Oil wellhead port sealing device

Abstract

The present invention relates to the technical field of oil wellhead sealing, and specifically to an oil wellhead port sealing device, comprising a sealing mechanism installed on the oil wellhead, the sealing mechanism comprising a shell fixedly installed on the top of the oil wellhead, the interior of the shell being provided with a first sealing unit, a second sealing unit, and a third sealing unit in sequence from top to bottom. In the process of the upper and lower movements of the light rod, the present invention utilizes the light rod to drive the rotating assembly to rotate, and then the rotating assembly drives the first packing to rotate, so as to continuously adjust the contact portion between the first packing and the light rod, thereby making the wear of the first packing more uniform and avoiding severe local wear of the first packing that causes sealing failure. At the same time, during the rotation of the rotating assembly, the centering clamp can center the light rod to prevent the light rod from deflecting when moving up and down, and avoid severe local wear of the first packing.

Description

Technical Field

[0001] The invention relates to the technical field of oil wellhead sealing, in particular to an oil wellhead port sealing device. Background Art

[0002] An oil well is a hole drilled by drilling. Generally, after reaching the oil layer, casing is lowered into the oil layer and oil well cement is injected into the annular space between the casing and the wellbore to protect the wellbore and seal the oil, gas, and water layers. Perforating guns are then used to perforate the oil layer according to the requirements of oilfield development, forming a channel. Oil pipes are then lowered and, using appropriate inducing flow methods, the oil is brought up from the bottom of the well to the wellhead.

[0003] The wellhead polished rod sealing device is an important part of the rod pumping system. Packing sealing is a common way to seal the wellhead polished rod. The sealing is achieved by squeezing the packing through the gland. However, the packing will wear during the reciprocating motion of the polished rod. Since the surface roughness of the polished rod is not completely consistent, and some impurities will adhere to the surface of the polished rod during the up and down movement, the friction between different parts of the polished rod and the packing is uneven, resulting in excessive wear of the packing in some parts, affecting the sealing effect; and when the polished rod is driven by the nodding machine to move up and down, the pulling force on the polished rod is not completely vertically upward, resulting in inconsistent squeezing pressure on different parts of the packing by the polished rod during the movement, further affecting the uniformity of packing wear; in addition, as the packing gradually wears, the gap between the packing and the polished rod becomes larger, resulting in a worsening of the sealing effect, which needs to be replaced frequently, and the use effect needs to be further improved. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides an oil wellhead port sealing device, including a sealing mechanism installed on the oil wellhead, the sealing mechanism including an outer shell fixedly installed on the top of the oil wellhead, and the interior of the outer shell is sequentially provided with a first sealing unit, a second sealing unit and a third sealing unit from top to bottom.

[0005] The first sealing unit includes a first packing installed inside the shell for sealing the polished rod and a rotating assembly that rotates the first packing as the polished rod moves up and down. The rotating assembly includes a rotating sleeve rotatably installed inside the shell for accommodating the rotating assembly. The first packing is installed in the rotating sleeve. A pressure cover is movably installed on the top of the rotating sleeve. A centering block for centering the polished rod is symmetrically installed on the top of the pressure cover. A diagonal groove is provided on the side of the centering block close to the center of the shell. A pressing component and an adaptive component for pressing the pressure cover are also installed on the shell.

[0006] The second sealing unit includes a sealing block symmetrically installed inside the first packing for secondary sealing of the polished rod, and extrusion components for pushing the sealing block to move toward the center of the housing are symmetrically installed on the left and right sides of the housing.

[0007] In one possible implementation, the top of the rotating sleeve is provided with a plurality of grooves evenly distributed circumferentially, and the outer ring wall of the gland is fixedly connected with protrusions corresponding one to one with the grooves. When the gland is pressed tightly against the top of the first packing, the protrusions slide up and down and are inserted into the corresponding grooves.

[0008] In one possible implementation, a sliding groove corresponding to the centering block is provided on the top of the pressure cover, and the centering block is installed in the corresponding sliding groove for sliding left and right. The side of the centering block close to the center of the shell is an inwardly concave arc surface, and the diagonal groove is arranged on the corresponding arc surface.

[0009] In one possible implementation, the clamping component includes a top cover threadedly mounted on the top of the outer shell, the bottom of the top cover is fixedly connected to a pressing ring located on the inner side of the outer shell, the bottom end of the pressing ring is pressed against the top of the pressure cover, and a plurality of balls are evenly installed circumferentially on the bottom of the pressing ring.

