Casing head and casing connecting device

Abstract

The embodiment of the invention provides a casing head and a casing connecting device. The casing head comprises a casing head body and a clamping mechanism, the casing head body is provided with a first connecting hole and a first side opening, the first connecting hole is formed in the axial direction of the casing head body, the first side opening is formed in the circumferential direction of the casing head body and communicates with the first connecting hole, and the first side opening is used for being connected with a second side opening in the side wall of a casing; the clamping mechanism comprises a plurality of clamping blocks and a driving assembly, the clamping blocks are evenly distributed on the casing head body in the circumferential direction of the first connecting hole, the driving assembly is connected with the clamping blocks, the distances between the clamping blocks and the axis of the first connecting hole are equal, and the clamping blocks are driven by the driving assembly to synchronously move in the radial direction of the first connecting hole. Therefore, the plurality of clamping blocks clamp or release the casing pipe together. Before the clamping blocks clamp the casing pipe, the second side opening in the casing pipe can be aligned with the first side opening in the casing pipe head body, and after the clamping blocks clamp the casing pipe together, the centering precision of the casing pipe in the casing pipe head is not affected.

Description

Technical Field

[0001] This application relates to the technical field of wellhead devices, and particularly to a casing head and a casing connection device. Background Art

[0002] In oil and gas drilling and production engineering, the casing head, as a key load-bearing component of the wellhead, is mainly used to fix the wellhead structure, connect the casing and wellhead equipment, and seal the annular space between each stage of the casing. In addition, a side port is provided on the side of the casing head body, and this side port can be used to perform construction operations such as squeezing mud, monitoring downhole conditions, and injecting balancing fluid.

[0003] Currently, the connection methods between the casing head and the casing mainly include threaded connection and slip connection. However, these two traditional connection methods have certain defects in practical applications: the threaded connection is likely to cause the side port of the casing head to be unable to accurately align with the side port of the casing, affecting the normal installation of wellhead auxiliary equipment and subsequent construction operations; the slip connection uses a radial clamping method, and although it has a certain self-locking ability, it may cause the casing to shift, affecting the centering accuracy of the casing in the casing head. Summary of the Invention

[0004] This application provides a casing head and a casing connection device to solve the technical problems that the side ports of the existing casing head and the casing cannot be accurately aligned and the casing cannot be centered after being fixed.

[0005] On the one hand, this application provides a casing head, including: a casing head body and a clamping mechanism. The casing head body is provided with a first connection hole and a first side port. The first connection hole is arranged along the axial direction of the casing head body, and the first side port is arranged on the circumferential direction of the casing head body and communicates with the first connection hole. The first connection hole is used for inserting the casing, and the first side port is used to connect the second side port on the side wall of the casing. The clamping mechanism includes a plurality of clamping blocks and a driving component. The plurality of clamping blocks are evenly distributed around the circumferential direction of the first connection hole on the casing head body. The driving component is connected to the plurality of clamping blocks. The distances between the plurality of clamping blocks and the axis of the first connection hole are equal. The plurality of clamping blocks are configured to synchronously move along the radial direction of the first connection hole under the drive of the driving component, so that the plurality of clamping blocks jointly clamp or release the casing.

[0006] Optionally, a first limiting portion is provided at one end of the clamping block close to the casing, and a second limiting portion is provided on the outer peripheral wall of the casing. The distance between the first limiting portion and the first side port is equal to the distance between the second limiting portion and the second side port. The first limiting portion and the second side port are rotationally matched along the circumferential direction of the casing.

[0007] Optionally, the second limiting portion is an annular member, the annular member is wound around the circumference of the sleeve, and at least one of a groove or a protrusion is provided on the annular member. A protrusion corresponding to the groove is provided on the first limiting portion, and / or a groove corresponding to the protrusion is provided on the first limiting portion.

[0008] Optionally, the driving assembly includes a plurality of driving rods and a plurality of driving gears. The first end of the driving rod is correspondingly connected to the clamping block, the driving gear is correspondingly connected to the second end of the driving rod, and adjacent two driving gears are in transmission connection. The driving gear is configured to drive the driving rods to rotate synchronously, so that the driving rods drive the clamping block to slide along the radial direction of the first connection hole.

[0009] Optionally, a plurality of guiding holes are provided in the casing head body. The two ends of the guiding hole communicate with the first connection hole and the outer wall of the casing head body respectively. The extending direction of the guiding hole is parallel to the sliding direction of the clamping block. The driving gear is arranged outside the casing head body, the clamping block is correspondingly arranged in the guiding hole, and the guiding hole is configured to limit the rotation of the clamping block. The driving rod connects the clamping block and the driving gear through the guiding hole.

