A tubing connection gas-tight connector

Abstract

The utility model relates to a gas seal joint of tubing connection, and it relates to the technical field of tubing connection, and its structure includes first tubing body, coupling body and second tubing body, first tubing body is connected in the inside of one end of coupling body threadedly, and the inside of the other end of coupling body is connected with pre-tightening sleeve threadedly, and second tubing body is connected in the inside of pre-tightening sleeve threadedly, and the sealing assembly is arranged in the coupling body, and the sealing assembly includes fixed ring, and the both end faces of fixed ring are provided with rubber seal layer respectively, when first tubing body is screwed on the coupling body, and second tubing body is screwed on the pre-tightening sleeve and pre-tightening sleeve is screwed on the coupling body, the rubber seal layer of one side is sealed on the threaded connection end face of first tubing body and coupling body, and the rubber seal layer of the other side is sealed on the threaded connection end face of second tubing body and pre-tightening sleeve. The utility model sets up rubber seal layer on the basis of existing ordinary tubing thread seal, and the gas seal ability of connection is improved greatly.

Description

Technical Field

[0001] This invention belongs to the field of oil pipe connection technology, and particularly relates to an oil pipe connection gas-tight connector. Background Technology

[0002] In the field of oil and gas extraction, the gas sealing capacity of ordinary tubing threads is limited and cannot meet the sealing requirements of gas production wells or gas-driven injection and production wells. Existing gas production wells and gas-driven injection and production wells generally use special threaded connections with higher sealing performance for their production tubing. Due to the high machining precision of special threads, the production tubing and connectors are more expensive. In addition, special threads have a short service life, so the production tubing needs to be replaced frequently, resulting in higher extraction costs for existing gas production wells. Summary of the Invention

[0003] To address the problem of poor gas sealing capability of existing ordinary oil pipe threads, this invention provides an oil pipe connection gas-sealing connector. This invention can significantly improve the gas sealing capability of ordinary oil pipe thread connections with minimal cost increase but substantial performance improvement.

[0004] The technical solution provided by this invention is: a gas-tight connector for oil pipe connections, comprising a first oil pipe body, a coupling body, and a second oil pipe body. The first oil pipe body is threaded to the inner side of one end of the coupling body, and a pre-tightening sleeve is threaded to the inner side of the other end of the coupling body. The second oil pipe body is threaded to the inner side of the pre-tightening sleeve. A sealing component is provided in the middle of the inner side of the coupling body. The sealing component includes a fixing ring, which slides with the coupling body. Rubber sealing layers are provided on both end faces of the fixing ring. When the first oil pipe body is tightened on the coupling body, and the second oil pipe body is tightened on the pre-tightening sleeve, and the pre-tightening sleeve is tightened on the coupling body, one side of the rubber sealing layer seals the threaded connection end face of the first oil pipe body and the coupling body, and the other side of the rubber sealing layer seals the threaded connection end face of the second oil pipe body and the pre-tightening sleeve. This solution adds a rubber sealing layer to the ordinary oil pipe thread connection, improving the gas-tight effect of the ordinary oil pipe thread.

[0005] A further technical solution is as follows: the inner side of the end of the coupling body connected to the pre-tightening sleeve has an enlarged diameter section, the outer side of the pre-tightening sleeve has an annular groove, a limit ring is provided in the annular groove, the limit ring can slide in the annular groove, an end ring is connected in the enlarged diameter section, the outer diameter of the limit ring is larger than the inner diameter of the end ring, during the process of the pre-tightening sleeve rotating outward relative to the coupling body, the end face of the end ring will abut against the end face of the limit ring, thereby restricting the pre-tightening sleeve from continuing to rotate outward relative to the coupling body.

[0006] A further technical solution is to provide a sealing ring in the annular groove on the side away from the end ring. After the pre-tightening sleeve is tightened, the sealing ring seals the threaded connection end face between the pre-tightening sleeve and the coupling body, thereby improving the sealing performance of the threaded connection.

[0007] A further technical solution is that the sealing ring is made of an elastic material, and the limiting ring is a ring structure composed of at least two parts.

[0008] A further technical solution is to vulcanize the rubber sealing layer with the fixing ring to improve the connection strength and sealing performance.

[0009] A further technical solution is that the fixing ring and the coupling body are connected by a spline, thereby preventing the fixing ring and the rubber sealing layer from rotating circumferentially relative to the coupling body.

[0010] A further technical solution is: the outer side of the fixing ring near the pre-tightening sleeve has a reduced diameter section, and an annular space is formed between the reduced diameter section and the coupling body. The end of the pre-tightening sleeve extends into the annular space, and the extended part of the pre-tightening sleeve is sealed and fitted with the coupling body and the fixing ring respectively.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention incorporates a sealing component within the coupling body. A pre-tightening sleeve is threadedly connected to one end of the coupling body. The sealing component achieves a tight seal at the threaded connection end face of the ordinary oil pipe by screwing the pre-tightening sleeve onto the coupling body, thereby improving the airtightness of the ordinary oil pipe threaded connection. In this design, although a pre-tightening sleeve is connected to one end of the coupling body, the coupling body and the pre-tightening sleeve form a single unit. The connection between this unit and the oil pipe body is end-to-end, similar to existing connectors. Workers using the new connector do not need to distinguish between the correct and incorrect orientations.

