UA114240C2 - PIPE THREADED CONNECTION - Google Patents

Abstract

The invention relates to the field of threaded pipe joints, which can be used for the installation of oil pipes or for the assembly of columns of drill and casing in the construction of oil and gas wells. Pipe threaded connection formed by threaded end portions (1) with an external abutment conical thread (2) of two coaxially located predominantly casing or oilfield pipes (3), as well as threaded end portions (4) of the coupling (5) with a corresponding internal abutment conical thread (6), connected in pairs by said threaded end sections (1, 4) by means of two threaded connections (7) with a counter thrust conical thread, while inside the coupling (5) is a sealing ring (8) with enclosing it (8) elastic-plastic element (9), made in an annular shape, interacting with the coupling (5). According to the invention, the sealing ring (8) is made with end outer annular grooves (10) and an inner concave curved surface (11), and the elastic-plastic element (9) is made with end inner annular protrusions (12), which are engaged with said end outer annular grooves (10) of the sealing ring (8), and has end outer conical surfaces (13), while the elastic-plastic element (9) is fastened to the sealing ring (8) by crosslinking the molecules and is in tight contact with internal abutment conical thread (6) of the end portions (4) of the middle part of the coupling (5). EFFECT: increase of tightness and reliability of pipe threaded connection.

Description

grooves (10) and an internal concave curved surface (11), and the elastic-plastic element (9) is made with end internal annular protrusions (12), which engage with the mentioned end external annular grooves (10) of the sealing ring (8), and has final external conical surfaces (13), while the elastic-plastic element (9) is fastened to the sealing ring (8) by means of molecular cross-linking and is in hermetic contact with the internal thrust conical thread (6) of the end sections (4) of the middle part couplings (5).

Technical result: increased tightness and reliability of pipe threaded connection.

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WITHOUT и и и ни Овие и а КК

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Y 7 y Sy o x KN i CHI ON ha y y i koi I from ghi ShK Zelenykh o y

Fig. 1

The invention belongs to the field of threaded pipe connections, which can be used for the installation of oil production pipes or for the assembly of drill and casing pipe columns during the construction of oil and gas wells.

In modern conditions, there is an increase in the requirements for the reliability of threaded pipe connections, based on the increase in their ability to transmit a large torque in a column of oil production pipes during drilling operations and their reliable tightness, associated with the constant complication of oil and gas production conditions.

The insufficient ability of threaded pipe connections to transmit a large torque in a column of oil production pipes significantly limits the technological capabilities of columns of drill and casing pipes in the construction of deep oil and gas wells when drilling strong rocks, which reduces their reliability during operation.

The leakiness of threaded pipe joints often leads to the premature appearance of corrosion damage to the metal in the area of threaded joints, leakage and, further, to the destruction of casing or oil pipelines, which also leads to a decrease in their reliability during operation.

One of the ways to increase the reliability of threaded pipe connections, based on increasing the ability to transmit a large torque in the oil pipeline column and increasing their tightness, is the choice of the optimal design of the connection elements, the design and layout of the main sealing link - the sealing ring, as well as the selection optimal ratios of geometric parameters of the elements of the threaded connection of pipes.

Threaded pipe connections are known from the prior art, which are similar in purpose and have similar essential features.

A pipe threaded connection is known, formed by threaded end sections with an external stop conical thread of two coaxially located mainly casing or oil production pipes, as well as threaded end sections of a coupling with a corresponding internal stop conical thread, connected in pairs by said threaded end sections using two threaded connections with a counter-stop conical thread, while a sealing ring is installed inside the coupling.

АРІ іShbipa5 apa sazipao5 apOa teiiod5 oi azbzetbriyd іShe zate "0О55689871А (fig. 2, 3),

Zo (SAVZTEM5EM, KEMMETN U) (05) В21К 21/16; 25.11.19971. P1Y

This connection (| has a high ability to transmit a large torque in a string of oil pipelines, since the torque is transmitted through the chain of metal components of the connection "pipe (metal) - sealing ring (metal) - pipe (metal)" and without axial force influence on the coupling.

The disadvantage of this connection (1| is that the metal sealing ring does not ensure reliable tightness of the connection in the place of its contact with the metal coupling, in addition, in the place of the previously mentioned metal-to-metal type contact, additional loads are created on the coupling, which can lead to its destruction.

