Leakage-proof combined casing head

Abstract

The utility model relates to the technical field of casing heads, in particular to a leakage-proof combined casing head which comprises a casing head body, a connecting hole concentric with an inner hole of the casing head body is formed in the lower end of the casing head body, the diameter of the connecting hole is larger than that of the inner hole of the casing head body, and internal threads are arranged on the inner surface of the connecting hole. The casing head further comprises an outer sealing ring assembly and an inner sealing ring assembly arranged in an inner cavity of the outer sealing ring assembly, an annular top wall is arranged between the inner hole of the casing head body and the connecting hole, an annular groove is formed in the annular top wall, and the outer sealing ring assembly is connected into the annular groove. The elastic pushing and pressing rod assemblies are connected to an inner hole of the casing head body in an annular array mode, and the lower ends of the elastic pushing and pressing rod assemblies are connected with the inner sealing ring assembly. The sealing device is reasonable in structure, and the maintenance frequency due to the sealing performance problem is reduced through the combined action of the outer sealing ring assembly and the inner sealing ring assembly.

Description

Technical Field

[0001] The utility model relates to the technical field of casing heads, in particular to a leak-proof combined casing head. Background Art

[0002] The casing head is a wellhead component installed at the top of the surface casing string, used to suspend additional casing and seal the annular space around the casing. The casing head is often used to connect the pipe and casing at the oil inlet. To ensure a tight seal, a rubber gasket is typically placed at the casing head joint to prevent corrosion and damage to components.

[0003] With respect to the above-mentioned related technologies, the inventors found that when only one layer of rubber sealing gasket is used for sealing at the connection of the casing head, the rubber sealing gasket is prone to severe wear after the casing head has been used for a long time. The worn rubber sealing gasket has a great impact on the sealing performance of the casing head connection, and the rubber sealing gasket needs to be replaced frequently. Utility Model Content

[0004] The main technical problem solved by the utility model is to provide a leak-proof combined casing head, which reduces the frequency of maintenance due to sealing problems through the joint action of the outer sealing ring component and the inner sealing ring component.

[0005] In order to solve the above technical problems, the present invention adopts a technical solution: providing a leak-proof combined cannula head, comprising: a cannula head body, wherein the lower end of the cannula head body is provided with a connecting hole concentric with the inner hole of the cannula head body, the diameter of the connecting hole is larger than the inner hole diameter of the cannula head body, and the inner surface of the connecting hole is provided with an internal thread;

[0006] It also includes an outer sealing ring assembly and an inner sealing ring assembly arranged in its inner cavity. An annular top wall is provided between the inner hole of the casing head body and the connecting hole. The annular top wall is provided with an annular groove. The outer sealing ring assembly is connected to the annular groove. It also includes several elastic pushing rod assemblies connected to the inner hole of the casing head body in an annular array. The lower end of the elastic pushing rod assembly is connected to the inner sealing ring assembly.

[0007] By adopting the above technical solution, during installation, the outer sealing ring assembly is fixed in the annular groove, and the inner sealing ring assembly is connected to the inner hole of the casing head body through the elastic pushing rod assembly, and the internal thread of the casing head body is threadedly connected to the surface tube below. The casing head body and the surface tube move toward each other to squeeze the outer sealing ring assembly to achieve the purpose of sealing. When the casing head body and the surface tube move toward each other, the elastic force of the elastic pushing rod assembly drives the inner sealing ring assembly to make close contact with the end of the surface tube. Since the inner sealing ring assembly is located inside the outer sealing ring assembly, the fluid first contacts the inner sealing ring assembly and then reduces the flow rate. The fluid after passing through the inner sealing ring assembly flows to the outer sealing ring assembly. Since the flow rate of the fluid is reduced, the wear of the fluid on the outer sealing ring assembly is reduced, the service life of the outer sealing ring assembly is extended, and the frequency of maintenance due to sealing problems is reduced.

