Double-end tubing nipple for oil field

Abstract

The invention relates to the technical field of oil pipe connecting pieces, in particular to a double-end oil pipe nipple for an oil field. Comprising a nipple body used for connecting two oil pipes, inner sleeves are concentrically, fixedly and hermetically connected into two ends of the nipple body, the inner sleeves are positioned on the inner sides of the oil pipes after the oil pipes are in threaded connection with the nipple body, and sealing components are arranged between the inner sleeves and the inner edges of the oil pipes. Through contact linkage of the chamfer at the end of the oil pipe and the guide rod, in the process that the oil pipe is screwed into the nipple body, the elastic rod is bent to drive the sliding ring to move, the pressing roller is driven to extrude the rubber sleeve, the annular cavity size is synchronously reduced, the pressurizing unit is activated, and sealing pressure is automatically enhanced along with the threaded connection progress. Extra operation is not needed in the oil pipe screwing process, sealing strengthening and thread locking are completed in one step, the connecting efficiency is guaranteed, and the connector is particularly suitable for oil field operation scenes with frequent disassembly and assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of tubing connectors, and particularly to a double-headed tubing nipple for oil fields. Background Art

[0002] The existing tubing nipples are used to connect tubing, and both ends are connected by threads. However, during the use of tubing nipples, disassembly and assembly are often required. Repeated disassembly and assembly cause wear of the threads, reducing the sealing performance at the connection with the tubing. At the same time, during the use of tubing nipples, due to impurities in the crude oil, the inside of the tubing nipples is prone to adhesion and blockage, and scale appears, which is not conducive to the transportation of crude oil. Therefore, a double-headed tubing nipple for oil fields is proposed.

[0003] In the prior art, a patent document with the authorization announcement number CN112145829B discloses a double-headed tubing nipple for oil fields. During assembly: First, the two ends of the tubing nipple are respectively threadedly connected to two petroleum pipelines. The left end of the tubing nipple is connected to the petroleum pipeline in the oil inlet direction of the crude oil. During the connection between the tubing nipple and the petroleum pipeline, the inner wall of the petroleum pipeline squeezes the elastic ring, and the elastic ring squeezes the rubber sealing airbag, so that one end of the rubber sealing airbag extends out of the chamber and contacts the inner wall of the petroleum pipeline. When the end of the petroleum pipeline touches the protrusion on the tubing nipple, the rubber sealing airbag is in the closest contact with the inner wall of the petroleum pipeline. Then, the adjusting screw ring is rotated until the inclined surface of the adjusting screw ring contacts the protrusion on the tubing nipple. During this process, the inclined surface of the adjusting screw ring squeezes the extrusion rod to move downward, the extrusion rod pushes the transmission rod to move, the transmission rod pushes the push rod to move, the push rod pushes the expansion ring to move outward, and the expansion ring pushes the rubber sealing ring into the annular card slot on the petroleum pipeline for clamping and sealing. During the connection between the tubing and the nipple, after the tubing and the nipple are connected, the adjusting screw ring still needs to be rotated to achieve a complete connection between the tubing and the nipple. This nipple increases the operation steps for connecting with the tubing and reduces the connection efficiency. Summary of the Invention

[0004] The main object of the present invention is to provide a double-headed tubing nipple that can improve the sealing performance and service life.

