Tubing coupling is a kind of drilling tool in oil field, which is mainly used for tubing

connection. The tubing coupling mainly solves the problem of fatigue fracture of existing

coupling due to stress concentration.

The tubing coupling structure is that the tubing end and the inner wall of the coupling

body are connected by tapered thread, and the end of the coupling body and the tubing

are connected by the same thread and the same pitch horizontal thread. The utility model

has the characteristics of alleviating the stress concentration at the root of the outer

thread of a single conical thread connecting tubing, and is not easy to produce fatigue

fracture, and has good connection effect. Effective prevention of tubing string break-off

accident.

resistance and thread stickiness resistance.

The coupling adopts phosphating treatment, which has good wear resistance, corrosion

Couplings are divided into tubing couplings and casing couplings.