A single-stage kelly bushing

Abstract

This invention discloses a slip-type single-stage wellhead casing head, relating to the field of casing head technology. The slip-type single-stage wellhead casing head includes: a flange shell; a slip hanger assembled into the flange shell, the slip hanger having a slip housing; an assembly groove located on the inner wall of the flange shell; a riser plate located within the assembly groove and higher than the slip housing; a set screw body arranged radially along the flange shell; and a transmission mechanism located between the set screw body and the riser plate. With this slip-type single-stage wellhead casing head, when the set screw body presses the slip teeth, the set screw body can also gradually move the riser plate from the assembly groove to the top of the flange shell, thus eliminating the need for on-site assembly of the riser plate and reducing the workload of workers. Furthermore, the radial width of the riser plate is not limited by the distance between the slip teeth and the inner wall of the flange shell, meaning the riser plate can be made wider.

Description

Technical Field

[0001] This invention relates to the field of casing head technology, specifically a slip-type single-stage wellhead casing head. Background Technology

[0002] In current oil drilling, the casing head slip hanger is typically installed as a separate component within the casing head to suspend the tubing string. During wellhead operations or when bottomhole temperatures rise, the tubing string expands and rises due to heat, causing the slip hanger to rise as well. This significant upward force can lead to the hanger lifting and seal failure. Simultaneously, as the temperature returns to normal, the tubing string begins to retract. During this retraction, the hanger, lacking sufficient restraint, may fail to return to its proper position, potentially causing the suspended tubing string to detach and fall downhole.

[0003] Patent CN209892147U discloses a lifting device for a sleeve head slip hanger. It includes lifting pads for resistance. The specification states that "during on-site installation, the slip hanger (composed of slip teeth 5, slip housing 6, annular sealing ring 7, and support base 8) is first installed into the inner hole of the sleeve head 4. Under the weight of the tubing 1, the gravity is transmitted through the slip teeth 5 to the slip housing 6, and then applied to the annular sealing ring 7, activating the annular sealing ring 7 to achieve a seal. Then, the annular split lifting pads 2 are installed sequentially, so that each lifting pad 2 presses against the slip housing 6, thereby achieving the purpose of pressing down the entire slip hanger. In this way, when the tubing 1 moves upward, the slip teeth 5 are restricted within the slip housing 6 by the lifting pads 2 and the set screw 3, preventing significant movement as the tubing 1 rises, thus ensuring the slip hanger remains stationary."

[0004] The aforementioned lifting pads can prevent the slips from moving upwards, but their on-site installation is quite troublesome. Because the slip hanger needs to be placed inside the flange housing first, and then the lifting pads are assembled, the radial width of the lifting pads is limited by the gap between the slip teeth and the inner wall of the flange housing. The radial width needs to be smaller than this gap so that the lifting pads can be inserted into the gap first and then pushed laterally into the lifting groove. On the one hand, the lifting strength of narrower lifting pads is insufficient, and on the other hand, during the oil pumping process, the lifting pads are easy to detach from the lifting groove, causing the entire pad to be located above the slip housing, thus preventing it from playing a lifting role. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a slip-type single-stage wellhead casing head, which solves the problems of slip hangers being inconvenient to assemble on-site, having insufficient lift resistance, and being prone to detaching from the lift resistance groove in existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a slip-type single-stage wellhead casing head, comprising:

[0007] Flange housing;

[0008] A slip hanger, wherein the slip hanger is assembled into a flange housing, the slip hanger having a slip housing, and a receiving cavity is provided inside the flange housing to accommodate the slip hanger;

[0009] An assembly slot is provided on the inner wall of the flange housing;

[0010] A lift plate, which is located in the assembly groove and is higher than the slip shell;

[0011] A set screw body, wherein the set screw bodies are arranged radially along the flange housing;

[0012] The transmission mechanism is located between the set screw body and the resistance plate, and is used to convert the preload torque of the set screw body into the radial displacement of the resistance plate, so that the resistance plate reaches the upper surface of the slip housing and constrains the slip housing to move upward.

