Torque shoulder of special screwed nipple for oil tubes and sleeves

Abstract

The invention relates to a torque shoulder of a special screwed nipple for oil tubes and sleeves. An external thread reverse shoulder inclined plane inclines towards the inner part of a tube on the external thread end part of a tubular nipple connecting thread and on the position behind an internal thread tool withdrawal groove meshed with the external thread end part, the external thread reverse shoulder inclined plane and the tube forms an radial included angle of 15-20 degrees, and the external thread reverse shoulder inclined plane has the radial height of 1.5-2mm; the vertical plane of a triangular shoulder forms a 90-degree included angle with the center line of the oil tube and the sleeve; the reverse shoulder inclined plane is connected with a sealing face connected with a chamfer angle, and the chamfer angle is connected with the connecting thread; an internal thread reverse shoulder and the triangular shoulder are positioned on a position in contact with the end face of the external thread after screwed on; the reverse shoulder inclined plane, the vertical plane of the triangular shoulder and the sealing face are correspondingly matched with the external thread reverse shoulder inclined plane, the vertical plane of the triangular shoulder and the sealing face; an internal thread sealing face is near the thread tool withdrawal groove; and an external thread chamfer angle which is screwed on is clamped in the tool withdrawal groove. Thus, the invention ensures the sealing of the torque shoulder and has the capability of resisting torque, fatigue and corrosion.

Description

technical field [0001] The invention relates to a torque shoulder of a special threaded joint for oil pipes and casings. Background technique [0002] Special threaded joints for tubing and casing are necessary technologies in the development of ultra-deep wells, horizontal wells, and high-temperature / high-pressure gas wells in oil and gas field exploration, and play an important role in the development of oil and gas wells. Due to the increase of deep wells and ultra-deep wells in the development of oil and gas wells in recent years, the demand for special threaded joints for tubing and casing has increased rapidly, and the performance requirements for special threaded joints for gas sealing are also increasing. [0003] Since the production of special threaded joints for tubing and casing, a variety of special threaded joints have been applied to oil and gas development. The core of these special threaded joint technologies includes three aspects: thread tooth shape, seal...

AI Technical Summary

Problems solved by technology

Under the action of tensile load, the shoulder of the reverse shoulder can still keep in contact with the inner and outer threads, and has a certain sealing ability; but the over-torque performance is insufficient, and it is easy to deform under the action of over-torque, reducing the sealing performance

The right-angle shoulder is not easy to deform under a certain over-torque, and has good over-torque resistance; but under the action of axial tensile load, the shoulders of the internal and external threads are separated, and the air-tight performance is poor

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