[0005] To achieve the above object, the technical solution provided by the present invention is: A double - headed tubing nipple for oil fields, comprising a nipple body. The nipple body is used to connect two tubing strings. Inner sleeves are concentrically and fixedly sealed at both ends inside the nipple body. After the tubing strings are thread - connected to the nipple body, the inner sleeves are located inside the tubing strings. A sealing assembly is arranged between the inner sleeves and the inner edges of the tubing strings. The sealing assembly includes a rubber sleeve located between the inner sleeve and the tubing string. An annular cavity is formed inside the rubber sleeve. The rubber sleeve is fixedly sleeved and sealed outside the inner sleeve. The outer edge of the rubber sleeve is in sealing contact with the inner edge of the tubing string. A fixing sleeve is fixed at one end of the rubber sleeve, and the fixing sleeve is fixed outside the inner sleeve. A sliding ring is slidably sleeved on the inner sleeve. A plurality of elastic rods are fixed on the outer edge of the inner sleeve between the sliding ring and the fixing sleeve. A guide rod is fixed at the end of the elastic rod away from the inner sleeve. A chamfer corresponding to the guide rod is machined at the end of the tubing string. During the process of threading the tubing string into the nipple body, after the chamfer contacts the guide rod, the tubing string pushes the guide rod to move in the direction of the tubing string screwing in. At the same time, one end of the guide rod away from the elastic rod moves towards the inner sleeve. The middle part of the elastic rod bends towards the side away from the fixing sleeve and drives the sliding ring to move. A pressure roller is fixed on the side of the guide rod facing the inner sleeve. After one end of the guide rod away from the elastic rod moves towards the inner sleeve, the pressure roller can squeeze a part of the rubber sleeve outside the tubing string and make the volume of the annular cavity smaller. A plurality of pull rods are fixed on the sliding ring. The pull rods penetrate through the fixing sleeve, and the pull rods are slidably and sealedly connected to the fixing sleeve. The pull rods are connected to a plurality of pressurizing units inside the annular cavity. When the sliding ring drives the pull rods and the pressurizing units to move, the pressurizing units can increase the pressure of the rubber sleeve on the inner edge of the tubing string.

[0006] Specifically, the axis of the guide rod is parallel to the axis of the inner sleeve.

[0007] Specifically, the plurality of elastic rods are circumferentially and evenly distributed according to the axis of the inner sleeve, and the plurality of pull rods are circumferentially and evenly distributed according to the axis of the sliding ring.

[0008] Specifically, a plurality of through - holes are circumferentially and evenly formed in the inner circumference of the fixing sleeve. Sealing rings are fixedly and sealedly connected in the through - holes. The pull rods penetrate through the sealing rings, and the pull rods are slidably and sealedly connected to the fixing sleeve through the sealing rings.

[0009] Specifically, a convex ring is concentrically, fixedly and sealedly connected to the side of the inner sleeve away from the port of the nipple body, and the convex ring is fixedly and sealedly connected to the nipple body.

[0010] Specifically, an outer long groove is formed on the pull rod between the fixing sleeve and the sliding ring. The elastic rod is located in the outer long groove, and the elastic rod is in sliding contact with the pull rod.

[0011] Specifically, support rings are arranged inside the multiple pull rods. The support rings are fixed on the rubber sleeves inside the ring cavities. The outer edges of the pull rods are in sliding contact with the outer edges of the support rings. The pressure boosting unit includes a conical ring fixedly sleeved outside the multiple pull rods. A retaining ring is sleeved outside the multiple pull rods. The outer edges of the pull rods are in sliding contact with the inner edges of the retaining ring. Inner long grooves are formed in the parts of the pull rods corresponding to the retaining ring. Connecting rods are arranged in the inner long grooves. One end of each connecting rod is fixedly connected to the inner edge of the retaining ring, and the other end of each connecting rod is fixedly connected to the outer edge of the support ring. The pull rods are in sliding contact with the connecting rods. A flange is arranged between the retaining ring and the conical ring. The flange is elastic and contacts the retaining ring. During the process of the pull rods pulling the conical ring to move closer to the retaining ring, the conical surface on the outside of the conical ring can squeeze the flange and pressurize part of the rubber sleeve outside the flange.

[0012] Specifically, the flange is made of rubber and is integrally formed with the rubber sleeve.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the contact linkage between the chamfer at the end of the oil pipe and the guide rod, during the process of screwing the oil pipe into the short joint body, the elastic rod bends to drive the displacement of the sliding ring, driving the pressure roller to squeeze the rubber sleeve, synchronously reducing the volume of the ring cavity and activating the pressure boosting unit, so as to realize the automatic enhancement of the sealing pressure along with the thread connection process. No additional operation is required during the process of screwing the oil pipe tightly. The sealing enhancement and thread locking are completed in one step, ensuring the connection efficiency, and it is especially suitable for the oilfield operation scenarios with frequent disassembly and assembly.

