A wellhead device

Abstract

The utility model discloses a wellhead device, including tension cross body and the tension casing hanger of setting in the main flow channel hole of tension cross body, tension casing hanger bottom is connected with the casing string, be equipped with at least two groups of tension mechanism for supporting tension casing hanger and at least two groups of locking mechanism for carrying out the locking of tension casing hanger on tension cross body, the outer circular surface of tension casing hanger is equipped with locking groove and bearing step surface, and tension mechanism includes the support seat of installing in the side of tension cross body and the support rod of setting in the support seat, and locking mechanism includes the locking sleeve of installing in the side of tension cross body and the locking rod of setting in the locking sleeve, the utility model discloses after the casing cementing, the casing hanger is lifted upward, makes casing string produce greater axial tension, thereby when the wellhead gas flow production, the casing will not produce vibration and thread loosening, to prolong the service life of casing string and wellhead.

Description

Technical Field

[0001] This utility model relates to the field of oil production equipment technology, and in particular to a wellhead device. Background Technology

[0002] In oil and gas drilling, a wellhead device is typically installed at the wellhead to connect with the wellhead for normal oil production. The wellhead device is a device installed at the wellhead to suspend the casing and tubing, and to seal the annular space between the tubing and the casing, as well as between the casing layers. It generally consists of a casing head, a tubing head, a blowout preventer assembly, a four-way connector, and a bypass fitting. The wellhead device mainly suspends the tubing that is lowered into the well through the casing head, and the tubing transports crude oil and natural gas from the oil and gas layer to the surface.

[0003] In existing Chinese technology, a stepped structure for supporting the tension casing hanger is usually required on the inner wall of the tension cross-shaped body. For example, in an integral wellhead with a nesting function as described in application number CN201922237397.7, the lower part of the wellhead base assembly is provided with a casing connection thread, the upper outer circular wall of the wellhead base assembly is provided with a sealing sleeve assembly, the middle part of the wellhead base assembly is provided with a flow channel hole, the inside of the wellhead base assembly is provided with a tubing hanger supporting step and a locking ring retention groove, and the wellhead base assembly is also provided with a tightening set screw. The wellhead base assembly is secured by tightening the set screw after reaching the inner hole step of the wellhead body assembly. However, this type of tension casing hanger (tubing hanger) cannot be pre-set below the inner bore step, meaning the inner bore step would axially limit it. The tension casing hanger is fixed by abutting against the inner bore step and tightening the set screw. This fixing method has significant limitations and cannot generate a large axial tension on the casing string. It also has poor vibration resistance when gas is produced at the wellhead, resulting in a short service life for the casing string.

[0004] Therefore, there is an urgent need in the market for a wellhead device that can improve the vibration resistance of the casing string to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a wellhead device. After cementing the casing, this invention raises the casing hanger (to a set position) to generate greater axial tension in the casing string, so that the casing will not vibrate or loosen its threads when gas is produced at the wellhead, thereby extending the service life of the casing string and the wellhead.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a wellhead device, comprising a tension crossbody and a tension casing hanger, wherein the tension crossbody has a main channel hole extending axially, and the tension casing hanger is slidably disposed within the main channel hole, with a casing string connected to the bottom of the tension casing hanger; the tension crossbody is provided with at least two sets of tension mechanisms for supporting the tension casing hanger and at least two sets of locking mechanisms for locking the tension casing hanger; The outer circular surface of the tension sleeve hanger is provided with a locking groove and a bearing step surface from top to bottom; The tension mechanism includes a support seat installed on the side of the tension four-way body and a support rod movably disposed on the support seat. When the support rod is in motion, it has an extended state in which the inner end abuts against the lower end of the bearing step surface of the tension sleeve hanger, and a retracted state in which the inner end disengages from the lower end of the bearing step surface of the tension sleeve hanger. The locking mechanism includes a locking sleeve installed on the side of the tension tube body and a locking rod movably disposed on the locking sleeve. When the locking rod is active, it has an extended state in which the inner end is inserted into the locking groove of the tension tube hanger, and a retracted state in which the inner end is disengaged from the locking groove of the tension tube hanger.