[0010] In one possible implementation, the adaptive component includes a lower pressure ring that is movably installed up and down inside the pressure sleeve and located above the pressure cover. A compression spring and a telescopic sleeve are rotatably installed between the top of the lower pressure ring and the bottom of the top cover. The compression spring is sleeved on the outside of the telescopic sleeve. The top cover, the lower pressure ring and the telescopic sleeve are all movably sleeved on the outside of the light rod. The bottom of the lower pressure ring is fixedly connected to wedge blocks that are symmetrically distributed on the left and right. The wedge blocks are located on the side of the centering block away from the center of the shell.

[0011] In one possible implementation, the gland is further provided with a left-right symmetrically distributed limiting component, the limiting component comprising a limiting block which is slidably mounted on the gland and located below the slide groove, a return spring being fixedly connected between the side of the limiting block close to the center of the outer shell and the inner wall of the gland, a push block being fixedly connected to the top of the limiting block, a movable window being provided at the bottom of the slide groove for the push block to slide left and right, a serrated groove being provided above the first packing on the inner wall of the rotating sleeve, and when the gland is pressed tightly against the top of the first packing, the limiting block is plugged into the serrated groove.

[0012] In one possible implementation, mounting ports for installing a sealing block are further provided on the left and right sides of the shell, and the extrusion assembly includes a side cover threadedly mounted on the mounting port, a push rod is slidably mounted left and right at the center of the side cover, an extrusion block for pressing the sealing block is rotatably mounted on the end of the push rod close to the center of the shell, the extrusion block is located on the side of the sealing block away from the center of the shell, a threaded sleeve is rotatably mounted on the side cover, the threaded sleeve is threadedly connected to the push rod, and a transmission component for driving the threaded sleeve to rotate is mounted on the shell.

[0013] In one possible implementation, the transmission component includes a driving ring gear fixedly mounted on the outer ring wall of the rotating sleeve, a driven gear located at the top of the mounting port is rotatably mounted on the outer shell, the driven gear is meshed with the driving ring gear, a transmission rod is coaxially rotatably mounted on the driven gear, the bottom end of the transmission rod extends to the interior of the mounting port and is connected to the threaded sleeve through a bevel gear mechanism, and a ratchet structure is installed between the driven gear and the transmission rod.

[0014] In a possible implementation, the third sealing unit includes a second packing installed inside the housing and below the sealing block, and a top pressure block is installed between the bottom of the second packing and the top of the oil wellhead.

[0015] The beneficial effects of the present invention are as follows: 1. In the process of the polished rod moving up and down, the present invention uses the polished rod to drive the rotating assembly to rotate, and then the rotating assembly drives the first packing to rotate, which can continuously adjust the contact position between the first packing and the polished rod, so that the wear of the first packing can be more uniform, and the failure of the seal caused by severe local wear of the first packing can be avoided. At the same time, during the rotation of the rotating assembly, the centering clamp can clamp the polished rod in the center, preventing the polished rod from deflecting when moving up and down, and avoiding severe local wear of the first packing.

[0016] 2. The gland, adaptive component and limiting component of the present invention cooperate with each other to adaptively press the first packing. When the gland presses the first packing, the adaptive component is used to give the gland a downward elastic force. When a gap appears between the first packing and the polished rod due to wear, the adaptive component pushes the gland downward to squeeze the first packing, causing the first packing to deform and fill the gap to prevent leakage, which can reduce the frequency of replacing the first packing. At the same time, the limiting component limits the gland after it moves downward to prevent the gland from moving upward, thereby preventing the gland from loosening when the polished rod moves upward.

[0017] 3. In the present invention, when the rotating sleeve drives the first packing to rotate, the rotating sleeve can slowly push the sealing block toward the center of the housing through the extrusion assembly, so that the sealing block can always be pressed tightly against the outer wall of the polished rod, avoiding the formation of a gap between the sealing block and the polished rod due to wear, thereby improving the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0019] Figure 2 It is a cross-sectional view of the front side of the present invention.

[0020] Figure 3 It is a partial cross-sectional view of the housing of the present invention.

[0021] Figure 4 It is an isolated view of the rotating assembly of the present invention.

[0022] Figure 5 It is a partial cross-sectional view of the limiting component of the present invention.

