Casing head device based on pressure control system

Abstract

The invention discloses a casing head device based on a pressure control system, and relates to the technical field of petroleum well facilities, the casing head device comprises a shell, and an intermediate casing is mounted on the lower side of the shell; the suspension fixing mechanism is used for installing the oil-string casing in the shell, and the lower end of the oil-string casing penetrates through the intermediate casing; the sealing mechanism is located on the lower side of the hanging and fixing mechanism and arranged between the oil-string casing and the inner wall of the shell; wherein the hanging and fixing mechanism comprises two metal soft belts and two tensioning and fixing assemblies, and each metal soft belt comprises an arc-shaped part wrapping the outer circumferential face of the intermediate casing and straightening parts connected to the two ends of the arc-shaped part. The two metal soft belts can be tensioned through the two tensioning and fixing assemblies, the oil-string casing is fixed through the arc-shaped parts of the two metal soft belts, the installation mode is more convenient to operate and high in efficiency, the construction period is shortened, and the labor intensity of installation personnel is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum well facilities, and in particular to a casing head device based on a pressure control system. Background Art

[0002] The casing head is a key component in oil drilling and completion operations. It is mainly used to fix the wellhead of the drilled well, connect the wellhead casing string, support the gravity of the technical casing and the oil layer casing, and seal the annular space between the layers of pipes. It provides a transition connection for the installation of blowout preventers, tubing heads, and Christmas trees, and through the two side ports on the casing head body, it can be used for construction operations such as squeezing mud, monitoring, and adding balance fluid.

[0003] The existing technical casing is generally fixed in the casing head by a casing hanger, which can be a slip type or a mandrel type. The slip type casing hanger hangs the casing by the clamping force of the slips, while the mandrel type casing hanger achieves suspension by the cooperation of the mandrel and the casing. The above two methods of fixing the technical casing are both cumbersome during installation, and the installer needs to spend a lot of effort to install and fix the technical casing and the casing head. The above installation includes the seal between the technical casing and the casing head. Summary of the invention

[0004] The purpose of the present invention is to provide a casing head device based on a pressure control system, which solves the problem that the existing technical casing methods are relatively cumbersome during installation and require installers to expend a lot of effort to install and fix the technical casing and the casing head.

[0005] The present invention solves the above technical problems through the following technical solutions, which include:

[0006] Shell, the technical sleeve is installed on the lower side of the shell;

[0007] A hanging and fixing mechanism, wherein the hanging and fixing mechanism is used to install the oil layer casing inside the shell, and the lower end of the oil layer casing passes through the technical casing; and

[0008] A sealing mechanism, which is located at the lower side of the suspension fixing mechanism and is arranged between the oil layer casing and the inner wall of the shell;

[0009] Among them, the hanging and fixing mechanism includes two metal soft belts and two tensioning and fixing components, and the two metal soft belts each include an arc-shaped portion covered on the outer circumferential surface of the technical casing and a straightening portion connected to the two ends of the arc-shaped portion. The two tensioning and fixing components are symmetrically installed in the shell, and the straightening portions at one end of the two metal soft belts are connected to one of the tensioning and fixing components, and the straightening portions at the other ends of the two metal soft belts are connected to the other tensioning and fixing component. The two tensioning and fixing components respectively tighten and straighten the two ends of the metal soft belts to achieve fixation of the oil layer casing.

[0010] Preferably, the tensioning and fixing assembly includes an outer vertical plate fixed to the ends of the straightened portions of the two metal soft belts, the outer vertical plate is laterally slidably installed in the shell, a plurality of hydraulic telescopic rods are installed on the inner side of the outer vertical plate, the plurality of hydraulic telescopic rods are connected to a first electronic valve through a pipeline, and the hydraulic telescopic rod is installed with a first pressure sensor for monitoring the hydraulic pressure in the hydraulic telescopic rod, the first electronic valve is connected to an external hydraulic station, an inner frame block is fixed to the telescopic end of the hydraulic telescopic rod, two symmetrically arranged abutment assemblies are installed on the inner side of the inner frame block, and a first spring is installed on the outer side of the outer vertical plate.

