Petroleum casing head with sealing structure

Abstract

The invention belongs to the technical field of oil casing heads, and provides an oil casing head with a sealing structure. Comprising a body, the upper side of the body is connected with an upper flange, the lower side of the body is connected with an intermediate casing, an annular sliding groove is formed in the upper side of the body, a sliding ring is slidably connected into the annular sliding groove, a mounting ring is fixedly connected to the upper side of the sliding ring, the mounting ring is slidably connected with the body, a sealing gasket is fixedly connected to the upper side of the mounting ring, and the sealing gasket is in extrusion fit with the upper flange. The main body is provided with first communicating holes which are evenly distributed in the circumferential direction. The extrusion degree of the sealing gasket is changed according to different pressures when materials are injected into the main body, so that the extrusion force borne by the sealing gasket when the material pressure in the main body is small is small, the extrusion force borne by the sealing gasket when the material pressure in the main body is large is large, and therefore the service life of the sealing gasket is prolonged while the sealing performance of the sealing gasket is guaranteed; and therefore, the non-production time in the oil exploitation process is shortened, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil casing heads, in particular to an oil casing head with a sealing structure. Background Art

[0002] The casing head is used to connect various layers of casing in oil production to ensure the sealing and stable connection from the surface casing to the oil layer casing. It can support the weight of other casings except the surface casing, including technical casing and production casing, and provide a solid foundation for the entire wellhead device. The casing head is often provided with a side port, which can be used for injecting mud, cement, well killing fluid or fire extinguishing agent and other materials, as well as injecting pressure balancing fluid during acid fracturing in special operations. The upper side of the casing head is usually connected to the wellhead device (including the blowout preventer group) through a flange or a clamp. When the casing head is connected to the flange, a sealing gasket is generally set to achieve sealing, so as to avoid leakage when injecting materials into the casing head. Leakage, the existing sealing methods are mostly metal spiral wound gaskets, non-metallic gaskets (such as rubber, graphite), etc., which are located between the two flange surfaces. When the flanges are tightened by bolts, the gaskets are squeezed and deformed, filling the tiny bumps between the flange surfaces to form a seal. When sealing in this way, the pressure on the gasket is set according to the maximum pressure of the material injected into the casing to ensure the sealing effect. Therefore, the gasket is always under high pressure after installation, resulting in a short service life of the gasket. The gasket needs to be replaced when its service life is about to end to avoid damage to the gasket during production and affect production. The short service life of the gasket will increase the non-production time during oil extraction and affect production efficiency. Summary of the invention

[0003] In order to overcome the shortcomings mentioned in the above background technology, the present invention provides a petroleum casing head with a sealing structure.

[0004] The technical solution of the present invention is: an oil casing head with a sealing structure, including a main body, the upper side of the main body is connected to the upper flange, the lower side of the main body is connected to the technical casing, the upper side of the main body is provided with an annular groove, a sliding ring is slidably connected in the annular groove, the upper side of the sliding ring is fixedly connected with a mounting ring, the mounting ring is slidably connected to the main body, the upper side of the mounting ring is fixedly connected with a sealing gasket, the sealing gasket is extrusion-fitted with the upper flange, the main body is provided with first communicating holes evenly distributed circumferentially, and the first communicating holes evenly distributed circumferentially jointly connect the annular groove with the inner side of the main body.

[0005] As a preferred technical solution of the present invention, the upper side of the sealing gasket is higher than the upper side of the main body, so that the sealing gasket is squeezed when the main body and the upper flange are connected.

[0006] As a preferred technical solution of the present invention, the upper side of the longitudinal section of the mounting ring is wavy, and the upper and lower sides of the longitudinal section of the sealing gasket are both wavy, which is used to increase the contact area between the mounting ring and the sealing gasket.

[0007] As a preferred technical solution of the present invention, two sealing rings are embedded in the main body, and both of the two sealing rings are slidably and extrusion-matched with the sliding ring.