[0010] Optionally, a threaded portion is provided at the first end of the driving rod, a first threaded hole is provided on the clamping block, and the threaded portion is threadedly connected in the first threaded hole. The extending direction of the first threaded hole is parallel to the sliding direction of the clamping block, and the driving rod and the casing head body are rotatably connected through a transmission member.

[0011] Optionally, a threaded portion is provided at the second end of the driving rod, and a part of the guiding hole is configured as a second threaded hole. The threaded portion is threadedly connected in the second threaded hole, and the driving rod and the clamping block are rotatably connected.

[0012] Optionally, the guiding hole (130) includes a connected first hole section and a second hole section. The first hole section communicates with the first connection hole (110), the second hole section communicates with the outer wall of the casing head body (100), the cross-sectional area of the first hole section is larger than that of the second hole section, the clamping block (210) is arranged in the first hole section, and the second hole section is configured as the second threaded hole.

[0013] Optionally, a sealing ring groove is provided on the pore wall of the first connection hole or the outer wall of the sleeve, and an annular sealing ring is installed in the sealing ring groove.

[0014] On the other hand, the present application provides a casing connection device, including: a casing and a casing head, and the casing is inserted into the first connection hole.

[0015] The beneficial effects of the present application are as follows. The casing head and the casing connection device provided by the present application provide preliminary guidance for the casing by setting the first connection hole, and drive a plurality of clamping blocks to move along the radial direction of the first connection hole simultaneously through the driving assembly in the clamping mechanism, so that the plurality of clamping blocks move towards the direction close to the axis of the first connection hole simultaneously to realize the clamping of the casing, or move the plurality of clamping blocks towards the direction away from the axis of the first connection hole simultaneously to realize the release of the casing. Since the clamping mechanism drives a plurality of clamping blocks to move synchronously and the clamping blocks are evenly distributed along the circumferential direction of the first connection hole, when the clamping blocks clamp the casing, the axis of the casing can always be kept collinear with the axis of the first connection hole, that is, the casing will not shift. In addition, before the clamping blocks clamp the casing and when the first side port and the second side port are not aligned, the position of the second side port on the casing can be conveniently adjusted by rotating the casing in the first connection hole, so that the second side port on the casing can be adjusted to be aligned and communicated with the first side port on the casing head body. During the clamping process of the casing by the clamping blocks, since the distances between the plurality of clamping blocks and the axis of the first connection hole are all equal, the casing can be kept in a centered position, and the centering accuracy of the casing in the casing head will not be affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0017] Figure 1 is a schematic structural diagram of the casing connection device from the first perspective;

[0018] Figure 2 is a schematic structural diagram of the casing connection device from the second perspective;

[0019] Figure 3 is a schematic cross-sectional structural diagram of the casing connection device;

[0020] Figure 4 is a schematic connection structural diagram of the driving rod, the clamping block and the casing head body;

[0021] Figure 5 is another schematic connection structural diagram of the driving rod, the clamping block and the casing head body;

[0022] Figure 6 is a relationship diagram of the tensile load and the maximum principal stress of the casing;

[0023] Figure 7 is a relationship diagram of the tensile load and the maximum principal stress of the casing head.

[0024] Reference numerals:

[0025] 100 - Casing head body; 110 - First connection hole; 120 - First side port; 130 - Guide hole; 131 - First hole section; 132 - Second hole section; 140 - Sealing ring groove;

[0026] 200 - Clamping mechanism; 210 - Clamping block; 211 - First limiting part; 220 - Driving assembly; 221 - Driving rod; 222 - Driving gear; 223 - Transmission gear; 224 - Transmission part;

[0027] 300 - Casing; 310 - Second side port; 320 - Second limiting part;

[0028] 400 - Mounting seat.

[0029] Through the above - mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0030] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0031] In the specification and claims of the present application and the above - mentioned drawings, terms such as "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein.

[0032] In the embodiments of the present application, words such as "exemplarily" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplarily" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplarily" or "for example" aims to present relevant concepts in a specific manner.

[0033] In the related art, the existing connection methods between the casing head and the casing at the wellhead mainly include threaded connection and slip connection. However, threaded connection is likely to cause the side ports of the casing head and the casing to fail to be accurately aligned, while slip connection is prone to cause the casing to shift, affecting the centering accuracy of the casing within the casing head. It can be seen that whether the existing threaded connection method or slip connection method is adopted, it is difficult to adjust the angle with the existing connection methods, and the precise docking requirements under complex working conditions cannot be met. These problems may lead to a decrease in connection reliability under complex well conditions, affecting the long-term service performance of the casing and the overall stability of the wellhead system.

[0034] The casing head and the casing connection device provided in this application are intended to solve the above technical problems in the prior art.

