Casing head with anti-leakage function and control system thereof

Abstract

The invention relates to the technical field of oil field wellhead devices, in particular to a casing head with an anti-leakage function and a control system thereof. A casing head with an anti-leakage function comprises a sealing mechanism, and the sealing mechanism comprises a rubber ring and a sealing assembly. The sealing assembly comprises three adjusting rings and two connecting units. The two axial ends of the rubber ring are the first end and the second end respectively. When sealing of the first end of the rubber ring fails, gas pushes the adjusting ring in the middle to move in the direction close to the second end of the rubber ring across the rubber ring, and the two connecting units drive the adjusting ring located at the first end of the rubber ring to move in the direction close to the second end of the rubber ring. And the adjusting ring at the second end of the rubber ring moves towards the direction close to the first end of the rubber ring to form a new seal. The invention provides a casing head with an anti-leakage function and a control system of the casing head to solve the problem that an existing sealing device is poor in sealing performance after being used for a long time.

Description

Technical Field

[0001] This invention relates to the field of oilfield wellhead equipment technology, specifically to a casing head with anti-leakage function and its control system. Background Technology

[0002] Wellhead equipment is the core equipment installed at the wellhead after oil and gas drilling, primarily used to control and regulate the production activities of oil, gas, and water wells. Its core functions include sealing the wellhead, suspending the tubing string, controlling fluid pressure and direction, and, as an important component of the well control system, ensuring the safe conduct of drilling operations. The casing head is one of the core components of the drilling wellhead equipment, mainly used to fix the wellhead structure and perform multiple functions. As a key hub connecting the downhole casing string to surface equipment, it not only suspends the weight of all casing layers except the surface casing, but also prevents pressure crosstalk by sealing the casing annular space, ensuring well control safety. During the drilling phase, the casing head provides the installation foundation for the blowout preventer (BOP), while during the production phase, it transitions to connecting the tubing head and the Christmas tree. Furthermore, its side opening function supports cementing, pressure balancing, and emergency fluid injection, significantly improving cementing quality and operational flexibility.

[0003] Currently, BT and P-type rubber seals are mostly used on the upper part of the hanger. However, with the continuous development of oil and gas, drilling conditions are becoming increasingly complex and severe. These types of rubber seals are prone to failure in high or low temperature environments, and also have problems such as easy assembly damage and insufficient pressure bearing capacity.

[0004] For example, the invention patent with announcement number CN117489291B provides a sleeve head with a compression sealing structure. Based on the compression sealing structure of the sealing sleeve and disc spring, it will not be damaged during assembly and has a stronger pressure resistance. However, after long-term use, oil and gas can damage the sealing device, affecting the sealing performance and causing oil and gas leakage. It needs to be replaced immediately, which is time-consuming, labor-intensive, and affects work efficiency. Summary of the Invention

[0005] This invention provides a sleeve head with anti-leakage function and its control system to solve the problem that existing sealing devices are easily worn after long-term use, resulting in poor sealing performance after wear.

[0006] The present invention provides a leak-proof sleeve head and its control system, employing the following technical solution: A leak-proof sleeve head includes a sleeve, an inner tube, and a sealing mechanism. The inner tube is disposed inside the sleeve and is coaxial with the sleeve. The sealing mechanism includes a rubber ring and two sealing components. The rubber ring is located between the sleeve and the inner tube and is coaxial with the sleeve. The two axial ends of the rubber ring are a first end and a second end, respectively. The air pressure at the first end of the rubber ring is the air pressure in the inner tube, and the air pressure at the second end of the rubber ring is atmospheric pressure. During operation, the air pressure in the inner tube is greater than atmospheric pressure.

[0007] A cavity is formed within the rubber ring. A fixing ring is fixedly installed within the rubber ring, dividing the cavity into two annular chambers distributed radially along the rubber ring. Each sealing assembly is disposed in one annular chamber. Each sealing assembly includes at least three adjusting rings coaxial with the rubber ring and at least two connecting units. The three adjusting rings are distributed axially along the rubber ring. The inner and outer sides of each adjusting ring abut against the fixing ring and the sidewall of the rubber ring, respectively. Each connecting unit connects two adjacent adjusting rings.