[0008] As a preferred technical solution of the present invention, the volume of the portion of the sealing ring embedded in the main body is larger than the volume of the portion of the sealing ring located in the annular groove, so as to prevent the sealing ring from shifting.

[0009] As a preferred technical solution of the present invention, the longitudinal section of the sliding ring is an isosceles trapezoid with a short upper base and a long lower base, which is used to change the force when the sliding ring and the two sealing rings are squeezed.

[0010] As a preferred technical solution of the present invention, it also includes a hollow ring, which is fixed to the upper side of the main body, and the hollow ring is extruded and fitted with the upper flange. The main body is provided with second connecting holes evenly distributed circumferentially, and the second connecting holes are connected to the hollow ring. A partition table is provided on the upper side of the main body, and the partition table is provided with an annular groove, and the second connecting hole is connected to the annular groove of the partition table.

[0011] As a preferred technical solution of the present invention, a sliding column is slidably connected to the side of the second connecting hole close to the axis of the main body, and the sliding columns evenly distributed circumferentially are commonly fixed with a pressure ring, and the pressure ring is slidably connected to the main body, and the second connecting hole and the hollow ring are filled with liquid.

[0012] As a preferred technical solution of the present invention, the upper side of the pressure ring is lower than the upper side of the main body, and the upper side of the pressure ring is flush with the upper side of the partition table, so that the material leaked due to damage of the sealing gasket can squeeze the pressure ring.

[0013] As a preferred technical solution of the present invention, the contact area between the pressure ring and the leaked material is larger than the contact area between the hollow ring and the leaked material.

[0014] Beneficial effect: The present invention changes the degree of extrusion of the sealing gasket according to the different pressures when the material is injected into the main body, so that the sealing gasket is subjected to a small extrusion force when the material pressure in the main body is small, and is subjected to a large extrusion force when the material pressure in the main body is large, thereby ensuring the sealing performance while extending the service life of the sealing gasket, thereby reducing the non-production time in the oil extraction process and improving production efficiency.

[0015] By setting the upper and lower sides of the longitudinal section of the sealing gasket to be wavy, the contact area between the sealing gasket and the mounting ring and the upper flange is increased, thereby improving the sealing performance of the sealing gasket. After the sealing gasket is damaged and broken, the upper side of the mounting ring is wavy, thereby forming a groove for accommodating the sealing gasket, thereby preventing the broken sealing gasket from separating to both sides of the fracture under the pressure of the material in the main body to form a larger fracture, thereby avoiding the gushing leakage of material caused by the break of the sealing gasket.

[0016] By setting the longitudinal section of the sliding ring to an isosceles trapezoid, when the material pressure in the main body is high, the sliding ring increases the squeezing force on the two sealing rings when it moves upward, thereby improving the sealing between the sliding ring and the two sealing rings and preventing material leakage.

[0017] After the material leaks, the pressure of the material acts on the pressure ring, causing the pressure ring to move downward and drive the hollow ring to expand, thereby increasing the pressure between the hollow ring and the upper flange, forming a temporary seal between the main body and the upper flange, providing time for subsequent staff to carry out maintenance and preventing large amounts of material leakage during this period from contaminating production equipment and causing waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a three-dimensional structural cross-sectional view of the main body and the upper flange of the present invention; Figure 3 It is a three-dimensional structural cross-sectional view of the sliding ring and the sealing gasket of the present invention; Figure 4 It is a three-dimensional structural cross-sectional view of the hollow ring and the pressure ring of the present invention.

[0019] Among them: 1-main body, 101-annular slide groove, 102-first connecting hole, 103-second connecting hole, 104-partitioning platform, 2-upper flange, 3-technical sleeve, 4-sliding ring, 5-mounting ring, 6-sealing gasket, 7-sealing ring, 8-hollow ring, 9-sliding column, 10-pressure ring. DETAILED DESCRIPTION

[0020] For those skilled in the art, the specific meanings of the above terms in this application can be understood in specific situations. The electronic device provided by the embodiment of the present application is described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0021] The existing casing head forms a seal by squeezing the sealing gasket, and the sealing gasket is under high pressure for a long time, resulting in a short service life of the sealing gasket. The short service life of the sealing gasket will increase the non-production time during the oil production process and affect the production efficiency.

