A casing head sealing performance testing device

Abstract

The present invention relates to the technical field of casing head detection equipment. The present invention discloses a casing head sealing performance testing device, which includes: a lower placement rack, on which the casing head is placed; upper fixing racks, two symmetrically arranged upper fixing racks are arranged on the top of the casing head; an upper sealing assembly, which is installed on the two upper fixing racks and is used to seal the top of the casing head; a lower sealing assembly, which is used to seal the top of the casing head, and the lower sealing assembly is installed on the two upper fixing racks through a screw-type lifting assembly, and the lower sealing assembly and the upper sealing assembly apply forces in two directions. In the casing head sealing performance testing device disclosed by the present invention, the upper sealing assembly and the lower sealing assembly apply forces to the top and bottom of the casing head in two directions, reducing the side tilt of the casing head while improving the stability of the top of the casing head.

Description

Technical Field

[0001] The present invention relates to the technical field of casing head detection equipment, and more specifically, to a casing head sealing performance testing device. Background Art

[0002] The casing head is used to fix the wellhead of the drilling well, connect the casing string at the wellhead, support the gravity of the technical casing and the production casing, seal the annular space between each layer of pipes, provide a transition connection for installing the blowout preventer, tubing head, and Christmas tree, and through two side ports on the casing head body, construction operations such as mud squeezing, monitoring, and filling balance fluid can be carried out. According to the requirements of GB / T22513-2013 and API Spec 6A standards, a sealing test should be carried out before the casing head leaves the factory. For conventional casing heads, usually during the pressure test, the bottom is blocked with a steel plug and then a blind flange is added, and a blind flange is added on the upper part, and the annular space between the two flanges is sealed with a steel gasket ring. Although the pressure test process can be completed, it will damage the gasket ring groove of the casing head body, and the indentation on the gasket ring groove will affect the seal.

[0003] Chinese Patent CN210689950U discloses a casing head sealing performance testing device, including a casing head, a second sealing mechanism and a first sealing mechanism respectively arranged at the upper and lower ends of the casing head. The casing head sealing performance testing device further includes a hydraulic cylinder arranged above the casing head, the piston rod of the hydraulic cylinder is connected to a pressure plate, and the pressure plate is concentric with the casing head. This casing head sealing performance testing device can improve work efficiency, reduce labor intensity, and effectively avoid abrasion and scratching of the inner wall of the casing head during sealing. However, the casing head is placed in a form where the upper part is wider and the lower part is narrower, resulting in a relatively high center of gravity. When the pressure plate drives the second sealing mechanism to press down the upper end of the casing head, the force application direction is unique. Once it is not centered and eccentric, the whole casing head is prone to tipping, thus there are certain safety hazards. Summary of the Invention

[0004] To achieve the above object, the present invention discloses a casing head sealing performance testing device, including:

[0005] A lower placement rack, on which the casing head is placed.

[0006] An upper fixing rack, two symmetrically arranged upper fixing racks are arranged at the top of the casing head.

[0007] An upper sealing assembly, which is installed on the two upper fixing racks and is used to seal the top of the casing head.

[0008] A lower sealing assembly, which is used to seal the top of the casing head. The lower sealing assembly is installed on the two upper fixing racks through a screw-type lifting assembly, and the lower sealing assembly and the upper sealing assembly apply forces in two directions.

[0009] Preferably, the upper sealing assembly includes:

[0010] The upper sealing cover is slidably installed on two upper fixing frames and is arranged near the bottom end of the upper fixing frames. The cover opening end of the upper sealing cover is buckled on the top end of the casing head, and the screw-type lifting assembly penetrates through the central position at the top end of the upper sealing cover;

[0011] The inner sealing cover is located inside the upper sealing cover. The inner sealing cover is arranged in an inverted dish shape. The bottom end of the inner sealing cover abuts against the inner ring at the top end of the casing head. The top end of the inner sealing cover is arranged in an open manner for the screw-type lifting assembly to penetrate through. The top end of the inner sealing cover is integrally installed on the upper sealing cover through an outer ring plate.