A pipe threaded connection is known, formed by threaded end sections with an external stop conical thread of two coaxially located mainly casing or oil production pipes, as well as threaded end sections of a coupling with a corresponding internal stop conical thread, connected in pairs by said threaded end sections using of two threaded connections with a counter-stop conical thread, while a sealing ring is installed inside the coupling, equipped with an elastic element ГРире соириипд сопесиоп зеаиипд аррагайе" 054679831A (fig. 1), (MLSSIAM R.

KIEESMIM5KI) (05) E16I 02/21; 07/14/19871. (21

The elastic element is made of plastic, has a U-shaped cross-section and covers the steel sealing ring from the inside.

At the same time, the side walls of the elastic element cover the ends of the sealing ring and in the working position are fixed together with the sealing ring in the ring grooves - clutch traps, ensuring their correct fit and tightness of the connection during operation.

Among the disadvantages of this connection |2| the following imperfections of its design can be attributed.

When high loads are applied, when the end surfaces of the pipes interact with the elastic element located inside the sealing ring, made of plastic, contact is formed along the chain of the component parts of the connection "pipe (metal) - side wall of the elastic ring (elastic material - plastic) and the sealing ring (metal) corrugated side wall of an elastic ring (elastic material - plastic) - pipe (metal)".

At the same time, the weaker and less durable contact link of this type is the plastic of the elastic element of the sealing ring, which reduces the reliability of torque transmission when screwing-unscrewing the pipes in the column and can lead to the destruction of the elastic element and depressurization of the connection.

In addition, when an elastic element is axially compressed under the influence of an axial load, the size of its inner diameter and, accordingly, the size of the passage section inside the connection decreases, which disrupts the optimal laminar movement of the transported medium - liquid or gas, which turns into an undesirable turbulent traffic that reduces the reliability of their regulatory transportation.

In the operating condition, the outer metal surface of the sealing ring interacts with the middle part of the inner surface of the coupling in the center, creating radial expansion forces that adversely affect the coupling.

At the same time, additional loads arise in the clutch, which can lead to its destruction.

A pipe threaded connection is known, formed by threaded end sections with an external stop conical thread of two coaxially located mainly casing or oil production pipes, as well as threaded end sections of a coupling with a corresponding internal stop conical thread, connected in pairs by said threaded end sections using two threaded connections with a counter-stop conical thread, while a sealing ring with two elastic rings is installed inside the coupling, which are installed on both sides of the sealing ring between the pipes and the coupling

G"Soiriipo, Ip Rapishshag Rog Soppesiipa Apspog Nodv" О52013264819А1 (КО2013130219А) (fig. 1A, 18), I5SNEVESK EVM5T EVIEOVISN IOEI; SOEVZSNII TE RGEVORIMAMO IOEII) E16Й 15/00; 10.10.2013. FROM)

This is a compound of ИZ| has a high ability to transmit a large torque in a column of oil pipelines, as the torque is transmitted through the chain of metal components of the connection "pipe (metal) - sealing ring (metal) - pipe (metal)" and without axial force impact on the coupling .

The disadvantage of this connection (Ж) is that the metal sealing ring with two elastic rings, which are installed on both sides of the sealing ring between the pipes and the coupling, do not ensure a reliable tightness of the connection due to the possibility of squeezing and breaking of thin

From elastic rings during the transmission of a large torque in the column of oil pipelines, which reduces the reliability of the sealing of this connection.

It is also known that the closest in terms of purpose, number of common features and the technical result that can be achieved is a pipe threaded connection formed by threaded end sections with an external stop conical thread of two coaxially located mainly casing or oil production pipes, as well as threaded end sections of a coupling with a corresponding internal with a counter-stop conical thread, connected in pairs by the mentioned threaded end sections by means of two threaded connections with a counter-stop counter-conical thread, while a sealing ring is installed inside the coupling with an elastic-plastic element, made of an annular shape, which interacts with the coupling, covering it (| "Soyripou bog yiBipud og sazipd apa teifyoi oi azzetriu" 0О54706997А (fig. 2) (SAVZTEM5EM KEMMETN U) (05) E161- 15/00; 17.11.19871. 4)

This connection |4|, as well as connection (1, C), has a high ability to transmit a large torque in a column of oil pipelines, since the torque is transmitted through the chain of metal component parts of the "pipe" connection (metal ) - sealing ring (metal) - pipe (metal)" and without axial force impact on the coupling.

The disadvantage of this connection (4) is the imperfection of its design and arrangement of the sealing ring and the elastic-plastic element covering it, as a result of which its high tightness is not achieved during operation.