[0013] Furthermore, the set screw body includes a threaded portion, and a follower wheel is engaged below the threaded portion. The rotation of the set screw body drives the follower wheel to rotate, and the follower wheel pushes and pulls the lifting plate through a transmission mechanism.

[0014] Furthermore, the transmission mechanism includes:

[0015] A steel wire rope, one end of which is fixed to the end of the lifting plate away from the slip housing;

[0016] A take-up reel, which is coaxial with the follower reel;

[0017] A guide wheel is installed in the assembly groove, and the other end of the wire rope is fixed on the winding wheel after being guided by the guide wheel.

[0018] A spring, one end of which is mounted on the side of the riser plate away from the slip housing, and the other end of which is fixed to the bottom of the assembly slot.

[0019] Furthermore, the transmission mechanism includes:

[0020] The driving gear is coaxial with the follower gear;

[0021] Driven gear, which meshes on one side of driving gear;

[0022] A rack plate, which is fixed on the upper surface of the riser plate and meshes with the driven gear.

[0023] Furthermore, the slip housing is provided with four slip teeth, and the outer surface of the slip teeth is provided with a lifting hole in the area opposite to the lifting plate. The lifting plate is provided with a plug on the side near the lifting hole, and the plug is inserted into the lifting hole to limit the slip teeth from rising.

[0024] The diameter of the riser hole is larger than the diameter of the plug.

[0025] Furthermore, the threaded portion has an insertion end near the receiving cavity, and a limit screw is connected to the insertion end along the radial thread. The flange shell has a set screw hole that matches the set screw body, and a flared groove is provided at the end of the set screw hole near the center of the flange shell. The flared groove restricts the set screw body from moving too far away from the slip hanger by the limit screw.

[0026] Furthermore, the flange housing includes a flange, a disc core, and a shell;

[0027] The flange is integrally formed on the upper part of the shell, and the flange has a second recessed step inside, and the assembly groove is opened at the bottom of the second recessed step.

[0028] The disc core is located within the second recessed step, and both the outer arc surface and the lower surface of the disc core are provided with sealing layers. The disc core is used to close the assembly groove, so that the assembly groove forms a closed groove with a radial opening.

[0029] The upper periphery of the disc core is provided with an integral outer extension ring, and the outer extension ring is provided with a first through hole. The upper end of the flange is provided with a first recessed step, and the first recessed step is provided with a second through hole. The outer extension ring is located inside the first recessed step. The countersunk bolt passes through the first through hole and the second through hole and is fixed with a nut.

[0030] Furthermore, the set screw hole includes:

[0031] The hole body is located on the side of the flange away from its own center, and the side of the hole body closer to the center is provided with a first threaded hole;

[0032] The second threaded hole is located on the side of the disc core away from its own center, and the flared groove is located on the side of the second threaded hole close to the center of the disc core.

[0033] Furthermore, the outer surface of the lifting plate is provided with a T-shaped slider, and the inner wall of the assembly groove is provided with a guide rail adapted to the T-shaped slider.

[0034] Furthermore, the end of the top-entry end near the center of the flange shell has a cone, and the upper end face of the slip tooth is set as a conical surface. When the top screw body is screwed into the receiving cavity, the cone can compress the conical surface.

[0035] The present invention has the following beneficial effects:

[0036] This slip-type single-stage wellhead casing head, when the set screw body tightens the slip teeth, can also allow the riser plate to gradually move from the assembly groove to the top of the flange shell, thus eliminating the need for on-site assembly of the riser plate and reducing the workload of the workers; on the other hand, since there is no need for on-site assembly of the riser plate, the radial width of the riser plate is not limited by the distance between the slip teeth and the inner wall of the flange shell, that is, the riser plate can be made wider, thereby maximizing the constraint on the upward movement of the slip shell.