[0022] Embodiment 1: A petroleum casing head with a sealing structure, such as Figure 1-Figure 4 As shown, it includes a main body 1, the upper side of the main body 1 is connected to the upper flange 2, the lower side of the main body 1 is connected to the technical sleeve 3, the upper side of the main body 1 is provided with an annular groove 101, the annular groove 101 is used to make the sliding ring 4 and the mounting ring 5 move in the up and down directions, the sliding ring 4 is slidably connected in the annular groove 101, the upper side of the sliding ring 4 is fixedly connected with the mounting ring 5, the mounting ring 5 is used to cooperate with the sealing gasket 6 to form a seal, the mounting ring 5 is slidably connected to the main body 1, the mounting ring 5 is located in the annular groove 101, the upper side of the mounting ring 5 is fixedly connected with the sealing gasket 6, the upper side of the sealing gasket 6 is higher than the upper side of the main body 1, which is used to make the sealing gasket 6 be squeezed when the main body 1 and the upper flange 2 are connected, and the sealing gasket 6 is squeezed and matched with the upper flange 2 When the main body 1 and the upper flange 2 are connected, the mounting ring 5 and the upper flange 2 squeeze the sealing gasket 6 to form a seal. The upper side of the longitudinal section of the mounting ring 5 is wavy, and the upper and lower sides of the longitudinal section of the sealing gasket 6 are both wavy, which is used to increase the contact area between the mounting ring 5 and the sealing gasket 6, thereby improving the sealing performance. The main body 1 is provided with a plurality of (six are taken as an example here) first connecting holes 102 uniformly distributed in the circumferential direction. The six first connecting holes 102 jointly connect the annular chute 101 with the inner side of the main body 1, so that the material flowing inside the main body 1 can enter the annular chute 101, and then use the pressure of the material to provide pressure to the sliding ring 4, so that the sliding ring 4 drives the mounting ring 5 to further squeeze the sealing gasket 6, thereby improving the sealing performance.

[0023] like Figure 3 and Figure 4 As shown, the main body 1 is embedded with two sealing rings 7, and the sealing rings 7 are used to provide sealing between the sliding ring 4 and the main body 1. The two sealing rings 7 are both slidably and extruded with the sliding ring 4. The sealing ring 7 and the sliding ring 4 are initially in an extruded state. When the sliding ring 4 moves upward, the sliding ring 4 further squeezes the two sealing rings 7, thereby improving the sealing performance. The volume of the portion of the sealing ring 7 embedded in the main body 1 is larger than the volume of the portion of the sealing ring 7 located in the annular groove 101, which is used to prevent the sealing ring 7 from shifting, thereby providing a good sealing effect. The longitudinal section of the sliding ring 4 is an isosceles trapezoid with a short upper base and a long lower base, which is used to change the force when the sliding ring 4 is squeezed by the two sealing rings 7. When the sliding ring 4 moves upward, the extrusion force of the sliding ring 4 on the sealing ring 7 becomes larger, thereby improving the sealing performance.

[0024] When using the device, first connect the main body 1 with the upper flange 2 and the technical casing 3, so that the material for assisting oil extraction can flow through the main body 1, the upper flange 2 and the technical casing 3. When the main body 1 is connected with the upper flange 2, the mounting ring 5 and the upper flange 2 jointly squeeze the sealing gasket 6, so that the three cooperate to form a seal to prevent material leakage. When the material is injected into the main body 1, the material flows into the first connecting hole 102, and then the sliding ring 4 moves upward under the pressure of the material, and the sliding ring 4 pushes the mounting ring 5 to move upward, and the mounting ring 5 further squeezes the sealing gasket 6, thereby improving the sealing between the mounting ring 5, the sealing gasket 6 and the upper flange 2 to prevent material leakage. When the material pressure in the main body 1 is small, The pressure of the material on the sliding ring 4 is small, and the extrusion force on the sealing gasket 6 by the mounting ring 5 is small, but sealing can still be achieved, thereby realizing the function of changing the sealing effect of the sealing gasket 6 according to the material pressure in the main body 1, so that the sealing gasket 6 is subjected to a small extrusion force when the material pressure in the main body 1 is small, and is subjected to a large extrusion force when the material pressure in the main body 1 is large, so that the sealing gasket 6 can extend its service life while ensuring the sealing performance, thereby reducing the non-production time in the oil production process and improving the production efficiency. When the sliding ring 4 moves upward, because its cross-section is trapezoidal, the sliding ring 4 will further squeeze the two sealing rings 7 when moving upward, thereby improving the sealing between the sliding ring 4 and the two sealing rings 7 to prevent material leakage.

