A ternary polymer-driven high-pressure sealing device

Abstract

A high-pressure sealing device resistant to ternary lithium-ion and polymer-driven oil and gas extraction technologies is disclosed. It includes a hollow shaft and a central tube. A dynamic sealing mechanism is provided between the upper end of the hollow shaft and the upper end of the central tube. The dynamic sealing mechanism includes: an inner sealing sleeve, fixedly connected to the outer side of the upper end of the central tube and sealingly engaging with the outer wall of the central tube; an outer sealing sleeve, fixedly connected to the inner side of the upper end of the hollow shaft and sealingly engaging with the inner wall of the hollow shaft; and a Y-shaped sealing ring, disposed between the inner and outer sealing sleeves to seal the gap between them. There are at least two Y-shaped sealing rings. This invention replaces the traditional double-mirror mechanical seal structure, reducing the manufacturing and installation costs of the sealing structure, lowering the skill requirements for workers, while still ensuring sealing effectiveness.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas extraction, and in particular to a ternary polymer-driven high-pressure sealing device. Background Technology

[0002] In a screw pump oil extraction system, the hollow shaft of the motor rotates continuously under the drive of the motor, while the central tube located inside the hollow shaft is fixed. Therefore, a dynamic sealing structure is required for the seal between the hollow shaft and the central tube.

[0003] Given the specific operating conditions of screw pumps, the current dynamic sealing structure mainly employs double-mirror mechanical seals. While this type of seal offers excellent sealing performance, it demands extremely high precision in the machining and assembly of all components, including the central tube. This results in high manufacturing costs and places significant demands on the technical skills of assembly workers; even slight errors can lead to seal failure. Therefore, it is necessary to optimize and improve the existing technology.

[0004] In addition, due to structural limitations, existing double-mirror mechanical seals are poorly adapted to operating conditions containing ternary or polymeric oil displacement agents. Utility Model Content

[0005] This invention provides a ternary, polymer-driven high-pressure sealing device. By redesigning the dynamic sealing structure between the hollow shaft and the central tube, it effectively eliminates the problems of high processing costs and high skill requirements for workers in the prior art.

[0006] The technical problem solved by this utility model is achieved by the following technical solution: This utility model provides a ternary, polymer-driven high-pressure sealing device, including a hollow shaft and a central tube, wherein a dynamic sealing mechanism is provided between the upper end of the hollow shaft and the upper end of the central tube, and the dynamic sealing mechanism includes:

[0007] The inner sealing sleeve is fixedly connected to the outer side of the upper end of the central tube and seals against the outer wall of the central tube.

[0008] The outer sealing sleeve is fixedly connected to the inner side of the upper end of the hollow shaft and seals against the inner wall of the hollow shaft.

[0009] Y-type sealing rings are placed between the inner and outer sealing sleeves to seal the gap between them; there are at least two Y-type sealing rings.

[0010] As a preferred option, the outer side of the inner sealing sleeve is machined with sealing surfaces of different diameters arranged in a stepped manner. The number of sealing surfaces is equal to the number of Y-type sealing rings and corresponds one-to-one. The diameter of each sealing surface gradually decreases from top to bottom.

[0011] As a preferred option, the Y-type sealing ring is installed in the sealing groove on the inner wall of the outer sealing sleeve.

[0012] As a preferred embodiment, each sealing surface on the outer side of the inner sealing sleeve is provided with an annular boss at its lower end. Each annular boss extends outward to the lower part of its corresponding Y-shaped sealing ring. When the upper side of the Y-shaped sealing ring is under pressure, the pressure squeezes the Y-shaped sealing ring downward, causing the lower end face of the Y-shaped sealing ring to fit against the upper part of the gap on the outer side of the annular boss, thereby sealing the gap on the outer side of the annular boss.

[0013] As a preferred option, a spacer ring is provided between two adjacent Y-shaped sealing rings, and the spacer ring is an open ring.

[0014] As a preferred embodiment, the inner side of the outer sealing sleeve is also machined with sealing surfaces of different diameters arranged in a stepped manner. By making the spacer ring stuck at the step formed between two adjacent sealing surfaces, the lower side of the spacer ring can be limited, and the upper end of the outer sealing sleeve can be pulled out as a whole by the inner sealing sleeve, the spacer ring and the Y-shaped sealing ring.