[0035] The technical solution of this application and how the technical solution of this application solves the above technical problems will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0036] As Figures 1 to 5 shown, in a first aspect, an embodiment of this application provides a casing head, including a casing head body 100 and a clamping mechanism 200. The casing head body 100 is provided with a first connection hole 110 and a first side port 120. The first connection hole 110 is arranged along the axial direction of the casing head body 100, and the first side port 120 is arranged on the circumferential direction of the casing head body 100 and communicates with the first connection hole 110. The first connection hole 110 is used for inserting the casing 300, and the first side port 120 is used to fluidly connect to a second side port 310 on the side wall of the casing 300. The clamping mechanism 200 includes a plurality of clamping blocks 210 and a driving assembly 220. The plurality of clamping blocks 210 are evenly distributed around the circumferential direction of the first connection hole 110 on the casing head body 100. The driving assembly 220 is connected to the plurality of clamping blocks 210. The distances between the plurality of clamping blocks 210 and the axis of the first connection hole 110 are equal. The plurality of clamping blocks 210 are configured to synchronously move along the radial direction of the first connection hole 110 under the drive of the driving assembly 220, so that the plurality of clamping blocks 210 jointly clamp or release the casing 300.

[0037] In the above technical solution, the first connection hole 110 provides preliminary guidance for the casing 300. Before the clamping block 210 clamps the casing 300, the casing 300 can rotate relative to and axially move relative to the casing head body 100 within the first connection hole, so that the position of the second side port 310 on the casing 300 can be adjusted to align and communicate with the first side port 120 on the casing head body 100. After the first side port 120 and the second side port 310 are aligned and communicated, the driving assembly 220 in the clamping mechanism 200 simultaneously drives a plurality of clamping blocks 210 to move along the radial direction of the first connection hole 110, so that the plurality of clamping blocks 210 simultaneously move towards the direction close to the axis of the first connection hole 110, realizing the clamping of the casing 300, so as to realize the relative fixation between the casing head body 100 and the casing 300, and keep the first side port 120 and the second side port 310 aligned and communicated. Or, the plurality of clamping blocks 210 simultaneously move towards the direction away from the axis of the first connection hole 110, realizing the release of the casing 300, thereby releasing the relative fixation between the casing 300 and the casing head body 100. Since the clamping mechanism 200 simultaneously drives the plurality of clamping blocks 210 to move synchronously, and the clamping blocks 210 are evenly distributed along the circumferential direction of the first connection hole 110, and the distances between the plurality of clamping blocks 210 and the axis of the first connection hole 110 are all equal, therefore, after the clamping blocks 210 clamp the casing 300, the axis of the casing 300 can always be kept collinear with the axis of the first connection hole 110, that is, the casing 300 will not be offset, keeping the casing 300 in a centered position and not affecting the centering accuracy of the casing 300 within the casing head.

[0038] It should be noted that in this embodiment, both ends of the first connection hole 110 penetrate through both axial ends of the casing head body 100. One end of the first connection hole 110 can be used for inserting the casing 300, and the other end can be used for connecting other wellhead equipment.

[0039] As Figure 3 shown, in some optional embodiments, the first connection hole 110 is a straight hole, and one end of the casing 300 for inserting into the first connection hole 110 is a straight pipe, so that the casing 300 can be inserted into the first connection hole 110 along a straight line. Optionally, the aperture of the first connection hole 110 is adapted to the outer diameter of the casing 300. So that the first connection hole 110 not only plays a guiding role for the casing 300, but also plays a limiting role.

[0040] Optionally, the number and position of the first side ports 120 can be adapted to the number and position of the second side ports 310, so that a plurality of first side ports 120 can respectively correspond to one second side port 310, and each group of corresponding first side ports 120 and second side ports 310 can be aligned and communicated simultaneously.

[0041] AsFigure 3 , Figure 4 and Figure 5 As shown in Figure 3 , Figure 4 and Figure 5 , in order to conveniently adjust the relative positions of the first side port 120 and the second side port 310, in some alternative embodiments, a first limiting portion 211 is provided at one end of the clamping block 210 close to the sleeve 300, a second limiting portion 320 is provided on the outer peripheral wall of the sleeve 300, the distance between the first limiting portion 211 and the first side port 120 is equal to the distance between the second limiting portion 320 and the second side port 310; the first limiting portion 211 and the second side port 310 are rotationally engaged along the circumferential direction of the sleeve 300.