[0008] When the seal at the first end of the rubber ring fails, the gas inside the inner tube pushes the middle adjusting ring towards the second end of the rubber ring through the rubber ring. This, in turn, drives the adjusting ring at the first end of the rubber ring to move towards the second end of the rubber ring via two connecting units. The adjusting ring at the second end of the rubber ring then moves towards the first end of the rubber ring, forming a new seal.

[0009] Furthermore, each adjusting ring includes a push ring, a friction ring, and multiple elastic strips. The push ring and friction ring are coaxially arranged with the rubber ring. The push ring abuts against the inner wall of the rubber ring, and the push ring is deformable. The friction ring abuts against the fixed ring. The elastic strips connect the push ring and the friction ring.

[0010] Furthermore, each sealing assembly also includes at least three pressure rings, which are coaxially arranged with and abut against the rubber ring. Each pressure ring abuts against a push ring, and the pressure rings and push rings are distributed sequentially along the axial direction. The rubber ring pushes the push ring by compressing the pressure ring.

[0011] Furthermore, the rubber ring includes an inner ring and an outer ring arranged coaxially, with the inner ring located inside the outer ring. The side of the outer ring away from the axis is cylindrical. The side of the outer ring near the axis has a wavy profile arranged circumferentially. The side of the inner ring near the axis is cylindrical. The side of the inner ring away from the axis has a wavy profile arranged circumferentially.

[0012] One sealing component corresponds to the outer ring, and the other sealing component corresponds to the inner ring. Both the push ring and the pressure ring are wavy and parallel to the corresponding inner or outer ring, used to prevent the push ring, pressure ring, and rubber ring from rotating relative to each other.

[0013] Furthermore, in the initial state, the elastic strips are set at an angle. Each elastic strip is connected to a protrusion on the side of the corresponding push ring near the friction ring. When the push ring moves, causing the elastic strip to change from an angled setting to a radial setting along the rubber ring, the elastic strip squeezes the push ring, thereby increasing the radius of the push ring.

[0014] Furthermore, the connecting unit between the middle adjusting ring and the adjusting ring at the first end of the rubber ring includes an elastic sheet, which is elastic and connects the two friction rings.

[0015] Furthermore, the connecting unit between the intermediate adjusting ring and the adjusting ring at the second end of the rubber ring includes multiple connecting plates, which are distributed sequentially along the circumference of the rubber ring. Each connecting plate includes a first plate and a second plate. The first plate is rotatably connected to the intermediate friction ring, and the second plate is rotatably connected to the friction ring at the second end of the rubber ring. The first plate and the second plate are hinged to each other. A connecting rod is provided at the hinge point of the first plate and the second plate, which is arranged radially along the rubber ring and fixedly connected to the fixing ring.

[0016] Furthermore, an oil inlet is provided on the side wall of the rubber ring for introducing hydraulic oil into the rubber ring.

[0017] Furthermore, the sleeve includes an outer tube and a flange, with the flange fixedly mounted at one end of the outer tube. The second end of the rubber ring is positioned relative to the first end near the connection between the outer tube and the flange, such that the air pressure experienced by the second end of the rubber ring is atmospheric pressure.

[0018] A control system for a casing head with anti-leakage function also includes a casing hanger, which is disposed inside the inner tube.

[0019] The beneficial effects of this invention are as follows: A sleeve head with anti-leakage function, through its sealing mechanism, when the first end of the rubber ring wears down, causing its engagement with the corresponding adjusting ring to lose its sealing effect, gas pushes the middle adjusting ring towards the second end of the rubber ring. This, along with two connecting units, drives the adjusting ring at the first end of the rubber ring towards the second end, and vice versa, forming a new seal. This results in a better sealing effect and extended service life. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. 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 effort.

[0021] Figure 1 This is a schematic diagram of the structure of a sleeve head with anti-leakage function and its control system provided in an embodiment of the present invention; Figure 2 A cross-sectional view of a sleeve head with anti-leakage function and its control system provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a rubber ring with anti-leakage function for a sleeve head provided in an embodiment of the present invention; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 for Figure 4 Enlarged view of point B in the middle; Figure 6 A partial structural schematic diagram of a sealing mechanism for a sleeve head with anti-leakage function provided in an embodiment of the present invention; Figure 7 for Figure 6 Enlarged view of point C in the middle; Figure 8 This is a cross-sectional view of a rubber ring and a retaining ring for a sleeve head with anti-leakage function provided in an embodiment of the present invention.