[0007] By adopting the above technical solution, the casing suspension bearing step structure within the tension four-way body (L section) is eliminated, facilitating flexible movement of the tension casing hanger within the L section. During cementing, the locking groove of the tension casing hanger is lower than the locking rod of the locking mechanism. After the cement has cured, the tension casing hanger is moved upwards, and it can temporarily rest on the tension mechanism (bearing the weight of the casing string). That is, the inner end of the support rod of the tension mechanism abuts against the lower end of the bearing step surface of the tension casing hanger, providing support for the tension casing hanger. The locking rod of the locking mechanism then locks it in place (bearing the weight of the casing string). The tension mechanism has a positioning function for locking the tension casing hanger with the locking rod, making the locking operation easier. By stretching the casing string after cement curing, a large axial tension can be generated in the casing string, thus preventing vibration and thread loosening during wellhead gas flow production, thereby extending the service life of the casing string and the wellhead.

[0008] The present invention is further configured such that the tension four-way body has a number of first mounting holes through the side, which are equivalent to the number of tension mechanisms; the support seat is threaded to the outer end of the first mounting hole; the support rod passes through the support seat and the two are threadedly engaged; the inner end of the support rod extends outward from the support seat and is provided with a limiting flange; the inner wall of the first mounting hole is provided with a first limiting step for limiting the inner stroke of the limiting flange.

[0009] By adopting the above technical solution, the support base and support rod are assembled by means of threaded connection, the assembly structure is simple and reliable, and disassembly and assembly are very convenient.

[0010] The present invention is further configured such that the tension mechanism includes a spring energy storage sealing ring and a locking nut. The spring energy storage sealing ring is sleeved on the outer circular surface of the support base to form a sealing fit with the inner circular surface of the first mounting hole. A support step is provided on the outer circular surface of the support base corresponding to one end of the spring energy storage sealing ring. The locking nut is threadedly connected to the outer circular surface of the support base corresponding to the other end of the spring energy storage sealing ring, and is used to restrict the spring energy storage sealing ring on the support step when tightened.

[0011] By adopting the above technical solution, good sealing between the support base and the tension cross body can be guaranteed, preventing the internal medium from leaking to the outside through the gap between the two.

[0012] The present invention is further configured such that the outer end of the support base is provided with a first sealing groove coaxial with the support rod, the first sealing groove is provided with a first sealing gasket for sealing between the outer circular surface of the support rod and the inner circular surface of the first sealing groove, and the support base is also threadedly connected with a pressure sleeve for pressing the first sealing gasket into the first sealing groove at the position corresponding to the outer end of the first sealing groove.

[0013] By adopting the above technical solution, the sealing between the support base and the support rod can be guaranteed, and media leakage can be avoided when the support rod moves axially.

[0014] The present invention is further configured such that the tension four-way body has a number of second mounting holes through the side, which are equivalent to the number of locking mechanisms. The locking sleeve is threadedly connected to the outer end of the second mounting hole, the locking rod passes through the locking sleeve, and the two are threadedly engaged. The inner end of the locking rod extends out of the locking sleeve to engage with the locking groove.

[0015] By adopting the above technical solution, the locking sleeve and locking rod are assembled using a threaded connection, resulting in a simple and reliable assembly structure that is very convenient to assemble and disassemble.

[0016] The present invention is further configured such that a second sealing groove coaxial with the locking rod is provided at the position of the outer end of the tension four-way body corresponding to the second mounting hole. A second sealing gasket is provided in the second sealing groove to achieve a seal between the outer circular surface of the locking rod and the inner circular surface of the second sealing groove. When the locking sleeve is tightened, the locking sleeve presses the second sealing gasket into the second sealing groove.

[0017] By adopting the above technical solution, good sealing between the locking sleeve and the locking rod can be guaranteed, preventing the internal medium from leaking to the outside through the gap between the two.

[0018] The present invention is further configured such that an annular sealing groove is provided on the inner circular surface of the locking sleeve, and a first O-ring is embedded in the annular sealing groove for forming a sealing fit with the outer circular surface of the locking rod.

[0019] By adopting the above technical solution, the gap between the locking sleeve and the locking rod can be sealed, further preventing media leakage when the locking rod moves axially.

[0020] The present invention is further configured such that the inner end of the locking rod is provided with a tapered locking part, the locking groove extends circumferentially along the outer circular surface of the tension sleeve hanger, and the cross-section of the locking groove is also tapered.