This is caused by the fact that the elastic-plastic element is in contact with the smooth inner surface of the metal bore of the coupling, and from the inside with the smooth outer surface of the metal of the sealing ring, which does not guarantee a high degree of sealing of the smooth contacting surfaces of the mentioned component sealing elements of the connection in the working position during operation in composition of the column of oil industry pipes, which reduces the operational reliability of the known pipe threaded connection.

The technical problem to which the claimed invention is directed is the improvement of the pipe threaded connection by: - choosing the optimal geometric shape of the sealing ring and the elastic-plastic element for their effective mechanical connection with each other, which ensures a tight and strong contact of the adjacent parts one of the connected surfaces; bo - execution of a sealing ring with an internal concave curved surface;

- additional connection of the contacting surfaces of the sealing ring and the elastic-plastic element at the molecular level; - ensuring the elastic hermetic contact of the elastic-plastic element with the internal thrust conical thread of the end sections of the middle part of the coupling.

The technical result, which is achieved by solving the given technical problem and using the improved hermetic threaded connection of metal pipes, consists in increasing the tightness and reliability of the threaded connection.

The set technical problem is solved, and the technical result is achieved by the fact that in the pipe threaded connection formed by the threaded end sections with an external thrust conical thread of two coaxially located mainly casing or oil production pipes, as well as the threaded end sections of the coupling with a corresponding internal thrust conical thread, are connected in pairs by the mentioned threaded end sections by means of two threaded connections with a counter-stop conical thread, while inside the coupling there is a sealing ring with an elastic-plastic element covering it, made of an annular shape, interacting with the coupling, according to the invention, the sealing ring is made with end outer annular grooves and an inner concave curved surface, and the elastic-plastic element is made with end inner annular protrusions that engage with said end outer annular grooves of the sealing ring, and has final external conical surfaces, while the elastic-plastic element is attached to the sealing ring by means of cross-linking of molecules and is in hermetic contact with the internal thrust conical thread of the final sections of the middle part of the coupling.

Due to the fact that the sealing ring is made with end external annular grooves, and the elastic-plastic element is made with end internal annular protrusions that engage with the mentioned end external annular grooves of the sealing ring, a reliable hermetic, tight and durable contact is ensured adjacent to each other connected stepped surfaces of the end parts of the sealing ring and elastic-plastic element.

Due to the fact that the sealing ring is made with an internal concave curve

From the surface, in the process of screwing pipes with a coupling and forming pipe threaded connections with the help of sealing rings with elastic-plastic elements covering them, made of an annular shape, the formation of bending moments applied to the end parts of the sealing ring is ensured.

At the same time, the mentioned bending moments affect the end parts of the sealing rings and bend them so that the middle parts bend towards the coupling, increasing in diameter, as a result of which the pressing force and the degree of sealing of the sealing rings with elastic-plastic elements and couplings in the column of oil pipelines increase .

The execution of an elastic-plastic element with final external conical surfaces in the working position during operation as part of a column of oil production pipes ensures convenient installation of a sealing ring with an elastic-plastic element when screwing pipes with a coupling, which is carried out without burrs and without violating the integrity of the elastic-plastic element, as a result of which the tightness of the threaded pipe connection is broken during their installation.

Due to the fact that the elastic-plastic element is fastened to the sealing ring with the help of crosslinking of molecules, a dense molecular connection of the contacting surfaces is ensured, which increases the tightness of their connection.

Due to the fact that the elastic-plastic element is in hermetic contact with the internal thrust conical thread of the end sections of the middle part of the coupling, their elastic or plastic hermetic contact with the turns of the mentioned conical thread of the coupling is achieved, which significantly increases the tightness of their interaction.

The mentioned main differences of the improved hermetic threaded connection of metal pipes provide a significant increase in its tightness and reliability.

The improved hermetic threaded connection of metal pipes, in addition to the mentioned main differences, has additional differences that increase or create an additional technical result.

In the hermetic threaded connection of metal pipes, according to the invention, the following additional improvements have been made.

The sealing ring is made with a width of 5, equal to З - (0.9-1.1) « 2) mm, where У is the distance from the end surface of the threaded end section of the pipe to the central transverse plane of the coupling, because with machine screwing of the standard connection АРИ 5рес 58 , which is U-12.7 mm.

Such a choice of width 5 - (0.9-1.1) « 27) (mm) of the sealing ring provides the tubular threaded connection with guaranteed reliability when transmitting large torques.

