Automatic sealing device for wellhead of oil and gas well

Abstract

An automatic wellhead sealing device for oil and gas wells relates to the field of wellhead sealing technology. The technical solution includes a packing box with a pressure plate inside. Multiple sealing packings are evenly spaced at the bottom of the packing box, with the pressure plate positioned above the sealing packings. A positioning box is connected above the packing box, containing multiple sets of limiting components. The beneficial effects of this technical solution are: it can convert the tilt displacement into the downward pressing action of the corresponding compression rod based on the tilt direction and angle of the polished rod, and, in conjunction with the inclined surface transmission of the tilting block, achieve precise local compression compensation on the side with increased gap in the sealing packings, fundamentally improving the wear and leakage problems caused by polished rod tilt; the return spring can provide a reverse restoring force when the polished rod tilts, effectively limiting and reducing the tilt amplitude while ensuring reliable automatic reset of the mechanism, achieving dynamic adaptive sealing and improving the operational stability and sealing reliability of the wellhead device.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas wellhead sealing technology, and in particular to an automatic sealing device for oil and gas wellheads. Background Technology

[0002] Pumping wells are the most common production method for oil wells. The wellhead packing box is a dynamic sealing device that seals the annular space between the tubing and the polished rod. The packing is usually placed in the packing box. As a device that seals the polished rod at the wellhead of the pumping unit, the packing box is an important component to prevent oil spillage. It is fitted over the outside of the polished rod of the pumping unit and fixed at the lower end to the wellhead device. During pumping operations, the polished rod of the pumping unit moves up and down repeatedly relative to the packing box.

[0003] However, due to factors such as well deviation, polished rod bending, or vibration, the polished rod is prone to skew during reciprocating motion, leading to uneven contact and friction between it and the packing. When the polished rod tilts to one side, it causes uneven stress on the sealing packing within the packing box. The sealing packing on the tilted side is excessively compressed and severely worn, while gaps appear on the other side, preventing a proper seal. This damages the integrity of the sealing surface, increases the risk of oil leakage, and results in resource waste and environmental pollution. Utility Model Content

[0004] The purpose of this invention is to solve the problem of gaps appearing in the sealing packing when the polished rod is tilted, which leads to the risk of crude oil leakage, and to propose an automatic sealing device for oil and gas wellheads.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An automatic sealing device for oil and gas wellheads includes a packing box, a pressure plate inside the packing box, and multiple sealing packings evenly spaced at the bottom of the packing box. The pressure plate is located above the sealing packings. A positioning box is connected to the top of the packing box, and multiple sets of limiting components are provided inside the positioning box. Each set of limiting components includes two opposing support members, and push rods are slidably connected to both support members. The two push rods in the set of limiting components are connected by a connector. One end of the push rod is connected to an arc-shaped clamping block. An inclined block is provided at the top of the positioning box, and a pressing rod is slidably connected to the lower surface of the inclined block. The lower end of the pressing rod passes through the push rod and extends below the push rod. The pressing rod is correspondingly arranged with the pressure plate.

[0007] When the smooth rod in the middle of the packing box tilts, the connecting parts will cause the push rod on the other side of the same group to move towards the smooth rod, thereby locally compensating for the increased sealing gap on the side and ensuring the reliability of the seal.

[0008] Preferably, the support member is provided with a groove, and a second sliding groove is provided on each of the two opposite side walls of the groove. A second slider is installed in the second sliding groove, and both ends of the two second sliders are connected to the side of the push rod. An opening is provided at the bottom of the groove, and an insertion hole is provided on the push rod. The lower end of the extrusion rod passes through the insertion hole and the opening and extends to the bottom of the support member.

[0009] The push rod slides back and forth along the second slide groove via the second slider to achieve stable horizontal movement, providing precise guidance for the push rod and preventing jamming or deflection during its movement. The fit between the opening and the insertion hole ensures smooth movement of the extrusion rod while also providing a limiting constraint on the extrusion rod.

[0010] Preferably, the lower surface of the inclined block is provided with two first sliding grooves, a first sliding block is installed in the first sliding groove, the upper end of the extrusion rod is connected to the first sliding block, and the end of the extrusion rod away from the first sliding block is connected to a push block, the lower surface of the push block is correspondingly arranged with the pressure plate.

[0011] Preferably, a fixed plate is connected to one side of the upper surface of the support member, a push plate is connected to the upper surface of the push rod, a slide rod is connected to the surface of the fixed plate, one end of the slide rod passes through the push plate and extends to one side of the push plate, and a return spring is sleeved on the slide rod, with both ends of the return spring fixed to the side walls of the push plate and the fixed plate, respectively.

