A blowout preventer for an oil production wellhead

Abstract

The utility model discloses a kind of oil extraction wellhead blowout preventers, comprising: casing structure, it is directly connected with oil well wellhead casing, main body is set as casing main body, the upper portion of casing main body outer wall is fixedly installed with water injection capsule;Four-way connecting pipe, it is fixedly installed in the top of casing structure;Half-enclosed gate valve blowout preventer, it is fixedly installed in the top of four-way connecting pipe, including two symmetrical half-enclosed gate valve main body set in the inside of blowout preventer box body.The utility model expands sealing half-enclosed gate valve double rubber pad clamping and full-enclosed gate valve multi-curved surface closed through water injection capsule, effectively cope with well surge pressure;Half-enclosed gate valve is installed sealing rubber pad by mounting groove, sealing rubber pad can be provided with greater deformation allowance, when clamping drill rod, more sealing rubber pad can be compressed into mounting groove inside, on the basis of guaranteeing sealing performance, reduce the contact area of sealing rubber pad and well surge liquid, improve the service life of sealing rubber pad.

Description

Technical Field

[0001] This utility model relates to the field of wellhead blowout prevention technology, and in particular to an oil wellhead blowout prevention device. Background Technology

[0002] In existing technologies, sealing devices are often required during oil extraction to close the wellhead during operations such as oil testing, well workover, and well completion, thus preventing blowout accidents.

[0003] A search revealed a Chinese patent application with patent number 202211577153.3, which discloses a blowout preventer sealing device for oil wellheads. The device uses a motor to rotate the sealing mechanism 180°. During this rotation, the counterweight moves under gravity, causing the rack to move and the locking block to continuously shift to a lateral position. This allows the locking block to smoothly enter the locking chamber. When a blowout occurs, the counterweight is pressured and moves upwards, freeing the rack from its restraint. This causes the locking block to reset and be locked by the lateral locking port, thus locking the two sealing mechanisms together and preventing separation due to failure of the two sealing mechanisms.

[0004] In actual use, the existing device has relatively weak sealing between the outer wall of the casing and the well wall, and mainly relies on the base sealing plate for wellhead sealing; the half gate and the drill pipe are in contact through the sealing gasket, so the sealing gasket is directly exposed to the air when clamping the drill pipe. If backflow occurs, it will accelerate the aging of the sealing gasket. Utility Model Content

[0005] The purpose of this utility model is to overcome the shortcomings of the existing technology and propose an oil wellhead blowout prevention device.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A blowout preventer for oil wellheads, comprising:

[0008] The casing structure is directly connected to the wellhead casing of the oil well. The main body is the casing body, and a water injection capsule is fixedly installed on the upper part of the outer wall of the casing body.

[0009] The four-way connecting pipe is fixedly installed at the top of the sleeve structure;

[0010] A semi-sealed gate blowout preventer is fixedly installed at the top of a four-way connecting pipe. It includes two semi-sealed gate bodies symmetrically arranged inside the blowout preventer housing. An installation groove is opened on the side of the two semi-sealed gate bodies that are close to each other. A sealing gasket is fixedly installed inside the installation groove. The two semi-sealed gate bodies clamp the drill rod and seal the drill rod channel.

[0011] A fully sealed gate blowout preventer is fixedly installed on the top of a semi-sealed gate blowout preventer. The semi-sealed gate body of the semi-sealed gate blowout preventer is replaced with a fully sealed gate body, which constitutes a fully sealed gate blowout preventer. One of the fully sealed gate bodies has a sealing groove on the top end face, a mating rubber gasket fixedly connected in the middle, and a sealing boss integrally formed at the bottom. The two fully sealed gate bodies are centrally symmetrical and cooperate with each other to seal the drill pipe channel.

[0012] As a further improvement of this utility model: the top of the sleeve body is integrally formed with a connecting flange, and the lower part of the outer wall of the sleeve body is integrally formed with a thickened threaded layer.

[0013] As a further embodiment of this utility model: a load-bearing connecting ring is integrally formed in the middle of the outer wall of the sleeve body, and a drain valve is fixedly connected to the top of the water injection capsule, with the drain valve passing through the connecting flange.

[0014] As a further improvement of this utility model: stabilizing slide rods are slidably installed at both ends between the two semi-sealed gate bodies, and slide rod retaining rings are fixedly sleeved at both ends of the stabilizing slide rods.