[0011] Preferably, the abutment assembly includes a mounting block installed on the inner frame block, two upper and lower sliders are installed on the mounting block for transverse sliding movement, a long wheel is rotatably installed between the two sliders, a connecting block is fixed together with the mounting block and the slider, a tightening block is rotatably installed between the two mounting blocks via a rotating shaft, a half gear is fixed on the rotating shaft, and a rack meshing with the half gear is fixed on the slider.

[0012] Preferably, the mounting block is detachably connected to the inner frame block via a coupling assembly, wherein the coupling assembly comprises a convex groove provided in the vertical portion of the inner frame block and a convex bar fixed to the mounting block, and the convex bar is plugged and fixed in the convex groove.

[0013] Preferably, the inner wall of the shell is connected to form a mounting groove, the outer side of the mounting groove is provided with a spring groove, one end of the first spring is installed in the spring groove, the inner end side wall of the mounting groove is fixed with a protrusion that limits the outer vertical plate; the side wall of the mounting groove is fixed with a guide rod, and the outer vertical plate is slidably installed on the guide rod.

[0014] Preferably, the casing head device also includes two groups of support mechanisms, which are symmetrically arranged on the shell, and the support mechanisms include multiple groups of sliding rods slidably installed on the shell, and the inner ends of each group of sliding rods are fixed with an arc-shaped support shell, and the outer side of the arc-shaped portion of the metal soft belt is fixed with an outer support block corresponding to the arc-shaped support shell, and the outer ends of the multiple groups of sliding rods are commonly fixed with a connecting plate, and a second spring is installed between the connecting plate and the outer wall of the shell, and a steel wire rope is fixed to the outer end of the clamping block, and the steel wire rope passes through the shell and extends to be fixed to the connecting plate, and a guide wheel is provided at the corner where the steel wire rope passes.

[0015] Preferably, the inner wall of the metal soft belt is fixed with multiple groups of vertically distributed inner support blocks, and the outer wall of the technical sleeve is provided with multiple vertically distributed arc grooves, and when the metal soft belt is tightened, the inner support blocks are clamped in the corresponding arc grooves.

[0016] Preferably, the sealing mechanism includes an annular expansion bag bonded and fixed to the inner wall of the shell, the outer side of the annular expansion bag is connected to a second electronic valve through a pipeline, the second electronic valve is connected to an external hydraulic station, the annular expansion bag is equipped with a second pressure sensor for monitoring the hydraulic pressure in the annular expansion bag, an outer annular sealing block is fixed to the inner side of the annular expansion bag, the inner wall of the outer annular sealing block has an annular groove, an inner annular sealing block is bonded and fixed to the outer wall of the oil layer casing, and the inner annular sealing block is adapted to the annular groove.

[0017] Preferably, an annular plastic bag is provided on the outer side of the inner annular sealing block, and sealant is stored in the annular plastic bag. A plurality of annularly distributed piercing members are fixed to the inner side wall of the annular groove, and a plurality of grooves are opened on the outer side of the inner annular sealing block, and the plurality of grooves respectively correspond to the plurality of piercing members.

[0018] Preferably, the piercing member includes a cross bar portion and a plurality of spike portions fixed to the end of the cross bar portion, and the plurality of spike portions are distributed in a ring shape and are inclined on the outside.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The present invention can tighten two metal soft belts through two tightening and fixing components, and fix the oil layer casing through the arc-shaped parts of the two metal soft belts. This installation method is more convenient to operate, has high efficiency, shortens the construction period, and reduces the labor intensity of the installers;

[0021] 2. The present invention can also clamp and fix the oil layer casing by the abutment assembly to achieve double fixation of the oil layer casing and ensure the stability of its installation;

[0022] 3. The supporting mechanism of the present invention can lift the oil layer casing in a linked manner, bear the weight of the oil layer casing, and ensure the stability of the installation of the oil layer casing;