[0021] By adopting the above technical solutions, the inner end of the locking rod is tapered, and the locking groove is tapered, which makes it easier for the inner end of the locking rod to be inserted into the locking groove, and the matching structure is more reliable. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the tension four-way body of this utility model; Figure 2 for Figure 1 Enlarged structural diagram of section A in the middle; Figure 3 for Figure 1 Enlarged structural diagram of section B in the middle; Figure 4 This is a schematic diagram of the tension sleeve hanger of this utility model; Figure 5 This is a schematic diagram of the structure of this utility model in the cementing state; Figure 6 This is a schematic diagram of the structure of this utility model after the tension sleeve hanger is installed; Figure 7 for Figure 6 Enlarged structural diagram of section C.

[0023] In the diagram: 1. Tension four-way body; 2. Tension sleeve hanger; 3. Main channel hole; 4. Sleeve column; 5. Tension mechanism; 6. Locking mechanism; 7. Locking groove; 8. Bearing step surface; 9. Support seat; 10. Support rod; 11. Locking sleeve; 12. Locking rod; 13. First mounting hole; 14. Limiting flange; 15. First limiting step; 16. Spring energy storage sealing ring; 17. Locking nut; 18. Supporting step; 19. First sealing groove; 20. First sealing gasket; 21. Pressure sleeve; 22. Second mounting hole; 23. Second sealing groove; 24. Second sealing gasket; 25. Annular sealing groove; 26. First O-ring; 27. Conical locking part. Detailed Implementation

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

[0025] Example: As attached Figures 1-7 The wellhead device shown includes a tension four-way body 1 and a tension casing hanger 2. The tension four-way body 1 has a main channel hole 3 extending axially inside. The tension casing hanger 2 is slidably disposed in the main channel hole 3. A casing string 4 is connected to the bottom of the tension casing hanger 2. The tension four-way body 1 is provided with at least two sets of tensioning mechanisms 5 for supporting the tension casing hanger 2 and at least two sets of locking mechanisms 6 for locking the tension casing hanger 2. The outer circular surface of the tension sleeve hanger 2 is provided with a locking groove 7 and a bearing step surface 8 from top to bottom; The tension mechanism 5 includes a support seat 9 installed on the side of the tension four-way body 1 and a support rod 10 movably disposed on the support seat 9. When the support rod 10 is active, it has an extended state in which the inner end abuts against the lower end of the bearing step surface 8 of the tension sleeve hanger 2, and a retracted state in which the inner end disengages from the lower end of the bearing step surface 8 of the tension sleeve hanger 2. The locking mechanism 6 includes a locking sleeve 11 installed on the side of the tension tube body 1 and a locking rod 12 movably disposed on the locking sleeve 11. When the locking rod 12 is active, it has an extended state in which the inner end is inserted into the locking groove 7 of the tension tube hanger 2, and a retracted state in which the inner end is disengaged from the locking groove 7 of the tension tube hanger 2.

[0026] The design eliminates the casing suspension bearing step structure within the tension four-way body 1 (section L), facilitating flexible movement of the tension casing hanger 2 within section L. During cementing, the locking groove 7 of the tension casing hanger 2 is lower than the locking rod 12 of the locking mechanism 6. After the cement hardens, the tension casing hanger 2 is moved upwards. The tension casing hanger 2 can temporarily rest on the tension mechanism 5 (bearing the weight of the casing string 4), with the inner end of the support rod 10 of the tension mechanism 5 abutting against the lower end of the bearing step surface 8 of the tension casing hanger 2, providing support. It is then locked in place using the locking rod 12 of the locking mechanism 6 (bearing the weight of the casing string 4). The tension mechanism 5 has a positioning function for locking the tension casing hanger 2 with the locking rod 12, making the locking operation easier. By stretching the casing string 4 after cement hardening, a larger axial tension is generated in the casing string 4, preventing vibration and thread loosening during wellhead gas flow production, thus extending the service life of the casing string 4 and the wellhead.

[0027] As attached Figure 2 As shown, the tension four-way body 1 has a number of first mounting holes 13, corresponding to the number of tension mechanisms 5, extending through its side. Each first mounting hole 13 has a smooth surface and a threaded portion. The support seat 9 is threaded to the outer end of the first mounting hole 13, meaning the support seat 9 has external threads. These external threads mate with the threaded portion of the first mounting hole 13. The support rod 10 passes through the support seat 9, meaning the support seat 9 has an axial through hole in its center, and the two are threaded together. Specifically, the outer surface of the support rod 10 has an external thread, and the support seat 9 has an internal thread that mates with this external thread. A limiting flange 14 extending outwards is provided at the inner end of the support rod 10 extending beyond the support seat 9. The inner wall of the first mounting hole 13 has a first limiting step 15 for limiting the inner stroke of the limiting flange 14. The support seat 9 and support rod 10 are assembled using a threaded connection, resulting in a simple and reliable assembly structure and convenient disassembly and assembly.

