Petroleum wellhead annulus sealing device

Abstract

The utility model discloses a petroleum wellhead annulus sealing device, which belongs to the technical field of petroleum wellhead sealing and comprises a four-way tubing head, a lower flange plate is arranged on the lower portion of the four-way tubing head, an oil guide pipe is sleeved on the inner side of the lower flange plate, and two sealing ring grooves are arranged on the inner wall of the lower flange plate. According to the utility model, the oil guide pipe and the four-way tubing head are sealed through the matching of the two groups of sealing rings and the power ring, and the oil guide pipe and the four-way tubing head are sealed again by injecting sealing grease into the second oil injection groove and the oil pressure detection groove; in addition, a pressure sensor in an oil pressure detection groove is used for detecting the oil pressure in the second oil injection groove and the oil pressure detection groove in real time, when the oil pressure is reduced, it is indicated that oil between the oil guide pipe and the four-way oil pipe head leaks, and then it is indicated that sealing between the oil guide pipe and the sealing ring fails; and the practicability of the petroleum wellhead annulus sealing device is improved.

Description

Technical Field

[0001] This utility model relates to the field of oil wellhead sealing technology, and more specifically, to an annular sealing device for oil wellheads. Background Technology

[0002] There are three main existing sealing methods for the annulus between the wellhead assembly and the tubing: BT seal, P-type seal, and FS seal. All three sealing devices use rubber components as the main sealing element, with a metal skeleton inside the rubber component. The sealing force is provided by injecting sealing grease or embedding springs to seal the annulus between the wellhead assembly and the tubing.

[0003] A search revealed that utility model patent CN207017968U discloses an annular sealing device for oil wellheads, used to seal the annulus between the wellhead sealing body and the oil pipe. The sealing body has at least one annular groove on its inner wall and an injection hole connected to the centrifugal end of the annular groove. The oil wellhead annular sealing device further includes: a sealing ring, fitted into the annular groove, which radially seals the annular groove by engaging with the groove wall and sealing the annulus by engaging with the outer wall of the oil pipe; a power ring, installed within the annular groove and positioned between the groove bottom and the sealing ring; and an injection assembly, installed at the inlet of the injection hole, for injecting fluid at a given pressure to cause the power ring to push the sealing ring to press against the oil pipe.

[0004] However, the above-mentioned patent still has the following shortcomings: when using the sealing ring to seal between the tubing and the sealing body, it is not convenient to monitor the sealing effect during use; in addition, the cap and the thread are located on the outside of the sealing body, and the thread is prone to loosening, which will affect the pushing of the sealing grease on the sealing ring, thereby affecting the sealing performance between the tubing and the sealing body. Therefore, we propose an annular sealing device for oil wellheads. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of this utility model is to provide an annular sealing device for oil wellheads.

[0006] To solve the above problems, the present invention adopts the following technical solution:

[0007] An annular sealing device for an oil wellhead includes a four-way tubing head. A lower flange is provided at the lower part of the four-way tubing head. An oil guide pipe is fitted inside the lower flange. Two sealing ring grooves are formed on the inner wall of the lower flange. A sealing ring is fitted inside the inner cavity of each sealing ring groove and outside the oil guide pipe. A power ring is fitted inside each inner cavity of the sealing ring groove. A first oil injection groove is formed on the inner wall of each sealing ring groove. A first threaded hole is provided at the end of each of the two first oil injection grooves. A first threaded post is threaded into the inner cavity of each first threaded hole. A second oil injection groove is formed on the inner wall of the lower flange. An oil pressure detection groove is provided at the end of the second oil injection groove. A second threaded hole is provided at the end of the pressure testing groove. A second threaded post is threaded into the inner cavity of the second threaded hole. A second hexagonal groove is provided at the end of the second threaded hole and on the outer side of the lower flange. A testing mechanism is provided on the second threaded post. An airtightness testing groove is provided on the inner wall of the lower flange. A third threaded hole is provided at the end of the airtightness testing groove. A third threaded post is threaded into the inner cavity of the third threaded hole. A first hexagonal groove is provided at the end of the two first threaded holes and the third threaded hole and on the outer side of the lower flange. An anti-loosening mechanism is provided in the inner cavity of each of the first hexagonal grooves. A lever block is fixedly connected to the end of the first threaded post and the third threaded post.