[0012] When the push rod is pushed outward by the guide rod, the push plate moves synchronously with the push rod and compresses the return spring; when the guide rod returns to the vertical position, the return spring releases its elastic force, and pushes the push rod and the arc-shaped clamp block to automatically reset through the push plate.

[0013] Preferably, a fixing rod is fixed on the side wall of the groove, and a baffle is connected to the end of the fixing rod away from the side wall of the groove. A rubber pad is provided on the surface of the baffle.

[0014] Preferably, the connector is U-shaped, with its two vertical sections connected to the corresponding push rods.

[0015] When one push rod in a set is pushed by the light rod, the U-shaped connector simultaneously drives the other push rod to move closer to the light rod, realizing the linkage between the two push rods in the set.

[0016] Preferably, the surface of the arc-shaped clamping block is provided with multiple balls at equal intervals.

[0017] Compared with the prior art, the beneficial effects of this utility model are: it can convert the tilt displacement into the downward pressing action of the corresponding squeezing rod according to the tilt direction and tilt angle of the polished rod, and cooperate with the inclined surface transmission of the tilting block to achieve precise local squeezing compensation on the side with increased sealing packing clearance, fundamentally improving the problem of uneven wear and leakage caused by polished rod tilt; the return spring can provide reverse return force when the polished rod is tilted, effectively limiting and reducing the tilt amplitude of the polished rod, while ensuring reliable automatic reset of the mechanism, which can realize dynamic adaptive sealing and improve the operational stability and sealing reliability of the wellhead device. Attached Figure Description

[0018] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the internal structure of a specific embodiment of the present invention.

[0020] Figure 2 This is an internal top view of a specific embodiment of the present invention.

[0021] Figure 3 for Figure 1 Enlarged view at point A.

[0022] Figure 4 This is a schematic diagram of the structure inside the support member in a specific embodiment of this utility model.

[0023] In the diagram: 1. Positioning box; 2. Extrusion rod; 3. Pressure plate; 4. Packing box; 5. Push plate; 6. Return spring; 7. Inclined block; 8. Arc-shaped clamping block; 9. Connector; 10. Push rod; 11. Support; 12. Sealing packing; 13. First slide groove; 14. First slider; 15. Slide rod; 16. Fixing plate; 17. Baffle; 18. Fixing rod; 19. Insertion hole; 20. Ball bearing; 21. Second slider; 22. Groove; 23. Push block. Detailed Implementation

[0024] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. 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.

[0025] Reference Figures 1-4 An automatic sealing device for oil and gas wellheads includes a packing box 4, within which a pressure plate 3 is installed. During use, the pressure plate 3 moves vertically along the packing box 4, with a vertical guide groove ensuring its vertical movement. Multiple sealing packings 12 are evenly spaced at the bottom of the packing box 4. An annular step is provided on the inner wall of the packing box 4, with each sealing packing 12 positioned on its corresponding step. This restricts radial movement of the sealing packing 12, ensuring effective expansion compensation for localized compression. The pressure plate 3 is positioned above the sealing packings 12. When the pressure plate 3 moves downwards, it compresses the sealing packing 12 below, causing deformation and ensuring a tight seal against the outer wall of the polished rod, preventing the polished rod from tilting and thus avoiding leakage of crude oil, etc. In case of leakage, a positioning box 1 is connected above the packing box 4. The packing box 4 and the positioning box 1 are connected by threads to ensure the sealing effect between the packing box 4 and the positioning box 1. The positioning box 1 is equipped with multiple sets of limiting components. During use, the entire positioning box 1 can be rotated according to the tilt direction of the light rod to adjust the position of the limiting components and prevent the light rod from tilting and failing to push the corresponding push rod 10 to move. The multiple sets of limiting components are arranged vertically. Generally, two or three sets of limiting components are used. The light rod is limited by the arc-shaped clamp 8 in the limiting components. Multiple balls 20 are evenly spaced on the surface of the arc-shaped clamp 8. The setting of the balls 20 makes the light rod and the balls 20 roll friction, reducing the friction between the light rod and the arc-shaped clamp 8.