[0037] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0038] Figure 1 This is an overall view of the present invention fitting onto the sleeve;

[0039] Figure 2 This is a schematic diagram of the internal structure of the flange shell after it has been cut open according to the present invention;

[0040] Figure 3 This is a schematic diagram showing the position of the riser plate of the present invention inside the flange housing;

[0041] Figure 4 For the present invention Figure 2 Enlarged view of area A;

[0042] Figure 5 For the present invention Figure 3 Enlarged view of area B;

[0043] Figure 6 This is a first-view view of the transmission mechanism in Embodiment 1 of the present invention;

[0044] Figure 7 This is a second perspective view of the transmission mechanism in Embodiment 1 of the present invention;

[0045] Figure 8 This is a third-view view of the transmission mechanism in Embodiment 1 of the present invention;

[0046] Figure 9 This is a diagram showing the state in which the set screw body extrudes the slip teeth and the resistance plate is located directly above the slip shell in Embodiment 1 of the present invention;

[0047] Figure 10 This is a diagram showing the state of the set screw body detaching from the slip teeth and the riser plate detaching from the slip shell in Embodiment 1 of the present invention.

[0048] Figure 11 This is an exploded view of the flange housing of the present invention;

[0049] Figure 12 This is a schematic diagram of the spring installation inside the flange in Embodiment 1 of the present invention;

[0050] Figure 13 This is a schematic diagram of the transmission mechanism in Embodiment 2 of the present invention;

[0051] Figure 14 This is a diagram showing the relative positions of the disk core and one of the resistance plates in Embodiment 2 of the present invention;

[0052] Figure 15 For the present invention Figure 14 Enlarged view of area C;

[0053] Figure 16 For the present invention Figure 14 Another perspective view;

[0054] Figure 17 For the present invention Figure 16 Enlarged view of area D.

[0055] In the diagram, 1. Sleeve; 2. Flange housing; 21. Flange; 212. Hole body; 213. First threaded hole; 214. First recessed step; 215. Second through hole; 216. Second recessed step; 217. Assembly groove; 218. Guide rail; 219. Receiving cavity; 22. Disc core; 221. First through hole; 222. Outer extension ring; 223. Second threaded hole; 224. Notch; 2241. Traveling rail; 225. Flared groove; 23. Countersunk bolt; 231. Nut; 24. Sealing layer; 25. 1. Housing; 3. Set screw body; 31. Exposed end; 32. Insertion end; 33. Threaded part; 34. Insertion end; 35. Cone; 36. Limit screw; 5. Follower wheel; 6. Transmission mechanism; 61. Take-up wheel; 62. Guide wheel; 63. Wire rope; 64. Spring; 65. Drive gear; 66. Driven gear; 67. Rack plate; 7. Lift plate; 71. Plug; 72. T-shaped slider; 8. Vase tooth; 81. Lift hole; 9. Vase housing; 91. Outer shell body; 92. Support base; 93. Vase base. Detailed Implementation

[0056] 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.

[0057] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0058] The following is based on Figures 1-17 This invention describes the slip-type single-stage wellhead casing head provided in an embodiment of the present invention.

[0059] Example 1:

[0060] Please see Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a slip-type single-stage wellhead casing head, including a flange shell 2 and a slip hanger.

[0061] The slip hanger here is a slip hanger known in the prior art. It should be a two-half coupled hanger, specifically including a slip housing 9 and slip teeth 8. The slip housing 9 includes an outer shell body 91, a support seat 92 located below the outer shell body 91, and a slip seat 93 located below the support seat 92. The outer shell body 91, the slip seat 93, and the support seat 92 are all composed of two semi-annular structures. Specifically, the support seat 92 and the slip seat 93 are interlocked, so that the support seat 92 and the slip seat 93 form an integral part and can move synchronously. A track is set on the upper surface of the slip seat 93, and the outer shell body 91 can rotate on the track, thereby realizing the engagement and disengagement of the slip hanger.