[0042] It can be understood that by making the distance between the first limiting portion 211 and the first side port 120 equal to the distance between the second limiting portion 320 and the second side port 310, when the first limiting portion 211 and the second limiting portion 320 cooperate to form a cooperating portion, the distance between the first side port 120 and the cooperating portion is equal to the distance between the second side port 310 and the cooperating portion, that is, the first side port 120 and the second side port 310 are at the same height. The first limiting portion 211 and the second limiting portion 320 can be rotationally engaged, which enables the sleeve 300 to rotate self - sufficiently under the cooperation and restraint of the first limiting portion 211 and the second limiting portion 320. At the same time, it can also restrict the axial relative movement between the sleeve 300 and the casing head body 100, so that there is no axial relative movement between the sleeve 300 and the casing head body 100. In this way, by rotating the sleeve 300, the relative positions of the first side port 120 and the second side port 310 can be adjusted more quickly, so that the first side port 120 and the second side port 310 can be quickly aligned.

[0043] It should be noted that the first limiting portion 211 and the second limiting portion 320 can be rotationally engaged, which means that when the clamping force exerted by the clamping block 210 on the sleeve 300 is relatively small, that is, when the clamping block 210 does not completely clamp the sleeve 300, after the first limiting portion 211 and the second limiting portion 320 cooperate with each other, the sleeve 300 and the casing head body 100 can rotate relative to each other. If the driving assembly 220 continuously increases the clamping force exerted by the clamping block 210 on the sleeve 300, the clamping of the sleeve 300 will eventually be achieved, making the sleeve 300 unable to move axially and rotate.

[0044] For more specific structures of the first limiting portion 211 and the second limiting portion 320, in some alternative embodiments, the second limiting portion 320 is an annular member, the annular member is wound around the circumferential direction of the sleeve 300, and at least one of a groove or a protrusion is provided on the annular member. A protrusion corresponding to the groove is provided on the first limiting portion 211, and / or a groove corresponding to the protrusion is provided on the first limiting portion 211.

[0045] It can be understood that the opposite groove walls of the groove are arranged at intervals along the axis of the casing 300. When the first limiting portion 211 is provided with a groove, the second limiting portion 320 is provided with an annular protrusion. When the first limiting portion is provided with a protrusion, the second limiting portion 320 is provided with an annular groove. After the protrusion is inserted into the groove, the opposite groove walls of the groove can limit the protrusion to restrict the axial movement between the casing head body 100 and the casing 300, so that the first side port 120 and the second side port 310 can be kept at the same height, preventing the first side port 120 and the second side port 310 from shifting axially in the first connection hole 110 after the casing head is paired with the casing 300. By setting the second limiting portion 320 as an annular member, the groove and the protrusion can be in an inserted state when the casing 300 rotates to any angle, avoiding falling off during the rotation process.

[0046] In some alternative embodiments, the first limiting portion 211 may be a first toothed portion, and the first toothed portion includes the above-mentioned grooves and protrusions alternately arranged along the axis of the casing head body 100. Correspondingly, the second limiting portion 320 may be a second toothed portion, and the first toothed portion can mesh with the second toothed portion.

[0047] In some alternative embodiments, the first toothed portion can be either an arc tooth or a straight tooth, and this application does not make specific limitations in this regard.

[0048] Of course, in other embodiments, the second toothed portion can also be a discontinuous annular member composed of a plurality of arc teeth arranged at intervals along the circumference of the casing 300. At this time, it is necessary to satisfy that the distance between the arc teeth provided on the casing 300 is smaller than the length of the arc teeth provided on the clamping block 210.

[0049] In some alternative embodiments, the second limiting portion 320 on the casing 300 can be directly machined by a lathe.

[0050] The material used for the casing 300 is the same as that of the clamping block 210, and both can select the 155V material, whose yield strength is 1069 MPa, and the rest uses the traditional material of the casing head body 100.

[0051] Regarding the specific structure of the driving assembly 220, in some alternative embodiments, the driving assembly 220 includes a plurality of driving rods 221 and a plurality of driving gears 222. The first end of the driving rod 221 is correspondingly connected to the clamping block 210, the driving gear 222 is correspondingly connected to the second end of the driving rod 221, and the adjacent two driving gears 222 are in transmission connection. The driving gear 222 is configured to drive the driving rod 221 to rotate synchronously so that the driving rod 221 drives the clamping block 210 to slide radially along the first connection hole 110.

[0052] By arranging a plurality of driving gears 222 and correspondingly connecting the driving gears 222 to the second ends of the driving rods 221, one driving gear 222 is fixedly connected to each driving rod 221, so that the driving gear 222 and the driving rod 221 can rotate synchronously. And through the transmission connection between two adjacent driving gears 222, when any driving gear 222 rotates, the rest of the driving gears 222 can be driven to rotate synchronously in sequence, and at the same time, all the driving rods 221 can be driven to rotate synchronously. By arranging a plurality of driving rods 221 and correspondingly connecting the driving rods 221 to the clamping blocks 210 respectively, each clamping block 210 is connected to one driving rod 221, and the movement of the clamping block 210 is driven by the rotation of the driving rod 221, so as to realize the synchronous movement of a plurality of clamping blocks 210.