[0022] In the diagram: 100, outer pipe; 110, flange; 111, oil passage; 200, rubber ring; 201, oil inlet; 210, push ring; 220, friction ring; 230, elastic strip; 240, pressure ring; 250, elastic sheet; 260, connecting plate; 270, connecting rod; 300, fixing ring. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Reference Figures 1 to 8 As shown in the figure, an embodiment of the present invention provides a sleeve head with anti-leakage function, including a sleeve, an inner tube, and a sealing mechanism. The inner tube is disposed inside the sleeve and is coaxial with the sleeve. The sealing mechanism includes a rubber ring 200 and two sealing components. The rubber ring 200 is located between the sleeve and the inner tube and is coaxial with the sleeve. The two axial ends of the rubber ring 200 are a first end and a second end, respectively. The air pressure at the first end of the rubber ring 200 is the air pressure of the inner tube, and the air pressure at the second end of the rubber ring 200 is atmospheric pressure. During operation, the air pressure in the inner tube is greater than atmospheric pressure, and the air pressure at the first end of the rubber ring 200 is greater than the air pressure at the second end.

[0025] A cavity is formed within the rubber ring 200. A fixing ring 300 is fixedly disposed within the rubber ring 200, dividing the cavity into two annular cavities distributed radially along the rubber ring 200. Each sealing assembly is disposed in one annular cavity. Each sealing assembly includes at least three adjusting rings coaxial with the rubber ring 200 and at least two connecting units. The three adjusting rings are distributed axially along the rubber ring 200. The inner and outer sides of each adjusting ring abut against the fixing ring 300 and the sidewalls of the rubber ring 200, respectively. Each connecting unit connects two adjacent adjusting rings.

[0026] When the seal at the first end of the rubber ring 200 fails, the gas inside the inner tube pushes the middle adjusting ring towards the second end of the rubber ring 200 through the rubber ring 200. This, in turn, drives the adjusting ring at the first end of the rubber ring 200 to move towards the second end of the rubber ring 200 via two connecting units. The adjusting ring at the second end of the rubber ring 200 then moves towards the first end of the rubber ring 200, forming a new seal. This results in a better sealing effect and extends the service life.

[0027] In this embodiment, each adjusting ring includes a push ring 210, a friction ring 220, and multiple elastic strips 230. The push ring 210 and friction ring 220 are coaxially arranged with the rubber ring 200. The push ring 210 abuts against the inner wall of the rubber ring 200, and the push ring 210 is deformable. The friction ring 220 abuts against the fixing ring 300, and the friction ring 220 and the fixing ring 300 are in frictional contact. The elastic strips 230 connect the push ring 210 and the friction ring 220. Multiple elastic strips 230 are sequentially distributed along the circumference of the friction ring 220, and the elastic strips 230 are inclined. The elastic strips 230 located at the first end and the middle of the rubber ring 200 gradually approach the adjusting ring along the direction from the first end to the second end of the rubber ring 200. The elastic strip 230 located at the second end of the rubber ring 200 gradually approaches the adjusting ring along the direction from the second end to the first end of the rubber ring 200.

[0028] In this embodiment, each sealing assembly further includes at least three pressure rings 240, which are coaxially arranged with and abut against the rubber ring 200. Each pressure ring 240 abuts against a push ring 210. The rubber ring 200 pushes the push ring 210 to move by compressing the pressure rings 240. Each pressure ring 240 has a first inclined surface and a second inclined surface on the side abutting against the rubber ring 200. The first inclined surface abuts against the rubber ring 200, and the second inclined surface abuts against the push ring 210.

[0029] The pressure of the liquid and gas inside the inner tube acts on the first end of the rubber ring 200. The gas pressure causes the rubber ring 200 to deform. After the rubber ring 200 comes into contact with the first inclined surface, it squeezes the pressure ring 240 to move. The pressure ring 240 squeezes the push ring 210 to move through the second inclined surface.