[0023] 4. The present invention proposes a new type of sealing method, which is easy to operate, reduces the installation intensity of the installers, improves the work efficiency, and has an excellent sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the main cross-sectional structure of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of a first three-dimensional structure of the middle suspension fixing mechanism;

[0026] Figure 3 for Figure 1 A second three-dimensional structural schematic diagram of the middle suspension fixing mechanism;

[0027] Figure 4 for Figure 3 The enlarged structural diagram at A in the middle;

[0028] Figure 5 for Figure 1 A schematic diagram of the top view of the structure of the middle suspension fixing mechanism;

[0029] Figure 6 for Figure 5 The enlarged structural diagram at B in the middle;

[0030] Figure 7 It is a schematic diagram of a side cross-sectional structure of a support mechanism;

[0031] Figure 8 for Figure 1 Schematic diagram of the structure of the sealing mechanism.

[0032] The numbers in the figure represent:

[0033] 1-shell; 2-pipeline component; 31-technical casing; 32-oil layer casing; 33-arc groove; 4-suspension fixing mechanism; 41-metal soft belt; 42-inner support block; 43-tension fixing assembly; 431-outer vertical plate; 432-guide rod; 433-first spring; 434-hydraulic telescopic rod; 435-inner frame block; 4361-mounting block; 4362-sliding block; 4363-connection block; 4364-long wheel; 4365 -half gear; 4366-rack; 4367-tightening block; 437-bump; 5-sealing mechanism; 51-annular expansion bag; 52-outer annular sealing block; 53-piercing piece; 54-inner annular sealing block; 55-annular plastic bag; 56-groove; 57-annular groove; 6-support mechanism; 61-outer support block; 62-arc-shaped support shell; 63-slide rod; 64-connecting plate; 65-second spring; 66-wire rope; 67-guide wheel. DETAILED DESCRIPTION

[0034] The above and other technical features and advantages of the present invention are described in more detail below in conjunction with the accompanying drawings.

[0035] This embodiment provides a technical solution: a casing head device based on a pressure control system, such as Figure 1 and Figure 5 As shown, it includes a shell 1, a hanging and fixing mechanism 4, two sets of supporting mechanisms 6 and a sealing mechanism 5. A pipeline component 2 is provided on the side of the shell 1, and a technical casing 31 is installed on the lower side of the shell 1. The technical casing 31 can be connected by welding, threading or other existing connection methods. The hanging and fixing mechanism 4 is used to install the oil layer casing 32 inside the shell 1, and the lower end of the oil layer casing 32 passes through the technical casing 31.

[0036] like Figures 1 to 6As shown, the suspension fixing mechanism 4 includes two metal soft belts 41 and two tensioning and fixing components 43. The metal soft belt 41 is made of metal braid as a whole, has a certain degree of flexibility, and can be bent. When the metal soft belt 41 is tightened and wrapped around the outer circumference of the technical casing 31 by the two tensioning and fixing components 43, the metal soft belt 41 forms an arc portion and a straightened portion connected to the two ends of the arc portion, and at this time, the metal soft belt 41 will be tightened and fit on the outer surface of the oil pipe casing 32. The two tensioning and fixing components 43 are symmetrically installed in the shell 1. The straightened portions at one end of the two metal soft belts 41 are connected to one of the tensioning and fixing components 43, and the straightened portions at the other ends of the two metal soft belts 41 are connected to the other tensioning and fixing component 43. The two tensioning and fixing components 43 tighten and straighten the two ends of the metal soft belt 41 respectively, and the arc portions of the two metal soft belts 41 squeeze and fix the oil layer casing 32 to achieve fixation of the oil layer casing 32.

[0037] As shown in FIG7 , in order to strengthen the reliability between the metal soft belt 41 and the technical sleeve 31, a plurality of groups of vertically distributed inner support blocks 42 are fixed to the inner wall of the metal soft belt 41, and the upper side of the inner support blocks 42 is flat, and a plurality of vertically distributed arc grooves 33 are arranged on the outer wall of the technical sleeve 31. When the metal soft belt 41 is tightened, the inner support blocks 42 are clamped in the corresponding arc grooves 33, thereby stably supporting the technical sleeve 31.

