaged, it undergoes further inspections, including hardness testing, pressure testing, and non-destructive testing.
Drill pipes are typically around nine meters in length.