[0012] 2. The pre-tightening sleeve in this invention has a limited degree of unscrewing within the coupling body. This feature has two beneficial effects: First, since the pre-tightening sleeve cannot be completely removed from the coupling body, when tightening the pre-tightening sleeve back onto the coupling body, only a few turns are needed, and the increased workload during the tightening process is minimal. Second, after the oil pipe is removed, the pre-tightening sleeve will not be accidentally unscrewed from the coupling body and lost during storage. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of the pre-tightening sleeve and the coupling body after tightening in this invention.

[0014] Figure 2 This is a cross-sectional view of the pre-tightening sleeve and the coupling body after loosening in this invention.

[0015] Figure 3This is a cross-sectional view showing the sealing fit between the end of the pre-tightening sleeve and the coupling body and the fixing ring in this invention.

[0016] Figure 4 This is a cross-sectional view of the fixing ring and the rubber sealing layer after vulcanization in this invention.

[0017] In the diagram: 1. First tubing body; 2. Coupling body; 3. Rubber sealing layer; 4. Fixing ring; 5. Pre-tightening sleeve; 6. Sealing ring; 7. Limiting ring; 8. End ring; 9. Second tubing body; 10. Expanding section; 11. Reducing section. Detailed Implementation

[0018] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0019] The present invention includes a first oil pipe body 1, a coupling body 2, and a second oil pipe body 9.

[0020] Both the first oil pipe body 1 and the second oil pipe body 9 are existing ordinary oil pipes. The first oil pipe body 1 and the second oil pipe body 9 have the same structure. They are named separately for easy distinction in this application. The ends of the first oil pipe body 1 and the second oil pipe body 9 are both machined with ordinary oil pipe threads. The above is the prior art and will not be described again.

[0021] The first oil pipe body 1 is threaded to the inner side of one end of the coupling body 2. The inner side of the other end of the coupling body 2 is threaded to a pre-tightening sleeve 5. The second oil pipe body 9 is threaded to the inner side of the pre-tightening sleeve 5. A sealing assembly is provided in the middle of the inner side of the coupling body 2. The sealing assembly includes a fixing ring 4, which slides with the coupling body 2. Rubber sealing layers 3 are provided on the two end faces of the fixing ring 4. The rubber sealing layers 3 are vulcanized with the fixing ring 4. The vulcanized connection has higher reliability and sealing performance. The position of the rubber sealing layer 3 on one side corresponds to the threaded connection of the first oil pipe body 1 and the coupling body 2, and the position of the rubber sealing layer 3 on the other side corresponds to the threaded connection of the second oil pipe body 9 and the pre-tightening sleeve 5.

[0022] In this invention, it is possible to connect either the first oil pipe body 1 or the second oil pipe body 9 first. In this invention, the coupling body 2 and the pre-tightening sleeve 5 form a whole. The connection between this whole and the two oil pipe bodies is not divided into ends. This is the same as the connection method of existing oil pipe connectors. This invention does not change the existing connection method. Workers do not need to distinguish the front and back of the connector when using the new connector.

[0023] This invention first tightens the two oil pipe bodies. When tightening the second oil pipe body 9, it is important to ensure that the tightening pliers are applied to the pre-tightening sleeve 5 and the second oil pipe body 9, not the coupling body 2 and the second oil pipe body 9. Finally, tighten the pre-tightening sleeve 5. During the tightening process, the entire structure formed by the second oil pipe body 9 and the pre-tightening sleeve 5 applies compressive force to the rubber sealing layer 3, forcing one side of the rubber sealing layer 3 to seal the threaded connection end face of the first oil pipe body 1 and the coupling body 2, and the other side of the rubber sealing layer 3 to seal the threaded connection end face of the second oil pipe body 9 and the pre-tightening sleeve 5. This invention does not replace the existing oil pipes, but only the existing oil pipe connectors. A sealing component is installed inside the coupling body 2, adding a rubber sealing layer 3 to the ordinary oil pipe threaded connection, thus improving the airtightness of the ordinary oil pipe threads.