[0030] The pressure ring 240 and the push ring 210 near the first end of the rubber ring 200 are distributed along the direction from the first end to the second end of the rubber ring 200. The pressure ring 240 and the push ring 210 located in the middle section of the rubber ring 200 are distributed along the direction from the first end to the second end of the rubber ring 200. The pressure ring 240 and the push ring 210 near the second end of the rubber ring 200 are distributed along the direction from the second end to the first end of the rubber ring 200.

[0031] When the rubber ring 200 compresses the pressure ring 240, the push ring 210 at the first end of the rubber ring 200 moves along the direction from the first end to the second end of the rubber ring 200. The push ring 210 at the second end of the rubber ring 200 moves along the direction from the second end to the first end of the rubber ring 200.

[0032] In this embodiment, the rubber ring 200 includes an inner ring and an outer ring coaxially arranged, with the inner ring located inside the outer ring. The side of the outer ring away from the axis is cylindrical. The side of the outer ring near the axis has a wavy profile arranged circumferentially. The side of the inner ring near the axis is cylindrical. The side of the inner ring away from the axis has a wavy profile arranged circumferentially.

[0033] One sealing component corresponds to the outer ring, and the other sealing component corresponds to the inner ring. Both the push ring 210 and the pressure ring 240 are wavy and parallel to the corresponding inner or outer ring, which is used to prevent the push ring 210, the pressure ring 240 and the rubber ring 200 from rotating relative to each other.

[0034] In this embodiment, each elastic strip 230 is connected to a protruding portion of a corresponding push ring 210 on the side near the friction ring 220. When the push ring 210 moves, causing the elastic strip 230 to change from an inclined setting to a radial setting along the rubber ring 200, the elastic strip 230 compresses the push ring 210 to increase the radius of the push ring 210.

[0035] In this embodiment, the connecting unit between the intermediate adjusting ring and the adjusting ring at the first end of the rubber ring 200 includes an elastic sheet 250. The elastic sheet 250 is elastic and connects two friction rings 220. Gas enters between the rubber ring 200 and the sleeve and inner tube, causing the rubber ring 200 to deform. Both the inner and outer rings of the rubber ring 200 are recessed into the cavity. When the rubber ring 200 and the elastic sheet 250 come into contact, the elastic sheet 250 is compressed and bent. The elastic sheet 250 drives the adjusting ring at the first end of the rubber ring 200 to move along the direction from the first end to the second end of the rubber ring 200.

[0036] In this embodiment, the connecting unit between the intermediate adjusting ring and the adjusting ring at the second end of the rubber ring 200 includes multiple connecting plates 260, which are sequentially distributed along the circumference of the rubber ring 200. Each connecting plate 260 includes a first plate and a second plate. The first plate is rotatably connected to the intermediate friction ring 220, and the second plate is rotatably connected to the friction ring 220 at the second end of the rubber ring 200. The first plate and the second plate are hinged to each other. A connecting rod 270 is provided at the hinge point of the first plate and the second plate. The connecting rod 270 is arranged radially along the rubber ring 200 and is fixedly connected to the fixing ring 300.

[0037] When the middle adjusting ring moves along the direction from the first end to the second end of the rubber ring 200, the connecting rod 270 and the fixing ring 300 are fixedly connected, and the connecting rod 270 is hinged to the first plate and the second plate. Therefore, when the middle adjusting ring moves, the first plate and the second plate bend, and the second plate drives the adjusting ring located at the second end of the rubber ring 200 to move along the direction from the second end to the first end of the rubber ring 200.

[0038] In this embodiment, an oil inlet 201 is provided on the side wall of the rubber ring 200 for introducing hydraulic oil into the rubber ring 200. The rubber ring 200 is supported by the retaining ring 300 and the internal oil.

[0039] In this embodiment, the sleeve includes an outer tube 100 and a flange 110, with the flange 110 fixedly disposed at one end of the outer tube 100. The second end of the rubber ring 200 is positioned relative to the first end near the connection between the outer tube 100 and the flange 110, such that the air pressure experienced by the second end of the rubber ring 200 is atmospheric pressure. An oil passage 111 is provided on the flange 110, and the oil passage 111 is connected to the oil inlet 201.

