A two-way air-tight drill pipe joint with tensile bending resistance

Abstract

The invention relates to an anti-stretching-bending bidirectional air-tight seal tool joint. The anti-stretching-bending bidirectional air-tight seal tool joint consists of an inner threaded workpiece and an outer threaded workpiece, wherein the inner threaded workpiece comprises a first outer circular bead surface, a first cylindrical hole, a conical hole matched with a wedge-shaped rubber ring, a second outer circular bead surface, a conical hole, an outer thread, an inner thread large-end sealing conical surface, a second cylindrical hole, an inner circular bead surface and an inner thread sealing ring groove; the inner circular bead surface and the second cylindrical hole as well as the second outer circular bead surface and the conical hole are in transition connection in sequence; the outer threaded workpiece comprises a wedge-shaped rubber sealing ring, a first outer circular bead surface, a first cylindrical surface, a rubber sealing ring mounting cylindrical surface, a second outer circular bead surface, a stress relieving groove, an outer thread, an outer thread nose end sealing conical surface, a second cylindrical surface, an inner circular bead surface, an outer thread sealing ring groove and a metal sealing ring. The anti-stretching-bending bidirectional air-tight seal tool joint has inner and outer sealing structures, and bidirectional sealing can be realized for the joint after engagement of the inner and outer threads, so that the sealing reliability of a drilling string system under stretching and bending loads is enhanced, and very high air-tight performance is achieved; the anti-stretching-bending bidirectional air-tight seal tool joint is suitable for exploiting oil and gas resources under the complex well conditions of high pressure wells, ultrahigh pressure wells, directional wells, large displacement wells, horizontal wells and the like.

Description

technical field [0001] The invention belongs to the technical field of threaded connection of oil well pipes, and relates to a drill pipe joint for oil and natural gas development, in particular to a tensile-bending two-way gas-sealed drill pipe joint. Background technique [0002] Drill pipes are connected by drill pipe joints to transport drilling fluid. Therefore, the drill pipe joints should have good liquid sealing performance. At the same time, due to the needs of well logging, higher requirements are put forward for the air sealing performance of the joints. . Due to the structure of the traditional threaded joint, there is a spiral leakage channel between the meshing teeth, which is mainly sealed by thread grease, but because the leakage channel is not effectively blocked, the thread grease will flow out, and the high temperature and high pressure will significantly reduce its sealing. performance. In this regard, the API joint adopts a sealing form in which single...

AI Technical Summary

Problems solved by technology

In this regard, the API joint adopts a sealing form in which single shoulders squeeze each other. This structure only seals the outer annulus and fails to prevent the internal high-temperature and high-pressure drilling fluid from eroding the thread teeth. At the same time, tensile and bending loads will cause platform Shoulder separation, rendering seal ineffective

[0003] In order to improve the sealing performance of the joint, the American Grant Company developed and designed the double-shoulder joint, but it still failed to effectively solve the leakage problem caused by the tensile load; the patent CN201826771U added a metal cone sealing structure at one end of the double-shoulder, which improved The sealing performance of the inner shoulder, but the drilling fluid can still erode the sealing cone surface through the gap of the inner shoulder, and the life of the sealing structure cannot be effectively guaranteed

At the same time, under the action of bending load, the outer shoulder has a tendency to open, which will also cause leakage

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