[0014] 2. The present invention has a multi-stage dynamic sealing enhancement design. First-stage sealing: The outer edge of the rubber sleeve is in direct contact with the inner wall of the oil pipe to form a basic sealing layer. The initial pressure is generated by the compression of the volume of the ring cavity, which adapts to the slight unevenness of the oil pipe surface. Second-stage sealing: The pressure roller squeezes the outer wall of the rubber sleeve, forcing the volume of the ring cavity to shrink and the internal pressure to increase, significantly improving the fitting degree of the sealing surface. Third-stage pressure boosting: The conical ring squeezes the flange through the movement of the pull rod to form a radial multi-point pressurized seal, and the local pressure of the outer wall of the rubber sleeve on the inner wall of the oil pipe is increased, effectively coping with the risk of high-pressure crude oil leakage.

[0015] 3. The bending deformation of the elastic rod allows the guide rod to adaptively adjust the angle when the oil pipe is screwed in, compensating for the axis deviation between the oil pipe and the short joint, and avoiding the sealing failure caused by thread misalignment.

[0016] 4. The cooperative design of the support ring and the retaining ring restricts the radial offset of the conical ring and the pull rod during the pressure boosting process, ensuring uniform pressure transmission to the flange and preventing local overload damage of the rubber sleeve. The flange is integrally formed with the rubber sleeve, and has strong anti-corrosion performance against crude oil.

[0017] 5. The convex ring design of the inner sleeve realizes the static seal between the short joint body and the inner sleeve, preventing crude oil from seeping into the inside of the short joint body from the thread gap and avoiding the blockage risk caused by impurity accumulation. Description of the Drawings

[0018] Figure 1 Schematic diagram of the connection between the tubing and the nipple body

[0019] Figure 2 is Figure 1 The enlarged view of area A in

[0020] Figure 3 State diagram of the guide rod and the elastic rod when the nipple body is not connected to the tubing

[0021] Figure 4 is Figure 2 The enlarged view of area B in

[0022] Figure 5 Side view of the fixed sleeve

[0023] Figure 6 Schematic diagram of the connection between the pull rod and the tapered ring

[0024] Figure 7 Side view of the connection between the support ring and the retaining ring

[0025] The names of the components in the attached drawings are: 1. Nipple body, 2. Tubing, 3. Inner sleeve, 4. Convex ring, 5. Slide ring, 6. Elastic rod, 7. Guide rod, 8. Pressure roller, 9. Chamfer, 10. Fixed sleeve, 11. Rubber sleeve, 12. Ring cavity, 13. Pull rod, 14. Outer long groove, 15. Support ring, 16. Retaining ring, 17. Tapered ring, 18. Flange, 19. Inner long groove, 20. Connecting rod, 21. Sealing ring Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments

[0027] As Figures 1-7 shown, a double - headed tubing nipple for oil fields includes a nipple body 1, and the nipple body 1 is used to connect two tubings 2

[0028] Inner sleeves 3 are concentrically, fixedly and sealingly connected to both ends inside the nipple body 1. After the tubing 2 is thread - connected to the nipple body 1, the inner sleeve 3 is located inside the tubing 2. Specifically, a convex ring 4 is concentrically, fixedly and sealingly connected to one side of the inner sleeve 3 away from the port of the nipple body 1, and the convex ring 4 is fixedly and sealingly connected to the nipple body 1

[0029] A sealing assembly is arranged between the inner edge of the inner sleeve 3 and the tubing 2

[0030] The sealing assembly includes a rubber sleeve 11 located between the inner sleeve 3 and the tubing 2. A ring cavity 12 is formed inside the rubber sleeve 11. The rubber sleeve 11 is fixedly sleeved and sealed on the outside of the inner sleeve 3, and the outer edge of the rubber sleeve 11 is in sealing contact with the inner edge of the tubing 2

[0031] One end of the rubber sleeve 11 is fixed with a fixing sleeve 10, and the fixing sleeve 10 is fixed on the outer side of the inner sleeve 3. A sliding ring 5 is slidably sleeved on the inner sleeve 3. A plurality of elastic rods 6 are fixed on the outer edge of the inner sleeve 3 between the sliding ring 5 and the fixing sleeve 10, and the plurality of elastic rods 6 are circumferentially and uniformly arranged according to the axis of the inner sleeve 3. One end of the elastic rod 6 far from the inner sleeve 3 is fixed with a guide rod 7, and the axis of the guide rod 7 is parallel to the axis of the inner sleeve 3.