[0062] After the slip hanger engages with the sleeve 1, the slip hanger is lowered into the flange housing 2, thus achieving the purpose of assembling the slip hanger into the flange housing 2. Essentially, a receiving cavity 219 capable of accommodating one slip hanger should be provided inside the flange housing 2. The lower part of the slip seat 93 is an inwardly tapered structure, and the lower part of the receiving cavity 219 is also set as an inwardly tapered structure (see reference). Figure 2 and Figure 3 When the lower part of the slip seat 93 is engaged with the lower part of the receiving cavity 219, the slip hanger is lowered and positioned.

[0063] Combination Figure 2 and Figure 3As shown, to prevent the casing 1 from expanding upwards due to heat when the bottom hole temperature rises during wellhead operations, which would cause the slip hanger to rise and the huge upward force to cause the hanger to rise, resulting in seal failure, an assembly groove 217 and a rise-resistant plate 7 are provided here. The assembly groove 217 is located on the inner wall of the flange housing 2. Preferably, there are four assembly grooves 217, and the four assembly grooves 217 are evenly arranged on the inner wall of the flange housing 2. The rise-resistant plate 7 is located in the assembly groove 217 and is higher than the slip housing 9. This is to ensure that the rise-resistant plate 7 is above the slip housing 9 to limit the upward movement of the slip housing 9.

[0064] Combination Figures 2-4 As shown, a set screw body 3 is also provided. Four sets of set screw bodies 3 are evenly arranged along the radial direction of the flange shell 2 and correspond to the centerline position of the corresponding riser plate 7. The position of the set screw body 3 is higher than that of the riser plate 7. When the set screw body 3 is screwed into the flange shell 2, it can apply pressure to the slip 8, thereby making the slip 8 grip the sleeve 1.

[0065] In essence, the present invention employs a method where, when a pre-tightening torque is applied to the top screw body 3, the lifting plate 7 is simultaneously driven to generate radial displacement in the flange housing 2, so that the lifting plate 7 can gradually reach directly above the slip housing 9; specifically, the lifting plate 7 in the assembly groove 217 can gradually move and gradually approach the center of the flange housing 2, thereby allowing the lifting plate 7 to gradually reach directly above the slip housing 9, thereby constraining the slip teeth 8 to move upward.

[0066] For this purpose, a transmission mechanism 6 is set up. The transmission mechanism 6 is located between the set screw body 3 and the baffle plate 7. When the set screw body 3 applies a pre-tightening torque, the action of the transmission mechanism 6 drives the baffle plate 7 to produce radial displacement, so that the baffle plate 7 reaches the upper surface of the slip housing 9 and constrains the slip housing 9 to move upward.

[0067] Therefore, the slip-type single-stage wellhead casing head provided by the present invention can also allow the riser plate 7 to gradually move from the assembly groove 217 to the top of the slip shell 9 when the top screw body 3 presses the slip teeth 8, thus eliminating the need for on-site assembly of the riser plate 7 and reducing the workload of the workers; on the other hand, since there is no need for on-site assembly of the riser plate 7, the radial width of the riser plate 7 is not limited by the distance between the slip teeth 8 and the inner wall of the flange shell 2, that is, the riser plate 7 can be made wider, thereby maximizing the constraint on the upward movement of the slip shell 9.

[0068] like Figure 3 and Figure 4As shown, the flange housing 2 is provided with a set screw hole that is adapted to the set screw body 3. The set screw body 3 includes a threaded part 33. The threaded part 33 is provided with an insertion end 34 at one end near the receiving cavity 219. The insertion end 34 is provided with a cone 35 at one end near the receiving cavity 219. An insertion end 32 is provided at the other end of the threaded part 33. An exposed end 31 is provided at the other end of the insertion end 32. By rotating the exposed end 31, the threaded part 33 and the set screw hole can generate thread force, so that the cone 35 can gradually apply force to the conical surface of the slip tooth 8.

[0069] Combination Figures 3-8 As shown, in order to enable the preload torque of the aforementioned set screw body 3 to drive the transmission mechanism 6 to work, a follower wheel 5 is engaged below the aforementioned threaded portion 33. This engagement is similar to that of a worm gear. When the threaded portion 33 (worm) rotates, it drives the follower wheel 5 (worm gear) to rotate. The follower wheel 5 pushes and pulls the lifting plate 7 through the transmission mechanism 6.