[0015] As a preferred embodiment, an annular slit is provided on the inner side of the bottom of the Y-shaped sealing ring, and the annular slit forms a bottom sealing lip at the bottom of the Y-shaped sealing ring.

[0016] The beneficial effects of this utility model are:

[0017] 1. This utility model, by adopting a sealing structure based on a Y-type sealing ring, meets the sealing requirements between the hollow shaft and the central pipe in a screw pump oil production system, thereby replacing the traditional double-mirror mechanical seal structure, reducing the manufacturing and installation costs of the sealing structure, and also reducing the technical requirements for workers.

[0018] 2. Y-type seals are typically used in linear reciprocating sliding sealing applications. When used in rotary dynamic sealing applications, they are prone to the problem of "soft wear on hard," meaning that the soft Y-type seal is prone to causing wear on the rotating parts inside.

[0019] In this invention, to prevent wear on the high-cost and difficult-to-replace central tube, an inner sealing sleeve is provided on the outer side of the upper end of the central tube. After the outer side of the inner sealing sleeve is worn by the Y-shaped sealing ring, it can be easily replaced from the top of the motor without disassembling the motor, and the manufacturing cost of the inner sealing sleeve is very low. Therefore, this invention effectively improves the convenience of maintenance by providing an inner sealing sleeve, while keeping maintenance costs within an acceptable range.

[0020] 3. In this utility model, by setting an annular boss on the outer side of the inner sealing ring, when the upper side of the Y-shaped sealing ring is under pressure, the pressure squeezes the Y-shaped sealing ring downward, so that the lower end face of the Y-shaped sealing ring fits against the upper part of the gap on the outer side of the annular boss, thereby sealing the gap on the outer side of the annular boss.

[0021] When the part of the Y-type sealing ring that contacts the inner sealing sleeve wears or fails due to aging, the seal at the bottom of the Y-type sealing ring will serve as a supplement to improve the reliability and effectiveness of the seal.

[0022] 4. In some embodiments of this utility model, by providing a stepped surface on the inner side of the outer sealing sleeve, the lower side of the spacer ring can be limited to prevent the spacer ring from pressing down on the Y-shaped sealing ring, and the upper end of the outer sealing sleeve can be pulled out as a whole by the inner sealing sleeve, the spacer ring and the Y-shaped sealing ring, which facilitates the disassembly and replacement of the sealing mechanism. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of the first embodiment of the present utility model.

[0024] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle.

[0025] Figure 3 This is a structural schematic diagram of the second embodiment of the present invention.

[0026] Figure 4 yes Figure 3 A magnified view of a section at point B in the middle.

[0027] Figure 5 Is Figure 4 A schematic diagram of the structure after adding a bottom sealing lip to the Y-shaped sealing ring.

[0028] In the diagram: 1. Hollow shaft; 2. Outer sealing sleeve; 3. Central tube; 4. Inner sealing sleeve; 5. Y-shaped sealing ring; 6. Sealing surface; 7. Spacer ring; 8. Annular slit; 9. Bottom sealing lip. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] First embodiment

[0031] like Figure 1 As shown, this embodiment includes a hollow shaft 1 and a central tube 3. A dynamic sealing mechanism is provided between the upper end of the hollow shaft 1 and the upper end of the central tube 3. The above is a common structure in the prior art, and will not be described in detail here.

[0032] like Figure 1As shown in Figure 3, in this embodiment, the dynamic sealing mechanism includes an inner sealing sleeve 4, an outer sealing sleeve 2, and a Y-shaped sealing ring 5. The inner sealing sleeve 4 is fixedly connected to the outer side of the upper end of the central tube 3 and seals against the outer wall of the central tube 3 to achieve a static seal connection. The outer sealing sleeve 2 is fixedly connected to the inner side of the upper end of the hollow shaft 1 and seals against the inner wall of the hollow shaft 1 to achieve a static seal connection. The Y-shaped sealing ring 5 is disposed between the inner sealing sleeve 4 and the outer sealing sleeve 2 to seal the gap between them. There are at least two Y-shaped sealing rings 5 ​​to ensure the reliability of the seal.