[0053] It can be understood that the moving direction of the clamping block 210 is along the radial direction of the first connection hole 110, specifically including the direction approaching the axis of the first connection hole 110 and the direction departing from the axis of the first connection hole 110. When the driving rod 221 rotates, the corresponding clamping blocks 210 all move towards the direction approaching the axis of the first connection hole 110 or the direction departing from the axis of the first connection hole 110. The rotation of the driving gear 222 can be realized by a driving motor.

[0054] In addition, it should be noted that the plurality of driving gears 222 are evenly spaced along the circumferential direction of the casing head body 100 to form a transmission structure with end-to-end transmission cooperation.

[0055] In this embodiment, two adjacent driving gears 222 refer to the driving gears 222 corresponding to two adjacent driving rods 221. The two adjacent driving gears 222 are transmission-connected through a transmission gear 223, that is, the transmission gear 223 meshes with the two adjacent driving gears 222 at the same time. The transmission gear 223 can be rotatably connected to the casing head body 100 through a rotating shaft. With such a setting, the rotation directions of all the driving gears 222 are the same during the rotation process, so as to realize the clamping blocks 210 moving together towards / away from the casing 300.

[0056] Of course, in other alternative embodiments, the two adjacent driving gears 222 can be transmission-connected through a chain, and in this way, the transmission gear 223 can be not provided.

[0057] In some alternative embodiments, a plurality of radially arranged guide holes 130 are provided in the casing head body 100. The two ends of the guide hole 130 are respectively communicated with the first connection hole 110 and the outer wall of the casing head body 100. The driving gear 222 is arranged outside the casing head body 100, the clamping block 210 is correspondingly arranged in the guide hole 130, the guide hole 130 is configured to limit the rotation of the clamping block 210, and the driving rod connects the clamping block 210 and the driving gear 222 through the guide hole 130.

[0058] It can be understood that the guiding hole 130 is arranged radially along the casing head body 100, the clamping block 210 is arranged in the guiding hole 130, and since the clamping block 210 is arranged circumferentially around the first connecting hole 110, therefore, the guiding hole 130 is also arranged circumferentially around the first connecting hole 110 in the casing head body 100. On the one hand, the guiding hole 130 plays a guiding role for the clamping block 210, so that the moving direction of the clamping block 210 is along the radial direction of the first connecting hole 110; on the other hand, the guiding hole 130 can also play a limiting role for the clamping block 210, so that the clamping block 210 is limited by the hole wall of the guiding hole 130 in the guiding hole 130, and the clamping block 210 will not rotate. When the first limiting portion 211 is a first toothed portion and the second limiting portion 320 is a second toothed portion, it can be ensured that the tooth position of the first toothed portion will not change, and there will be no situation where the first toothed portion and the second toothed portion cannot be inserted. Moreover, the guiding hole 130 can also allow the driving rod 221 to pass through, so that the driving rod 221 can smoothly connect the driving gear 222 and the clamping block 210. By arranging the driving gear 222 outside the casing head body 100, it is more convenient to control the rotation of the driving gear 222.

[0059] It can be understood that the above-mentioned guiding hole 130 is a non-circular hole, and the contour shape of the clamping block 210 is adapted to the cross-sectional contour shape of the guiding hole 130, so that the clamping block 210 can only move along the extending direction of the guiding hole 130 in the guiding hole 130, and will not move in other directions. For example, the guiding hole 130 can be a rectangular hole, and correspondingly, the clamping block 210 is a rectangular block. Or, the guiding hole 130 is an oval hole, and correspondingly, the clamping block 210 is an oval block.

[0060] The embodiment of the present application provides two implementation manners in which when the driving rod 221 rotates, the clamping block 210 slides radially along the first connecting hole 110.

[0061] Among them, the first optional implementation manner is that a threaded portion is provided at the first end of the driving rod 221, a first threaded hole is provided on the clamping block 210, the threaded portion is threadedly connected in the first threaded hole, the extending direction of the first threaded hole is parallel to the sliding direction of the clamping block 210, and the driving rod 221 is rotatably connected to the casing head body 100 through a transmission member.

[0062] It can be understood that the sliding direction of the clamping block 210 is along the radial direction of the first connection hole 110. Through the threaded connection between the threaded portion and the first threaded hole, the threaded connection between the driving rod 221 and the clamping block 210 is realized. Since the guiding hole 130 restricts the rotation of the clamping block 210, when the driving rod 221 rotates, the clamping block 210 will move along the extending direction of the first threaded hole. In this way, when the driving rod 221 rotates, the clamping block 210 moves along the radial direction of the first connection hole 110. Moreover, the movement of the clamping block 210 driven by the threaded structure can accurately control the moving distance of the clamping block 210 by controlling the number of rotation turns of the driving rod 221, realizing the precise control of the position of the clamping block 210.