[0023] Figure 6 It is a schematic diagram of the three-dimensional structure of the centering clamp of the present invention.

[0024] Figure 7 It is a partial cross-sectional view of the driven gear of the present invention.

[0025] Figure 8 It is a schematic diagram of the three-dimensional structure of the adaptive component of the present invention.

[0026] Figure: 1, oil wellhead; 2, sealing mechanism; 21, housing; 211, mounting port; 22, first packing; 23, rotating assembly; 231, rotating sleeve; 2311, groove; 232, gland; 2321, bump; 2322, slide; 233, centering block; 2331, diagonal groove; 234, pressing component; 2341, top cover; 2342, pressing collar; 2343, ball bearing; 235, adaptive component; 2351, lower pressure ring; 2352, compression spring; 2353, telescopic sleeve; 2 354. Wedge block; 236. Limiting component; 2361. Limiting block; 2362. Return spring; 2363. Push block; 2364. Serrated groove; 237. Mechanical seal structure; 24. Sealing block; 25. Extrusion assembly; 251. Side cover; 252. Push rod; 253. Extrusion block; 254. Threaded sleeve; 255. Transmission component; 2551. Driving ring gear; 2552. Driven gear; 2553. Transmission rod; 2554. Ratchet structure; 26. Second packing; 27. Pressing block; 3. Polished rod. DETAILED DESCRIPTION

[0027] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described below, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] See also Figure 1 - Figure 8 A sealing device for an oil wellhead port includes a sealing mechanism 2 installed on an oil wellhead 1. The sealing mechanism 2 includes a shell 21 fixedly installed on the top of the oil wellhead 1. The shell 21 is connected to the oil wellhead 1 by bolts. The interior of the shell 21 is provided with a first sealing unit, a second sealing unit and a third sealing unit in sequence from top to bottom.

[0029] The first sealing unit includes a first packing 22 installed inside the housing 21 for sealing the polished rod 3 and a rotating assembly 23 that rotates the first packing 22 as the polished rod 3 moves up and down. The rotating assembly 23 includes a rotating sleeve 231 rotatably installed inside the housing 21 for accommodating the rotating assembly 23. The first packing 22 is installed in the rotating sleeve 231. A pressure cover 232 is movably installed on the top of the rotating sleeve 231. A centering clamp is symmetrically installed on the top of the pressure cover 232 to center the polished rod 3. Block 233, a diagonal groove 2331 is provided on one side of the centering block 233 close to the center of the shell 21, and a pressing component 234 and an adaptive component 235 for pressing the pressure cover 232 are also installed on the shell 21. A mechanical sealing structure 237 is also installed between the bottom of the rotating sleeve 231 and the inner wall of the shell 21. The mechanical sealing structure 237 is used to dynamically seal the gap between the rotating sleeve 231 and the shell 21 to avoid leakage in the gap between the shell 21 and the rotating sleeve 231, thereby ensuring the sealing effect.

[0030] The second sealing unit includes a sealing block 24 symmetrically installed inside the first packing 22 for secondary sealing of the polished rod 3. Extrusion assemblies 25 for pushing the sealing block 24 toward the center of the housing 21 are symmetrically installed on the left and right sides of the housing 21.

[0031] During specific use, the pressure cover 232 is inserted into the top of the rotating sleeve 231, and the pressing component 234 is used to give the pressure cover 232 a downward thrust, so that the pressure cover 232 presses the first packing 22, so that the first packing 22 seals the polished rod 3, and at the same time the adaptive component 235 pushes the centering clamp 233 to move toward the center of the shell 21, so that the centering clamp 233 clamps the polished rod 3 in a centering manner, preventing the polished rod 3 from deflecting during the up and down movement, ensuring that the polished rod 3 produces uniform extrusion pressure on different parts of the packing, and reducing wear differences.

[0032] When the polished rod 3 moves up and down, the friction force exerted by the polished rod 3 on the centering clamp 233 will generate a component of force in the horizontal direction under the action of the diagonal groove 2331, so that the centering clamp 233 can rotate. The centering clamp 233 drives the pressure cover 232 to rotate, and the pressure cover 232 drives the rotating sleeve 231 and the first packing 22 to rotate, which can continuously adjust the contact point between the first packing 22 and the polished rod 3, so that the friction of the first packing 22 is more uniform, avoiding local excessive wear and leakage.