[0025] There is a risk of damage to the gasket during use. Once the gasket is damaged, it will affect production and cause material leakage, contaminating production equipment and affecting maintenance.

[0026] Embodiment 2: Based on embodiment 1, Figure 2-Figure 4 As shown, it also includes a hollow ring 8, which is made of elastic material. The hollow ring 8 is fixed to the upper side of the main body 1, and the hollow ring 8 is squeezed and matched with the upper flange 2. Initially, the squeezing force between the hollow ring 8 and the upper flange 2 is small, thereby preventing the hollow ring 8 from failing. The main body 1 is provided with a plurality of (six are taken as an example here) second connecting holes 103 uniformly distributed in the circumferential direction. The second connecting holes 103 are U-shaped, and the second connecting holes 103 are connected with the hollow ring 8. A partition table 104 is provided on the upper side of the main body 1. The partition table 104 is used to allow the leaked material to reach its upper side. The partition table 104 is provided with an annular groove, and the second connecting hole 103 is connected with the annular groove of the partition table 104.

[0027] like Figure 2-Figure 4As shown, a sliding column 9 is slidably connected to one side of the second connecting hole 103 close to the axis of the main body 1, and six sliding columns 9 are commonly fixed with a pressure ring 10, which is slidably connected to the main body 1 and is located in the annular groove of the partition table 104. When the material reaches the upper side of the partition table 104 and the pressure ring 10, the material squeezes the pressure ring 10 and moves downward. The upper side of the pressure ring 10 is lower than the upper side of the main body 1, and the upper side of the pressure ring 10 is flush with the upper side of the partition table 104, so that the material leaked due to damage to the sealing gasket 6 can squeeze the pressure ring 10. The contact area between the pressure ring 10 and the leaked material is larger than the contact area between the hollow ring 8 and the leaked material, so that the pressure ring 10 can press the liquid in the second connecting hole 103 (the liquid mentioned here and below is hydraulic oil, used for transmission) into the hollow ring 8 through the sliding column 9, and the second connecting hole 103 and the hollow ring 8 are both filled with liquid.

[0028] When the sealing gasket 6 or the sealing ring 7 is damaged due to the exhaustion of its service life due to failure to replace it in time, the material leaks from the inner side of the main body 1 to the upper side of the partition 104 due to poor sealing. After the partition 104 and the upper side of the pressure ring 10 are filled with materials, the pressure of the material acts on the pressure ring 10, and the material squeezes the pressure ring 10 to move downward. The pressure ring 10 pushes the six sliding columns 9 to move downward, and the sliding columns 9 squeeze the liquid in the adjacent second connecting hole 103 into the hollow ring 8. The amount of liquid in the hollow ring 8 increases, the pressure increases, the hollow ring 8 expands, and the extrusion force between it and the upper flange 2 increases, thereby achieving temporary sealing, providing time for subsequent staff to carry out maintenance. To prevent a large amount of material leakage during this period from polluting the production equipment and causing waste, the staff then stops injecting material into the main body 1 and removes the upper flange 2 from the main body 1. At this time, the partition table 104 and the upper side of the pressure ring 10 are connected to the air, and the pressure of the leaked material on the pressure ring 10 decreases. The hollow ring 8 recovers under the action of its own elasticity and presses the liquid inside it into the six second connecting holes 103, and then pushes the six sliding columns 9 to drive the pressure ring 10 to reset, and then replaces the damaged sealing gasket 6 or sealing ring 7, and at the same time cleans the part of the upper side of the main body 1 contaminated by the leaked material, and then reinstalls the upper flange 2 to continue production.