[0032] The end of the oil pipe 2 is machined with a chamfer 9 corresponding to the guide rod 7. During the process of threadedly connecting the oil pipe 2 into the short joint body 1, after the chamfer 9 contacts the guide rod 7, the oil pipe 2 pushes the guide rod 7 to move in the screwing-in direction of the oil pipe 2. At the same time, one end of the guide rod 7 far from the elastic rod 6 moves towards the inner sleeve 3, and the middle part of the elastic rod 6 bends towards the side away from the fixing sleeve 10 and drives the sliding ring 5 to move.

[0033] A pressure roller 8 is fixed on the side of the guide rod 7 facing the inner sleeve 3. After one end of the guide rod 7 far from the elastic rod 6 moves towards the inner sleeve 3, the pressure roller 8 can squeeze a part of the rubber sleeve 11 outside the oil pipe 2 and make the volume of the annular cavity 12 smaller.

[0034] A plurality of pull rods 13 are fixed on the sliding ring 5, and the plurality of pull rods 13 are circumferentially and uniformly arranged according to the axis of the sliding ring 5. The pull rods 13 penetrate through the fixing sleeve 10, and the pull rods 13 are slidably and sealingly connected with the fixing sleeve 10. Specifically, a plurality of through holes are circumferentially and uniformly formed in the inner circumference of the fixing sleeve 10, and a sealing ring 21 is fixedly and sealingly connected in the through holes. The pull rods 13 penetrate through the sealing ring 21, and the pull rods 13 are slidably and sealingly connected with the fixing sleeve 10 through the sealing ring 21.

[0035] An outer long groove 14 is formed in the pull rod 13 between the fixing sleeve 10 and the sliding ring 5. The elastic rod 6 is located in the outer long groove 14, and the elastic rod 6 is in sliding contact with the pull rod 13.

[0036] The pull rod 13 is connected with a plurality of pressurizing units in the annular cavity 12. When the sliding ring 5 drives the pull rod 13 and the pressurizing units to move, the pressurizing units can increase the pressure of the rubber sleeve 11 on the inner edge of the oil pipe 2.

[0037] A support ring 15 is arranged inside multiple pull rods 13. The support ring 15 is fixed on a rubber sleeve 11 inside the ring cavity 12. The outer edge of the pull rod 13 is in sliding contact with the outer edge of the support ring 15. The pressurizing unit includes a conical ring 17 fixedly sleeved outside the multiple pull rods 13. A retaining ring 16 is sleeved outside the multiple pull rods 13. The outer edge of the pull rod 13 is in sliding contact with the inner edge of the retaining ring 16. An inner long groove 19 is formed in a part of the pull rod 13 corresponding to the retaining ring 16. A connecting rod 20 is arranged in the inner long groove 19. One end of the connecting rod 20 is fixedly connected to the inner edge of the retaining ring 16, and the other end of the connecting rod 20 is fixedly connected to the outer edge of the support ring 15. The pull rod 13 is in sliding contact with the connecting rod 20. A flange 18 is arranged between the retaining ring 16 and the conical ring 17. The flange 18 has elasticity and is in contact with the retaining ring 16. Specifically, the flange 18 is made of rubber and is integrally formed with the rubber sleeve 11.

[0038] During the process that the pull rod 13 pulls the conical ring 17 to move and approach the retaining ring 16, the conical surface on the outside of the conical ring 17 can squeeze the flange 18 and pressurize a part of the rubber sleeve 11 outside the flange 18.