[0012] Preferably, a sealing ring is installed at the central position of the top end of the upper sealing cover, and the sealing ring is sleeved on the screw-type lifting assembly.

[0013] Preferably, the screw-type lifting assembly includes:

[0014] A fixed cross frame, which is installed at the top ends of two upper fixing frames;

[0015] A rotating screw, which is installed on the fixed cross frame;

[0016] A lifting screw sleeve, which is sleeved on the rotating screw. Symmetrically installed at the top end of the lifting screw sleeve are support cross arms. At the end of the support cross arm far from the lifting screw sleeve, a limit sliding sleeve is installed, and the limit sliding sleeve is sleeved on the upper fixing frame. The lifting screw sleeve penetrates through the upper sealing cover and the inner sealing cover in sequence and extends into the casing head;

[0017] A lower installation stud, which is connected to the bottom end of the lifting screw sleeve, and the lower sealing assembly is detachably installed on the lower installation stud.

[0018] Preferably, the lower sealing assembly includes:

[0019] A lower sealing cover, the cover opening end of which is buckled on the bottom end of the casing head, and a central hole for the lower installation stud to penetrate through is opened at the bottom end of the lower sealing cover;

[0020] A sealing cushion layer, which is installed inside the lower sealing cover;

[0021] A fixed screw block, which is screwed on the lower installation stud to lock the lower sealing cover.

[0022] Preferably, a centering assembly adapted to the inner ring setting of the inner sealing cover is installed on the lifting screw sleeve. The centering assembly includes:

[0023] The fixed ring seat is installed on the lifting screw sleeve. There are four flipping plates circumferentially distributed on the fixed ring seat. The flipping plates are arranged with obtuse-angle bends. The bent sections of the flipping plates are rotatably installed on the fixed ring seat through fixed rotating shafts. The top ends of the flipping plates abut against the inner ring of the inner sealing cover, and the bottom ends of the flipping plates abut against the inner wall of the casing head and avoid the set screws.

[0024] Preferably, an annular sealing block is installed on the inner ring of the inner sealing cover. The thickness of the annular sealing block gradually becomes thicker near the bottom end of the inner sealing cover. An extrusion block for extruding the annular sealing block is installed on the flipping plate. Under the extrusion of the extrusion block, the thickness of the annular sealing block becomes thinner and flows towards the bottom end of the inner sealing cover.

[0025] Preferably, a soft rubber cushion block is installed at the bottom end of the upper fixing frame.

[0026] Preferably, the extrusion block is set as an arc-shaped plate structure.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] A casing head sealing performance testing device provided by the present invention. The upper sealing assembly and the lower sealing assembly apply force to the top end and the bottom end of the casing head in two directions, reducing the side tilt of the casing head and improving the stability of the top end of the casing head at the same time. The casing head to be detected is hoisted onto the lower placement frame, so that the bottom end of the casing head is in a suspended state. Then the upper fixing frame is erected on the top end of the casing head. At this time, the upper sealing assembly installed on the upper fixing frame seals the top end of the casing head. During the process of erecting the upper fixing frame on the top end of the casing head, the screw-type lifting assembly passes through the casing head, and the lower sealing assembly is installed on the screw-type lifting assembly. The bolt-type lifting assembly works, driving the lower sealing assembly installed thereon to perform a lifting action. The lower sealing assembly seals the top end of the casing head and drives the casing head to perform a lifting action. Because the upper fixing frame abuts against the top end of the casing head to prevent the casing head from lifting, in this way, the lower sealing assembly pulls the upper fixing frame and the upper sealing assembly installed on the upper fixing frame in the reverse direction through the screw-type lifting assembly. The upper sealing assembly and the lower sealing assembly apply force to the top end and the bottom end of the casing head in two directions.