[0015] As a further improvement of this utility model: both ends of the blowout preventer housing are fixedly installed with end caps, and the sliding rod retaining ring inside the same end of the blowout preventer housing is fixedly connected to the end cap.

[0016] As a further embodiment of this utility model: a protective sleeve is integrally formed on one side of the end cap, and an internally threaded sleeve is slidably installed inside the protective sleeve, with one end of the internally threaded sleeve being fixedly connected to the main body of the semi-sealed gate.

[0017] As a further embodiment of this utility model: a transmission threaded rod is installed on the internal thread of the internal threaded sleeve, and an installation pipe head is rotatably installed on the outer wall of the transmission threaded rod, and the installation pipe head is fixedly connected to the protective sleeve.

[0018] As a further embodiment of this utility model: a bearing cap is fixedly installed at the end of the mounting tube head, and a control handle is fixedly installed at one end of the transmission threaded rod.

[0019] Compared with the prior art, this utility model provides a blowout preventer for oil wellheads, which has the following beneficial effects:

[0020] 1. This wellhead blowout preventer uses a three-stage sealing system, consisting of a water-injected bladder expansion seal, a semi-sealing gate with double rubber gaskets, and a fully sealed gate with multi-curved surfaces, to effectively cope with well kick pressure. The semi-sealing gate has a groove for installing the sealing gasket, which provides greater deformation allowance for the gasket. When clamping the drill pipe, more of the sealing gasket can be compressed into the groove, reducing the contact area between the sealing gasket and the kick fluid while ensuring sealing performance, thus improving the service life of the sealing gasket.

[0021] 2. The blowout preventer at the wellhead of this oil production well adopts a quick-release end cap and a coaxial variable diameter gate, which does not require complete disassembly during maintenance.

[0022] The parts of this device not covered herein are the same as or can be implemented using existing technologies. This utility model has a simple structure and is easy to operate. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the overall assembly of this utility model;

[0024] Figure 2 This is a partial cross-sectional view of the overall assembly of this utility model.

[0025] Figure 3 This utility model Figure 2 A magnified schematic diagram of the local structure at point A;

[0026] Figure 4 This utility model Figure 2 A magnified schematic diagram of the structure at point B in the middle.

[0027] In the diagram: 1. Sleeve structure; 2. Four-way connecting pipe; 3. Semi-sealed gate blowout preventer; 4. Fully sealed gate blowout preventer; 5. Sleeve body; 6. Thickened threaded layer; 7. Bearing connecting ring; 8. Water injection capsule; 9. Drain valve; 10. Connecting flange; 11. Blowout preventer housing; 12. Connecting pipe head; 13. Semi-sealed gate body; 14. Sealing gasket; 15. Stabilizing slide bar; 16. Slide bar retainer; 17. End cap; 18. Fixing retainer; 19. Internal threaded sleeve; 20. Transmission threaded rod; 21. Protective sleeve; 22. Mounting pipe head; 23. Bearing cap; 24. Control handle; 25. Bearing bearing; 26. Fully sealed gate body; 27. Sealing groove; 28. Matching gasket; 29. ​​Sealing boss. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0029] A blowout preventer for oil wellheads, such as Figures 1 to 4 As shown, it includes: casing structure 1, four-way connecting pipe 2, semi-sealed gate blowout preventer 3, and fully sealed gate blowout preventer 4; casing structure 1 is directly connected to the wellhead casing for guiding well fluid; four-way connecting pipe 2 is fixedly installed at the top of casing structure 1 for connecting other drilling equipment, such as drilling fluid introduction equipment and flowback fluid export equipment; semi-sealed gate blowout preventer 3 is fixedly installed at the top of four-way connecting pipe 2, and when the drill pipe is inside the well and a well kick occurs, semi-sealed gate blowout preventer 3 clamps the drill pipe and seals the well; fully sealed gate blowout preventer 4 is fixedly installed at the top of semi-sealed gate blowout preventer 3 for sealing the well.

[0030] In some wellhead blowout preventers, a shearing blind flange blowout preventer (a mature existing technology) is added between the semi-sealed gate blowout preventer 3 and the fully sealed gate blowout preventer 4 to cut off the drill pipe; an annular blowout preventer (a mature existing technology) is installed at the top of the fully sealed gate blowout preventer 4.