[0070] Since a fixed number of rotations of the follower wheel 5 is necessary to ensure the transmission mechanism 6 transmits a fixed torque and to guarantee the radial displacement of the lifting plate 7, the stroke of the set screw body 3 from the state of moving away from the slip tooth 8 to the state of pressing against the slip tooth 8 should be fixed. That is, the number of rotations required to loosen and tighten the set screw body 3 should be approximately the same each time. Assuming the state of the set screw body 3 is... Figure 10 In the loosened state shown, the set screw body 3 needs to be rotated so that it can gradually approach the conical surface of the vault tooth 8. If rotating the set screw body 3 a turns can make it move from... Figure 10 The state shown has been reached. Figure 9 The state shown indicates that when the set screw body 3 is unlocked from the locking tooth 8 (from...) Figure 9 state to Figure 10 If the state is in the unlocking process, then the set screw body 3 needs to be rotated in the opposite direction by a turns in order to allow the set screw body 3 to move from the unlocking state. Figure 9 The state shown has been reached. Figure 10 The state shown indicates that the number of rotations of the set screw body 3 is set to a certain number at the factory. Of course, due to the error caused by mechanical wear, the number of rotations near the number of rotations of the set screw body 3 can be adjusted according to the specific situation on site. This ensures that the movement or retraction of the set screw body 3 is a certain distance each time, thereby ensuring that the threaded part 33 can provide a certain torque to the follower wheel 5, so that the radial movement distance of the lifting plate 7 is approximately the same each time.

[0071] During the insertion of the aforementioned set screw body 3, when it presses against the slip teeth 8, the operator is prompted by the restriction effect of the slip teeth 8. That is, when the set screw body 3 can no longer be rotated after pressing, it means that the set screw body 3 is pressed into place. However, during the subsequent disassembly process, the set screw body 3 needs to be withdrawn and no longer press against the slip teeth 8. At this time, the operator may easily withdraw the set screw body 3 excessively, causing a change in the inherent number of rotations of the set screw body 3. Therefore, a flared groove 225 is provided at the end of the set screw hole near the center of the flange shell 2. A limit screw 36 is connected radially threaded on the insertion end 34. The flared groove 225 restricts the set screw body 3 from moving too far away from the slip hanger through the limit screw 36. When the set screw body 3 withdraws to the maximum threshold, the limit screw 36 is blocked by the bottom of the flared groove 225, thus prompting the operator to withdraw the set screw body 3 into place.

[0072] Combination Figure 2 , Figures 5-8 As shown, the aforementioned transmission mechanism 6 includes a wire rope 63, a take-up reel 61, a guide wheel 62, and a spring 64. One end of the wire rope 63 is fixed to the end of the lifting plate 7 away from the slip housing 9. The take-up reel 61 is coaxial with the follower wheel 5. The guide wheel 62 is installed in the assembly groove 217. The other end of the wire rope 63 is fixed to the take-up reel 61 after being guided by the guide wheel 62. One end of the spring 64 is installed on the side of the lifting plate 7 away from the slip housing 9, and the other end of the spring 64 is fixed to the bottom of the assembly groove 217.

[0073] Preferably, a hole for accommodating the spring 64 is formed in the lifting plate 7.