[0038] like Figures 3 to 6As shown, the tensioning and fixing assembly 43 includes an outer vertical plate 431 fixed to the ends of the straightened parts of the two metal soft belts 41, and the outer vertical plate 431 is installed in the shell body 1 for transverse sliding. Specifically, the inner wall of the shell body 1 is connected to open a mounting groove, and the inner end side wall of the mounting groove is fixed with a protrusion 437 for limiting the outer vertical plate 431; the side wall of the mounting groove is fixed with a guide rod 432, and the outer vertical plate 431 is slidably installed on the guide rod 432, and the outer vertical plate 431 can only be displaced in the mounting groove. A plurality of hydraulic telescopic rods 434 are installed on the inner side of the outer vertical plate 431. The plurality of hydraulic telescopic rods 434 are connected to a first electronic valve through a pipeline, and a first pressure sensor for monitoring the hydraulic pressure in the hydraulic telescopic rod 434 is installed on the hydraulic telescopic rod 434. The first electronic valve is connected to an external hydraulic station, and the plurality of hydraulic telescopic rods 434 can be driven to operate through the hydraulic station to shrink or extend, and the hydraulic flow in the pipeline can be closed through the first electronic valve, so that the hydraulic telescopic rod 434 is in an extended state for a long time. The pressure monitored by the first pressure sensor can be used to control the hydraulic pressure. The working pressure of the telescopic rod 434, the telescopic end of the hydraulic telescopic rod 434 is fixed with an inner frame block 435, and two symmetrically arranged abutment components are installed on the inner side of the inner frame block 435. The abutment components are used to tightly fix the oil layer casing 32 and guide the metal soft belt 41. The outer side of the outer vertical plate 431 is installed with a first spring 433, and a spring groove is opened on the outer side of the mounting groove. One end of the first spring 433 is installed in the spring groove. When the first spring 433 is squeezed, it can be completely compressed into the spring groove, and the outer vertical plate 431 will abut against the side wall of the mounting groove.

[0039] like Figure 4 and Figure 6As shown, the abutment assembly includes a mounting block 4361 mounted on the inner frame block 435, and two upper and lower sliders 4362 are mounted on the mounting block 4361 for horizontal sliding movement. Specifically, the mounting block 4361 is provided with a slide groove, and the slider 4362 is slidably arranged in the slide groove. An elongated wheel 4364 is rotatably mounted between the two sliders 4362, and the elongated wheel 4364 contacts the straightened portion of the metal soft belt 41. The elongated wheels 4364 of the two abutment assemblies can tightly fix the two metal soft belts 41. The mounting block 4361 and the slider 4362 are jointly fixed with a connecting block 4363, and the connecting block 4363 can only withstand a certain horizontal force. When the force exceeds the set threshold, the connecting block 4363 will break and split from the mounting block 4361, so that the slider 4362 moves into the slide groove. A clamping block 4367 is rotatably installed between the two mounting blocks 4361 through a rotating shaft, a half gear 4365 is fixed to the rotating shaft, and a rack 4366 meshingly connected to the half gear 4365 is fixed to the slider 4362. When the slider 4362 slides, the rack 4366 and the half gear 4365 cooperate to drive the clamping block 4367 to flip to the side of the oil layer casing 32 until the elongated wheel 4364 and the clamping block 4367 simultaneously clamp the oil layer casing 32, and the rack 4366 and the half gear 4365 are stuck, so that the oil layer casing 32 can be fixed at multiple points, thereby increasing the reliability. The setting of this structure can further fix the oil layer casing 32.