[0028] As attached Figure 2 As shown, the tension mechanism 5 also includes a spring-storage sealing ring 16 and a locking nut 17. The spring-storage sealing ring 16 is sleeved on the outer circumferential surface of the support base 9 to form a sealing fit with the inner circumferential surface of the first mounting hole 13. A support step 18 is provided on the outer circumferential surface of the support base 9 corresponding to one end of the spring-storage sealing ring 16. The locking nut 17 is threaded to the outer circumferential surface of the support base 9 corresponding to the other end of the spring-storage sealing ring 16, and is used to restrict the spring-storage sealing ring 16 on the support step 18 when tightened. This design can ensure good sealing between the support base 9 and the tension four-way body 1, and prevent the internal medium from leaking to the outside through the gap between them.

[0029] As attached Figure 2 As shown, the outer end of the support base 9 is provided with a first sealing groove 19 coaxial with the support rod 10. A first sealing gasket 20 is provided in the first sealing groove 19 to achieve a seal between the outer circular surface of the support rod 10 and the inner circular surface of the first sealing groove 19. Furthermore, the support base 9 is threadedly connected to a pressure sleeve 21 at the outer end of the first sealing groove 19 to press the first sealing gasket 20 into the first sealing groove 19. That is, the pressure sleeve 21 has an external thread, and the inner wall of the first sealing groove 19 near the outer end has an internal thread that matches the external thread. The inner diameter of the pressure sleeve 21 is approximately equal to the outer diameter of the support rod 10 at that position. This design ensures the sealing between the support base 9 and the support rod 10, preventing media leakage when the support rod 10 moves axially.

[0030] As attached Figure 3As shown, the tension four-way body 1 has a number of second mounting holes 22 through its side, corresponding to the number of locking mechanisms 6. Each second mounting hole 22 has a smooth surface and a threaded portion. The locking sleeve 11 is threaded to the outer end of the second mounting hole 22, meaning the outer circumference of the locking sleeve 11 has an external thread that mates with the threaded portion of the second mounting hole 22. The locking rod 12 passes through the locking sleeve 11, and the two are threaded together; the outer circumference of the locking rod 12 has an external thread, and the inner circumference of the locking sleeve 11 has an internal thread that matches this external thread. The inner end of the locking rod 12 extends out of the locking sleeve 11 to engage with the locking groove 7. The locking sleeve 11 and locking rod 12 are assembled using a threaded connection, resulting in a simple and reliable assembly structure that is very convenient for assembly and disassembly.

[0031] As attached Figure 3 As shown, the tension four-way body 1 has a second sealing groove 23 coaxial with the locking rod 12 at the position corresponding to the outer end of the second mounting hole 22. A second sealing gasket 24 is provided in the second sealing groove 23 to achieve a seal between the outer circular surface of the locking rod 12 and the inner circular surface of the second sealing groove 23. When the locking sleeve 11 is tightened, the locking sleeve 11 presses the second sealing gasket 24 into the second sealing groove 23. This design ensures good sealing between the locking sleeve 11 and the locking rod 12, preventing internal media from leaking to the outside through the gap between them.

[0032] As attached Figure 3 As shown, an annular sealing groove 25 is formed on the inner circular surface of the locking sleeve 11, and a first O-ring 26 is embedded in the annular sealing groove 25 to form a sealing fit with the outer circular surface of the locking rod 12. This design can seal the gap between the locking sleeve 11 and the locking rod 12, and further prevent media leakage when the locking rod 12 moves axially.

[0033] Furthermore, the inner end of the locking rod 12 is provided with a tapered locking part 27, and the locking groove 7 extends circumferentially along the outer circular surface of the tension sleeve hanger 2, and the cross-section of the locking groove 7 is also tapered. The tapered design of the inner end of the locking rod 12 and the tapered design of the locking groove 7 make it easier for the inner end of the locking rod 12 to be inserted into the locking groove 7, and the mating structure is more reliable.