[0033] During the rotation of the rotating sleeve 231, the rotating sleeve 231 pushes the sealing block 24 to slowly move toward the center of the housing 21 through the extrusion assembly 25, thereby compensating for the gap caused by friction between the sealing block 24 and the polished rod 3, improving the sealing effect, and using the first sealing unit, the second sealing unit and the third sealing unit for triple sealing, fully ensuring the sealing effect of the polished rod 3 and avoiding leakage.

[0034] See also Figure 2 - Figure 4 The top of the rotating sleeve 231 is provided with a plurality of grooves 2311 evenly distributed along the circumference. The outer annular wall of the gland 232 is fixedly connected with protrusions 2321 corresponding one to one with the grooves 2311. When the gland 232 is pressed against the top of the first packing 22, the protrusions 2321 slide up and down and are inserted into the corresponding grooves 2311. It should be noted that when the gland 232 is pressed against the top of the first packing 22, the bottom ends of the protrusions 2321 do not contact the bottoms of the grooves 2311, and the protrusions 2321 can move up and down inside the grooves 2311.

[0035] During specific use, after the pressure cover 232 is installed on the top of the rotating sleeve 231, the protrusion 2321 is inserted into the corresponding groove 2311. When the polished rod 3 drives the pressure cover 232 to rotate, the pressure cover 232 can drive the rotating sleeve 231 to rotate together through the mutual engagement of the protrusion 2321 and the groove 2311, so that the rotating sleeve 231 drives the first packing 22 to rotate, thereby improving the uniformity of the wear of the first packing 22.

[0036] See also Figure 3 - Figure 6The top of the pressure cover 232 is provided with a sliding groove 2322 corresponding to the centering clamp 233. The centering clamp 233 is slidably installed in the corresponding sliding groove 2322. The side of the centering clamp 233 close to the center of the shell 21 is an inwardly concave arc surface, and the oblique groove 2331 is set on the corresponding arc surface.

[0037] During specific use, by providing an arc surface on the pressure cover 232, the pressure cover 232 is convenient for clamping and limiting the polished rod 3, preventing the polished rod 3 from moving forward, backward, left and right. When the centering clamp 233 is installed on the outside of the polished rod 3, the adaptive component 235 pushes the left and right centering clamps 233 closer to each other, so that the centering clamp 233 clamps the polished rod 3 in the center, avoiding the polished rod 3 from deflecting during the up and down movement, resulting in uneven contact between the polished rod 3 and the first packing 22, preventing the first packing 22 and the polished rod 3 from having a leakage channel, and improving the sealing effect.

[0038] See also Figure 2 and Figure 8 The pressing component 234 includes a top cover 2341 threadedly installed on the top of the shell 21. The bottom of the top cover 2341 is fixedly connected to a pressing ring 2342 located on the inner side of the shell 21. The bottom end of the pressing ring 2342 is pressed against the top of the pressure cover 232. A number of balls 2343 are evenly installed on the bottom of the pressing ring 2342 in a circumferential direction.

[0039] When in use, the pressing component 234 is detachably mounted on the housing 21, which is convenient for subsequent replacement of the first packing 22. During installation, the first packing 22 is first filled into the rotating sleeve 231, and then the pressure cover 232 is inserted into the top of the rotating sleeve 231, and finally the top cover 2341 is threadedly mounted on the top of the housing 21, so that the pressing ring 2342 presses the pressure cover 232, and the pressure cover 232 presses the first packing 22, so that the first packing 22 seals the polished rod 3; by providing the ball bearings 2343, when the pressure cover 232 rotates, the ball bearings 2343 will rotate, and the sliding friction between the pressing ring 2342 and the pressure cover 232 will be converted into rolling friction, thereby reducing the friction between the pressing ring 2342 and the pressure cover 232, which is conducive to the smooth rotation of the pressure cover 232.

[0040] See also Figure 2 、 Figure 5 and Figure 8The adaptive component 235 includes a lower pressure ring 2351 that is movably installed up and down inside the pressure ring 2342 and located above the pressure cover 232. A compression spring 2352 and a telescopic sleeve 2353 are rotatably installed between the top of the lower pressure ring 2351 and the bottom of the top cover 2341. The compression spring 2352 is sleeved on the outside of the telescopic sleeve 2353. The top cover 2341, the lower pressure ring 2351 and the telescopic sleeve 2353 are all movably sleeved on the outside of the light rod 3. The bottom of the lower pressure ring 2351 is fixedly connected with a wedge block 2354 that is symmetrically distributed on the left and right. The wedge block 2354 is located on the side of the centering clamp 233 away from the center of the shell 21.

