Blocking device for oil pipe

Abstract

The utility model provides a plugging device for an oil pipe, which comprises a central pipe, a plugging component arranged on the periphery of the central pipe and a ball seat sleeved at the bottom end of the central pipe, the bottom end of the central pipe extends into the internal space of the ball seat, and a lower channel communicated with the internal space is arranged at one end of the ball seat far away from the central pipe. The valve ball is arranged in the inner space of the ball seat and blocks the lower channel. The plugging device disclosed by the utility model can bear larger wellhead pressing pressure, and can realize pressure relief at the same time, so that the well control safety of well repair operation is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of well workover technology, specifically, it relates to a plugging device for oil tubing. Background Technology

[0002] During well workover in oil and water wells, a gate blowout preventer (BOP) needs to be installed at the wellhead. After the BOP is installed, a pressure test is required to ensure the gate seal is secure, and subsequent operations can proceed only after the test is passed. Due to prolonged water and gas injection development, the formation pressure system in oilfields is often quite chaotic, and abnormal pressure build-up in the wellbore occurs frequently.

[0003] For gate blowout preventer (BOP) pressure testing, a test plug needs to be installed on the tubing hanger via threads to seal the lower space of the tubing. Then, the gate BOP is closed for pressure testing, and the plug is removed after the test is complete. If the wellbore pressure increases abnormally during the test, and there is a possibility that the pressure cannot be effectively released, the plug cannot be removed, and subsequent well workover operations will be impossible. Utility Model Content

[0004] One objective of this invention is to provide a plugging device for tubing that can withstand high wellhead pressure while simultaneously releasing pressure to ensure well control safety during well workover operations.

[0005] According to the present invention, a plugging device for an oil pipe is provided, comprising: a central pipe, a plugging assembly disposed on the outer periphery of the central pipe, and a ball seat fitted at the bottom end of the central pipe, the bottom end of the central pipe extending into the internal space of the ball seat, the ball seat having a lower channel communicating with the internal space at one end away from the central pipe, and a valve ball disposed in the internal space of the ball seat and blocking the lower channel.

[0006] In a preferred embodiment, the blocking device further includes a protective element disposed within the internal space of the ball seat and connected to the bottom end of the central tube.

[0007] In a preferred embodiment, the outer surface of the central tube is sealed to the ball seat by a first sealing ring.

[0008] In a preferred embodiment, the sealing assembly includes: a bushing fitted over the outer surface of the central tube and a rubber sleeve fitted over the outer surface of the bushing.

[0009] In a preferred embodiment, a second sealing ring is provided between the bushing and the central tube.

[0010] In a preferred embodiment, the lower part of the rubber tube is provided with a lower guide ring, a spacer ring is provided between the lower guide ring and the rubber tube, a retaining ring is provided at the lower part of the lower guide ring, the retaining ring is sealed to the central tube by a third sealing ring, and the ball seat is provided at the lower part of the retaining ring.

[0011] In a preferred embodiment, the lower guide ring is connected to the outer surface of the central tube by a set screw.

[0012] In a preferred embodiment, the sealing assembly further includes an upper cone, a lower cone, and a slip disposed on the outer surface of the central tube, wherein the slip is disposed between the upper cone and the lower cone and contacts the upper cone and the lower cone respectively through an inclined surface.

[0013] In a preferred embodiment, the chuck is provided with a return spring that is connected to the outer surface of the central tube.

[0014] In a preferred embodiment, the sealing assembly further includes: a friction block disposed on the outer surface of the central tube, the friction block being disposed on the upper part of the upper cone, and a spring being disposed between the friction block and the central tube.

[0015] This utility model has at least the following technical effects:

[0016] According to this utility model, a central tube, a plugging assembly disposed on the outer periphery of the central tube, and a ball seat fitted at the bottom end of the central tube are provided. The bottom end of the central tube extends into the internal space of the ball seat. The ball seat has a lower channel communicating with the internal space at the end away from the central tube. A valve ball is disposed in the internal space of the ball seat and blocks the lower channel. When the gate blowout preventer needs to be pressure tested, the plugging device for the tubing is seated and sealed inside the tubing by the plugging assembly, thereby allowing the pressure test to be performed in the space above the plugging assembly. During the pressure test, pressure enters the internal space of the ball seat through the central tube. Because the valve ball is disposed in the internal space of the ball seat and blocks the lower channel, the pressure inside the well rises, thus enabling it to withstand a larger wellhead pressurization pressure. If the pressure inside the well increases abnormally after the pressure test is stopped, causing the fluid inside the well to rise, the fluid can enter the lower channel and force open the valve ball, and rise along the central tube to the wellhead, thereby achieving pressure relief and ensuring well control safety during well workover operations. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of a plugging device for an oil pipe according to an embodiment of the present invention is shown.

[0018] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not drawn to scale. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] In the description of the utility model, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0021] In this utility model, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] like Figure 1 As shown, the plugging device 100 for oil pipes of this utility model is disposed inside an oil pipe (not shown in the figure) and includes: a central pipe 4, a plugging assembly disposed on the outer periphery of the central pipe 4, and a ball seat 21 sleeved on the bottom end of the central pipe 4. The plugging assembly is used to plug the internal annulus of the oil pipe. The bottom end of the central pipe 4 extends into the internal space of the ball seat 21. The ball seat 21 has a lower channel communicating with the internal space at the end away from the central pipe 4. The valve ball 24 is disposed in the internal space of the ball seat 21 and blocks the lower channel.