[0026] A set of limiting components includes two opposing support members 11, each of which is slidably connected to a push rod 10. The two push rods 10 within the set of limiting components are connected by a connector 9, which is U-shaped. The two vertical sections of the connector 9 are respectively connected to the corresponding push rods 10. When one push rod 10 within the set is pushed by the smooth rod, the U-shaped connector 9 simultaneously drives the other push rod 10 to move closer to the smooth rod, thus achieving linkage between the two push rods 10 within the set. One end of the push rod 10 is connected to an arc-shaped clamping block 8. An inclined block 7 is provided at the top of the positioning box 1, and a pressing element is slidably connected to the lower surface of the inclined block 7. The lower end of the compression rod 2 passes through the push rod 10 and extends below the push rod 10. The compression rod 2 is correspondingly set with the pressure plate 3. When the rod tilts to one side, it will push the arc-shaped clamping block 8 in the tilting direction to move, thereby driving the push rod 10 to move. When the push rod 10 moves, it drives another push rod 10 in the group to move through the setting of the connecting piece 9, thereby driving the corresponding compression rod 2 to move. Due to the setting of the upper tilting block 7, the compression rod 2 will push the pressure plate 3 downward to move. The pressure plate 3 will squeeze the sealing packing 12 below. After the sealing packing 12 is squeezed, the sealing gap is locally pressurized to compensate for the sealing and ensure the reliability of the seal.

[0027] Reference Figure 2 and Figure 4The support member 11 is provided with a groove 22. Two opposite side walls of the groove 22 are provided with second sliding grooves. The second sliding grooves are arranged along the length of the groove 22 to facilitate the movement of the push rod 10 along the length of the support member 11. A second slider 21 is installed in the second sliding groove. Both ends of the two second sliders 21 are connected to the side of the push rod 10. An opening is provided at the bottom of the groove 22. The push rod 10 is provided with an insertion hole 19. The extrusion rod 2 can move up and down along the insertion hole 19. When the push rod 10 moves, it pushes the extrusion rod 2 to move together under the action of the insertion hole 19. The lower end of the extrusion rod 2 passes through the insertion hole 19 and the opening and extends to the bottom of the support member 11. The opening facilitates the movement of the extrusion rod 2.

[0028] Reference Figure 1 and Figure 3 The lower surface of the inclined block 7 is provided with two first sliding grooves 13, and a first slider 14 is installed in the first sliding groove 13. The upper end of the extrusion rod 2 is connected to the first slider 14. There are two extrusion rods 2. The length direction of the inclined block 7 is parallel to the length direction of the support member 11. When the push rod 10 moves, the push rod 10 will push the extrusion rod 2 to move together. Under the action of the inclined block 7, the height of the extrusion rod 2 will be automatically adjusted. The end of the extrusion rod 2 away from the first slider 14 is connected to a push block 23. The push blocks 23 of multiple limiting members are arranged along the circumference of the pressure plate 3. The lower surface of the push block 23 is corresponding to the pressure plate 3. The pressure rod 2 applies pressure to the push block 23, which in turn applies pressure to the pressure plate 3, thereby squeezing the sealing packing 12 below to prevent leakage and improve the sealing effect. When the lower surface of the push block 23 abuts against the pressure plate 3 to form a limited stop, the push block 23 restricts the movement of the push rod 10. Through the setting of the connecting piece 9, the movement of another connecting piece 9 in the same group is blocked, thereby limiting the deviation of the smooth rod. At the same time, a graphite coating can be set on the lower surface of the push block 23 to reduce the sliding friction between the push block 23 and the pressure plate 3, and to prevent the push block 23 from getting stuck and the movement from being obstructed.

[0029] Reference Figures 1-4A fixed plate 16 is connected to one side of the upper surface of the support member 11. A push plate 5 is connected to the upper surface of the push rod 10. A slide rod 15 is connected to the surface of the fixed plate 16. One end of the slide rod 15 passes through the push plate 5 and extends to one side of the push plate 5. A return spring 6 is sleeved on the slide rod 15. The two ends of the return spring 6 are fixed to the side walls of the push plate 5 and the fixed plate 16, respectively. When the push rod 10 moves, it will drive the push plate 5 to move together. One of the two return springs 6 in the set is squeezed and the other is stretched, which will also limit the tilt angle of the light rod. When the light rod is in a vertical state, the return spring 6 controls the push rod 10 to return to its original position. The arc-shaped clamp 8 abuts against the outer wall of the light rod. A damping pad is provided on the fixed plate 16. When the return spring 6 is squeezed or stretched, it will consume the corresponding kinetic energy to avoid the arc-shaped clamp 8 pushing the light rod when the return spring 6 returns to its original position.