[0029] (2) For the casing head sealing performance testing device provided by the present invention, when manually rotating the rotating screw, the lifting nut sleeved on the rotating screw drives the lower sealing cover to perform a lifting action, and the fixed ring seat installed on the lifting nut synchronously performs a lifting action, thereby driving the four turning plates circumferentially distributed on the fixed ring seat to perform a lifting action. As shown in the figure, when the top end of the turning plate abuts against the inner ring of the inner sealing cover, as the lifting nut continues to lift, since the inner sealing cover is arranged in an inverted dish shape, the diameter of the top end of the inner sealing cover is smaller than the diameter of the bottom end of the inner sealing cover, so that the top end of the turning plate turns towards the direction close to the lifting nut. On the contrary, the bottom end of the turning plate turns away from the lifting nut and gradually abuts against the inner wall of the casing head. The four turning plates and the four set screws are arranged in an avoiding manner, that is, each turning plate is located between two adjacent set screws. In this way, when the bottom end of the turning plate abuts against the inner wall of the casing head, there will be no movement interference with the set screws. When the top ends of the four turning plates abut against the casing head, the lower sealing cover has not blocked the bottom end of the casing head, and it can continue to lift together with the turning plate when the rotating screw rotates. When the top ends of the four turning plates abut against the casing head, the centering of the lifting nut in the casing head can be well achieved. When the lifting sleeve is located at the center line position of the casing head, the upper sealing cover and the inner sealing cover are centered and adjusted in time, so as to ensure that both the upper sealing assembly and the lower sealing assembly can apply force to the top end and the bottom end of the casing head in a completely centered manner, eliminating the possibility of the casing head tilting. And as the rotating screw continues to rotate, the turning plate and the lower sealing cover continue to lift. While the lower sealing cover completely blocks the bottom end of the casing head, the bottom end of the turning plate disengages from the inner wall of the casing head and drives the extrusion block to extrude the annular sealing block located in the inner ring of the inner sealing cover. During the process that the thicker part of the annular sealing block is extruded and thinned, it flows towards the bottom end of the inner sealing cover to block the bottom end of the inner sealing cover and the inner ring of the top end of the casing head, thereby improving the sealing performance of the connection between the inner sealing cover and the top end of the casing head. Description of the Drawings

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 It is the external view of the present invention;

[0032] Figure 2 It is the cross-section of the present invention Figure 1 (when the screw-type lifting assembly is not working);

[0033] Figure 3 It is the cross-section of the present inventionFigure 2 When the screw-type lifting component is in the first working state;

[0034] Figure 4 The cross-section of the present invention Figure 3 When the screw-type lifting component is in the second working state;

[0035] Figure 5 The external view of the screw-type lifting component of the present invention.

[0036] In the figure: 10. Lower placement rack; 11. Casing head; 12. Upper fixing rack; 13. Upper sealing component; 14. Lower sealing component; 15. Screw-type lifting component; 16. Upper sealing cover; 17. Inner sealing cover; 18. Outer ring plate; 19. Sealing ring; 20. Fixed cross-rack; 21. Rotating screw; 22. Lifting screw sleeve; 23. Supporting cross-arm; 24. Limiting sliding sleeve; 25. Lower mounting stud; 26. Lower sealing cover; 27. Sealing cushion layer; 28. Fixed screw block; 29. Fixed ring seat; 30. Flipping plate; 31. Set screw; 32. Annular sealing block; 33. Extrusion block; 34. Soft rubber cushion block. Detailed implementation mode

[0037] Next, the technical solution of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment 1

[0038] Next, the present invention will be further described in conjunction with the accompanying drawings.

[0039] As Figures 1 to 5 shown, a casing head sealing performance testing device provided in this embodiment includes:

[0040] Lower placement rack 10, on which the casing head 11 is placed;

[0041] Upper fixing rack 12, two symmetrically arranged upper fixing racks 12 are placed on the top of the casing head 11;

[0042] Upper sealing component 13, the upper sealing component 13 is installed on the two upper fixing racks 12, and the upper sealing component 13 is used to block the top of the casing head 11;

[0043] Lower sealing component 14, the lower sealing component 14 is used to block the top of the casing head 11, the lower sealing component 14 is installed on the two upper fixing racks 12 through the screw-type lifting component 15, and the lower sealing component 14 and the upper sealing component 13 apply forces in two directions.