[0008] In a preferred embodiment of this utility model, the detection mechanism includes a pressure sensor fixedly installed at one end of the second threaded column and a connecting pipe fixedly connected to the other end of the second threaded column. The pressure sensor is located in the inner cavity of the oil pressure detection groove. A mounting box is fixedly connected to the end of the connecting pipe. A battery is installed in the inner cavity of the mounting box. A remote signal transmitter is fixedly installed on the inner wall of the mounting box. An electrical wire is fixedly connected to the remote signal transmitter. The end of the electrical wire passes through the electrical wire and is connected to the pressure sensor. A second hexagonal rubber block is movably sleeved on the outside of the connecting pipe. Two insertion holes are opened at the end of the second hexagonal rubber block. The second hexagonal rubber block is sleeved in the inner cavity of the second hexagonal groove. Two insertion posts are fixedly connected to the other end of the second threaded column. The ends of the two insertion posts are movably sleeved into the inner cavity of the insertion holes.

[0009] As a preferred embodiment of the present invention, the anti-loosening mechanism includes a first hexagonal rubber block sleeved in the inner cavity of the first hexagonal groove, one end of the first hexagonal rubber block having a slot, the end of the lever block being movably sleeved into the inner cavity of the slot, and the other end of the first hexagonal rubber block being fixedly connected to a picking post.

[0010] In a preferred embodiment of this utility model, the top and bottom surfaces of the sealing ring are respectively fitted with the top and bottom surfaces of the inner cavity of the sealing ring groove.

[0011] In a preferred embodiment of this utility model, the inner wall of the insertion hole and the outer surface of the insertion post are fitted together.

[0012] In a preferred embodiment of this utility model, the side of the first hexagonal rubber block is in contact with the inner wall of the first hexagonal groove, and the inner wall of the slot is in contact with the side of the lever block.

[0013] Compared with existing technologies, the advantages of this utility model are:

[0014] (1) In this utility model, the oil guide pipe and the four-way oil pipe head are sealed by the cooperation of two sets of sealing rings and power rings. In addition, sealing grease is injected into the second oil injection tank and the oil pressure detection tank to reseal the oil guide pipe and the four-way oil pipe head. In addition, the pressure sensor in the oil pressure detection tank detects the oil pressure in the second oil injection tank and the oil pressure detection tank in real time. The detection information is transmitted to the control console remotely by the remote signal transmitter. When the oil pressure decreases, it indicates that there is a leak in the oil between the oil guide pipe and the four-way oil pipe head, which indicates that the seal between the oil guide pipe and the sealing ring has failed. This realizes the function of real-time detection of the sealing performance between the four-way oil pipe head and the oil guide pipe.

[0015] (2) In this utility model, the end of the airtightness test groove is sealed by the threaded engagement between the third screw hole and the third threaded post, the grease in the first oil filling groove and the inner cavity of the sealing ring groove is sealed by the threaded engagement between the first screw hole and the first threaded post, and the first hexagonal rubber block is inserted into the first hexagonal groove at the end of the third screw hole and the first screw hole, so that the wrench at the end of the first threaded post and the third threaded post is inserted into the slot on the first hexagonal rubber block. The engagement between the first hexagonal rubber block and the first hexagonal groove is used to prevent the first threaded post and the third threaded post from loosening, which is practical. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the four-way oil pipe head of this utility model;

[0018] Figure 3 This is a cross-sectional view of the present invention;

[0019] Figure 4 This is a schematic diagram of the structure of the first threaded column of this utility model;

[0020] Figure 5 This is a cross-sectional schematic diagram of the second hexagonal rubber block of this utility model;

[0021] Figure 6 This is a schematic diagram of the structure of the first hexagonal rubber block of this utility model.

