Tubing is pipe used for the transportation of crude oil and natural gas from an oil or gas layer to the surface after drilling is complete. It is made to withstand the pressure generated from the extraction process. For the manufacture of tubing, green pipes undergo an "upsetting" process to thicken the walls of the pipes. Then, green pipes are threaded on each end. The threading is then inspected and, if necessary, rethreaded to ensure that the thread accurately connects to the coupling. The tubing are strengthened by surface treatment and are subject to various inspections, including drifting and hydrostatic tests before they are coated and packaged into tubing.
Tubing pipes typically have diameters of 60.3 mm to 114.3 mm.