When choosing a width of the sealing ring less than 5 x 0.9 « 27 (mm) - additional loads are created in the thread even before the ends of the pipes come into contact with the sealing ring, which negatively affects the bearing capacity of the thread, and when choosing a width of the sealing ring more than 521.1 g 2) - optimal engagement of the thread teeth is not ensured, additional gaps appear, as a result of which the load-bearing capacity of the thread teeth decreases, which can lead to their damage, as well as to the loss of tightness of the threaded connection.

In the sealing ring, the inner concave curved surface is made with a radius K equal to K-50-1000 mm.

This ensures the optimal curvature of the inner »concave curved surface of the sealing ring, at which bending moments of the required magnitude occur, causing the middle part of the sealing ring to bend towards the coupling to increase the tightness of the connection.

The sealing ring is made of steel, preferably of the same grade as the pipes and coupling.

This ensures the manufacturability of the design because it reduces the nomenclature of steel used for the manufacture of pipes, coupling and sealing ring of the connection.

The end surfaces of the sealing ring are made with hardness NKS1-40-60 and roughness

B21-200-400 μm, and the end surfaces of the threaded end sections of the pipes are made with hardness

NKS»2-27-32 and roughness K22-10-30 μm.

With such optimal values of hardness NKS1-40-60 and roughness K21-200-400 μm and

A22-10-30 μm in the contact zone of the end surfaces of the sealing ring and the end surfaces of the end parts of the pipes, due to the increased hardness of NKS1-40-60 roughness

B21-200-400 of the end surfaces of the sealing ring, the friction coefficient y, the friction force E and the value of the torque M increase, which accordingly increases the reliability and tightness of the connection when transmitting large torques.

The end external annular grooves of the sealing ring and the end internal annular protrusions of the elastic-plastic element are made with a length Y, equal to I -3-5 mm, and a height H,

With equal H-1-3 mm.

This provides optimal geometric parameters of the end outer annular grooves of the sealing ring and the end internal annular protrusions of the elastoplastic element, which achieves a reliable hermetic, dense and longitudinally shear-resistant stepped contact of the adjacent stepped surfaces of the end parts of the sealing ring and the elastoplastic element element

The sealing ring is made with an outer diameter Ok, equal to Ok - (Utip-2Nk) and 0.5, mm, where: Utip is the minimum inner diameter of the tops of the profile of the internal thrust conical thread of the threaded end sections of the coupling, mm; yk - height of the profile of the thrust conical thread of the threaded end sections of the coupling, mm.

Due to this, free installation of the sealing ring in the coupling is ensured without damage to the profile of its internal stop conical thread.

The inner surfaces of the pipes are made with a Kiz roughness equal to Klz-20-40 μm, and the inner concave curved surface of the sealing ring is made with a K74 roughness equal to

B24-5-20 μm.

This ensures laminar movement of the flowing medium (liquid or gas) without turbulent eddies.

The internal chamfers of the end surfaces of the threaded end sections of the pipes, as well as the internal chamfers of the end surfaces of the sealing ring are rounded, with radii of rounding, respectively, Ki, Rg, equal to K:-P2 "x 0.5 mm.

This allows you to avoid swirls at the junction of the end surfaces of the threaded end sections of the pipes and the sealing ring, which ensures a laminar flow regime of the transported liquid (oil) or gas, and also reduces the probability of accumulation of stress concentrators.

In the elastic-plastic element, the final external conical surfaces are made with a length | equal to 1-3-6 mm and with a cone angle VD equal to DV - 400-602.

Due to this, it is possible to simplify the installation of the sealing ring in the middle part of the coupling without the occurrence of additional loads on the coupling, as well as without breaking the hermetic, tight and strong contact of the adjacent stepped surfaces of the end parts of the sealing ring and the elastic-plastic element.

The elastic-plastic element is made of an elastic-plastic material with a strength limit b equal to co - 10-200 MPa, and a hardness of НВз-5-90 НВ, and the thickness B of the elastic-plastic element in the middle part is equal to В 2 pPkO.25, where Pk is the height of the profile of the internal thrust conical thread of the threaded end sections of the coupling, mm.

This makes it possible to install the sealing ring without damaging the internal conical thrust thread of the coupling, since the strength limit с and the hardness НВз of the elastic-plastic element are smaller than the strength limit 01 and the hardness НВае of the steel from which the coupling is made.

The thickness B in the middle part of the elastic-plastic element, equal to B 2 pknO0.25, provides a gap between the metal surfaces of the thrust conical thread of the coupling and the metal ring, as a result of which the occurrence of additional loads on the coupling is prevented.

In the following, the invention is explained by an example of its implementation with references to the attached drawings.

In fig. 1 shows a pipe thread connection, general view.