[0074] In this implementation plan, Figure 10 In the indicated state (i.e., the state where the set screw body 3 is withdrawn and the lifting plate 7 is fully located within the assembly slot 217), the spring 64 is compressed. As the set screw body 3 gradually screws in and approaches the slip teeth 8, the follower wheel 5 is driven by the set screw body 3, thereby driving the coaxial take-up wheel 61 to rotate, causing the take-up wheel 61 to unwind the wire rope 63. As the wire rope 63 is released, the spring 64 rebounds, gradually pushing the lifting plate 7, causing the lifting plate 7 to gradually move above the slip housing 9, thereby constraining the slip housing 9 to move upward; conversely, when it is desired that the set screw body 3 is withdrawn from the assembly slot 217, the spring 64 is compressed. Figure 9 state to Figure 10 When the state is reversed, the top screw body 3 needs to be rotated in the opposite direction, so that the follower wheel 5 rotates in the opposite direction and drives the winding wheel 61 to wind the wire rope 63, so that the wire rope 63 pulls the lifting plate 7 back into the assembly slot 217, at which time the spring 64 is gradually compressed.

[0075] In the above overall structure, when the lifting plate 7 prevents the slip housing 9 from moving upward, the force on the lifting plate 7 will be transmitted to the slip housing 9, and will not be transmitted to the spring 64 or the wire rope 63.

[0076] Preferably, the outer surface of the lifting plate 7 is provided with a T-shaped slider 72, and the inner wall of the assembly groove 217 is provided with a guide rail 218 adapted to the T-shaped slider 72. The guide rail 218 has a structure that is closed at both ends.

[0077] Preferably, a lifting hole 81 is provided on the outer surface of the slip tooth 8 in the area opposite to the lifting plate 7. A plug 71 is provided on the side of the lifting plate 7 near the lifting hole 81. The plug 71 is inserted into the lifting hole 81 to restrict the rise of the slip tooth 8. In this embodiment, when the lifting plate 7 gradually moves to the upper surface of the slip housing 9, the plug 71 gradually inserts into the lifting hole 81. When the lifting plate 7 gradually moves into the assembly groove 217, the plug 71 also gradually enters the assembly groove 217 and is hidden to avoid affecting the rotation of the slip and its installation into the flange housing 2.

[0078] In addition, to prevent the plug 71 from failing to be inserted into the riser hole 81 due to radial and axial displacement caused by pressure on each of the slip teeth 8 during the gradual insertion of the set screw body 3, the diameter of the riser hole 81 is larger than the diameter of the plug 71 to compensate for the displacement of the slip teeth 8.

[0079] Therefore, the slip-type single-stage wellhead casing head provided by the present invention can not only prevent the slip housing 9 from moving upward through the rise plate 7, but also prevent the slip teeth 8 from moving upward through the cooperation of the plug 71 and the rise hole 81.

[0080] Combination Figure 11 and Figure 12 As shown, in order to facilitate the assembly of the transmission mechanism 6 and the follower wheel 5, the flange housing 2 is made into a split structure. The flange housing 2 includes an external structure and an internal structure. The external structure consists of a flange 21 and a housing 25 integrally formed below the flange 21. The internal structure is a disc core 22.

[0081] Specifically, the flange 21 has a second recessed step 216 inside, and an assembly groove 217 is opened at the bottom of the second recessed step 216. The disc core 22 is embedded in the second recessed step 216, so the disc core 22 actually fills the second recessed step 216, thus it can close the upper surface of the assembly groove 217, making the assembly groove 217 a closed groove with a radial opening. The follower wheel 5 is assembled in the disc core 22, and the disc core 22 has a notch 224 to accommodate the follower wheel 5. The upper part of the notch 224 is connected to the set screw hole, and the lower part is connected to the assembly groove 217.

[0082] Preferably, a sealing layer 24 is provided on both the outer arc surface and the lower surface of the disc core 22 to ensure the seal between the disc core 22 and the flange 21 and prevent oil leakage from the gap between them.

[0083] In addition, in order to connect the disc core 22 and the flange 21, an integral outer extension ring 222 is provided on the upper periphery of the disc core 22. The outer extension ring 222 has a first through hole 221. The upper end of the flange 21 has a first recessed step 214. The first recessed step 214 has a second through hole 215. The outer extension ring 222 is located inside the first recessed step 214. The countersunk bolt 23 passes through the first through hole 221 and the second through hole 215 and is fixed with a nut 231, thereby ensuring a tight connection between the disc core 22 and the flange 21 and preventing them from loosening.