[0040] When in use, the oil layer casing 32 is hoisted into the housing 1 by the hoisting device, and passes through the gap between the arc-shaped parts of the two metal soft belts 41 (at this time, the gap is larger than the outer diameter of the oil layer casing 32), and then the telescopic end of the hydraulic telescopic rod 434 is extended, so that the inner frame block 435 can be displaced to one side of the oil layer casing 32, and the two elongated wheels 4364 can straighten the straightened parts of the two metal soft belts 41 until the two elongated wheels 4364 abut against the oil layer casing 32 and cannot move. At this time, the extension of the hydraulic telescopic rod 434 continues, which will squeeze and push the outer vertical plate 431 outward, and in this process, the metal soft belt 41 will be pulled outward, and the arc-shaped parts of the two metal soft belts 41 will be pulled outward. The gap between the parts is reduced, so that the oil layer casing 32 can be fixed by the metal soft belt 41, and finally the outer vertical plate 431 is pressed against the wall of the installation groove, and the telescopic end of the hydraulic telescopic rod 434 is continuously extended, and the force acting on the long wheel 4364 is increased, and the rack 4366 is finally separated from the installation block 4361, and the slider 4362 will shrink into the slide groove. At this time, under the action of the half gear 4365 and the rack 4366, the pressing block 4367 will be driven to flip inward, and finally the long wheel 4364 and the pressing block 4367 are pressed against the metal soft belt 41 on the outside of the oil layer casing 32 to achieve double fixation of the oil layer casing 32 and ensure its stability.

[0041] like Figure 4 and Figure 6As shown, further, in order to enable the abutment assembly to be disassembled, the mounting block 4361 is detachably connected to the inner frame block 435 via a coupling assembly, and the coupling assembly includes a convex groove opened in the vertical portion of the inner frame block 435 and a convex bar fixed to the mounting block 4361, and the convex bar is inserted and fixed in the convex groove. When the convex bar is taken out of the convex groove, the abutment assembly can be disassembled.

[0042] like Figure 5 and Figure 6 As shown, two groups of support mechanisms 6 are symmetrically arranged on the housing 1, and the support mechanism 6 includes multiple groups of slide bars 63 slidably installed on the housing 1. In order to ensure the stability of the slide bars 63 when sliding, a linear bearing cylinder can be installed at the corresponding position of the housing 1. The slide bars 63 pass through the inner cavity of the linear bearing cylinder. The inner end of each group of slide bars 63 is fixed with an arc-shaped support housing 62, and the interior of the arc-shaped support housing 62 has a support chamber. The outer side of the arc-shaped portion of the metal soft belt 41 is fixed with an outer support block 61 corresponding to the arc-shaped support housing 62. The bottom of the support chamber and the arc-shaped support housing 62 are both flat. A connecting plate 64 is fixed to the outer ends, and a second spring 65 is installed between the connecting plate 64 and the outer wall of the shell 1. The second spring 65 will give the connecting plate 64 and the arc-shaped support shell 62 a force to move outward. A wire rope 66 is fixed to the outer end of the tightening block 4367 (a wire rope 66 is fixed to the outer end of each tightening block 4367, which is simplified in the figure). The wire rope 66 runs through the shell 1 and extends to be fixed to the connecting plate 64. A guide wheel 67 is provided at the corner where the wire rope 66 passes to guide the wire rope 66 and reduce friction, so that the wire rope 66 can be pulled more smoothly.

[0043] When the clamping block 4367 is flipped to one side of the oil layer casing 32, the wire rope 66 will be pulled, causing the connecting plate 64 and the arc-shaped support shell 62 to move inward and compress the second spring 65. The outer support block 61 will enter the arc-shaped support shell 62, thereby increasing the supporting strength of the technical casing 31 and preventing the technical casing 31 from sinking. During dismantling, the inner frame block 435 moves outward, the clamping block 4367 will flip outward by itself, the wire rope 66 will become loose, and the arc-shaped support shell 62 will move outward due to the action of the second spring 65.