In fig. 2 shows the removed element A in fig. 1.

In fig. C shows a sealing ring with an elastic-plastic element.

In fig. 4 shows the removed element B in fig. 2.

The threaded pipe connection (Fig. 1-4) is formed by threaded end sections 1 with an external stop conical thread 2 of two coaxially located mainly casing or oil production pipes 3, as well as threaded end sections 4 of a coupling 5 with a corresponding internal stop conical thread b, in pairs connected to each other by the mentioned threaded end sections 1,4 with the help of two threaded connections 7 with counter-stop conical threads, while inside the coupling 5 a sealing ring 8 is installed with an elastic-plastic element 9 covering it, made of an annular shape, which interacts with coupling 5.

The main features of the threaded pipe connection are the following improvements in its design.

The sealing ring 8 is made with end external annular grooves 10 and an internal concave curved surface 11.

The elastic-plastic element 9 is made with end internal annular protrusions

From 12, which engages with the mentioned end external annular grooves 10 of the sealing ring 8, and has end external conical surfaces 13.

At the same time, the elastic-plastic element 9 is fastened to the sealing ring 8 by means of crosslinking of molecules and is in hermetic contact with the internal thrust conical thread 6 of the end sections 4 of the middle part of the coupling 5.

Additional features of the threaded pipe connection are the following improvements in its design.

The sealing ring 8 is made with a width of 5, equal to 3 - (0.9-1.1) g 2) mm, where ARI Zres 58V connection, which is 9-12.7 mm.

In the sealing ring 8, the inner concave curved surface 11 is made with a radius

E, equal to K-50-1000 mm.

The sealing ring 8 is made of steel, preferably of the same grade as the pipes C and coupling 5.

The end surfaces 16 of the sealing ring 8 are made with a hardness of НКС1-40-60 and a roughness of К71-200-400 μm, and the end surfaces 17 of the threaded end sections 1 of pipes C are made with a hardness of НКС2-27-32 and a roughness of К22-10-30 μm.

The end external annular grooves 10 of the sealing ring 8 and the end internal annular protrusions 12 of the elastic-plastic element 9 are made with a length I equal to 1-3-5 mm and a height H equal to H-1-3 mm.

Sealing ring 8 is made with an outer diameter Ok, equal to Ok - (Otip-2Nk) and 0.5, mm, where: Yultip is the minimum inner diameter of the tops of the profile of the internal thrust conical thread 6 of the threaded end sections 4 of the coupling 5, mm; yk - the height of the profile of the internal thrust conical thread 6 of the threaded end sections (4) of the coupling 5, mm.

The inner surfaces 17 of pipes C are made with a roughness of Kiz equal to K23-20-40 μm, and the inner concave curved surface 11 of the sealing ring 8 is made with a roughness of K74, equal to

B24-5-20 μm.

The internal chamfers 18 of the end surfaces 14 of the threaded end sections 1 of the pipes 3, as well as the internal chamfers 19 of the end surfaces 16 of the sealing ring 8 are rounded, with 60 radii of rounding, respectively, Ki, B2, equal to K:-B52 x 0.5 mm.

In the elastic-plastic element 9, the final external conical surfaces 13 are made with a length of 1-3-6 mm and with a cone angle of VD equal to DV - 400-602.

The elastic-plastic element 9 is made of an elastic-plastic material with a strength limit b equal to co - 10-200 MPa, and a hardness of НВз-5-90 НВ, and the thickness B of the elastic-plastic element 9 in the middle part is equal to В 2 Пкі0 ,25, where pc is the height of the profile of the internal thrust conical thread of the threaded end sections 4 of the coupling 5, mm.

Example

The experimental sample of pipe threaded connection (Fig. 1-4) was formed in accordance with paragraphs 1-11 of the claims of the invention and was made in accordance with the current standards for "Buttress" type threads from P110 metal (pipe, coupling, sealing ring) and had the following geometric parameters.

The size of the pipes is 5 2".

The sealing ring 8 is made with a width of 5 equal to 5-27 mm.

The inner concave curved surface 11 has a radius K equal to K-450 mm.

The roughness of the end surfaces of 16 sealing rings is 8 K721-320 μm.

The hardness of the end surfaces of 16 sealing rings 8 NAS.1-50.

The roughness of the end surfaces of 14 threaded end sections of 1 pipe is К22-27 μm.

Hardness of the end surfaces of 14 threaded end sections of 1 pipe Z NKS2-29.

The minimum internal diameter of the tops of the profile of the internal thrust conical thread 4 couplings 5 Otip-132.4 mm.