[0041] When in use, before the top cover 2341 is installed to the bottom of the shell 21, the wedge block 2354 is first inserted downward into the corresponding slide groove 2322, and the inclined surface at the bottom of the wedge block 2354 is used to push the centering clamp 233 toward the center of the shell 21, so that the centering clamp 233 can clamp the polished rod 3 in the center. When the top cover 2341 is completely installed on the top of the shell 21, the compression spring 2352 is in a compressed state, and the compression spring 2352 is used to give the lower pressure ring 2351 and the wedge block 2354 a downward thrust, and the lower pressure ring 2351 and the wedge block 2354 give the pressure cover 232 downward thrust. The thrust of movement, when the first packing 22 is worn, the pressure cover 232 continues to squeeze the first packing 22 to deform, adaptively filling the gap between the first packing 22 and the light rod 3 due to wear, and improving the sealing effect; when the lower pressure ring 2351 moves up and down, the telescopic sleeve 2353 can expand and contract with the movement of the lower pressure ring 2351, and the telescopic sleeve 2353 can improve the stability of the upper and lower movement of the lower pressure ring 2351, and prevent the lower pressure ring 2351 from being deflected. At the same time, the telescopic sleeve 2353 can also play a sealing role, reducing the possibility of rust on the compression spring 2352.

[0042] See also Figure 4 and Figure 5 The pressure cover 232 is also equipped with a limiting component 236 that is symmetrically distributed on the left and right. The limiting component 236 includes a limiting block 2361 that is slidably installed on the pressure cover 232 and is located below the slide groove 2322. The end of the limiting block 2361 away from the center of the shell 21 is serrated. A return spring 2362 is fixedly connected between the side of the limiting block 2361 close to the center of the shell 21 and the inner wall of the pressure cover 232. A push block 2363 is fixedly connected to the top of the limiting block 2361. A movable window is provided at the bottom of the slide groove 2322 for the push block 2363 to slide left and right. A serrated groove 2364 is provided on the inner wall of the rotating sleeve 231 above the first packing 22. When the pressure cover 232 is pressed tightly against the top of the first packing 22, the limiting block 2361 is plugged into the serrated groove 2364.

[0043] During specific use, when the pressure cover 232 is inserted into the top of the rotating sleeve 231, the limit block 2361 will move toward the center of the shell 21 under the push of the rotating sleeve 231, and the return spring 2362 will be compressed and contracted, causing the limit block 2361 to retract into the inside of the pressure cover 232 to avoid affecting the downward movement of the pressure cover 232. After the pressure cover 232 is pressed against the top of the first packing 22, it will no longer move downward. At this time, the limit block 2361 moves in the direction away from the center of the shell 21 under the push of the return spring 2362, so that the limit block 2361 is snapped into the serrated groove 2364, and the serrated groove 2364 is used to limit the limit block 2361 to prevent the pressure cover 232 from loosening when moving upward, thereby ensuring that the pressure cover 232 presses the first packing 22 firmly.

[0044] When the first packing 22 needs to be replaced, the top cover 2341 is rotated and removed, and the wedge block 2354 is pulled out from the slide groove 2322 to expose the push block 2363. Then, the push block 2363 is moved from the slide groove 2322 toward the center of the shell 21, so that the limit block 2361 retracts into the interior of the pressure cover 232, and the lock on the pressure cover 232 is released, so that the pressure cover 232 can be removed from the top of the rotating sleeve 231, making it easier to replace the first packing 22.

[0045] See also Figure 2 - Figure 4 , mounting ports 211 for mounting the sealing block 24 are also provided on the left and right sides of the shell 21, and the extrusion assembly 25 includes a side cover 251 threadedly mounted on the mounting port 211, and a push rod 252 is slidably mounted left and right at the center of the side cover 251, and an extrusion block 253 for pressing the sealing block 24 is rotatably mounted on the end of the push rod 252 close to the center of the shell 21, and the extrusion block 253 is located on the side of the sealing block 24 away from the center of the shell 21, and a threaded sleeve 254 is rotatably mounted on the side cover 251, and the threaded sleeve 254 is threadedly connected to the push rod 252, and a transmission component 255 for driving the threaded sleeve 254 to rotate is installed on the shell 21.