[0022] Explanation of the labels in the diagram:

[0023] 1. Four-way oil pipe head; 2. Lower flange; 3. Oil guide pipe; 4. Sealing ring groove; 5. Sealing ring; 6. Power ring; 7. First oil filling groove; 8. First threaded hole; 9. First threaded post; 10. Second oil filling groove; 11. Oil pressure detection groove; 12. Second threaded hole; 13. Detection mechanism; 15. Air tightness detection groove; 16. Third threaded hole; 17. Third threaded post; 18. Actuating block; 19. Anti-loosening mechanism; 20. First hexagonal groove; 21. First hexagonal rubber block; 22. Pick-up post; 23. Slot; 24. Second hexagonal groove; 25. Second threaded post; 26. Pressure sensor; 27. Insert post; 28. Second hexagonal rubber block; 29. ​​Insertion hole; 30. Connecting pipe; 31. Mounting box; 32. Remote signal transmitter; 33. Battery; 34. Electrical wire. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0025] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; 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 a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Example:

[0028] Please see Figure 1-6An annular sealing device for an oil wellhead includes a four-way tubing head 1, a lower flange 2 at the lower part of the four-way tubing head 1, an oil guide pipe 3 sleeved on the inner side of the lower flange 2, two sealing ring grooves 4 formed on the inner wall of the lower flange 2, a sealing ring 5 sleeved on the inner cavity of the sealing ring groove 4 and located outside the oil guide pipe 3, a power ring 6 sleeved on the inner cavity of the sealing ring groove 4, a first oil injection groove 7 formed on the inner wall of the sealing ring groove 4, a first threaded hole 8 formed at the end of the two first oil injection grooves 7, a first threaded post 9 threaded into the inner cavity of the first threaded hole 8, a second oil injection groove 10 formed on the inner wall of the lower flange 2, an oil pressure detection groove 11 formed at the end of the second oil injection groove 10, and a pressure detection groove 11 formed at the end of the oil pressure detection groove 11. A second threaded hole 12 is provided, and a second threaded post 25 is installed in the inner cavity of the second threaded hole 12. A second hexagonal groove 24 is provided at the end of the second threaded hole 12 and on the outside of the lower flange 2. A detection mechanism 13 is provided on the second threaded post 25. An airtightness detection groove 15 is provided on the inner wall of the lower flange 2. A third threaded hole 16 is provided at the end of the airtightness detection groove 15. A third threaded post 17 is installed in the inner cavity of the third threaded hole 16. A first hexagonal groove 20 is provided at the end of the two first threaded holes 8 and the third threaded hole 16 and on the outside of the lower flange 2. An anti-loosening mechanism 19 is provided in the inner cavity of the first hexagonal groove 20. A lever block 18 is fixedly connected to the ends of the first threaded post 9 and the third threaded post 17.

[0029] For details, please refer to Figure 1 , Figure 3 and Figure 5 The detection mechanism 13 includes a pressure sensor 26 fixedly installed at one end of the second threaded post 25 and a connecting pipe 30 fixedly connected to the other end of the second threaded post 25. The pressure sensor 26 is located in the inner cavity of the oil pressure detection groove 11. The end of the connecting pipe 30 is fixedly connected to a mounting box 31. A battery 33 is installed in the inner cavity of the mounting box 31. A remote signal transmitter 32 is fixedly installed on the inner wall of the mounting box 31. A wire 34 is fixedly connected to the remote signal transmitter 32. The end of the wire 34 passes through the wire 34 and is connected to the pressure sensor 26. A second hexagonal rubber block 28 is movably sleeved on the outside of the connecting pipe 30. Two insertion holes 29 are opened at the end of the second hexagonal rubber block 28. The second hexagonal rubber block 28 is sleeved in the inner cavity of the second hexagonal groove 24. Two insertion posts 27 are fixedly connected to the other end of the second threaded post 25. The ends of the two insertion posts 27 are movably sleeved into the inner cavity of the insertion holes 29.

[0030] In this embodiment, the second hexagonal rubber block 28 is interference-fitted into the inner cavity of the second hexagonal groove 24, and the battery 33 is used to power the remote signal transmitter 32 and the pressure sensor 26.

[0031] For details, please refer to Figures 1 to 6The anti-loosening mechanism 19 includes a first hexagonal rubber block 21 fitted inside the first hexagonal groove 20. One end of the first hexagonal rubber block 21 is provided with a slot 23. The end of the lever block 18 is movably fitted into the inner cavity of the slot 23. The other end of the first hexagonal rubber block 21 is fixedly connected to a picking post 22.

