High torsion resistance fully sealed drill pipe threaded joint

Abstract

The invention discloses a high torsion-resistant fully sealed drill pipe threaded joint, comprising an external threaded joint and an internal threaded joint; the main end surface of the internal threaded joint of the internal threaded joint is a torus with an inclination angle, and the end hole of the internal thread is a conical hole ; The outer shoulder surface on the externally threaded joint is a torus with an inclination angle, the base of the tapered pipe thread of the externally threaded joint is an elliptical arc surface, the length of the major semi-axis of the ellipse section of the elliptical arc surface is b, and the ellipse of the elliptical arc surface The length of the minor axis of the section is 2a, and the ratio 2a / b of the minor axis length 2a to the major semiaxis length b is equal to the conical hole taper of the end hole of the internal thread; the pitch T of the external thread of the front section and the internal thread of the front section 2 Greater than or equal to the pitch T of the rear external thread and the rear internal thread 1 . It can not only effectively improve the anti-torque ability of the threaded drill pipe joint, but also the sealing surface is reliable, the elastic deformation of the sealing contact is stable, and the sealing is tight. It is very suitable for the exploration and exploitation of oil and gas deep wells, ultra-deep wells and complex wells.

Description

technical field [0001] The present invention relates to a threaded connection device for petroleum drill pipes used in the exploration and production of oil and gas, in particular to a connection device with a tapered screw thread of an external threaded joint and an internal threaded joint threaded with each other. The threaded connection device is used to transmit the torque of the drill pipe and has a tight sealing performance. Background technique [0002] Oil drill pipe is the main equipment for oil and gas exploration and exploitation. Oil and gas well operations rely on the drill pipe to transmit the torque between the uphole and the downhole, and deliver drilling fluid and mud to the well; when the oil drill pipe is drilling, it mainly bears complex loads such as torsion, compression, bending, vibration, etc. During normal working process, the inside is filled with drilling fluid. The main function of drilling fluid is to carry cuttings from the bottom of the well t...

AI Technical Summary

Problems solved by technology

The Chinese patent "Curved Surface Double Shoulder Tool Joint" (patent number: 201220608835.1) is to change the contact surface of the main and auxiliary shoulders of the double shoulder joint from a flat surface to a curved surface, thereby increasing the contact area, although it has a certain impact on the sealing performance. improvement, but its sealing performance still depends on axial load and axial contact stress

These sealing structures all have shortcomings such as small contact surface, great influence on the load condition of the drill pipe, small contact elastic deformation and small contact stress of the sealing mating surface, so that reliable sealing performance cannot be guaranteed, especially in deep well or ultra-deep well operation. ideal

Images