Coupling of tubing

Abstract

This utility model relates to the oil and gas piping industry, specifically to connecting elements for tubing used in well operations under cyclic loads and threaded connection wear. It can be used to repair and restore threaded connections in tubing. An asymmetric tubing coupling comprises a cylindrical body with internal threads on two opposite sides for connection to tubing. The coupling body has an asymmetrical internal geometry, with one of the threaded portions being designed as a repairable portion of the body, intended to be positioned on the side of the connection subject to predominant wear.The invention comprises an internal thread section and an adjacent, elongated, repairable section of the housing, having an axial length exceeding the threaded portion and the end face length of the coupling, and forming a localized reserve of material for forming a threaded profile. Moreover, said repairable section is formed only on one side of the housing, while the opposite threaded section is designed without the possibility of repair and without a structural reserve of material for its implementation. The technical result consists in ensuring the operability of the coupling when one of the threaded sections is predominantly worn by localizing the reserve of material for restoring the threaded profile within one side of the housing with minimal metal consumption. 3 ill.

Description

[0001] The utility model relates to the pipe industry in the oil and gas industry, in particular to connecting elements of oil and gas pipes used in the operation of wells under conditions of cyclic loads and wear of threaded connections, and can be used in the repair and restoration of threaded connections of oil and gas pipes.

[0002] Patent US20050242583A1 is known, which describes a coupling for connecting two pipes with external threads, wherein the internal thread of the coupling is made multi-conical and includes several threaded sections with different geometries.

[0003] The disadvantage of this technical solution is that the coupling design does not provide a structural reserve of material for restorative machining of the threaded sections. The multi-taper design of the internal thread is designed to distribute loads during operation and does not allow for the reshaping of the thread profile after wear. If the threaded sections are damaged or worn, the coupling must be replaced, which increases repair costs and reduces the service life of the connection.

[0004] A coupling for oil well tubing according to GOST 633-80 or GOST 31446-2017 is known, made in the form of a cylindrical body with internal pipe threads located on two opposite sides and intended for connecting oil well tubing of standard sizes.

[0005] The disadvantage of this technical solution is that the coupling body has a fixed axial length, which does not provide additional material reserves for repair operations. If the coupling's internal threads are worn or damaged, restoring the connection is only possible by completely replacing the coupling, removing it from both connected pipes, which increases the labor intensity of repairs and operating costs. The design of the standard coupling does not allow for the reshaping of the internal thread profile without changing its geometric dimensions, nor does it allow for repairs to be performed on one threaded section while maintaining the functionality of the opposite threaded section.

[0006] The closest technical solution to the claimed technical solution is patent RU 2021090, "Method for Restoring Tubing with Worn Threaded Connections." This solution aims to improve the processability and reliable operation of worn threaded connections. It utilizes simpler equipment. The method for restoring tubing involves unscrewing a coupling, threading its worn portion onto the worn threaded end of the pipe, and creating a permanent connection between the coupling and the pipe body. During the restoration of threaded pipe connections, joint heating of the pipe end and the coupling seated on it to a hardening temperature, which relaxes stresses in the connection, significantly facilitating coupling removal.The strength of the connection is also increased by the fact that before screwing the coupling with the worn part onto the worn threaded end of the pipe, their threads are lubricated with epoxy glue, which increases the strength of the connection.

[0007] The disadvantage of the known method is that the design of the coupling does not provide a reserve of material for re-forming the internal thread profile.

[0008] The technical result of the claimed utility model is to ensure the operability of the coupling when one of the threaded parts is predominantly worn out by localizing the reserve of material for restoring the threaded profile within one side of the housing with minimal metal consumption.

[0009] The specified result is achieved by creating a tubing coupling that contains a cylindrical body with internal threads made on two opposite sides for connection to tubing.