The outer diameter of the sealing ring is 8 OK-129 mm.

The height of the Pk thread profile is 1.575 mm.

The end external annular grooves 10 of the sealing ring 8 and the end internal annular protrusions 12 of the elastic-plastic element are made with a length of GI equal to 1-3 mm and a height H equal to H - 1.3 mm.

The outer diameter of the sealing ring 8 Ok:

Ok - (Otip-2Nk) same 0.5-132.4-2 1.575 - (132.4-3.15) - 005-129 mm.

The inner surfaces 17 of pipes C are made with a roughness of Kz equal to K23-25 μm, and the inner concave curved surface 11 of the sealing ring 8 is made with a roughness of K74, equal to

From B24-8 microns.

The internal chamfers 18 of the end surfaces 14 of the threaded end sections 1 of the pipes 3, as well as the internal chamfers 19 of the end surfaces 16 of the sealing ring 8 are rounded, with the radii of rounding, respectively, Ki, B2, equal to K:-H2-0.4 mm.

The final external conical surfaces 13 in the elastic-plastic element 9 are made with a length of I 1 equal to I-5 mm and with a cone angle VD equal to VD - 459.

The elastic-plastic element 9 was made of elastic-plastic rubber, with a strength limit b equal to c - 50 MPa, and a hardness of НВз-40 НВ, and the thickness B of the elastic-plastic element 9 in the middle part was made equal to В - 1.8 mm

The elastic-plastic element 9 can be made of any elastic-plastic material with a strength limit o equal to o - 10-200 MPa, and hardness НВз-5-90 НВ, since in these ranges the elastic-plastic material 9 is less strong and softer than the material of the coupling, and accordingly does not damage the internal stop conical thread b of the coupling 5 when installing the sealing ring 8.

The manufacture, installation and operation of a threaded pipe connection is carried out as follows.

The test sample was made in accordance with the АРИ Zres 5B standard from P110 metal (pipes, coupling, sealing ring).

After the production of the metal sealing ring 8 on a lathe, shot blasting or shot peening of the end surfaces 16 of the sealing ring 8 is used to achieve the required parameters of roughness Cl: and hardness

NVS..

By changing the shot delivery modes on the end surfaces 16 of the sealing ring 8, it is possible to adjust the parameters of roughness Кl: and hardness НАС.

This makes it possible to select the optimal parameter of roughness K21-200-400 μm and hardness NAKS-40-60, at which the connection will meet the maximum level of reliability and tightness.

Instead of shot blasting or shot peening, other types of processing can be used, which increase the parameters of roughness Кl: and hardness НЕСi of the end surfaces 16 of the sealing ring 8.

The end surfaces of 14 threaded end sections 1 of pipes C have the necessary parameters of roughness K272-10-30 μm and hardness NEKS2-27-32 after mechanical processing.

Then, a layer of elastic-plastic material of an elastic-plastic element 9 of the required shape and given geometric parameters is applied to the sealing ring 8 on a special device.

At the same time, the process of crosslinking of the molecules of the elastic-plastic material of the elastic-plastic element 9 with the outer surface of the sealing ring 8 takes place, as a result of which a reliable hermetic, dense and strong contact is ensured at the molecular level of the adjacent stepped surfaces of the end parts of the sealing ring 8 and elastically -plastic element 9.

After that, the finished sealing ring 8 with the elasto-plastic element 9 covering it (pre-lubricated) is placed to be fixed in the coupling manually or with the help of a special device.

Then there is a process of screwing one pipe C with a coupling 5 in the direction of the previously inserted sealing ring 8 with an elastic-plastic element 9 covering it.

At the same time, the moment of contact of the end surface 14 of the pipe C with the end surface 16 of the sealing ring 8 occurs.

Screwing occurs to the base of the triangular stamp (or it may not reach the base by 1-2 mm).

Thus, the sealing ring 8 in the clutch 5 is centered.

Next, the process of screwing the other pipe C with the coupling 5 until the end surface 14 of the pipe C meets the end surface 16 of the ring 8 is carried out.

In the contact zone of the end surfaces 16 of the sealing ring 8 and the end surfaces 14 of the end parts of the pipes 3, due to the increased hardness of NKS1-40-60 roughness K721-200-400 of the end surfaces of the sealing ring, the coefficient of friction (M, friction forces E and the amount of torque moment of M.