[0040] A control system for a casing head with anti-leakage function also includes a casing hanger, which is disposed inside the inner casing. The casing hanger is prior art.

[0041] Working process: Install the rubber ring 200 between the sleeve and the inner tube. Since the rubber ring 200 is located between the sleeve and the inner tube, and the second end of the rubber ring 200 is located near the connection between the outer tube 100 and the flange 110 relative to the first end, the air pressure at the second end of the rubber ring 200 is atmospheric pressure.

[0042] Initially, the elastic strip 230 is tilted. Multiple push rings 210 compress the rubber ring 200, sealing the gap between the sleeve and the inner tube. When gas and liquid are introduced into the inner tube, the pressure of the liquid and gas in the inner tube acts on the first end of the rubber ring 200, and the air pressure at the first end of the rubber ring 200 is greater than the air pressure at the second end of the rubber ring 200. The rubber ring 200 compresses the pressure ring 240, and the pressure ring 240 compresses the push ring 210, causing the pressure ring 240 and the push ring 210 at the first end of the rubber ring 200 to move in the direction from the first end to the second end of the rubber ring 200. The elastic strip 230 gradually changes from being inclined to being arranged radially along the rubber ring 200. The elastic strip 230 is compressed, and the elastic strip 230 compresses the protruding part of the push ring 210 towards the elastic strip 230, causing the push ring 210 to deform and the radius of the push ring 210 to increase. This further compresses the rubber ring 200, thereby improving the sealing performance of the rubber ring 200.

[0043] After the rubber ring 200 has been in use for a long time, the first end of the rubber ring 200 will be worn, and the adjusting ring at the first end of the rubber ring 200 will lose its sealing function. The adjusting ring at the first end of the rubber ring 200 will not be able to make the first end of the rubber ring 200 completely fit with the sleeve and inner tube, and gas can enter between the rubber ring 200 and the sleeve and inner tube. At this time, the middle adjusting ring will play a sealing role.

[0044] Gas then enters between the rubber ring 200 and the sleeve and inner tube, causing the rubber ring 200 to deform. Both the inner and outer rings of the rubber ring 200 are recessed into the cavity, with the recessed portion located between the adjusting ring at the first end and the middle adjusting ring of the rubber ring 200. When the rubber ring 200 and the elastic sheet 250 come into contact, the elastic sheet 250 is compressed and bent. The elastic sheet 250 drives the adjusting ring at the first end of the rubber ring 200 to move along the direction from the first end to the second end of the rubber ring 200, thereby changing the position of the adjusting ring at the first end of the rubber ring 200, so that the adjusting ring at the first end of the rubber ring 200 and the rubber ring 200 form a new seal.

[0045] After the gas stored between the rubber ring 200 and the sleeve and inner tube gradually dissipates, the elastic plate 250 resets, pushing the middle adjusting ring to move along the direction from the first end to the second end of the rubber ring 200, further strengthening the seal of the middle adjusting ring on the rubber ring 200.

[0046] Furthermore, since the connecting rod 270 and the fixing ring 300 are fixedly connected, the connecting rod 270 is hinged to the hinge joint of the first plate and the second plate. Therefore, when the middle adjusting ring moves, the first plate and the second plate bend, and the second plate drives the adjusting ring at the second end of the rubber ring 200 to move along the direction from the second end of the rubber ring 200 to the first end, causing the elastic strip 230 at the second end of the rubber ring 200 to deform, and the radius of the pushing ring 210 to increase, further strengthening the seal of the rubber ring 200 by the adjusting ring at the second end of the rubber ring 200.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sleeve head with anti-leakage function, characterized in that: It includes a sleeve, an inner tube, and a sealing mechanism; the inner tube is located inside the sleeve and is coaxial with the sleeve; the sealing mechanism includes a rubber ring and two sealing components; the rubber ring is located between the sleeve and the inner tube and is coaxial with the sleeve; the two ends of the rubber ring in the axial direction are the first end and the second end, respectively, the air pressure at the first end of the rubber ring is the air pressure in the inner tube, and the air pressure at the second end of the rubber ring is atmospheric pressure; during operation, the air pressure in the inner tube is greater than atmospheric pressure; A cavity is formed inside the rubber ring; a fixing ring is fixedly installed inside the rubber ring, dividing the cavity into two annular cavities distributed radially along the rubber ring; each sealing assembly is disposed in one annular cavity; each sealing assembly includes at least three adjusting rings coaxial with the rubber ring and at least two connecting units, the three adjusting rings being distributed axially along the rubber ring; the inner and outer sides of each adjusting ring abut against the fixing ring and the sidewall of the rubber ring, respectively; each connecting unit connects two adjacent adjusting rings; When the seal at the first end of the rubber ring fails, the gas inside the inner tube pushes the middle adjusting ring towards the second end of the rubber ring through the rubber ring. This, in turn, drives the adjusting ring at the first end of the rubber ring to move towards the second end of the rubber ring via two connecting units. The adjusting ring at the second end of the rubber ring then moves towards the first end of the rubber ring, forming a new seal.