[0039] When the short joint body 1 is threadedly connected to the oil pipe 2, the inner sleeve 3 and a part of the rubber sleeve 11 are located inside the oil pipe 2. The outer edge of the rubber sleeve 11 is in sealing contact with the inner edge of the oil pipe 2. When the chamfer 9 at the end of the oil pipe 2 contacts the guide rod 7, as the oil pipe 2 rotates and advances inside the short joint body 1, the oil pipe 2 pushes the guide rod 7 to move in the direction of the oil pipe 2 screwing in. At the same time, one end of the guide rod 7 far from the elastic rod 6 moves towards the inner sleeve 3. The middle part of the elastic rod 6 bends towards the side away from the fixed sleeve 10 and drives the sliding ring 5 to move towards the convex ring 4. After one end of the guide rod 7 far from the elastic rod 6 moves towards the inner sleeve 3, the pressure roller 8 can squeeze a part of the rubber sleeve 11 outside the oil pipe 2 and make the volume of the ring cavity 12 become smaller. After the volume of the ring cavity 12 becomes smaller, the pressure inside the ring cavity 12 increases. Therefore, the pressure of the rubber sleeve 11 on the inner edge of the oil pipe 2 can be increased, and the sealing effect between the rubber sleeve 11 and the inner wall of the oil pipe 2 is improved.

[0040] When the middle part of the elastic rod 6 bends towards the side away from the fixed sleeve 10 and drives the sliding ring 5 to move towards the convex ring 4, the pull rod 13 pulls the conical ring 17 to move towards the convex ring 4. The outer conical surface of the conical ring 17 can squeeze the flange 18. After the flange 18 is squeezed, the pressure of a part of the rubber sleeve 11 outside the flange 18 on the inner wall of the oil pipe 2 increases, and further improves the sealing performance between the rubber sleeve 11 and the inner wall of the oil pipe 2. After multiple flanges 18 are respectively squeezed by multiple conical rings 17, multiple enhanced sealing areas are formed on the inner wall of the oil pipe 2 by the rubber sleeve 11.

[0041] By providing the support ring 15, the support ring 15 can radially support the pull rod 13. When the tapered ring 17 presses against the flange 18, the deformation amounts of the tapered ring 17 and the pull rod 13 in the radial direction can be reduced. By providing the retaining ring 16, the displacement amount of the flange 18 in the horizontal direction can be reduced when the tapered ring 17 presses against the flange 18. By providing the retaining ring 16 and the support ring 15, the pressure of the flange 18 on the outer rubber sleeve 11 portion when the flange 18 is pressed by the tapered ring 17 is increased, ensuring the sealing effect of the rubber sleeve 11 on the inner edge of the oil pipe 2.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A double-ended oil pipe nipple for oil fields, comprising a nipple body (1), the nipple body (1) being used to connect two oil pipes (2), characterized in that: Both ends of the short joint body (1) are concentrically fixedly sealed with an inner sleeve (3); after the oil pipe (2) and the short joint body (1) are threadedly connected, the inner sleeve (3) is located inside the oil pipe (2); a sealing component is arranged between the inner sleeve (3) and the inner edge of the oil pipe (2); the sealing component comprises a rubber sleeve (11) located between the inner sleeve (3) and the oil pipe (2); an annular cavity (12) is provided inside the rubber sleeve (11); the rubber sleeve (11) is fixedly sleeved and sealed outside the inner sleeve (3); the outer edge of the rubber sleeve (11) is in contact with the oil pipe (2 ) inner edge is sealed in contact with the inner sleeve (3), a fixed sleeve (10) is fixed at one end of the rubber sleeve (11), the fixed sleeve (10) is fixed on the outer side of the inner sleeve (3), a sliding sleeve on the inner sleeve (3) is provided with a slip ring (5), a plurality of elastic rods (6) are fixed at the outer edge of the inner sleeve (3) between the slip ring (5) and the fixed sleeve (10), a guide rod (7) is fixed at one end of the elastic rod (6) away from the inner sleeve (3), a chamfer (9) corresponding to the guide rod (7) is processed at the end of the oil pipe (2), and the oil pipe (2) is threadedly connected to the short section body (1) During the process of inserting the chamfer (9) into the inner sleeve (3), after the chamfer (9) contacts the guide rod (7), the oil pipe (2) pushes the guide rod (7) to move in the direction of screwing into the oil pipe (2). At the same time, the end of the guide rod (7) away from the elastic rod (6) moves toward the inner sleeve (3), and the middle part of the elastic rod (6) bends toward the side away from the fixed sleeve (10) and drives the slip ring (5) to move. A pressure roller (8) is fixed on the side of the guide rod (7) facing the inner sleeve (3). After the end of the guide rod (7) away from the elastic rod (6) moves toward the inner sleeve (3), the pressure roller (8) is pressed. The roller (8) can squeeze the rubber sleeve (11) portion outside the oil pipe (2) and reduce the volume of the annular cavity (12); a plurality of tie rods (13) are fixed on the slip ring (5); the tie rods (13) penetrate the fixed sleeve (10); the tie rods (13) and the fixed sleeve (10) are connected in a sliding and sealing manner; the tie rods (13) are connected to a plurality of boosting units in the annular cavity (12); when the slip ring (5) drives the tie rods (13) and the boosting units to move, the boosting units can increase the pressure of the rubber sleeve (11) on the inner edge of the oil pipe (2).

2. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: The axis center of the guide rod (7) is parallel to the axis center of the inner sleeve (3).

3. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: The plurality of elastic rods (6) are evenly distributed along the circumference of the axis of the inner sleeve (3), and the plurality of pull rods (13) are evenly distributed along the circumference of the axis of the slip ring (5).

4. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: The fixed sleeve (10) is evenly distributed with a plurality of through holes on its inner circumference, a sealing ring (21) is fixedly and sealedly connected in the through hole, the pull rod (13) passes through the sealing ring (21), and the pull rod (13) is slidably and sealedly connected to the fixed sleeve (10) via the sealing ring (21).

5. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: A convex ring (4) is coaxially fixedly and sealingly connected to the side of the inner sleeve (3) away from the port of the short section body (1), and the convex ring (4) is fixedly and sealingly connected to the short section body (1).

6. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: An outer long groove (14) is provided on the pull rod (13) between the fixed sleeve (10) and the slip ring (5), and the elastic rod (6) is located in the outer long groove (14), and the elastic rod (6) is in sliding contact with the pull rod (13).

7. The double-ended oil pipe nipple for oil field according to claim 1, characterized in that: A support ring (15) is arranged on the inner side of the plurality of tie rods (13), the support ring (15) is fixed on the rubber sleeve (11) on the inner side of the annular cavity (12), the outer edge of the tie rod (13) is in sliding contact with the outer edge of the support ring (15), the booster unit comprises a cone ring (17) fixedly sleeved on the outer side of the plurality of tie rods (13), a retaining ring (16) is sleeved on the outer side of the plurality of tie rods (13), the outer edge of the tie rod (13) is in sliding contact with the inner edge of the retaining ring (16), an inner long groove (19) is provided on the portion of the tie rod (13) corresponding to the retaining ring (16), and a connecting rod (20) is arranged in the inner long groove (19) One end of the connecting rod (20) is fixedly connected to the inner edge of the retaining ring (16), and the other end of the connecting rod (20) is fixedly connected to the outer edge of the supporting ring (15). The pull rod (13) is in sliding contact with the connecting rod (20). A flange (18) is provided between the retaining ring (16) and the cone ring (17). The flange (18) is elastic and in contact with the retaining ring (16). When the pull rod (13) pulls the cone ring (17) to move and approach the retaining ring (16), the conical surface on the outer side of the cone ring (17) can squeeze the flange (18) and pressurize the rubber sleeve (11) on the outer side of the flange (18).

8. The double-ended oil pipe nipple for oil field according to claim 7, characterized in that: The flange (18) is made of rubber material, and the flange (18) and the rubber sleeve (11) are integrally formed.

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