Due to the fact that the elastic-plastic element 9 is in hermetic contact with the internal thrust conical thread of the end sections 4 of the middle part of the coupling 5, their elastic or plastic hermetic contact with the turns of the mentioned conical thread is achieved

From clutch 5, which significantly increases the tightness of their interaction.

Also, at the same time, there are bending moments of the required magnitude, causing the middle part of the sealing ring 8 to bend to the side of the coupling 5 to increase the tightness of the connection.

Thus, with the help of the sealing ring 8, a greater torque is simultaneously transmitted and the tightness of the threaded connection increases.

The quality of screwing of pipe threaded connection is controlled: - by the torque value; - according to the screwing diagram (if the appropriate equipment is available); - in the absence of unacceptable damage on the body of the pipe Z and coupling 5.

Tests of the experimental sample of the improved pipe threaded connection allowed the applicant to visually verify the improvement of its tightness and reliability in real conditions.

The given information confirms the possibility of industrial suitability of the proposed pipe threaded connection, which has increased tightness and reliability in operation, does not require large costs during manufacture and installation, and can be widely used for the installation of casing or drill pipe columns in the construction of oil and gas wells.

List of designations: 1) threaded end sections of pipes (3); 2) external thrust conical thread of threaded end sections (1) of pipes (3); 3) pipes (mainly casing or oil pipes); 4) threaded end sections of the coupling (5); 5) clutch; b) internal stop conical thread of the threaded end sections (4) of the coupling (5); 7) two threaded connections with a counter-stop conical thread of two coaxially located pipes (3) with a coupling (5); 8) sealing ring; 9) elastic-plastic element of the sealing ring (8); 10) end external annular grooves of the sealing ring (8); 11) inner concave curved surface of the sealing ring (8); 12) end internal annular protrusions of the elastic-plastic element (9); bo 13) final external conical surfaces of the elastic-plastic element (9);

14) end surfaces of threaded end sections (1) of pipes (3); 15) central transverse plane of the coupling (5); 16) end surfaces of the sealing ring (8); 17) inner surfaces of pipes (3); 18) internal chamfers of end surfaces (14) of threaded end sections (1) of pipes (3); 19) internal chamfers of the end surfaces (16) of the sealing ring (8);

C - width of the sealing ring (8), mm; C - (0.9-1.1) « 2) mm;

Y - the distance from the end surface (14) of the threaded end section (1) of the pipe (3) to the central transverse plane (15) of the coupling (5) during machine screwing of the standard connection АРИ зрес 58, mm; U-12.7 mm;

B - inner concave curved surface of the coupling (5), mm; K-50-1000 mm;

NES; - the hardness of the end surfaces (16) of the sealing ring (8); nex.-40-60;

Vaz - roughness of the end surfaces (16) of the sealing ring (8), μm;

B21-200-400 μm;

NES" - hardness of end surfaces (14) of threaded end sections (1) of pipes (3); NES"-27-32;

НВз - hardness of the elastic-plastic element (9) of the sealing ring (8);

HB: 5-90; o - strength limit of the elastic-plastic element (9) of the sealing ring (8); o - 10-200 MPa;

B22 - roughness of end surfaces (14) of threaded end sections (1) of pipes (3); NKOS2-10- 30 μm;

And - the length of the end external annular grooves (10) of the sealing ring (8), the length of the end internal annular protrusions (12) of the elastic-plastic element (9); And -3-5 mm;

H - the height of the end external annular grooves (10) of the sealing ring (8), the height of the end internal annular protrusions (12) of the elastic-plastic element (9); H-1-3 mm;

Ok - the outer diameter of the sealing ring (8); Ok - (Otip-2Nk) same 0.5, mm;

Zo Yutip - the minimum internal diameter of the top profile of the internal thrust conical thread (6) of the threaded end sections (4) of the coupling (5), mm;

Nk - the height of the profile of the internal thrust conical thread (6) of the threaded end sections (4) of the coupling (5), mm;

Vaz - roughness of the inner surface (17) of the pipes (3), μm; K23-20-40 μm;

Va - roughness of the inner concave curved surface (11) of the sealing ring (8), μm; K24-5-20 μm;

B: - the radius of rounding of the internal chamfers (18) of the end surfaces (14) of the threaded end sections (1) of the pipes (3), mm; K-P" x 0.5 mm;

B» - the radius of rounding of the internal chamfers (19) of the end surfaces (16) of the sealing ring (8), mm;; K2-Vi: x 0.5 mm;

It is the length of the final external conical surfaces (13) of the elastic-plastic element (9),

І 1-3-5 mm;

B - cone angle of the final external conical surfaces (13) of the elastic-plastic element (9);

B - 400-609;

B - thickness of the elastic-plastic element (9), mm; In 2 pPk--0.25, mm.