[0044] like Figure 1 and Figure 8As shown, the sealing mechanism 5 is located at the lower side of the suspension fixing mechanism 4, and is arranged between the oil layer casing 32 and the inner wall of the shell 1, and is used to seal the gap between the oil layer casing 32 and the inner wall of the shell 1; the sealing mechanism 5 includes an annular expansion bag 51 bonded and fixed to the inner wall of the shell 1, and the outer side of the annular expansion bag 51 is connected to a second electronic valve through a pipeline, and the second electronic valve is connected to an external hydraulic station. The annular expansion bag 51 is equipped with a second pressure sensor for monitoring the hydraulic pressure in the annular expansion bag 51, and the hydraulic pressure can be delivered to or extracted from the annular expansion bag 51 through the hydraulic station, so that the annular expansion bag 51 is in a state of being ... The bag 51 expands inwardly, and the degree of expansion of the annular expansion bag 51 can be controlled according to the pressure detected by the second pressure sensor. An outer annular sealing block 52 is fixed on the inner side of the annular expansion bag 51, which has a certain shrinkage deformation performance. The inner wall of the outer annular sealing block 52 has an annular groove 57, and an inner annular sealing block 54 is bonded and fixed to the outer wall of the oil layer casing 32. The inner annular sealing block 54 is adapted to the annular groove 57. When the outer annular sealing block 52 is squeezed inwardly due to the expansion of the annular expansion bag 51, the inner annular sealing block 54 will enter the annular groove 57 to achieve sealing.

[0045] like Figure 8 As shown, further, an annular plastic bag 55 is provided on the outer side of the inner annular sealing block 54, and sealant is stored in the annular plastic bag 55. The annular plastic bag 55 is made of a puncturable material, and a plurality of annularly distributed puncturing members 53 are fixed to the inner side wall of the annular groove 57. The number and spacing of the puncturing members 53 are set according to needs. A plurality of grooves 56 are opened on the outer side of the inner annular sealing block 54, and the grooves 56 are located on the inner side of the annular plastic bag 55, and the plurality of grooves 56 correspond to the plurality of puncturing members 53 respectively.

[0046] When the annular expansion bag 51 squeezes and contracts the outer annular sealing block 52 inward, the piercing member 53 pierces the annular plastic bag 55, causing the sealant in the annular plastic bag 55 to overflow. As the annular expansion bag 51 continues to be squeezed, the sealant in the annular plastic bag 55 overflows into the gap between the inner annular sealing block 54 and the outer annular sealing block 52, thereby sealing the inner annular sealing block 54 and the outer annular sealing block 52 to ensure sealing. Finally, the piercing member 53 will be located in the groove 56.

[0047] like Figure 8 As shown, further, the piercing member 53 includes a cross bar portion and a plurality of spike portions fixed to the end of the cross bar portion, the plurality of spike portions are distributed in a ring shape and are inclined on the outside, this arrangement can make the hole pierced in the annular plastic bag 55 larger and will not be blocked by the piercing member 53 itself, so as to ensure that the sealant in the annular plastic bag 55 overflows smoothly and quickly.

[0048] The above description is only a preferred embodiment of the present invention, which is only illustrative and not restrictive of the present invention. Those skilled in the art understand that many changes, modifications, and even equivalences may be made to the present invention within the spirit and scope defined by the claims of the present invention, but all of them will fall within the scope of protection of the present invention.

Claims

1. A casing head device based on a pressure control system, characterized in that: include: A housing (1), a technical sleeve (31) is mounted on the lower side of the housing (1); A hanging and fixing mechanism (4), wherein the hanging and fixing mechanism (4) is used to install the oil layer casing (32) inside the housing (1), and the lower end of the oil layer casing (32) penetrates the technical casing (31); and A sealing mechanism (5), the sealing mechanism (5) being located at the lower side of the suspension fixing mechanism (4) and arranged between the oil layer casing (32) and the inner wall of the housing (1); The suspension fixing mechanism (4) comprises two metal soft belts (41) and two tension fixing components (43), and the two metal soft belts (41) each comprise an arc portion wrapped around the outer circumference of the technical casing (31) and a straightening portion connected to both ends of the arc portion. The two tension fixing components (43) are symmetrically installed in the shell (1). The straightening portions at one end of the two metal soft belts (41) are connected to one of the tension fixing components (43), and the straightening portions at the other end of the two metal soft belts (41) are connected to another tension fixing component (43). The two tension fixing components (43) respectively tighten and straighten the two ends of the metal soft belt (41) to fix the oil layer casing (32).