[0044] The working principle and beneficial effects of the above technical solution are as follows:

[0045] A casing head sealing performance testing device provided by the present invention hoists the casing head 11 to be detected onto the lower placement frame 10, so that the bottom end of the casing head 11 is in a suspended state. Then, the upper fixing frame 12 is erected on the top end of the casing head 11. At this time, the upper sealing assembly 13 installed on the upper fixing frame 12 seals the top end of the casing head 11. During the process of erecting the upper fixing frame 12 on the top end of the casing head 11, the screw-type lifting assembly 15 passes through the casing head 11, and the lower sealing assembly 14 is installed on the screw-type lifting assembly 15. The screw-type lifting assembly 15 works to drive the lower sealing assembly 14 installed thereon to perform a lifting action. The lower sealing assembly 14 seals the top end of the casing head 11 and drives the casing head 11 to perform a lifting action. Since the upper fixing frame 12 abuts against the top end of the casing head 11 to prevent the casing head 11 from lifting, in this way, the lower sealing assembly 14 pulls the upper fixing frame 12 and the upper sealing assembly 13 installed on the upper fixing frame 12 in the reverse direction through the screw-type lifting assembly 15. The upper sealing assembly 13 and the lower sealing assembly 14 apply forces to the top end and the bottom end of the casing head 11 in two directions, improving the stability of the top end of the casing head 11. In a casing head sealing performance testing device disclosed by the present invention, the upper sealing assembly 13 and the lower sealing assembly 14 apply forces to the top end and the bottom end of the casing head 11 in two directions, reducing the side inclination of the casing head while improving the sealing performance of the casing head 11.

[0046] In one embodiment, the upper sealing assembly 13 includes:

[0047] An upper sealing cover 16, which is slidably installed on two upper fixing frames 12 and is disposed near the bottom end of the upper fixing frames 12. The cover end of the upper sealing cover 16 is buckled on the top end of the casing head 11, and the screw-type lifting assembly 15 passes through the center position at the top end of the upper sealing cover 16;

[0048] An inner sealing cover 17, which is located inside the upper sealing cover 16. The inner sealing cover 17 is arranged in an inverted dish shape. The bottom end of the inner sealing cover 17 abuts against the inner ring of the top end of the casing head 11. The top end of the inner sealing cover 17 is provided with an open end for the screw-type lifting assembly 15 to pass through. The top end of the inner sealing cover 17 is integrally installed on the upper sealing cover 16 through an outer ring plate 18.

[0049] The working principle and beneficial effects of the above technical solution are as follows:

[0050] The upper sealing assembly 13 includes the upper sealing cover 16 and the inner sealing cover 17. The bottom end of the inner sealing cover 17 abuts against the inner ring of the top end of the casing head 11, and the cover end of the upper sealing cover 16 is buckled on the top end of the casing head 11. The two achieve double-layer sealing of the top end of the casing head 11 to improve the sealing performance of the upper sealing assembly.

[0051] In one embodiment, a sealing ring 19 is installed at the center of the top end of the upper sealing cover 16, and the sealing ring 19 is sleeved on the spiral lifting assembly 15.

[0052] The beneficial effects of the above technical solution are as follows:

[0053] The setting of the sealing ring 19 improves the sealing performance between the spiral lifting assembly 15 and the upper sealing cover 16.