[0046] During specific use, the push rod 252 pushes the extrusion block 253 toward the center of the housing 21, so that the extrusion block 253 presses the sealing block 24 toward the center of the housing 21, and the sealing block 24 is used to perform secondary sealing on the polished rod 3 to further prevent leakage when the polished rod 3 moves up and down.

[0047] See also Figure 2 、 Figure 3 and Figure 7The transmission component 255 includes a driving ring gear 2551 fixedly mounted on the outer ring wall of the rotating sleeve 231, and a driven gear 2552 located at the top of the mounting opening 211 is rotatably mounted on the housing 21. The driven gear 2552 is meshed with the driving ring gear 2551. A transmission rod 2553 is coaxially mounted on the driven gear 2552. The bottom end of the transmission rod 2553 extends to the interior of the mounting opening 211 and is connected to the threaded sleeve 254 through a bevel gear mechanism. A ratchet structure 2554 is installed between the driven gear 2552 and the transmission rod 2553.

[0048] During specific use, when the rotating sleeve 231 rotates, the rotating sleeve 231 drives the driven gear 2552 to rotate through the active ring gear 2551. When the rotating sleeve 231 rotates clockwise, the driven gear 2552 drives the transmission rod 2553 to rotate through the ratchet structure 2554, and then the transmission rod 2553 drives the threaded sleeve 254 to rotate through the bevel gear mechanism. The threaded sleeve 254 is used to drive the push rod 252 to slowly move toward the center of the housing 21, so that the extrusion block 253 presses the sealing block 24 toward the center of the housing 21, thereby making up for the gap between the sealing block 24 and the polished rod 3 due to wear, thereby improving the sealing effect of the sealing block 24 on the polished rod 3.

[0049] When the rotating sleeve 231 rotates counterclockwise, the driven gear 2552 cannot drive the transmission rod 2553 to rotate through the ratchet structure 2554, thereby preventing the transmission rod 2553 from rotating in the opposite direction and preventing the sealing block 24 from loosening.

[0050] See also Figure 2 and Figure 3 The third sealing unit includes a second packing 26 installed inside the housing 21 and located below the sealing block 24 , and a top pressure block 27 is installed between the bottom of the second packing 26 and the top of the oil wellhead 1 .

[0051] During specific use, after the outer shell 21 is bolted to the oil wellhead 1, the extrusion force between the outer shell 21 and the oil wellhead 1 is used to push the top pressure block 27 to squeeze the second packing 26, so that the second packing 26 seals the polished rod 3, fully ensuring the sealing effect when the polished rod 3 moves up and down.

[0052] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "connected," "installed," and "connected" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, integral or sliding connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0053] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil wellhead port sealing device, characterized by: The invention comprises a sealing mechanism (2) installed on an oil wellhead (1), wherein the sealing mechanism (2) comprises a housing (21) fixedly installed on the top of the oil wellhead (1), and a first sealing unit, a second sealing unit and a third sealing unit are sequentially arranged inside the housing (21) from top to bottom; The first sealing unit comprises a first packing (22) installed inside the housing (21) for sealing the polished rod (3) and a rotating assembly (23) for rotating the first packing (22) as the polished rod (3) moves up and down, the rotating assembly (23) comprising a rotating sleeve (231) rotatably installed inside the housing (21) for accommodating the rotating assembly (23), the first packing (22) being installed in the rotating sleeve (231), a pressure cover (232) being movably installed on the top of the rotating sleeve (231), a centering clamp (233) for centering the polished rod (3) being symmetrically installed on the top of the pressure cover (232), a diagonal groove (2331) being provided on the side of the centering clamp (233) close to the center of the housing (21), and a pressing component (234) and an adaptive component (235) for pressing the pressure cover (232) being further installed on the housing (21); The second sealing unit comprises a sealing block (24) symmetrically mounted inside the first packing (22) for performing secondary sealing on the polished rod (3), and extrusion assemblies (25) for pushing the sealing block (24) toward the center of the housing (21) are symmetrically mounted on the left and right sides of the housing (21); The pressing component (234) includes a top cover (2341) threadedly mounted on the top of the housing (21); the bottom of the top cover (2341) is fixedly connected to a pressing collar (2342) located inside the housing (21); the bottom end of the pressing collar (2342) is pressed against the top of the pressure cover (232); and a plurality of balls (2343) are evenly mounted on the bottom of the pressing collar (2342) in a circumferential direction. The adaptive component (235) includes a lower pressure ring (2351) movably mounted inside the pressing ring (2342) and located above the pressure cover (232); a compression spring (2352) and a telescopic sleeve (2353) are rotatably mounted between the top of the lower pressure ring (2351) and the bottom of the top cover (2341); the compression spring (2352) is sleeved on the outside of the telescopic sleeve (2353); the top cover (2341), the lower pressure ring (2351) and the telescopic sleeve (2353) are all movably sleeved on the outside of the light rod (3); the bottom of the lower pressure ring (2351) is fixedly connected to wedge blocks (2354) symmetrically distributed on the left and right; the wedge blocks (2354) are located on the side of the centering clamp (233) away from the center of the housing (21).