[0031] The main body of the casing structure 1 is a casing body 5. The top of the casing body 5 is integrally formed with a connecting flange 10, which is fixedly connected to the flange of the four-way connecting pipe 2. The lower part of the outer wall of the casing body 5 is integrally formed with a thickened threaded layer 6, which is directly threaded into the inside of the wellhead casing.

[0032] A load-bearing connecting ring 7 is integrally formed in the middle of the outer wall of the casing body 5. A water injection capsule 8 is fixedly sleeved on the upper part of the outer wall of the casing body 5 above the load-bearing connecting ring 7. A drain valve 9 is fixedly connected to the top of the water injection capsule 8 and passes through the connecting flange 10. After the casing structure 1 is installed, clean water is injected into the water injection capsule 8 through the drain valve 9, causing the water injection capsule 8 to expand and fit against the inner wall of the wellhead casing, thereby enhancing the sealing of the casing structure 1.

[0033] The semi-sealed gate blowout preventer 3 includes two semi-sealed gate bodies 13 symmetrically arranged inside the blowout preventer housing 11. Connecting pipe heads 12 are welded to the top and bottom of the blowout preventer housing 11 for connecting other components.

[0034] The two semi-sealing gate bodies 13 have a semi-cylindrical groove on one side close to each other. The side wall of the semi-cylindrical groove has an installation groove. A sealing gasket 14 is fixedly installed inside the installation groove. The sealing gasket 14 consists of two parts, one part is fixed inside the installation groove, and the other part is set in a semi-circular shape and is set inside the semi-cylindrical groove. The two semi-sealing gate bodies 13 clamp the drill pipe through the sealing gasket 14 and seal the drill pipe channel. This method can reduce the contact area between the sealing gasket 14 and the well fluid, reduce the rate at which the well fluid affects the sealing gasket 14, and ensure the service life of the sealing gasket 14.

[0035] Stabilizing rods 15 are slidably installed at both ends between the two semi-sealed gate bodies 13. The stabilizing rods 15 can enhance the ability of the semi-sealed gate body 13 to resist well kick impact and ensure the sealing capability of the semi-sealed gate blowout preventer 3.

[0036] Both ends of the stabilizing slide bar 15 are fixedly sleeved with slide bar retaining rings 16, and both ends of the blowout preventer housing 11 are fixedly installed with end caps 17. The two slide bar retaining rings 16 inside the same end of the blowout preventer housing 11 are fixedly connected to the end caps 17.

[0037] A protective sleeve 21 is integrally formed on the side of the end cap 17 away from the semi-sealed gate body 13. An internally threaded sleeve 19 is slidably installed inside the protective sleeve 21. The internally threaded sleeve 19 can only slide on the protective sleeve 21 and cannot rotate. One end of the internally threaded sleeve 19 passes through the end cap 17 and is fixedly installed with a retaining ring 18. The retaining ring 18 is welded to the semi-sealed gate body 13.

[0038] The internal thread of the internal threaded sleeve 19 is fitted with a transmission threaded rod 20. The outer wall of the transmission threaded rod 20 is fitted with a bearing 25. The outer ring of the bearing 25 is fixedly fitted with an installation tube head 22. The installation tube head 22 is fixedly connected to the protective sleeve 21.

[0039] A bearing cap 23 is fixedly installed at the end of the mounting pipe head 22 to protect the load bearing 25, and a control handle 24 is fixedly installed at the end of the transmission threaded rod 20 away from the semi-sealed gate body 13 to control the rotation of the transmission threaded rod 20.

[0040] The aforementioned control handle 24 is a component for manually controlling the opening and closing of the semi-sealed gate body 13. It can be replaced with a hydraulic drive. The structure of the hydraulically driven semi-sealed gate body 13 is existing technology and will not be described in detail in this application.

[0041] The main structure of the fully enclosed gate blowout preventer 4 is the same as that of the semi-enclosed gate blowout preventer 3. The difference between the two lies in the gate. The gate of the fully enclosed gate blowout preventer 4 is set as a fully enclosed gate body 26.

[0042] One of the fully enclosed gate body 26 has a sealing groove 27 on the top of its end face, a mating rubber gasket 28 fixedly connected in the middle, and a sealing boss 29 integrally formed at the bottom. The two fully enclosed gate body 26 are centrally symmetrical and cooperate with each other. The sealing boss 29 of one fully enclosed gate body 26 is inserted into the sealing groove 27 of the other fully enclosed gate body 26 to form a multi-curved surface seal. With the pressing and fitting of the two mating rubber gaskets 28, the drill rod channel is sealed.