[0054] In one embodiment, the screw-type lifting assembly 15 includes:

[0055] A fixed cross frame 20, and the fixed cross frame 20 is installed at the top ends of the two upper fixing frames 12;

[0056] A rotating screw 21, and the rotating screw 21 is installed on the fixed cross frame 20;

[0057] A lifting nut 22, and the lifting nut 22 is sleeved on the rotating screw 21. Symmetrically installed at the top end of the lifting nut 22 are support cross arms 23. At the end of the support cross arm 23 away from the lifting nut 22, a limit sliding sleeve 24 is installed, and the limit sliding sleeve 24 is sleeved on the upper fixing frame 12. The lifting nut 22 sequentially penetrates through the upper sealing cover 16 and the inner sealing cover 17 and extends into the casing head 11;

[0058] A lower mounting stud 25, and the lower mounting stud 25 is connected to the bottom end of the lifting nut 22. The lower sealing assembly 14 is detachably installed on the lower mounting stud 25.

[0059] The working principle and beneficial effects of the above technical solution are as follows:

[0060] When the upper fixing frame 12 is erected on the top end of the casing head 11, the upper sealing assembly 13 seals the top end of the casing head 11. The rotating screw 21 is connected to the upper fixing frame 12 through the fixed cross frame 20, and the lifting nut 22 sleeved on the rotating screw 21 passes through the casing head 11. After manually fixing the lower sealing assembly 14 to the lower mounting stud 25, then the rotating screw 21 rotates. The rotating screw 21 drives the lifting nut 22 sleeved on it, the support cross arms 23 connected to the lifting nut 22, and the limit sliding sleeves 24 installed on the support cross arms 23 to slide upward along the upper fixing frame 12, thereby driving the lower sealing assembly 14 installed on the lower mounting stud 25 to perform a lifting action, and the lower sealing assembly 14 seals the top end of the casing head 11. Since the upper fixing frame 12 abuts against the top end of the casing head 11 to prevent the lower sealing assembly 14 from driving the casing head 11 to lift, in this way, the lower sealing assembly 14 pulls the upper fixing frame 12 and the upper sealing cover 16 and the inner sealing cover 17 installed on the upper fixing frame 12 in the reverse direction through the spiral lifting assembly 15. The upper sealing cover 16, the inner sealing cover 17 and the lower sealing assembly 14 apply forces to the top and bottom ends of the casing head 11 in two directions, improving the sealing performance of the casing head 11.

[0061] In one embodiment, the lower sealing assembly 14 includes:

[0062] A lower sealing cover 26, the cover end of the lower sealing cover 26 is buckled on the bottom end of the casing head 11, and a central hole is provided at the bottom end of the lower sealing cover 26 for the lower mounting stud 25 to pass through;

[0063] A sealing cushion layer 27, the sealing cushion layer 27 is installed inside the lower sealing cover 26;

[0064] A fixing screw block 28, the fixing screw block 28 is screwed on the lower mounting stud 25, thereby locking the lower sealing cover 26.

[0065] The working principle and beneficial effects of the above technical solution are:

[0066] The lifting nut 22 sleeved on the rotating screw 21 passes through the casing head 11. Manually pass the lower sealing cover 26 through the central hole on the lower mounting stud 25, and then fasten the fixing screw block 28 on the lower mounting stud 25. The fixing screw block 28 locks the lower sealing cover 26 at the end of the lifting nut 22 close to the lower mounting stud 25. In this way, when the rotating screw 21 is manually rotated, the lower sealing cover 26 makes a lifting movement. The cover end of the lower sealing cover 26 is buckled on the bottom end of the casing head 11, and the sealing cushion layer 27 is clamped between the bottom end of the casing head 11 and the cover end of the lower sealing cover 26, improving the sealing performance. The sealing cushion layer 27 is a rubber layer.

[0067] In one embodiment, a centering component is installed on the lifting nut 22 and is arranged to fit the inner circle of the inner sealing cover 17. The centering component includes:

[0068] A fixed ring seat 29, the fixed ring seat 29 is installed on the lifting nut 22. Four turning plates 30 are circumferentially distributed on the fixed ring seat 29. The turning plates 30 are bent at an obtuse angle. The bent section of the turning plate 30 is rotatably installed on the fixed ring seat 29 through a fixed rotating shaft. The top end of the turning plate 30 abuts against the inner circle of the inner sealing cover 17, and the bottom end of the turning plate 30 abuts against the inner wall of the casing head 11 and avoids the set screw 31.