2. The oil wellhead port sealing device according to claim 1, characterized in that: The top of the rotating sleeve (231) is provided with a plurality of grooves (2311) evenly distributed in the circumferential direction, and the outer ring wall of the pressure cover (232) is fixedly connected with protrusions (2321) corresponding to the grooves (2311) one by one. When the pressure cover (232) is pressed tightly against the top of the first packing (22), the protrusions (2321) slide up and down and are inserted into the corresponding grooves (2311).

3. The oil wellhead port sealing device according to claim 2, characterized in that: The top of the pressure cover (232) is provided with a sliding groove (2322) corresponding to the centering clamp (233). The centering clamp (233) is slidably installed in the corresponding sliding groove (2322) to the left and right. The side of the centering clamp (233) close to the center of the shell (21) is an inwardly concave arc surface, and the diagonal groove (2331) is provided on the corresponding arc surface.

4. The oil wellhead port sealing device according to claim 3, characterized in that: The pressure cover (232) is also provided with a symmetrically distributed limiting component (236), the limiting component (236) comprising a limiting block (2361) which is slidably installed on the pressure cover (232) and is located below the slide groove (2322), a return spring (2362) is fixedly connected between the side of the limiting block (2361) close to the center of the shell (21) and the inner wall of the pressure cover (232), a push block (2363) is fixedly connected to the top of the limiting block (2361), a movable window for the push block (2363) to slide left and right is provided at the bottom of the slide groove (2322), a serrated groove (2364) located above the first packing (22) is provided on the inner wall of the rotating sleeve (231), and when the pressure cover (232) is pressed against the top of the first packing (22), the limiting block (2361) and the serrated groove (2364) are plugged together.

5. The oil wellhead port sealing device according to claim 4, characterized in that: The left and right sides of the housing (21) are further provided with mounting openings (211) for mounting a sealing block (24). The extrusion assembly (25) includes a side cover (251) threadedly mounted on the mounting opening (211). A push rod (252) is slidably mounted on the center of the side cover (251). An extrusion block (253) for pressing the sealing block (24) is rotatably mounted on one end of the push rod (252) close to the center of the housing (21). The extrusion block (253) is located on a side of the sealing block (24) away from the center of the housing (21). A threaded sleeve (254) is rotatably mounted on the side cover (251). The threaded sleeve (254) is threadedly connected to the push rod (252). A transmission component (255) for driving the threaded sleeve (254) to rotate is mounted on the housing (21).

6. The oil wellhead port sealing device according to claim 5, characterized in that: The transmission component (255) includes a driving ring gear (2551) fixedly mounted on the outer ring wall of the rotating sleeve (231); a driven gear (2552) located at the top of the mounting opening (211) is rotatably mounted on the housing (21); the driven gear (2552) is meshed with the driving ring gear (2551); a transmission rod (2553) is coaxially rotatably mounted on the driven gear (2552); the bottom end of the transmission rod (2553) extends to the interior of the mounting opening (211) and is transmission-connected to the threaded sleeve (254) via a bevel gear mechanism; a ratchet structure (2554) is mounted between the driven gear (2552) and the transmission rod (2553).

7. The oil wellhead port sealing device according to claim 6, characterized in that: The third sealing unit comprises a second packing (26) installed inside the housing (21) and located below the sealing block (24), and a top pressure block (27) is installed between the bottom of the second packing (26) and the top of the oil wellhead (1).

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