[0033] like Figure 2 As shown, in this embodiment, the outer side of the inner sealing sleeve 4 is machined with sealing surfaces 6 of different diameters arranged in a stepped pattern. The number of sealing surfaces 6 is equal to the number of Y-type sealing rings 5 ​​and corresponds one-to-one. The diameter of each sealing surface 6 gradually decreases from top to bottom. Compared with setting three sealing rings on the same sealing surface 6, this structure is easier to disassemble and maintain, and the sealing effect is also better.

[0034] like Figure 1 As shown, in this embodiment, the Y-shaped sealing ring 5 is installed in the sealing groove on the inner wall of the outer sealing sleeve 2. When replacing the Y-shaped sealing ring 5, the outer sealing sleeve 2 needs to be removed.

[0035] This invention employs a dynamic sealing structure based on a Y-type sealing ring 5. It meets the sealing requirements between the hollow shaft 1 and the central pipe 3 in a screw pump oil production system, replacing the traditional double-mirror mechanical seal structure. This reduces the manufacturing and installation costs of the sealing structure and also lowers the skill requirements for workers.

[0036] In the prior art, the problem with using the Y-type sealing ring 5 in rotary dynamic seals is that it easily leads to a "soft-on-hard" problem, meaning the soft Y-type sealing ring 5 easily causes wear on the inner rotating parts. Correspondingly, in this invention, to prevent wear on the central tube 3, which is costly to manufacture and difficult to replace, an inner sealing sleeve 4 is provided on the outer side of the upper end of the central tube 3. After the outer side of the inner sealing sleeve 4 is worn by the Y-type sealing ring 5, it can be easily replaced from the top of the motor without disassembling the motor, and the manufacturing cost of the inner sealing sleeve 4 is very low. Therefore, this invention, by providing the inner sealing sleeve 4, can effectively improve the convenience of maintenance while keeping maintenance costs within an acceptable range.

[0037] Second embodiment

[0038] The difference between this embodiment and the first embodiment lies in the installation structure of the Y-shaped sealing ring 5.

[0039] like Figure 3 , 4As shown in Figure 5, in this embodiment, each sealing surface 6 on the outer side of the inner sealing sleeve 4 is provided with an annular protrusion at its lower end. Each annular protrusion extends outward to the lower part of its corresponding Y-shaped sealing ring 5. When the upper side of the Y-shaped sealing ring 5 is under pressure, the pressure squeezes the Y-shaped sealing ring 5 downward, causing the lower end face of the Y-shaped sealing ring 5 to fit against the upper part of the gap on the outer side of the annular protrusion, thereby sealing the gap on the outer side of the annular protrusion. The advantage of this design is that:

[0040] When the hollow shaft 1 and the central tube 3 rotate relative to each other, the Y-shaped sealing ring 5 and the outer sealing sleeve 2 remain relatively stationary, while the Y-shaped sealing ring 5 and the inner sealing sleeve 4 rotate relative to each other. In this situation, the contact area between the Y-shaped sealing ring 5 and the inner sealing sleeve 4 is more prone to sealing problems. This embodiment addresses this by providing an annular boss below the Y-shaped sealing ring 5, creating a secondary seal at the outer edge of the annular boss. When the contact area between the Y-shaped sealing ring 5 and the inner sealing sleeve 4 wears or ages and fails, the seal at the bottom of the Y-shaped sealing ring 5 serves as a supplement, improving the reliability and effectiveness of the seal. Furthermore, while adding this secondary seal, the required installation space for the Y-shaped sealing ring 5 increases almost entirely.

[0041] In this embodiment, a spacer ring 7 is provided between two adjacent Y-shaped sealing rings 5, and the spacer ring 7 is an open ring.