[0063] Optionally, the transmission member 224 is a first bearing, and the driving rod 221 and the casing head body 100 are rotationally connected through the first bearing. The first bearing is sleeved on the driving rod 221. On the one hand, it can reduce the resistance during the rotation of the driving rod 221. On the other hand, it can also function to restrict the axial movement of the driving rod 221, so that the driving rod 221 will not have axial displacement during rotation. At the same time, it can also ensure that when the casing 300 is connected to the casing head body 100 and under high load, the driving rod 221 can still rotate freely.

[0064] Of course, in other embodiments, a limiting block can also be provided on the driving rod 221 to limit the axial displacement of the driving rod 221.

[0065] It can be understood that since the driving rod 221 will not have axial displacement during rotation, that is, the position of the driving rod 221 and the casing head body 100 is relatively fixed and the driving rod 221 can rotate relative to the casing head body 100. Therefore, the driving gear 222 connected to the driving rod 221 will not have axial displacement either, so the requirement for the thickness of the driving gear 222 is relatively low.

[0066] Optionally, in this embodiment, the guiding hole 130 may include a connected first hole section 131 and a second hole section 132. The first hole section 131 communicates with the first connection hole 110, and the second hole section 132 communicates with the outer wall of the casing head body 100. The clamping block 210 is arranged in the first hole section 131, and the transmission member is arranged in the second hole section 132.

[0067] Among them, the cross-sectional shape of the first hole section 131 is non-circular to prevent the clamping block 210 from rotating. The cross-sectional shape of the second hole section is circular to facilitate the installation of the first bearing.

[0068] In a second alternative implementation, a threaded portion is provided at the second end of the driving rod 221, and a part of the guiding hole 130 is configured as a second threaded hole. The threaded portion is threadedly connected to the second threaded hole, and the extending direction of the second threaded hole is parallel to the sliding direction of the clamping block 210. The driving rod 221 and the clamping block 210 are rotatably connected by a transmission member.

[0069] It can be understood that the sliding direction of the clamping block 210 is along the radial direction of the first connection hole 110. By threadedly connecting the threaded portion to the second threaded hole, a threaded connection between the driving rod 221 and the casing head body 100 is achieved. Therefore, when the driving rod 221 rotates, it can be axially displaced. Since the guiding hole 130 restricts the rotation of the clamping block 210, and the clamping block 210 and the driving rod 221 are rotatably connected, when the driving rod 221 rotates, the clamping block 210 will not rotate. When the driving rod 221 is axially displaced, it can drive the clamping block 210 to move synchronously, thereby achieving that when the driving rod 221 rotates, the clamping block 210 moves along the radial direction of the first connection hole 110. Moreover, by driving the movement of the clamping block 210 through the threaded structure, the moving distance of the clamping block 210 can be accurately controlled by controlling the number of turns of the driving rod 221, achieving accurate control of the position of the clamping block 210.

[0070] It should be noted that in this embodiment, the distance from the position where the clamping block 210 clamps the casing 300 to the position where the first limiting portion 211 and the second limiting portion 320 are completely disengaged is the first distance. The thickness of the driving gear 222 needs to be set to be greater than the first distance of the clamping block 210, so that when the clamping block 210 switches between the position of releasing the casing 300 and the position of clamping the casing 300, the engaged driving gear 222 will not become disengaged.

[0071] In some alternative implementations, the transmission member 224 is a second bearing, and the driving rod 221 and the clamping block 210 are rotatably connected through the second bearing. By providing the second bearing, it can not only reduce the resistance when the driving rod 221 and the clamping block 210 rotate, but also make the driving rod 221 and the clamping block 210 relatively fixed, so that when the driving rod 221 moves, it can drive the clamping block 210 to move synchronously.

[0072] Of course, in other implementations, a limiting structure can also be provided between the driving rod 221 and the clamping block 210 to enable the driving rod 221 and the clamping block 210 to move synchronously.

[0073] In an embodiment where the clamping block 210 is rotatably connected to the driving rod 221 through a transmission member, the guiding hole 130 may include a first hole section 131 and a second hole section 132 connected to each other. The first hole section 131 communicates with the first connection hole 110, and the second hole section 132 communicates with the outer wall of the casing head body 100. The cross-sectional area of the first hole section 131 is larger than that of the second hole section 132. The clamping block 210 is disposed in the first hole section 131, and the second hole section 132 is configured to form a second threaded hole.