[0010] What is new is that one of the threaded parts is made in the form of a repairable part of the housing, intended for placement on the side of the connection that is subject to predominant wear, and includes a section of the internal thread and an adjacent repair section of the housing, having an axial length exceeding the length of the threaded part and the length of the end of the coupling and forming a localized reserve of material for forming a threaded profile, wherein said repair section is made only on one side of the housing.

[0011] Fig. 1 shows a general isometric view of the device.

[0012] Fig. 2 shows a general front view.

[0013] Fig. 3 shows a general side view in section.

[0014] The tubing coupling comprises a cylindrical body 1, configured to connect two tubing strings (not shown in the drawings). The inner surface of the body 1 is provided with internal threads on two opposite sides of the body and designed for screwing onto the external threads of the tubing strings. The design, materials, and manufacturing methods of the body comply with current standards, such as GOST 633-80 or GOST 31446-2017.

[0015] One of the threaded sections of the housing is designed as a repairable section 3, intended for placement on the side of the connection subject to predominant wear. Repairable section 3 comprises an internal thread section and an adjacent extended repair section.

[0016] The recovery section of the housing is made integral with the housing 1 and has an axial length that exceeds the length of the threaded part and the length of the end face of the coupling.

[0017] The specified restoration section forms a localized reserve of material for forming the thread profile during restoration repairs. The axial extension of this section ensures the availability of a sufficient volume of material for forming a new thread profile when removing the worn section of the thread. The opposite threaded section of the housing 2 is designed without a structural reserve of material for restoration and complies with the standard geometric parameters of tubing couplings. This section of the housing does not contain a restoration section and is not intended for restoration operations. The axial dimensions of the repaired section of the housing 3 are selected such that, after removing the damaged section of the internal thread, it is possible to re-form the thread profile while maintaining the required geometric parameters and strength characteristics of the coupling in accordance with current standards.For example, the length of the extended recovery section is 43-48 mm. The coupling body material meets the requirements for tubing couplings and can be made, for example, of carbon or alloy steel, used for the manufacture of standard tubing couplings.

[0018] The damaged thread is removed to a length corresponding to the wear depth. A new section of internal thread is then formed using the localized material reserve created by the extended repair section of the housing, preserving the geometric parameters of the thread profile. Re-threading is performed using standard thread-cutting tools used for processing tubing, without the need to modify the coupling design or use additional components according to known standards. The coupling housing material meets the requirements for tubing couplings and can be made, for example, of alloy or carbon steel, similar to those used for standard tubing couplings.

[0019] The device operates as follows.

[0020] During operation of tubing, the threaded connections of the coupling are subject to cyclic loads and wear. Wear may be predominantly localized on one side of the coupling. The coupling is installed so that the section of housing 3 being repaired is positioned on the side of the connection subject to predominant wear. If the threaded section of housing 3 being repaired wears, the damaged section of the thread is removed. After removing the damaged section, a new thread profile is formed using the localized reserve of material formed by the extended repair section of the housing. The opposite threaded section of housing 2 is not subject to repair and maintains its connection to the tubing.

[0021] Using the proposed coupling will ensure the coupling's operability in the event of predominant wear of one of the threaded parts due to the localization of the material reserve on only one side of the housing, increase the efficiency of material use due to its concentration in the restoration zone, reduce the material consumption of the structure by eliminating the excessive distribution of the material reserve, and also maintain the strength characteristics of the coupling after restoration operations due to the formation of a threaded profile within a localized restoration area while maintaining the geometric parameters in accordance with current standards.

Claims

A tubing coupling comprising a cylindrical body with internal threads made on two opposite sides for connection with tubing, characterized in that one of the threaded parts is made in the form of a repairable part of the body, intended for placement on the side of the connection subject to predominant wear and including a section of the internal thread and an adjacent repair section of the body, having an axial length exceeding the length of the threaded part and the length of the end face of the coupling, and forming a localized reserve of material for forming a threaded profile, wherein said repair section is made only on one side of the body.

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