[0069] The working principle and beneficial effects of the above technical solution are:

[0070] When the rotating screw 21 is manually rotated, the lifting nut 22 sleeved on the rotating screw 21 drives the lower sealing cover 26 to make a lifting movement. The fixed ring seat 29 installed on the lifting nut 22 makes a synchronous lifting movement, thereby driving the four turning plates 30 circumferentially distributed on the fixed ring seat 29 to make a lifting movement, as Figure 3As shown in the figure, when the top end of the flipping plate 30 abuts against the inner ring of the inner sealing cover 17, as the lifting screw sleeve 22 continues to rise, since the inner sealing cover 17 is arranged in an inverted dish shape, the diameter of the top end of the inner sealing cover 17 is smaller than the diameter of the bottom end of the inner sealing cover 17, so that the top end of the flipping plate 30 flips towards the direction close to the lifting screw sleeve 22. On the contrary, the bottom end of the flipping plate 30 flips towards the direction away from the lifting screw sleeve 22 and gradually abuts against the inner wall of the casing head 11. The four flipping plates 30 and the four setscrews 31 are distributed in an avoiding manner, that is, each flipping plate 30 is located between two adjacent setscrews 31. In this way, when the bottom end of the flipping plate 30 abuts against the inner wall of the casing head 11, there will be no movement interference with the setscrews 31. When the top ends of the four flipping plates 30 abut against the casing head 11, the lower sealing cover 26 has not yet blocked the bottom end of the casing head 11 and can continue to rise together with the flipping plate 30 as the rotating screw 21 rotates. When the top ends of the four flipping plates 30 abut against the casing head 11, the centering of the lifting screw sleeve 22 in the casing head 11 can be well realized. When the lifting sleeve 22 is located at the center line position of the casing head 11, the upper sealing cover 16 and the inner sealing cover 17 are centered and adjusted in time, so as to ensure that both the upper sealing assembly 13 and the lower sealing assembly 14 can apply force to the top and bottom ends of the casing head 11 in a completely centered manner, eliminating the possibility of the casing head tilting.

[0071] In one embodiment, an annular sealing block 32 is installed on the inner ring of the inner sealing cover 17. The thickness of the annular sealing block 32 is gradually increased towards the bottom end of the inner sealing cover 17. An extrusion block 33 for extruding the annular sealing block 32 is installed on the flipping plate 30. Under the extrusion of the extrusion block 33, the thickness of the annular sealing block 32 becomes thinner and flows towards the bottom end of the inner sealing cover 17.

[0072] The working principle and beneficial effects of the above technical solution are as follows:

[0073] As the rotating screw 21 continues to rotate, the flipping plate 30 and the lower sealing cover 26 continue to rise. While the lower sealing cover 26 completely blocks the bottom end of the casing head 11, the bottom end of the flipping plate 30 disengages from the inner wall of the casing head 11 and drives the extrusion block 33 to extrude the annular sealing block 32 located on the inner ring of the inner sealing cover 17. During the process that the thicker part of the annular sealing block 32 is extruded and thinned, it flows towards the bottom end of the inner sealing cover 17 to seal the bottom end of the inner sealing cover 17 and the inner ring of the top end of the casing head 11, thereby improving the sealing performance of the connection between the inner sealing cover 17 and the top end of the casing head 11.

[0074] In one embodiment, a soft rubber cushion block 34 is installed at the bottom end of the upper fixing frame 12.

[0075] In one embodiment, the extrusion block 33 is provided with an arc-shaped plate structure.