[0029] The above is a detailed introduction to the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A petroleum casing head with a sealing structure, comprising a main body (1), wherein the upper side of the main body (1) is connected to an upper flange (2), and the lower side of the main body (1) is connected to a technical casing (3), characterized in that: An annular groove (101) is provided on the upper side of the main body (1), a sliding ring (4) is slidably connected in the annular groove (101), a mounting ring (5) is fixedly connected to the upper side of the sliding ring (4), the mounting ring (5) is slidably connected to the main body (1), a sealing gasket (6) is fixedly connected to the upper side of the mounting ring (5), the sealing gasket (6) is extrusion-fitted with the upper flange (2), and the main body (1) is provided with first connecting holes (102) evenly distributed in the circumference, and the first connecting holes (102) evenly distributed in the circumference together connect the annular groove (101) with the inner side of the main body (1).

2. The oil casing head with a sealing structure according to claim 1, characterized in that: The upper side of the sealing gasket (6) is higher than the upper side of the main body (1), so that the sealing gasket (6) is compressed when the main body (1) and the upper flange (2) are connected.

3. The oil casing head with a sealing structure according to claim 1, characterized in that: The upper side of the longitudinal section of the mounting ring (5) is wavy, and the upper and lower sides of the longitudinal section of the sealing gasket (6) are both wavy, so as to increase the contact area between the mounting ring (5) and the sealing gasket (6).

4. The petroleum casing head with a sealing structure according to claim 1, characterized in that: The main body (1) is embedded with two sealing rings (7), and the two sealing rings (7) are both slidably and extrusion-fitted with the sliding ring (4).

5. The petroleum casing head with a sealing structure according to claim 4, characterized in that: The volume of the portion of the sealing ring (7) embedded in the main body (1) is larger than the volume of the portion of the sealing ring (7) located in the annular sliding groove (101), so as to prevent the sealing ring (7) from shifting.

6. The petroleum casing head with a sealing structure according to claim 5, characterized in that: The longitudinal section of the sliding ring (4) is an isosceles trapezoid, with a short upper base and a long lower base, and is used to change the force when the sliding ring (4) and the two sealing rings (7) are squeezed.

7. The petroleum casing head with a sealing structure according to claim 1, characterized in that: The invention also comprises a hollow ring (8), the hollow ring (8) being fixedly connected to the upper side of the main body (1), the hollow ring (8) being pressed and fitted with the upper flange (2), the main body (1) being provided with second communicating holes (103) evenly distributed in the circumferential direction, the second communicating holes (103) being communicated with the hollow ring (8), the upper side of the main body (1) being provided with a partition table (104), the partition table (104) being provided with an annular groove, the second communicating holes (103) being communicated with the annular groove of the partition table (104).

8. The petroleum casing head with a sealing structure according to claim 7, characterized in that: A sliding column (9) is slidably connected to one side of the second connecting hole (103) close to the axis of the main body (1); the sliding columns (9) uniformly distributed in the circumference are fixedly connected to a pressure ring (10); the pressure ring (10) is slidably connected to the main body (1); and the second connecting hole (103) and the hollow ring (8) are both filled with liquid.

9. The petroleum casing head with a sealing structure according to claim 8, characterized in that: The upper side of the pressure ring (10) is lower than the upper side of the main body (1), and the upper side of the pressure ring (10) is flush with the upper side of the partition table (104), so that the material leaking due to damage of the sealing gasket (6) can press the pressure ring (10).

10. The petroleum casing head with a sealing structure according to claim 8, characterized in that: The contact area between the pressure ring (10) and the leaked material is greater than the contact area between the hollow ring (8) and the leaked material.

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