2. A sleeve head with anti-leakage function according to claim 1, characterized in that: Each adjusting ring includes a push ring, a friction ring, and multiple elastic strips; the push ring and the friction ring are coaxially arranged with the rubber ring; the inner wall of the push ring and the rubber ring abuts against each other, and the push ring is deformable; the friction ring abuts against the fixed ring; the elastic strips connect the push ring and the friction ring.

3. A sleeve head with anti-leakage function according to claim 2, characterized in that: Each sealing assembly also includes at least three pressure rings, which are coaxially arranged with and abut against the rubber ring; each pressure ring abuts against a push ring, and the pressure rings and push rings are distributed sequentially along the axial direction; the rubber ring pushes the push ring to move by squeezing the pressure ring.

4. A sleeve head with anti-leakage function according to claim 3, characterized in that: The rubber ring includes an inner ring and an outer ring arranged coaxially, with the inner ring inside the outer ring; the outer ring is cylindrical on the side away from the axis; the outer ring has a wavy profile along the circumference on the side near the axis; the inner ring is cylindrical on the side near the axis; the inner ring has a wavy profile along the circumference on the side away from the axis. One sealing component corresponds to the outer ring, and the other sealing component corresponds to the inner ring; both the push ring and the pressure ring are wavy and parallel to the corresponding inner or outer ring, which is used to prevent the push ring, pressure ring and rubber ring from rotating relative to each other.

5. A sleeve head with anti-leakage function according to claim 4, characterized in that: In the initial state, the elastic strips are set at an angle; each elastic strip is connected to a protrusion on the side of the corresponding push ring near the friction ring; when the push ring moves, causing the elastic strips to change from an angled setting to a radial setting along the rubber ring, the elastic strips squeeze the push ring to increase the radius of the push ring.

6. A sleeve head with anti-leakage function according to claim 2, characterized in that: The connecting unit between the middle adjusting ring and the first adjusting ring at the first end of the rubber ring includes an elastic sheet, which is elastic and connects the two friction rings.

7. A sleeve head with anti-leakage function according to claim 2, characterized in that: The connecting unit between the middle adjusting ring and the second adjusting ring at the second end of the rubber ring includes multiple connecting plates, which are distributed sequentially along the circumference of the rubber ring. Each connecting plate includes a first plate and a second plate. The first plate is rotatably connected to the middle friction ring, and the second plate is rotatably connected to the friction ring at the second end of the rubber ring. The first plate and the second plate are hinged to each other. A connecting rod is provided at the hinge of the first plate and the second plate. The connecting rod is arranged radially along the rubber ring and is fixedly connected to the fixing ring.

8. A sleeve head with anti-leakage function according to claim 1, characterized in that: An oil inlet is provided on the side wall of the rubber ring for introducing hydraulic oil into the rubber ring.

9. A sleeve head with anti-leakage function according to claim 1, characterized in that: The sleeve includes an outer tube and a flange, with the flange fixedly installed at one end of the outer tube; the second end of the rubber ring is located at the end closest to the connection between the outer tube and the flange relative to the first end, so that the air pressure on the second end of the rubber ring is atmospheric pressure.

10. A control system for a sleeve head with anti-leakage function, comprising the sleeve head with anti-leakage function as described in any one of claims 1-9, characterized in that: It also includes a casing hanger, which is installed inside the inner tube.

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