[0074] By setting the cross-sectional area of the first hole section 131 to be larger than that of the second hole section 132, the second hole section 132 can form a stop structure at the end face of the first hole section 131. This stop structure is used to limit the moving position of the clamping block 210 when it moves in a direction away from the casing 300. Further, it is avoided that the engaged driving gears 222 are disengaged.

[0075] Optionally, the above-mentioned driving rod 221 has a hollow internal structure to reduce the weight of the driving rod 221 and optimize the mechanical properties while ensuring that the driving rod 221 meets the usage requirements, so as to enhance the flexibility and stability of the rotation of the casing 300 within the casing head body 100.

[0076] In order to improve the sealing performance of the casing 300 inserted into the casing head, in some optional embodiments, a sealing ring groove 140 is provided on the inner wall of the first connection hole 110 or the outer wall of the casing 300, and an annular sealing ring is installed in the sealing ring groove 140. By pressing the annular sealing ring between the first connection hole 110 and the casing 300, a sealed connection between the first connection hole 110 and the casing 300 can be achieved.

[0077] Optionally, the sealing ring groove 140 is located above the guiding hole 130.

[0078] Optionally, the number of the sealing ring grooves 140 is multiple, and the multiple sealing ring grooves 140 are arranged at intervals along the axial direction of the first connection hole 110. An annular sealing ring is installed in each sealing ring groove 140. By providing multiple sealing ring grooves 140 and multiple annular sealing rings, a multiple sealing between the first connection hole 110 and the casing 300 can be achieved, and the sealing effect can be improved.

[0079] In some optional embodiments, a mounting seat 400 is further provided at the bottom of the casing head body 100. The mounting seat 400 is fixedly connected to the casing head body 100, and the mounting seat 400 is used to support and fix the casing head body 100.

[0080] In a second aspect, an embodiment of the present application provides a casing connection device, which includes a casing 300 and the above-mentioned casing head, and the casing 300 is inserted into the first connection hole 110.

[0081] It can be understood that the casing head in the casing connection device has all the effects of the casing head provided in the first aspect of this embodiment. After the casing 300 is inserted into the first connection hole 110, the clamping mechanism 200 on the casing head can clamp and fix the casing 300, so that the casing 300 and the casing head are relatively fixed.

[0082] Through the above technical solution, compared with the existing slip connection method between the casing head and the casing 300, it has better connection force. Next, it is verified by performing finite element analysis on the casing 300 and the casing head respectively.

[0083] As Figure 6 shown, specifically, after modeling the structure of the casing 300 and performing finite element analysis, first verify the maximum stress that the casing 300 can bear under the yield and limit conditions. Set a fixed support at the upper end of the casing 300, apply a force at the lower end of the casing 300, and the force increases in increments of 1000 KN. Finally, when the force increases to 12660 KN, the maximum principal stress reaches the yield strength of 1069 MPa. It is obtained that the maximum bearing tensile force of the casing 300 is 12660 KN, and it is obtained that the maximum principal stress is linearly related to the tensile force. The abscissa of the red dot in the figure is the maximum tensile force of 12660 KN, and the ordinate is 1069 MPa.

[0084] It is known that when using the slip connection, due to the slip effect, the maximum tensile force of the casing 300 in the case of slip connection cannot reach 12660 KN. According to the slip effect calculation formula:

[0085]

[0086]

[0087]

[0088]

[0089]

[0090] Among them, T S is the axial tensile ultimate load (N) of the casing 300 without the slip effect; μ is the friction coefficient; K is the lateral load coefficient; A L is the lateral area of the slip (mm 2 ); A1 is the cross-sectional area of the casing 300 (mm 2 ); δ S is the yield strength of the casing 300 (MPa); α is the half taper angle of the back of the slip (°); L is the effective length of the slip (mm). r in is the inner radius of the pipe sleeve (mm), r out is the outer radius of the pipe sleeve (mm).

[0091] Substitute T S equal to 12660 kN into the above formula, and the axial tensile ultimate load of the casing 300 under the slip effect can be obtained as 7165.56 kN.

[0092] As Figure 6 shown, perform finite element analysis on the casing connection device. Set up a mounting seat 400 at the bottom of the base of the casing head body 100 for fixed support, and set an axial tensile load at the bottom of the casing 300. Similarly, take 1000 kN as the initial value and increase it in steps of 1000 kN. Mark the maximum principal stress of the casing 300 at 7165.56 kN, and continue to increase to find the ultimate load of the casing 300. Referring to Figure 7 the point No. 1 shown in [reference], when the tensile load is 7165.56 kN, the maximum principal stress of the casing 300 is 1065.6 MPa. The point No. 2 in the figure represents the maximum tensile ultimate load when reaching the yield limit of the casing 300, which is 8015 kN. It can be seen from the finite element analysis that under the condition of the same size and material of the casing head body 100, the connection method increases the maximum tensile load by 11.85% and at the same time ensures the reliability of the casing head in practical applications.