[0023] According to this utility model, a central tube 4, a sealing assembly disposed on the outer periphery of the central tube 4, and a ball seat 21 fitted onto the bottom end of the central tube 4 are provided. The bottom end of the central tube 4 extends into the internal space of the ball seat 21. The ball seat 21 has a lower channel communicating with the internal space at the end away from the central tube 4. A valve ball 24 is disposed in the internal space of the ball seat 21 and seals the lower channel. When the gate blowout preventer needs to be pressure tested, the sealing assembly causes the plugging device 100 for the tubing to be seated inside the tubing and seal the tubing, thereby allowing the pressure test to be performed in the space above the sealing assembly. During the pressure test, pressure enters the internal space of the ball seat 21 through the central tube 4. Because the valve ball 24 is disposed in the internal space of the ball seat 21 and seals the lower channel, the pressure inside the well rises, thereby enabling it to withstand a larger wellhead pressurization pressure. If the pressure inside the well increases abnormally after the pressure test is stopped, causing the fluid inside the well to rise, the fluid inside the well can enter the lower channel and open the valve ball 24, and rise along the central pipe 4 to the wellhead, thereby achieving pressure relief and ensuring well control safety during well workover operations.

[0024] In one or more embodiments, the plugging device 100 for oil tubing according to the present invention further includes: a protective member 23 disposed within the internal space of the ball seat 21 and connected to the bottom end of the central tube 4, used to prevent the valve ball 24 from colliding with the bottom end of the central tube 4 when the pressure inside the well rises abnormally. Optionally, the protective member 23 is a rubber tube.

[0025] In one or more embodiments, the outer surface of the central tube 4 is sealed to the ball seat 21 by a first sealing ring 20.

[0026] In one or more embodiments, the plugging assembly includes: a bushing 16 fitted on the outer surface of the central tube and a rubber sleeve 17 fitted on the outer surface of the bushing, wherein the rubber sleeve 17, after expansion, can contact the inner wall of the oil pipe to plug the annulus in the oil pipe.

[0027] In one or more embodiments, a second sealing ring 15 is provided between the bushing 16 and the central tube 4.

[0028] In one or more embodiments, a lower guide ring 18 is provided at the lower part of the rubber sleeve 17, a spacer ring 25 is provided between the lower guide ring 18 and the rubber sleeve 17, a retaining ring 26 is provided at the lower part of the lower guide ring 18, the retaining ring 26 is sealed to the central tube 4 through a third sealing ring 27, and the ball seat 21 is provided at the lower part of the retaining ring 26.

[0029] In one or more embodiments, the lower guide ring 18 is connected to the outer surface of the central tube by a set screw 19.

[0030] In one or more embodiments, the sealing assembly further includes an upper cone 11, a lower cone 14, and a slip 12 disposed on the outer surface of the central tube 4. The slip 12 is disposed between the upper cone 11 and the lower cone 14 and contacts the upper cone 11 and the lower cone 14 respectively via an inclined surface. The upper cone 14 can descend and open the slip 12 so that the slip 12 engages with the inner wall of the tubing. The lower cone 14 and the shear pin 22 are connected to the slip 12.

[0031] In one or more embodiments, the chuck 12 is provided with a return spring 13 connected to the outer surface of the central tube 4.

[0032] In one or more embodiments, the sealing assembly further includes: a friction block 7 disposed on the outer surface of the central tube 4, the friction block 7 being disposed on the upper part of the upper cone 11, and a spring 6 being disposed between the friction block 7 and the central tube 4.

[0033] In one or more embodiments, the sealing assembly further includes: a slip sleeve 9 disposed on the outer surface of the upper cone 11 and located below the friction block 7, the slip sleeve 9 being connected to the friction block 7 via a first positioning pin 8, and the slip sleeve 9 being connected to the upper cone 11 via a second positioning pin 10.

[0034] Although the present invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A plugging device for oil pipes, characterized in that, include: The device comprises a valve ball, a central tube, a sealing assembly disposed on the outer periphery of the central tube, and a ball seat fitted at the bottom end of the central tube. The bottom end of the central tube extends into the internal space of the ball seat. The ball seat has a lower channel communicating with the internal space at one end away from the central tube. The valve ball is disposed in the internal space of the ball seat and blocks the lower channel.

2. The plugging device for oil pipes according to claim 1, characterized in that, Also includes: A protective element disposed within the internal space of the ball seat and connected to the bottom end of the central tube.

3. The plugging device for oil pipes according to claim 1 or 2, characterized in that, The outer surface of the central tube is sealed to the ball seat by a first sealing ring.

4. The plugging device for oil pipes according to claim 1, characterized in that, The sealing assembly includes: a bushing fitted on the outer surface of the central tube and a rubber sleeve fitted on the outer surface of the bushing.

5. The plugging device for oil pipes according to claim 4, characterized in that, A second sealing ring is provided between the bushing and the central tube.

6. The plugging device for oil pipes according to claim 4, characterized in that, The lower part of the rubber tube is provided with a lower guide ring, a spacer ring is provided between the lower guide ring and the rubber tube, a retaining ring is provided at the lower part of the lower guide ring, the retaining ring is sealed to the central tube by a third sealing ring, and the ball seat is provided at the lower part of the retaining ring.

7. The plugging device for oil pipes according to claim 6, characterized in that, The lower guide ring is connected to the outer surface of the central tube by a set screw.

8. The plugging device for oil pipes according to claim 1, characterized in that, The sealing assembly further includes an upper cone, a lower cone, and a slip disposed on the outer surface of the central tube. The slip is disposed between the upper cone and the lower cone and contacts the upper cone and the lower cone respectively through an inclined surface.

9. The plugging device for oil pipes according to claim 8, characterized in that, The chuck is internally equipped with a return spring that is connected to the outer surface of the central tube.

10. The plugging device for oil pipes according to claim 9, characterized in that, The sealing assembly further includes a friction block disposed on the outer surface of the central tube, the friction block being disposed on the upper part of the upper cone, and a spring being disposed between the friction block and the central tube.

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