[0008] In a preferred example, the present invention can be further configured as follows: the outer sealing ring assembly includes a wave spring and an outer rubber sealing layer wrapped around the outer surface of the wave spring.

[0009] By adopting the above technical solution and using a wave spring, elastic force is created between the casing head body and the surface pipe, thereby reducing the probability of loosening between the casing head body and the surface pipe, and enhancing the sealing effect between the casing head body and the surface pipe through the action of the outer rubber sealing layer.

[0010] In a preferred example, the present invention can be further configured as follows: the inner sealing ring assembly includes a movable tube body and an annular rubber body, the upper plane of the annular rubber body is provided with an annular fixing groove, and the lower end of the movable tube body extends into the inner cavity of the annular fixing groove and is fixedly connected thereto.

[0011] By adopting the above technical solution, the movable tube body is tightly and elastically connected to the surface tube through the annular rubber body, preventing the fast-flowing fluid from directly contacting the outer sealing ring assembly, thereby reducing the wear of the outer sealing ring assembly caused by the fluid.

[0012] In a preferred example, the present invention can be further configured as follows: the elastic pushing rod assembly includes a fixed plate and a round rod passing through the fixed plate, the upper end of the round rod is connected to a top plate, the outer circle of the lower end of the round rod is sleeved with an annular limiting plate, a spring is sleeved on the round rod, the upper end of the spring is in contact with the fixed plate, and the lower end is connected to the annular limiting plate, the lower end of the round rod is connected to the top of the movable tube body, and the fixed plate is connected to the inner hole of the casing head body.

[0013] By adopting the above technical solution, when the casing head body and the surface tube move toward each other, the surface tube pushes the round rod to move axially, and the round rod squeezes the spring through the annular limit plate. The spring is compressed to generate a reverse elastic force, so that the annular rubber body of the inner sealing ring assembly is in close contact with the end of the surface tube, thereby enhancing the sealing effect.

[0014] In a preferred example, the present invention can be further configured as follows: a guide ring is sleevedly connected to the outer circle of the upper end of the movable tube body, and the outer circle surface of the guide ring is slidably connected to the inner hole of the casing head body.

[0015] By adopting the above technical solution, the inner sealing ring assembly can move smoothly due to the action of the guide ring, and the guide ring has the function of preventing the fluid from flowing toward the outer sealing ring assembly.

[0016] In a preferred example, the present invention can be further configured as follows: the lower plane of the inner sealing ring assembly is lower than the lower plane of the outer sealing ring assembly.

[0017] By adopting the above technical solution, since the lower plane of the inner sealing ring assembly is lower than the lower plane of the outer sealing ring assembly, the distance the inner sealing ring assembly is squeezed is expanded, and the sealing between the inner sealing ring assembly and the surface pipe is enhanced.

[0018] In summary, the present invention has at least one of the following beneficial technical effects:

[0019] The fluid first contacts the inner sealing ring assembly and its flow rate is reduced. After passing through the inner sealing ring assembly, the fluid flows to the outer sealing ring assembly. Since the flow rate of the fluid is reduced, the wear of the fluid on the outer sealing ring assembly is reduced, the service life of the outer sealing ring assembly is extended, and the frequency of maintenance due to sealing problems is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. Among them:

[0021] Figure 1 It is a structural schematic diagram of a preferred embodiment of a leak-proof combined casing head of the utility model.

[0022] Figure 2 yes Figure 1 Sectional view along line AA.

[0023] Figure 3 yes Figure 2 Schematic diagram of the structure of the elastic push rod assembly.

[0024] Figure 4 yes Figure 2 Schematic diagram of the structure of the wave spring.

[0025] Figure 5It is a structural diagram of the connection between the guide ring and the inner sealing ring assembly.