[0076] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or variations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A casing head sealing performance testing device, characterized in that Comprising: A lower placement rack (10), on which a casing head (11) is placed; An upper fixing rack (12), two symmetrically arranged upper fixing racks (12) are placed on the top of the casing head (11); An upper sealing assembly (13), the upper sealing assembly (13) is installed on the two upper fixing racks (12), and the upper sealing assembly (13) is used to seal the top of the casing head (11); A lower sealing assembly (14), the lower sealing assembly (14) is used to seal the top of the casing head (11), and the lower sealing assembly (14) is installed on the two upper fixing racks (12) through a screw-type lifting assembly (15), and the lower sealing assembly (14) and the upper sealing assembly (13) apply forces in two directions; The upper sealing assembly (13) includes: an upper sealing cover (16) slidably installed on the two upper fixing racks (12), and is arranged near the bottom end of the upper fixing rack (12). The cover end of the upper sealing cover (16) is buckled on the top of the casing head (11), and the screw-type lifting assembly (15) passes through the center position of the top of the upper sealing cover (16); an inner sealing cover (17) is located inside the upper sealing cover (16), and the inner sealing cover (17) is arranged in an inverted dish shape. The bottom end of the inner sealing cover (17) abuts against the inner ring at the top of the casing head (11), and the top end of the inner sealing cover (17) is open for the screw-type lifting assembly (15) to pass through. The top end of the inner sealing cover (17) is integrally installed on the upper sealing cover (16) through an outer ring plate (18); The screw-type lifting assembly (15) includes: a fixed cross-rack (20) installed at the top ends of the two upper fixing racks (12); a rotating screw (21) is installed on the fixed cross-rack (20); a lifting nut (22) is sleeved on the rotating screw (21). At the top of the lifting nut (22), support cross arms (23) are symmetrically installed. At the end of the support cross arm (23) away from the lifting nut (22), a limit sliding sleeve (24) is installed, and the limit sliding sleeve (24) is sleeved on the upper fixing rack (12). The lifting nut (22) passes through the upper sealing cover (16) and the inner sealing cover (17) in sequence and extends into the casing head (11); a lower installation stud (25) is connected to the bottom end of the lifting nut (22), and the lower sealing assembly (14) is detachably installed on the lower installation stud (25); A centering component adapted to the inner ring of the inner sealing cover (17) is installed on the lifting nut (22). The centering component includes: a fixed ring seat (29) installed on the lifting nut (22), and four turning plates (30) are circumferentially distributed on the fixed ring seat (29). The turning plates (30) are bent at an obtuse angle, and the bent section of the turning plate (30) is rotatably installed on the fixed ring seat (29) through a fixed rotating shaft. The top end of the turning plate (30) abuts against the inner ring of the inner sealing cover (17), and the bottom end of the turning plate (30) abuts against the inner wall of the casing head (11) and avoids the set screw (31); 2. The casing head sealing performance testing device according to claim 1, characterized in that, A sealing ring (19) is installed at the center position of the top of the upper sealing cover (16), and the sealing ring (19) is sleeved on the screw-type lifting assembly (15).

3. The casing head sealing performance testing device according to claim 1, characterized in that, The lower sealing assembly (14) includes: a lower sealing cover (26), a sealing cushion layer (27), and a fixing screw block (28). The cover end of the lower sealing cover (26) is buckled on the bottom end of the casing head (11), and a central hole is formed at the bottom end of the lower sealing cover (26) to facilitate the penetration of the lower mounting stud (25); the sealing cushion layer (27) is installed inside the lower sealing cover (26); the fixing screw block (28) is screwed onto the lower mounting stud (25) to lock the lower sealing cover (26).

4. The casing head sealing performance testing device according to claim 1, characterized in that, An annular sealing block (32) is installed on the inner ring of the inner sealing cover (17). The thickness of the annular sealing block (32) gradually increases towards the bottom end of the inner sealing cover (17). An extrusion block (33) for extruding the annular sealing block (32) is installed on the flip plate (30). Under the extrusion of the extrusion block (33), the thickness of the annular sealing block (32) becomes thinner and flows towards the bottom end of the inner sealing cover (17).

5. The casing head sealing performance testing device according to claim 1, wherein, A soft rubber cushion block (34) is installed at the bottom end of the upper fixing frame (12).

6. The casing head sealing performance testing device according to claim 4, wherein, The extrusion block (33) is configured as an arc-shaped plate structure.

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