[0032] For details, please refer to Figure 3 The top and bottom surfaces of the sealing ring 5 are respectively fitted with the top and bottom surfaces of the inner cavity of the sealing ring groove 4.

[0033] In this embodiment, the sealing performance of the sealing ring 5 in the inner cavity of the sealing ring groove 4 is ensured, and the sealing grease in the first oil injection groove 7 and the sealing ring groove 4 is prevented from entering between the oil guide pipe 3 and the four-way oil pipe head 1.

[0034] For details, please refer to Figure 5 The inner wall of the socket 29 fits against the outer surface of the plug 27.

[0035] In this embodiment, the second hexagonal rubber block 28 fixes the second threaded post 25 by the cooperation of the insert post 27 and the insertion hole 29.

[0036] For details, please refer to Figures 1 to 6 The side of the first hexagonal rubber block 21 is in contact with the inner wall of the first hexagonal groove 20, and the inner wall of the slot 23 is in contact with the side of the lever block 18.

[0037] In this embodiment, the first hexagonal rubber block 21 is interference-fitted into the inner cavity of the first hexagonal groove 20 to ensure the stability of the first hexagonal rubber block 21 in the first hexagonal groove 20. In addition, the first threaded post 9 and the third threaded post 17 are fixed by the cooperation of the slot 23 and the lever block 18.

[0038] Working principle: In use, firstly, the sealing ring 5 and the power ring 6 are respectively fitted into the two sealing ring grooves 4, and the oil guide pipe 3 is fitted into the inner cavity of the lower flange 2, so that the inner side of the sealing ring 5 and the outer side of the oil guide pipe 3 are in contact. At this time, sealing grease is injected into the first oil injection groove 7 and the sealing ring groove 4 through the first screw hole 8. The grease in the sealing ring groove 4 pushes the power ring 6 and the sealing ring 5, so that the sealing ring 5 and the oil guide pipe 3 are tightly fitted. In addition, the first threaded post 9 is threaded into the first screw hole 8. Then, gas is introduced into the airtightness test groove 15 through the third screw hole 16. When a certain amount of gas is introduced... When gas cannot be refilled, it indicates that the oil guide pipe 3 and the four-way oil pipe head 1, and the area between the two sealing rings 5, are in a sealed state. Conversely, it indicates that the area between the sealing rings 5 ​​and the oil guide pipe 3 is not sealed. Then, when the oil guide pipe 3 and the four-way oil pipe head 1 are in a sealed state, the third threaded post 17 is threaded into the third threaded hole 16 to seal the end of the airtightness test groove 15. At this time, sealing grease is injected from the oil pressure test groove 11 and the second oil injection groove 10 through the second threaded hole 12, allowing the grease to enter between the oil guide pipe 3 and the inner wall of the lower flange 2, while ensuring that the grease is located between the two... Between the sealing rings 5, the second threaded post 25 is threaded into the second threaded hole 12, and the pressure sensor 26 is placed in the inner cavity of the oil pressure detection groove 11. Additionally, the second hexagonal rubber block 28 is inserted into the inner cavity of the second hexagonal groove 24, and the insertion post 27 at the end of the second threaded post 25 is inserted into the insertion hole 29 on the second hexagonal rubber block 28. The fit between the second hexagonal rubber block 28 and the second hexagonal groove 24 prevents the second threaded post 25 from loosening. Finally, the first hexagonal rubber blocks 21 are fitted into the inner cavities of the multiple first hexagonal grooves 20, and the first threaded post 9 and the third threaded post 25 are then connected. The lever block 18 at the end of the column 17 is inserted into the slot 23 on the first hexagonal rubber block 21. The fit between the first hexagonal rubber block 21 and the first hexagonal slot 20 prevents the first threaded column 9 and the third threaded column 17 from becoming loose. In addition, the pressure sensor 26 is used to detect the oil pressure in the second oil filling groove 10 and the oil pressure detection groove 11 in real time, and the detection information is transmitted to the control console remotely using the remote signal transmitter 32. When the oil pressure decreases, it indicates that there is a leak of oil between the oil guide pipe 3 and the four-way oil pipe head 1, which in turn indicates that the seal between the oil guide pipe 3 and the sealing ring 5 has failed.