[0026] In the figure: 1, casing head body; 2, connecting hole; 3, internal thread; 40, external sealing ring assembly;

[0027] 50. Inner sealing ring assembly; 6. Annular top wall; 7. Annular groove; 80. Elastic push rod assembly; 9. Guide ring;

[0028] 41. Wave spring; 42. Outer rubber sealing layer;

[0029] 51. movable tube body; 52. annular rubber body; 53. annular fixing groove;

[0030] 81. Fixed plate; 82. Round rod; 83. Top plate; 84. Annular limit plate; 85. Spring. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0032] It should be noted that these drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0033] Reference Figures 1 to 5 , a leak-proof combined casing head disclosed in the utility model, includes: a casing head body 1, a connecting hole 2 concentric with its inner hole is provided at the lower end of the casing head body 1, the diameter of the connecting hole 2 is larger than the inner hole diameter of the casing head body 1, and an internal thread 3 is provided on the inner surface of the connecting hole 2; the internal thread 3 on the casing head body 1 is threadedly connected to the surface pipe below.

[0034] The outer sealing ring assembly 40 is provided with an annular top wall 6 between the inner hole of the casing head body 1 and the connecting hole 2, and an annular groove 7 is provided on the annular top wall 6. The outer sealing ring assembly 40 is connected to the annular groove 7. The outer sealing ring assembly 40 is also included in the outer sealing ring assembly 50. The outer sealing ring assembly 50 includes a plurality of elastic pushing rod assemblies 80 connected to the inner hole of the casing head body 1 in an annular array. The lower end of the elastic pushing rod assembly 80 is connected to the inner sealing ring assembly 50; the inner sealing ring assembly 50 includes a movable tube body 51 and an annular rubber body 52. The upper plane of the annular rubber body 52 is provided with an annular fixing groove 53. The lower end of the movable tube body 51 extends into the inner cavity of the annular fixing groove 53 and is fixedly connected thereto; the movable tube body 51 is tightly elastically connected to the surface tube through the annular rubber body 52, preventing the fast-flowing fluid from directly contacting the outer sealing ring assembly 40, thereby reducing the wear of the outer sealing ring assembly 40 caused by the fluid.

[0035] The outer sealing ring assembly 40 includes a wave spring 41 and an outer rubber sealing layer 42 wrapped around the outer surface of the wave spring 41; through the use of the wave spring 41, there is elastic force between the casing head body 1 and the surface pipe, which reduces the probability of loosening between the casing head body 1 and the surface pipe, and through the action of the outer rubber sealing layer 42, the sealing effect between the casing head body 1 and the surface pipe is enhanced.

[0036] The elastic pushing rod assembly 80 includes a fixed plate 81 and a round rod 82 passing through the fixed plate 81. The upper end of the round rod 82 is connected to a top plate 83, and the outer circle of the lower end of the round rod 82 is sleeved with an annular limit plate 84. A spring 85 is sleeved on the round rod 82. The upper end of the spring 85 is in contact with the fixed plate 81, and the lower end is connected to the annular limit plate 84. The lower end of the round rod 82 is connected to the top of the movable tube body 51, and the fixed plate 81 is connected to the inner hole of the casing head body 1; when the casing head body 1 and the surface tube move toward each other, the surface tube pushes the round rod 82 to move axially, and the round rod 82 squeezes the spring 85 through the annular limit plate 84. The spring 85 is compressed to generate a reverse elastic force, so that the annular rubber body 52 of the inner sealing ring assembly 50 is in close contact with the end of the surface tube, thereby enhancing the sealing effect.

[0037] The outer circle of the upper end of the movable tube body 51 is sleeved with a guide ring 9, and the outer circle surface of the guide ring 9 is slidably connected to the inner hole of the casing head body 1; through the action of the guide ring 9, the inner sealing ring assembly 50 can move smoothly, and the guide ring 9 has the function of preventing the fluid from flowing to the outer sealing ring assembly 40.