Claims (11)

FORMULA OF THE INVENTION 1. Pipe threaded connection formed by threaded end sections (1) with an external stop conical thread (2) of two coaxially located mainly casing or oil production pipes (3), as well as threaded end sections (4) of a coupling (5) with a corresponding internal with a counter-stop conical thread (b), connected in pairs by the mentioned threaded end sections (1, 4) with the help of two threaded connections (7) with counter-stop counter-conical threads, while a sealing ring (8) is installed inside the coupling (5) ) with an elastic-plastic element (9) covering it (8), made of an annular shape, interacting with a coupling (5), which is characterized by the fact that the sealing ring (8) is made with end external annular grooves (10) and an internal concave curved surface (11), and the elastic-plastic element (9) is made with end internal annular protrusions (12), which engage with the mentioned end external annular grooves (10) of the sealing ring this (8), and has finite external conical surfaces (13), while the elastic-plastic element (9) is attached to the sealing ring (8) by means of cross-linking of molecules and is in hermetic contact with the internal thrust conical thread (b) of the end sections (4) of the middle part of the coupling (5). 2. Tubular threaded connection according to claim 1, which is characterized by the fact that the sealing ring (8) is made with a width of 5, equal to 5-(0.9-1.1)g29U mm, where .) is the distance from the end surface (14 ) of the threaded end section (1) of the pipe (3) to the central transverse plane (15) of the coupling (5) during machine screwing of the standard connection АРИ 5рес 5В, which is 9U-12.7 mm. Z. Pipe threaded connection according to any of claims 1, 2, which is characterized by the fact that in the sealing ring (8) the inner concave curved surface (11) is made with a radius K equal to K-50-1000 mm. 4. Pipe threaded connection according to any of claims 1-3, which is characterized by the fact that the sealing ring (8) is made of steel, preferably of the same grade as the pipes (3) and coupling (5). 5. Pipe threaded connection according to any of claims 1-4, which is characterized by the fact that the end surfaces (16) of the sealing ring (8) are made with a hardness of НКС1-40-60 and a roughness of Кл71 - 200-400 microns, and the end surfaces (17) of the threaded end sections (1) of the pipes (3) are made with a hardness of NKS»2-27-32 and a roughness of K22-10-30 microns. 6. Tubular threaded connection according to any of claims 1-5, which is characterized by the fact that the end external annular grooves (10) of the sealing ring (8) and the end internal annular protrusions (12) of the elastic-plastic element (9) are made length Г, equal to I -3-5 mm, and height H, equal to НА-1-3 mm. 7. Pipe threaded connection according to any of claims 1-6, which is characterized by the fact that the sealing ring (8) is made with an outer diameter Ок, equal to ХОк-(Ютий-2Нк)0.5, mm, where: Otip - the minimum inner diameter of the tops of the profile of the internal thrust conical thread (b) of the threaded end sections (4) of the coupling (5), mm; Pk - the height of the profile of the internal thrust conical thread (6) of the threaded end sections (4) of the coupling (5), mm. 8. Pipe threaded connection according to any of claims 1-7, which is characterized by the fact that the inner surfaces (17) of the pipes (3) are made with a roughness Kz equal to K23-20-40 μm, and the inner concave curved surface ( 11) of the sealing ring (8) is made with a roughness of К, equal to B24-5-20 μm. Zo 9. Pipe threaded connection according to any of claims 1-8, which is characterized in that the internal chamfers (18) of the end surfaces (14) of the threaded end sections (1) of the pipes (3), as well as the internal chamfers (19) end surfaces (16) of the sealing ring (8) are rounded, with radii of rounding, respectively, K:, Rg, equal to K-H220.5 mm. 10. Tubular threaded connection according to any of claims 1-9, which is characterized by the fact that in the elastic-plastic element (9) the final outer conical surfaces (13) are made with a length of 1 equal to 1-3-6 mm, and with a VD cone angle equal to VD-40-6092. 11. Pipe threaded connection according to any of claims 1-10, which is characterized by the fact that the elastic-plastic element (9) is made of an elastic-plastic material with a strength limit b equal to 0-10-200 MPa and hardness НВз-5-90 НВ, and the thickness B of the elastic-plastic element (9) in the middle part is equal to В»ПкнО,25, where Пк is the height of the profile of the internal thrust conical thread (6) of the threaded end sections (4) of the coupling (5), mm Fig. 1