[0043] Working principle:

[0044] Please refer to Figures 1 to 4 Assemble the device as shown in the figure;

[0045] During installation, the casing body 5 is first installed inside the wellhead casing through the thickened threaded layer 6. Then, water is injected into the water injection capsule 8 through the drain valve 9, causing the water injection capsule 8 to expand and seal the wellhead casing opening. Next, a four-way connecting pipe 2, a semi-sealed gate blowout preventer 3, and a fully sealed gate blowout preventer 4 are installed sequentially at the top of the casing structure 1. When a well kick occurs inside the well, the semi-sealed gate blowout preventer 3 and the fully sealed gate blowout preventer 4 are controlled to close the drill pipe passage based on feedback from the well monitoring structure (existing technology, using sensors to monitor the pressure, temperature, etc. inside the well).

[0046] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A blowout preventer for oil wellheads, characterized in that, include: The casing structure (1) is directly connected to the wellhead casing of the oil well. The main body is set as the casing body (5), and a water injection capsule (8) is fixedly installed on the upper part of the outer wall of the casing body (5). The four-way connecting pipe (2) is fixedly installed at the top of the sleeve structure (1); The semi-sealed gate blowout preventer (3) is fixedly installed at the top of the four-way connecting pipe (2). It includes two semi-sealed gate bodies (13) symmetrically arranged inside the blowout preventer housing (11). The two semi-sealed gate bodies (13) are provided with an installation groove on the side close to each other. A sealing gasket (14) is fixedly installed inside the installation groove. The two semi-sealed gate bodies (13) clamp the drill rod and seal the drill rod channel. A fully sealed gate blowout preventer (4) is fixedly installed on the top of a semi-sealed gate blowout preventer (3). The semi-sealed gate body (13) of the semi-sealed gate blowout preventer (3) is replaced with a fully sealed gate body (26), which is the fully sealed gate blowout preventer (4). One of the fully sealed gate bodies (26) has a sealing groove (27) on the top end face, a mating gasket (28) is fixedly connected in the middle, and a sealing boss (29) is integrally formed at the bottom. The two fully sealed gate bodies (26) are centrally symmetrical and cooperate with each other to seal the drill pipe channel.

2. The blowout preventer for oil wellheads according to claim 1, characterized in that: The top of the sleeve body (5) is integrally formed with a connecting flange (10), and the lower part of the outer wall of the sleeve body (5) is integrally formed with a thickened threaded layer (6).

3. The blowout preventer at the wellhead of an oil well according to claim 2, characterized in that: The outer wall of the sleeve body (5) is integrally formed with a load-bearing connecting ring (7), and the top of the water injection capsule (8) is fixedly connected with a drain valve (9), which is connected through the flange (10).

4. The blowout preventer for oil wellheads according to claim 1, characterized in that: Stabilizing slide rods (15) are slidably installed at both ends between the two semi-sealed gate bodies (13), and slide rod retaining rings (16) are fixedly sleeved at both ends of the stabilizing slide rods (15).

5. The blowout preventer at the wellhead of an oil well according to claim 4, characterized in that: Both ends of the blowout preventer housing (11) are fixedly installed with end caps (17), and the sliding rod retaining ring (16) inside the same end of the blowout preventer housing (11) is fixedly connected to the end cap (17).

6. The blowout preventer for oil wellheads according to claim 5, characterized in that: One side of the end cap (17) is integrally formed with a protective sleeve (21), and an internal threaded sleeve (19) is slidably installed inside the protective sleeve (21). One end of the internal threaded sleeve (19) is fixedly connected to the semi-sealed gate body (13).

7. The blowout preventer at the wellhead according to claim 6, characterized in that: The internal thread of the internal threaded sleeve (19) is fitted with a transmission threaded rod (20), and an installation tube head (22) is rotatably mounted on the outer wall of the transmission threaded rod (20). The installation tube head (22) is fixedly connected to the protective sleeve (21).

8. The blowout preventer for oil wellheads according to claim 7, characterized in that: The end of the mounting tube (22) is fixedly fitted with a bearing cap (23), and one end of the transmission threaded rod (20) is fixedly fitted with a control handle (24).

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