[0024] The inner side of the end of the coupling body 2 connected to the pre-tightening sleeve 5 has an expanded diameter section 10. The outer side of the pre-tightening sleeve 5 has an annular groove, and a limiting ring 7 is provided in the annular groove. For ease of installation, the limiting ring 7 is an annular structure composed of at least two parts. The limiting ring 7 can slide within the annular groove. An end ring 8 is connected within the expanded diameter section 10. The end ring 8 is further connected to the coupling body 2 by an anti-rotation pin to prevent the end ring 8 from rotating relative to the coupling body 2. The outer diameter of the limiting ring 7 is larger than the inner diameter of the end ring 8. During the outward rotation of the pre-tightening sleeve 5 relative to the coupling body 2, the end face of the end ring 8 will abut against the end face of the limiting ring 7, thereby restricting the pre-tightening sleeve 5 from continuing to rotate outward relative to the coupling body 2. The pre-tightening sleeve 5 in this invention has a limited degree of rotation out of the coupling body 2. This feature has two beneficial effects. First, since the pre-tightening sleeve 5 cannot be completely removed from the coupling body 2, when tightening the pre-tightening sleeve 5 on the coupling body 2 again, only a few turns are needed, and the increased workload during the tightening process is not significant. Second, after the oil pipe body is removed, the pre-tightening sleeve 5 will not be accidentally rotated out of the coupling body 2 and lost during storage.

[0025] A sealing ring 6 is also provided in the annular groove on the side away from the end ring 8. After the pre-tightening sleeve 5 is tightened, the sealing ring 6 seals the threaded connection between the pre-tightening sleeve 5 and the coupling body 2, thereby improving the sealing performance of the threaded connection.

[0026] To prevent the rubber sealing layer 3 from rotating, the fixing ring 4 and the coupling body 2 are connected by a spline, thereby preventing the fixing ring 4 and the rubber sealing layer 3 from rotating circumferentially relative to the coupling body 2.

[0027] like Figure 3As shown, the outer side of the fixing ring 4, which is close to the pre-tightening sleeve 5, has a reduced diameter section 11. The reduced diameter section 11 and the coupling body 2 form an annular space. The end of the pre-tightening sleeve 5 extends into the annular space. The extended part of the pre-tightening sleeve 5 is sealed with the coupling body 2 and the fixing ring 4 respectively by O-rings to further improve the sealing performance of the connection between the pre-tightening sleeve 5 and the coupling body 2.

[0028] In summary, this invention improves the airtightness of existing ordinary oil pipe threads by changing the structure of the oil pipe connector. This invention does not require replacing the oil pipe itself, only the oil pipe connector, resulting in lower operating costs. The invention has a reasonable structure, adds minimal workload during pre-tightening, and is a typical solution to a complex problem through a simple structure, making it suitable for widespread use.

Claims

1. A gas-tight connector for oil pipe connection, comprising a first oil pipe body (1), a coupling body (2), and a second oil pipe body (9), characterized in that: The first oil pipe body (1) is threaded to the inner side of one end of the coupling body (2), and the inner side of the other end of the coupling body (2) is threaded to a pre-tightening sleeve (5). The second oil pipe body (9) is threaded to the inner side of the pre-tightening sleeve (5). A sealing component is provided in the middle of the inner side of the coupling body (2). The sealing component includes a fixing ring (4). The fixing ring (4) is slidably engaged with the coupling body (2). Rubber sealing layers (3) are provided on the two end faces of the fixing ring (4). When the first oil pipe body (1) is tightened on the coupling body (2), the second oil pipe body (9) is tightened on the pre-tightening sleeve (5), and the pre-tightening sleeve (5) is tightened on the coupling body (2), the rubber sealing layer (3) on one side seals the threaded connection end face of the first oil pipe body (1) and the coupling body (2), and the rubber sealing layer (3) on the other side seals the threaded connection end face of the second oil pipe body (9) and the pre-tightening sleeve (5). The inner side of the end of the coupling body (2) connected to the pre-tightening sleeve (5) has an enlarged diameter section (10). The outer side of the pre-tightening sleeve (5) has an annular groove. A limit ring (7) is provided in the annular groove. The limit ring (7) can slide in the annular groove. An end ring (8) is connected in the enlarged diameter section (10). The outer diameter of the limit ring (7) is larger than the inner diameter of the end ring (8). During the process of the pre-tightening sleeve (5) rotating outward relative to the coupling body (2), the end face of the end ring (8) will abut against the end face of the limit ring (7), thereby restricting the pre-tightening sleeve (5) from continuing to rotate outward relative to the coupling body (2). The outer side of the fixing ring (4) near the pre-tightening sleeve (5) has a reduced diameter section (11). The reduced diameter section (11) and the coupling body (2) form an annular space. The end of the pre-tightening sleeve (5) extends into the annular space. The extended part of the pre-tightening sleeve (5) is sealed with the coupling body (2) and the fixing ring (4) respectively.

2. The gas-tight connector for oil pipe connection according to claim 1, characterized in that: A sealing ring (6) is also provided in the annular groove on the side away from the end ring (8).

3. The gas-tight connector for oil pipe connection according to claim 2, characterized in that: The sealing ring (6) is made of elastic material, and the limiting ring (7) is a ring structure composed of at least two parts.

4. The gas-tight connector for oil pipe connection according to claim 1, characterized in that: The rubber sealing layer (3) is vulcanized and connected to the fixing ring (4).

5. The gas-tight connector for oil pipe connection according to claim 4, characterized in that: The fixing ring (4) and the coupling body (2) are connected by a spline, thereby preventing the fixing ring (4) and the rubber sealing layer (3) from rotating circumferentially relative to the coupling body (2).

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