Claims

1. A wellhead device, comprising a tensioned four-way body (1) and a tensioned casing hanger (2), the tensioned four-way body (1) is provided with a main flow hole (3) extending in the axial direction, the tensioned casing hanger (2) is arranged in the main flow hole (3) and can slide in the axial direction, and a casing string (4) is connected to the bottom of the tensioned casing hanger (2); characterized in that: The tension four-way body (1) is provided with at least two sets of tension mechanisms (5) for supporting the tension sleeve hanger (2) and at least two sets of locking mechanisms (6) for locking the tension sleeve hanger (2). The outer circular surface of the tension sleeve hanger (2) is provided with a locking groove (7) and a bearing step surface (8) from top to bottom; The tension mechanism (5) includes a support seat (9) installed on the side of the tension four-way body (1) and a support rod (10) movably disposed on the support seat (9). When the support rod (10) is active, it has an extended state in which the inner end abuts against the lower end of the bearing step surface (8) of the tension sleeve hanger (2) and a retracted state in which the inner end is disengaged from the lower end of the bearing step surface (8) of the tension sleeve hanger (2). The locking mechanism (6) includes a locking sleeve (11) installed on the side of the tension tube body (1) and a locking rod (12) movably disposed on the locking sleeve (11). When the locking rod (12) is active, it has an extended state in which the inner end is inserted into the locking groove (7) of the tension tube hanger (2) and a retracted state in which the inner end is disengaged from the locking groove (7) of the tension tube hanger (2).

2. A wellhead assembly according to claim 1, characterised in that: The tension four-way body (1) has a number of first mounting holes (13) that are equal to the number of tension mechanisms (5) through it. The support base (9) is threaded to the outer end of the first mounting hole (13). The support rod (10) passes through the support base (9) and the two are threaded together. The inner end of the support rod (10) extends outward from the support base (9) and is provided with a limiting flange (14). The inner wall of the first mounting hole (13) is provided with a first limiting step (15) for limiting the inner stroke of the limiting flange (14).

3. A wellhead assembly according to claim 2, characterised in that: The tension mechanism (5) also includes a spring energy storage sealing ring (16) and a locking nut (17). The spring energy storage sealing ring (16) is sleeved on the outer circular surface of the support base (9) to form a sealing fit with the inner circular surface of the first mounting hole (13). The outer circular surface of the support base (9) is provided with a support step (18) at one end of the spring energy storage sealing ring (16). The locking nut (17) is threaded to the other end of the outer circular surface of the support base (9) corresponding to the spring energy storage sealing ring (16) and is used to restrict the spring energy storage sealing ring (16) on the support step (18) when tightened.

4. A wellhead assembly according to claim 2, characterised in that: The outer end of the support base (9) is provided with a first sealing groove (19) coaxial with the support rod (10). The first sealing groove (19) is provided with a first sealing gasket (20) for sealing between the outer circular surface of the support rod (10) and the inner circular surface of the first sealing groove (19). The support base (9) is also threadedly connected with a pressure sleeve (21) for pressing the first sealing gasket (20) into the first sealing groove (19) at the position corresponding to the outer end of the first sealing groove (19).

5. A wellhead assembly according to claim 1, characterized in that: The tension four-way body (1) has a number of second mounting holes (22) that are equal to the number of locking mechanisms (6) through it. The locking sleeve (11) is threaded to the outer end of the second mounting hole (22). The locking rod (12) passes through the locking sleeve (11) and the two are threaded together. The inner end of the locking rod (12) extends out of the locking sleeve (11) to cooperate with the locking groove (7).

6. A wellhead assembly according to claim 5, characterised in that: The tension four-way body (1) is provided with a second sealing groove (23) coaxial with the locking rod (12) at the position of the outer end of the second mounting hole (22). A second sealing gasket (24) is provided in the second sealing groove (23) to achieve a seal between the outer circular surface of the locking rod (12) and the inner circular surface of the second sealing groove (23). When the locking sleeve (11) is tightened, the locking sleeve (11) presses the second sealing gasket (24) into the second sealing groove (23).

7. A wellhead assembly according to claim 5, characterised in that: The inner circular surface of the locking sleeve (11) is provided with an annular sealing groove (25), and a first O-ring (26) is embedded in the annular sealing groove (25) to form a sealing fit with the outer circular surface of the locking rod (12).

8. A wellhead assembly according to claim 1, characterized in that: The inner end of the locking rod (12) is provided with a tapered locking part (27), the locking groove (7) extends circumferentially along the outer circular surface of the tension sleeve hanger (2), and the cross section of the locking groove (7) is also tapered.

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