[0038] The lower plane of the inner sealing ring assembly 50 is lower than the lower plane of the outer sealing ring assembly 40; since the lower plane of the inner sealing ring assembly 50 is lower than the lower plane of the outer sealing ring assembly 40, the distance by which the inner sealing ring assembly 50 is squeezed is expanded, thereby enhancing the sealing between the inner sealing ring assembly 50 and the surface pipe.

[0039] The implementation principle of this embodiment is as follows: the outer sealing ring assembly 40 is fixed in the annular groove 7, the inner sealing ring assembly 50 is connected to the inner hole of the casing head body 1 through the elastic pushing rod assembly 80, the internal thread 3 of the casing head body 1 is threadedly connected to the surface pipe below, the casing head body 1 and the surface pipe move toward each other to squeeze the outer sealing ring assembly 40 to achieve the purpose of sealing, and when the casing head body 1 and the surface pipe move toward each other, the elastic force of the elastic pushing rod assembly 80 drives the inner sealing ring assembly 50 to make close contact with the end of the surface pipe. Since the inner sealing ring assembly 50 is located inside the outer sealing ring assembly 40, the fluid first contacts the inner sealing ring assembly 50 and then reduces the flow rate. The fluid after passing through the inner sealing ring assembly 50 flows to the outer sealing ring assembly 40. Since the flow rate of the fluid is reduced, the wear of the fluid on the outer sealing ring assembly 40 is reduced, the service life of the outer sealing ring assembly 40 is extended, and the frequency of maintenance due to sealing problems is reduced.

[0040] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A leak-proof combined casing head, comprising: The casing head body (1) is characterized in that a connecting hole (2) concentric with the inner hole of the casing head body (1) is provided at the lower end of the casing head body (1), the diameter of the connecting hole (2) is larger than the inner hole diameter of the casing head body (1), and the inner surface of the connecting hole (2) is provided with an internal thread (3); The invention also includes an outer sealing ring assembly (40) and an inner sealing ring assembly (50) arranged in the inner cavity thereof, an annular top wall (6) is provided between the inner hole of the sleeve head body (1) and the connecting hole (2), an annular groove (7) is provided on the annular top wall (6), and the outer sealing ring assembly (40) is connected to the annular groove (7), and also includes a plurality of elastic pushing rod assemblies (80) connected to the inner hole of the sleeve head body (1) in an annular array, and the lower end of the elastic pushing rod assembly (80) is connected to the inner sealing ring assembly (50).

2. The leak-proof combined casing head according to claim 1, characterized in that: The outer sealing ring assembly (40) comprises a wave spring (41) and an outer rubber sealing layer (42) wrapped around the outer surface of the wave spring (41).

3. The leak-proof combined casing head according to claim 1, characterized in that: The inner sealing ring assembly (50) comprises a movable tube body (51) and an annular rubber body (52). An annular fixing groove (53) is provided on the upper plane of the annular rubber body (52). The lower end of the movable tube body (51) extends into the inner cavity of the annular fixing groove (53) and is fixedly connected thereto.

4. The leak-proof combined casing head according to claim 3, characterized in that: The elastic pushing rod assembly (80) includes a fixed plate (81) and a round rod (82) passing through the fixed plate (81), the upper end of the round rod (82) is connected to a top plate (83), the outer circle of the lower end of the round rod (82) is sleeved with an annular limiting plate (84), and a spring (85) is sleeved on the round rod (82), the upper end of the spring (85) is in contact with the fixed plate (81), and the lower end is connected to the annular limiting plate (84), the lower end of the round rod (82) is connected to the top of the movable tube body (51), and the fixed plate (81) is connected to the inner hole of the sleeve head body (1).

5. The leak-proof combined casing head according to claim 3, characterized in that: The outer circle of the upper end of the movable tube body (51) is sleeved with a guide ring (9), and the outer circle surface of the guide ring (9) is slidably connected to the inner hole of the casing head body (1).

6. The leak-proof combined casing head according to claim 1, characterized in that: The lower plane of the inner sealing ring assembly (50) is lower than the lower plane of the outer sealing ring assembly (40).

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