[0039] 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 its improved concept should be covered within the protection scope of the present utility model.

Claims

1. An annular sealing device for oil wellheads, comprising a four-way tubing head (1), characterized in that: The lower part of the four-way oil pipe head (1) is provided with a lower flange (2). An oil guide pipe (3) is sleeved on the inner side of the lower flange (2). Two sealing ring grooves (4) are opened on the inner wall of the lower flange (2). A sealing ring (5) is sleeved on the inner cavity of the sealing ring groove (4) and on the outer side of the oil guide pipe (3). A power ring (6) is sleeved on the inner cavity of the sealing ring groove (4). A first oil injection groove (7) is opened on the inner wall of the sealing ring groove (4). A first threaded hole (8) is provided at the end of the two first oil injection grooves (7). A first threaded post (9) is threaded into the inner cavity of the first threaded hole (8). A second oil injection groove (10) is opened on the inner wall of the lower flange (2). An oil pressure detection groove (11) is provided at the end of the second oil injection groove (10). A second threaded hole (12) is provided at the end of the oil pressure detection groove (11). The inner cavity of the second screw hole (12) is threaded with a second threaded post (25). The end of the second screw hole (12) and located on the outside of the lower flange (2) is provided with a second hexagonal groove (24). The second threaded post (25) is provided with a detection mechanism (13). The inner wall of the lower flange (2) is provided with an airtightness detection groove (15). The end of the airtightness detection groove (15) is provided with a third screw hole (16). The inner cavity of the third screw hole (16) is threaded with a third threaded post (17). The ends of the two first screw holes (8) and the third screw hole (16) and located on the outside of the lower flange (2) are respectively provided with a first hexagonal groove (20). The inner cavity of the first hexagonal groove (20) is provided with an anti-loosening mechanism (19). The ends of the first threaded post (9) and the third threaded post (17) are fixedly connected with a lever block (18).

2. The annular sealing device for an oil wellhead according to claim 1, characterized in that: The detection mechanism (13) includes a pressure sensor (26) fixedly installed at one end of the second threaded post (25) and a connecting pipe (30) fixedly connected to the other end of the second threaded post (25). The pressure sensor (26) is located in the inner cavity of the oil pressure detection tank (11). A mounting box (31) is fixedly connected to the end of the connecting pipe (30). A battery (33) is installed in the inner cavity of the mounting box (31). A remote signal transmitter (32) is fixedly installed on the inner wall of the mounting box (31). A remote signal transmitter (32) is fixedly connected to the remote signal transmitter (32). There is an electrical wire (34), the end of which passes through the electrical wire (34) and is connected to the pressure sensor (26). A second hexagonal rubber block (28) is movably sleeved on the outside of the connecting tube (30). Two insertion holes (29) are opened at the end of the second hexagonal rubber block (28). The second hexagonal rubber block (28) is sleeved in the inner cavity of the second hexagonal groove (24). Two insertion pins (27) are fixedly connected to the other end of the second threaded post (25). The ends of the two insertion pins (27) are movably sleeved into the inner cavity of the insertion hole (29).

3. The annular sealing device for oil wellheads according to claim 1, characterized in that: The anti-loosening mechanism (19) includes a first hexagonal rubber block (21) sleeved in the inner cavity of the first hexagonal groove (20). One end of the first hexagonal rubber block (21) is provided with a slot (23). The end of the lever block (18) is movably sleeved into the inner cavity of the slot (23). The other end of the first hexagonal rubber block (21) is fixedly connected to a picking post (22).

4. The annular sealing device for an oil wellhead according to claim 1, characterized in that: The top and bottom surfaces of the sealing ring (5) are respectively attached to the top and bottom surfaces of the inner cavity of the sealing ring groove (4).

5. The annular sealing device for an oil wellhead according to claim 2, characterized in that: The inner wall of the insertion hole (29) and the outer surface of the insertion post (27) are in contact.

6. The annular sealing device for an oil wellhead according to claim 3, characterized in that: The side of the first hexagonal rubber block (21) is in contact with the inner wall of the first hexagonal groove (20), and the inner wall of the slot (23) is in contact with the side of the lever block (18).

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