[0084] The aforementioned set screw hole includes a hole body 212 and a second threaded hole 223. The hole body 212 is located on the side of the flange 21 away from its own center, and the side of the hole body 212 close to the center is provided with a first threaded hole 213. The second threaded hole 223 is located on the side of the disc core 22 away from its own center. The flared groove 225 is located on the side of the second threaded hole 223 close to the center of the disc core 22. The threaded part 33 is threadedly connected to both the first threaded hole 213 and the second threaded hole 223.

[0085] When in use (during operation):

[0086] 1) Move the slip hanger down into the flange housing 2, manually measure and adjust the slip hanger to be concentric with the flange housing 2, forming... Figure 10 The state shown;

[0087] 2) Raise casing 1 and maintain the lifting state. The net pulling force for the oil layer casing is 50-60 tons.

[0088] 3) Tighten each set screw body 3 into place, so that the set screw body 3 gradually presses the conical surface of the slip tooth 8. During the rotation of the set screw body 3, the threaded part 33 can drive the follower wheel 5 to rotate, thereby driving the coaxial winding wheel 61 to rotate, so that the winding wheel 61 unwinds the wire rope 63. As the wire rope 63 is released, the spring 64 rebounds and gradually pushes the lifting plate 7, so that the lifting plate 7 gradually moves above the slip housing 9, thereby constraining the slip housing 9 to move upward. At the same time, the plug 71 is inserted into the lifting hole 81 to restrict the slip tooth 8 from moving upward.

[0089] 4) Release the weight of sleeve 1 to zero, apply the weight of sleeve 1 to the slip tooth 8, and make it grip sleeve 1 tightly. Note that the sliding distance of sleeve 1 relative to slip tooth 8 should not be greater than 10mm, otherwise it must be re-seatened.

[0090] Example 2:

[0091] Combination Figures 13-17The difference between this embodiment and Embodiment 1 is that the transmission mechanism 6 here includes a driving gear 65, a driven gear 66, and a rack plate 67. The driving gear 65 is coaxial with the follower wheel 5, so that the driving gear 65 can also rotate when the follower wheel 5 rotates. The driven gear 66 meshes with one side of the driving gear 65, thereby driving the driven gear 66 to rotate. The rack plate 67 is fixed on the upper surface of the lifting plate 7, and the rack plate 67 meshes with the driven gear 66, so that when the driven gear 66 rotates, the lifting plate 7 can be moved by the rack plate 67.

[0092] Preferably, the driven gear 66 and the driving gear 65 are installed in the notch 224.

[0093] Preferably, a travel track 2241 is provided on the bottom surface of the disc core 22, and the upper part of the rack plate 67 is inserted into the travel track 2241 and moves within the travel track 2241. This arrangement allows the upper surface of the baffle plate 7 to fit against the bottom surface of the disc core 22, preventing the driven gear 66 from extending into the assembly groove 217 and reducing the leakage of oil through the gap between the disc core 22 and the baffle plate 7.

[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0095] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A slip-type single-stage wellhead casing head, characterized by, include: Flange housing (2); The slip hanger is assembled into the flange housing (2). The slip hanger has a slip shell (9). The flange housing (2) is provided with a receiving cavity (219) that can accommodate the slip hanger. Assembly slot (217), the assembly slot (217) is provided on the inner wall of the flange shell (2); The lifting plate (7) is located in the assembly groove (217) and is higher than the slip shell (9). The set screw body (3) is arranged radially along the flange shell (2); The transmission mechanism (6) is located between the top screw body (3) and the lifting plate (7), and the transmission mechanism (6) is used to convert the pre-tightening torque of the top screw body (3) into the radial displacement of the lifting plate (7), so that the lifting plate (7) reaches the upper surface of the slip shell (9) and constrains the slip shell (9) to move upward. The set screw body (3) includes a threaded part (33), and a follower wheel (5) is engaged below the threaded part (33). The rotation of the set screw body (3) is used to drive the follower wheel (5) to rotate. The follower wheel (5) pushes and pulls the lifting plate (7) through the transmission mechanism (6). The slip housing (9) is provided with four slip teeth (8). The outer surface of the slip teeth (8) is provided with a lifting hole (81) in the area opposite to the lifting plate (7). The lifting plate (7) is provided with a plug (71) on the side near the lifting hole (81). The plug (71) is inserted into the lifting hole (81) to limit the slip teeth (8) from rising. The diameter of the riser hole (81) is larger than the diameter of the plug (71).