[0093] After considering the specification and the invention disclosed herein in practice, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the following claims.

[0094] It should be understood that the present application is not limited to the exact structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. A casing head, characterized in that, Comprising: A casing head body (100), the casing head body (100) being provided with a first connection hole (110) and a first side port (120), the first connection hole (110) being arranged along the axial direction of the casing head body (100), the first side port (120) being arranged in the circumferential direction of the casing head body (100) and communicating with the first connection hole (110), the first connection hole (110) being for inserting a casing (300), and the first side port (120) being for connecting to a second side port (310) on the side wall of the casing (300); A clamping mechanism (200), comprising a plurality of clamping blocks (210) and a driving assembly (220), the plurality of clamping blocks (210) being evenly distributed around the circumferential direction of the first connection hole (110) on the casing head body (100), the driving assembly (220) being connected to the plurality of clamping blocks (210), the distances between the plurality of clamping blocks (210) and the axis of the first connection hole (110) being equal, and the plurality of clamping blocks (210) being configured to synchronously move along the radial direction of the first connection hole (110) under the drive of the driving assembly (220) so as to jointly clamp or release the casing (300).

2. The casing head according to claim 1, wherein, One end of the clamping block (210) close to the casing (300) is provided with a first limiting portion (211), the outer peripheral wall of the casing (300) is provided with a second limiting portion (320), and the distance between the first limiting portion (211) and the first side port (120) is equal to the distance between the second limiting portion (320) and the second side port (310); the first limiting portion (211) and the second side port (310) are in rotational fit along the circumferential direction of the casing (300).

3. The casing head according to claim 2, wherein, The second limiting portion (320) is an annular member, the annular member being wound around the circumferential direction of the casing (300), and at least one of a groove or a protrusion being provided on the annular member, a protrusion corresponding to the groove being provided on the first limiting portion (211), and / or a groove corresponding to the protrusion being provided on the first limiting portion (211).

4. The casing head according to any one of claims 1-3, characterized in that The driving assembly (220) includes a plurality of driving rods (221) and a plurality of driving gears (222), a first end of the driving rod (221) being correspondingly connected to the clamping block (210), the driving gear (222) being correspondingly connected to a second end of the driving rod (221), adjacent two of the driving gears (222) being in transmission connection, and the driving gear (222) being configured to drive the driving rod (221) to rotate synchronously so as to drive the clamping block (210) to slide along the radial direction of the first connection hole (110).

5. The casing head according to claim 4, characterized in that, A plurality of radially arranged guiding holes (130) are provided in the casing head body (100). Two ends of each guiding hole (130) communicate with the first connection hole (110) and the outer wall of the casing head body (100) respectively. The driving gear (222) is arranged outside the casing head body (100). The clamping block (210) is correspondingly arranged in the guiding hole (130). The guiding hole (130) is configured to restrict the rotation of the clamping block (210). The driving rod (221) connects the clamping block (210) and the driving gear (222) through the guiding hole (130).

6. The casing head according to claim 5, wherein A threaded portion is provided at a first end of the driving rod (221). A first threaded hole is provided on the clamping block (210). The threaded portion is threadedly connected in the first threaded hole. The extending direction of the first threaded hole is parallel to the sliding direction of the clamping block (210). The driving rod (221) and the casing head body (100) are rotatably connected through a transmission member.

7. The casing head according to claim 5, characterized in that, A threaded portion is provided at a second end of the driving rod (221). A second threaded hole is formed in a part of the guiding hole (130). The threaded portion is threadedly connected in the second threaded hole. The extending direction of the second threaded hole is parallel to the sliding direction of the clamping block (210). The driving rod (221) and the clamping block (210) are rotatably connected through a transmission member.

8. The casing head according to claim 7, characterized in that, The guiding hole (130) includes a connected first hole section (131) and second hole section (132). The first hole section (131) communicates with the first connection hole (110). The second hole section (132) communicates with the outer wall of the casing head body (100). The cross-sectional area of the first hole section (131) is larger than that of the second hole section (132). The clamping block (210) is arranged in the first hole section (131). The second hole section (132) forms the second threaded hole.

9. The casing head according to claim 1 or 2, characterized in that, A sealing ring groove (140) is provided on the pore wall of the first connection hole (110) or the outer wall of the casing (300). An annular sealing ring is installed in the sealing ring groove (140).

10. A casing connection device, characterized in that, It includes a casing (300) and the casing head according to any one of claims 1-9. The casing (300) is inserted into the first connection hole (110).

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