Tubing coupling is a type of oilfield drilling tool mainly used for connecting oil pipes.
The structure of the oil pipe coupling is that the end of the oil pipe is connected to the inner wall of the coupling through a conical thread, and the end of the coupling body is connected to the oil pipe through a flat thread with the same thread and pitch. It has the characteristic of relieving the stress concentration at the root of the external thread of a single conical thread connecting oil pipe, and is not prone to fatigue fracture, with good connection effect. Effectively prevent the occurrence of oil well string breakage accidents.
Couplings are divided into tubing couplings and casing couplings. Commonly used steel grades include J55, K55, N80, L80, P110, etc.