The oil drill pipe is the main component of the drill string. The service environment is extremely harsh and the loading state is very complicated. All countries of the world have attached great importance to drilling rod products. For the development of drill pipe, intelligent drill pipe and fast buckle super high torque joint are the top two outstanding representatives.

There are some problems in the production process of drill pipes for oil exploitation.

Removal of welding flown

The internal and external flown will be formed during the friction welding of the drill rod, and the high steel grade drilling rod is very difficult to remove the internal flying edge because the inner diameter of the joint is smaller than the inner diameter of the welded joint of the pipe body. Because of the limitation of the inner diameter of the lathe, the diameter of the lathe tool is easy to cause the vibration of the tool bar when machining, which seriously affects the machining quality and efficiency.

At present, most manufacturers use punching to remove internal flash, and the processing efficiency is higher. Because of the influence of the punch form, the punching cutting opportunity and the punching force, sometimes it causes the burr to scratch the inner wall of the tube or the inner wall adhesion and so on, which affects the normal use of the drill rod.

Application of sulphur resistant drill rod

Hydrogen sulfide corrosion will cause drill pipe failure. Domestic drilling rod manufacturers have also developed sulfur resistant drill rods, but it has not been widely applied. There are two points: 1) the price of the sulfur resistant drill rod is high, about 2 times that of the ordinary drill pipe. Because of the special material of sulfur resistant drill pipe and the complex production process, the price is high. 2) the strength needs to be improved. When drilling in sulphur welding, the higher the strength of drill pipe steel, the greater the risk of corrosion and fracture.

Strength and toughness

The contradiction between strength and toughness is often encountered in the production and manufacture of drill pipes. In the course of drilling, most wells are not vertical, and the application of inclined and horizontal wells is more and more. The drill rod in the "dog leg" is subjected to alternating stress, and the toughness is poor, it is easy to break or pierce the accident.