2. A slip-type single-stage wellhead casing head according to claim 1, characterized in that: The transmission mechanism (6) includes: A steel wire rope (63), one end of which is fixed to the end of the lifting plate (7) away from the slip housing (9); The winding wheel (61) is coaxial with the follower wheel (5); Guide wheel (62), the guide wheel (62) is installed in the assembly groove (217), and the other end of the wire rope (63) is fixed on the winding wheel (61) after being guided by the guide wheel (62); A spring (64) is installed at one end on the side of the lifting plate (7) away from the slip housing (9), and the other end of the spring (64) is fixed to the bottom of the assembly groove (217).

3. A slip-type single-stage wellhead casing head as claimed in claim 1, characterized in that: The transmission mechanism (6) includes: The driving gear (65) is coaxial with the follower gear (5); Driven gear (66), which meshes on one side of driving gear (65); A rack plate (67) is fixed on the upper surface of the lift plate (7) and meshes with the driven gear (66).

4. A slip-type single-stage wellhead casing head according to claim 2 or 3, characterised in that: The threaded part (33) is provided with an insertion end (34) at one end near the receiving cavity (219). A limit screw (36) is connected radially to the insertion end (34). The flange shell (2) is provided with a top screw hole that is adapted to the top screw body (3). The top screw hole is provided with a flared groove (225) at one end near the center of the flange shell (2). The flared groove (225) restricts the top screw body (3) from moving too far away from the slip hanger by the limit screw (36).

5. A slip-type single-stage wellhead casing head according to claim 4, characterized in that: The flange housing (2) includes a flange (21), a disc core (22), and a housing (25); The flange (21) is integrally formed on the upper part of the shell (25), and the flange (21) has a second recessed step (216) inside, and the assembly groove (217) is opened at the bottom of the second recessed step (216); The disc core (22) is located inside the second sunken step (216), and the outer arc surface and the lower surface of the disc core (22) are both provided with a sealing layer (24). The disc core (22) is used to close the assembly groove (217), so that the assembly groove (217) forms a closed groove with a radial opening. The upper periphery of the disc core (22) is provided with an integral outer extension ring (222), the outer extension ring (222) is provided with a first through hole (221), the upper end of the flange (21) is provided with a first recessed step (214), the first recessed step (214) is provided with a second through hole (215), the outer extension ring (222) is located inside the first recessed step (214), and the countersunk bolt (23) passes through the first through hole (221) and the second through hole (215) and is fixed with a nut.

6. A slip-type single-stage wellhead casing head according to claim 5, characterized in that: The set screw hole includes: The hole body (212) is located on the side of the flange (21) away from its own center, and the hole body (212) is provided with a first threaded hole (213) on the side of the hole body (212) close to the center. The second threaded hole (223) is located on the side of the disc core (22) away from its own center, and the flared groove (225) is located on the side of the second threaded hole (223) close to the center of the disc core (22).

7. A slip-type single-stage wellhead casing head according to claim 6, characterized in that: The outer surface of the riser plate (7) is provided with a T-shaped slider (72), and the inner wall of the assembly groove (217) is provided with a guide rail (218) adapted to the T-shaped slider (72).

8. A slip-type single-stage wellhead casing head according to claim 7, characterized in that: The top inlet end (34) has a cone (35) at one end near the center of the flange housing (2). The upper end face of the slip tooth (8) is set as a conical surface. When the top screw body (3) is screwed into the receiving cavity (219), the cone (35) can squeeze the conical surface.

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