[0030] Reference Figure 4 A fixing rod 18 is fixed on the side wall inside the groove 22. A baffle 17 is connected to the end of the fixing rod 18 away from the side wall of the groove 22. A rubber pad is provided on the surface of the baffle 17. The length of the fixing rod 18 is greater than the stroke of the return spring 6 when it is squeezed, so as to avoid damage to the return spring 6. The baffle 17 and the rubber pad restrict the movement of the push rod 10 and prevent the rod from tilting at too large an angle.

[0031] When the central guide rod tilts, it pushes the corresponding arc-shaped clamp 8, which in turn moves the push rod 10. As the push rod 10 moves, it drives another push rod 10 in the same group to move closer to the guide rod through the connecting piece 9. At this time, the push rod 10 moves along with the compression rod 2, which in turn pushes the push block 23 to move. The push block 23 then compresses the pressure plate 3, which in turn compresses the sealing packing 12 below, thus compressing the other side of the guide rod in the tilting direction. This causes the sealing packing 12 to expand, compensating for the increased sealing gap when the guide rod tilts. As the push rod 10 moves, it also drives the push plate 5 to move. When the push plate 5 moves, it first compresses the return spring 6, and at the same time stretches the other return spring 6 in the same group, reducing the tilt angle of the guide rod. The end of the push rod 10 abuts against the rubber pad of the baffle 17, blocking the movement of the push rod 10 and preventing the guide rod from tilting too much.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic sealing device for oil and gas wellheads, characterized in that: The packing box (4) includes a pressure plate (3) inside the packing box (4). Multiple sealing packings (12) are evenly spaced at the bottom of the packing box (4). The pressure plate (3) is located above the sealing packings (12). A positioning box (1) is connected above the packing box (4). Multiple sets of limiting components are provided inside the positioning box (1). One set of limiting components includes two opposing support components (11). Push rods (10) are slidably connected to both support components (11). The two push rods (10) in one set of limiting components are connected by a connector (9). One end of the push rod (10) is connected to an arc-shaped clamping block (8). An inclined block (7) is provided at the top of the positioning box (1). A pressing rod (2) is slidably connected to the lower surface of the inclined block (7). The lower end of the pressing rod (2) passes through the push rod (10) and extends to the bottom of the push rod (10). The pressing rod (2) is correspondingly set with the pressure plate (3).

2. The automatic wellhead sealing device for oil and gas wells according to claim 1, characterized in that: The support member (11) is provided with a groove (22), and a second sliding groove is provided on the two opposite side walls of the groove (22). A second slider (21) is installed in the second sliding groove. Both ends of the two second sliders (21) are connected to the side of the push rod (10). An opening is provided at the bottom of the groove (22). An insertion hole (19) is provided on the push rod (10). The lower end of the extrusion rod (2) passes through the insertion hole (19) and the opening and extends to the bottom of the support member (11).

3. The automatic wellhead sealing device for oil and gas wells according to claim 2, characterized in that: The lower surface of the inclined block (7) is provided with two first grooves (13), and a first slider (14) is installed in the first groove (13). The upper end of the extrusion rod (2) is connected to the first slider (14), and the end of the extrusion rod (2) away from the first slider (14) is connected to a push block (23). The lower surface of the push block (23) is correspondingly set with the pressure plate (3).

4. The automatic sealing device for oil and gas wellheads according to claim 1, characterized in that: A fixed plate (16) is connected to one side of the upper surface of the support member (11), a push plate (5) is connected to the upper surface of the push rod (10), a slide rod (15) is connected to the surface of the fixed plate (16), one end of the slide rod (15) passes through the push plate (5) and extends to one side of the push plate (5), and a return spring (6) is sleeved on the slide rod (15). The two ends of the return spring (6) are fixed to the side walls of the push plate (5) and the fixed plate (16) respectively.

5. The automatic sealing device for oil and gas wellheads according to claim 2, characterized in that: A fixing rod (18) is fixed on the side wall inside the groove (22). A baffle (17) is connected to one end of the fixing rod (18) away from the side wall of the groove (22). A rubber pad is provided on the surface of the baffle (17).

6. The automatic sealing device for oil and gas wellheads according to claim 1, characterized in that: The connector (9) is U-shaped, and the two vertical sections of the connector (9) are connected to the corresponding push rods (10).

7. The automatic sealing device for oil and gas wellheads according to claim 1, characterized in that: The surface of the arc-shaped clamp (8) is provided with multiple balls (20) at equal intervals.

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