[0042] like Figure 4 As shown in this embodiment, the inner side of the outer sealing sleeve 2 is also machined with sealing surfaces 6 of different diameters arranged in a stepped pattern. By having the spacer ring 7 engage at the step formed between two adjacent sealing surfaces 6, the lower side of the spacer ring 7 can be limited, and the upper end of the outer sealing sleeve 2 can be pulled out as a whole, consisting of the inner sealing sleeve 4, the spacer ring 7, and the Y-shaped sealing ring 5. By providing a stepped surface on the inner side of the outer sealing sleeve 2, the lower side of the spacer ring 7 can be limited, preventing the spacer ring 7 from pressing down on the Y-shaped sealing ring 5, and the upper end of the outer sealing sleeve 2 can be pulled out as a whole, facilitating the disassembly and replacement of the sealing mechanism.

[0043] like Figure 5 As shown, in some embodiments, an annular slit 8 is provided on the inner side of the bottom of the Y-shaped sealing ring 5, which forms a bottom sealing lip 9 at the bottom of the Y-shaped sealing ring 5. When the sealing capacity of the inner sealing part of the Y-shaped sealing ring 5 decreases, the fluid from above reaches the inner side of the bottom sealing lip 9 and enters the annular slit 8. Under the action of fluid pressure, the bottom sealing lip 9 presses down against the upper surface of the annular boss, thereby more effectively ensuring the seal between the bottom of the Y-shaped sealing ring 5 and the annular boss.

Claims

1. A ternary, polymer-driven high-pressure sealing device, comprising a hollow shaft (1) and a central tube (3), wherein a dynamic sealing mechanism is provided between the upper end of the hollow shaft (1) and the upper end of the central tube (3), characterized in that, The dynamic sealing mechanism includes: The inner sealing sleeve (4) is fixedly connected to the outer side of the upper end of the central tube (3) and seals with the outer wall of the central tube (3); The outer sealing sleeve (2) is fixedly connected to the inner side of the upper end of the hollow shaft (1) and seals with the inner wall of the hollow shaft (1); Y-type sealing ring (5) is disposed between the inner sealing sleeve (4) and the outer sealing sleeve (2) to seal the gap between the inner sealing sleeve (4) and the outer sealing sleeve (2); there are at least two Y-type sealing rings (5); The outer side of the inner sealing sleeve (4) is machined with sealing surfaces (6) of different diameters arranged in a stepped manner. The number of sealing surfaces (6) is equal to the number of Y-type sealing rings (5) and they correspond one-to-one. The diameter of each sealing surface (6) gradually decreases from top to bottom.

2. A high pressure seal resistant to a ternary, polymer flood according to claim 1, characterized in that: The Y-type sealing ring (5) is installed in the sealing groove on the inner wall of the outer sealing sleeve (2).

3. A high pressure seal resistant to a ternary, polymer flood according to claim 1, characterized in that: The lower end of each sealing surface (6) on the outer side of the inner sealing sleeve (4) is provided with an annular boss. Each annular boss extends outward to the lower part of its corresponding Y-shaped sealing ring (5). When the upper side of the Y-shaped sealing ring (5) is under pressure, the pressure squeezes the Y-shaped sealing ring (5) downward, so that the lower end face of the Y-shaped sealing ring (5) fits against the upper part of the annular boss's outer gap, thereby sealing the annular boss's outer gap.

4. A high pressure seal resistant to ternary, polymer flooding according to claim 3, characterized in that: A spacer ring (7) is provided between two adjacent Y-shaped sealing rings (5), and the spacer ring (7) is an open ring.

5. A high pressure seal resistant to ternary, polymer flooding according to claim 4, characterized in that: The inner side of the outer sealing sleeve (2) is also machined with sealing surfaces (6) of different diameters arranged in a stepped manner. By making the spacer (7) stuck at the step formed between two adjacent sealing surfaces (6), the lower side of the spacer (7) can be limited, and the upper end of the outer sealing sleeve (2) can be pulled out as a whole by the inner sealing sleeve (4), the spacer (7) and the Y-shaped sealing ring (5).

6. A high-pressure sealing device resistant to ternary materials and polymers according to any one of claims 3-5, characterized in that: The inner side of the bottom of the Y-shaped sealing ring (5) is provided with an annular slit (8), which makes the bottom of the Y-shaped sealing ring (5) form a bottom sealing lip (9).

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