2. The casing head device based on the pressure control system according to claim 1, characterized in that: The tensioning and fixing assembly (43) comprises an outer vertical plate (431) fixed to the ends of the straightened parts of the two metal soft belts (41), the outer vertical plate (431) being installed in a transverse sliding manner in the housing (1), a plurality of hydraulic telescopic rods (434) being installed on the inner side of the outer vertical plate (431), the plurality of hydraulic telescopic rods (434) being connected to a first electronic valve through a pipeline, and the hydraulic telescopic rod (434) being installed with a first pressure sensor for monitoring the hydraulic pressure in the hydraulic telescopic rod (434), the first electronic valve being connected to an external hydraulic station, an inner frame block (435) being fixed to the telescopic end of the hydraulic telescopic rod (434), two symmetrically arranged abutment assemblies being installed on the inner side of the inner frame block (435), and a first spring (433) being installed on the outer side of the outer vertical plate (431).

3. The casing head device based on the pressure control system according to claim 2, characterized in that: The abutment assembly comprises a mounting block (4361) mounted on the inner frame block (435); two upper and lower sliders (4362) are mounted on the mounting block (4361) for horizontal sliding movement; a long wheel (4364) is rotatably mounted between the two sliders (4362); a connecting block (4363) is fixed to the mounting block (4361) and the slider (4362); a tightening block (4367) is rotatably mounted between the two mounting blocks (4361) via a rotating shaft; a half gear (4365) is fixed to the rotating shaft; and a rack (4366) meshingly connected to the half gear (4365) is fixed to the slider (4362).

4. The casing head device based on the pressure control system according to claim 3, characterized in that: The mounting block (4361) is detachably connected to the inner frame block (435) via a coupling assembly, wherein the coupling assembly comprises a convex groove provided in the vertical portion of the inner frame block (435) and a convex strip fixed to the mounting block (4361), and the convex strip is inserted and fixed in the convex groove.

5. The casing head device based on the pressure control system according to claim 3, characterized in that: The inner wall of the housing (1) is connected to a mounting groove, the outer side of the mounting groove is provided with a spring groove, one end of the first spring (433) is installed in the spring groove, and the inner end side wall of the mounting groove is fixed with a protrusion (437) for limiting the outer vertical plate (431); the side wall of the mounting groove is fixed with a guide rod (432), and the outer vertical plate (431) is slidably installed on the guide rod (432).

6. The casing head device based on the pressure control system according to claim 3, characterized in that: The casing head device also includes two groups of support mechanisms (6), the two groups of support mechanisms (6) are symmetrically arranged on the shell (1), the support mechanism (6) includes a plurality of slide rods (63) slidably mounted on the shell (1), the inner end of each group of slide rods (63) is fixed with an arc-shaped support shell (62), the outer side of the arc-shaped portion of the metal soft belt (41) is fixed with an outer support block (61) corresponding to the arc-shaped support shell (62), the outer ends of the plurality of groups of slide rods (63) are commonly fixed with a connecting plate (64), a second spring (65) is installed between the connecting plate (64) and the outer wall of the shell (1), a steel wire rope (66) is fixed to the outer end of the tightening block (4367), the steel wire rope (66) passes through the shell (1) and extends to be fixed to the connecting plate (64), and a guide wheel (67) is provided at the corner where the steel wire rope (66) passes.

7. The casing head device based on the pressure control system according to claim 1, characterized in that: The inner wall of the metal flexible belt (41) is fixed with a plurality of groups of vertically distributed inner support blocks (42), and the outer wall of the technical sleeve (31) is provided with a plurality of vertically distributed arc-shaped grooves (33); when the metal flexible belt (41) is tightened, the inner support blocks (42) are clamped in the corresponding arc-shaped grooves (33).

8. The casing head device based on the pressure control system according to claim 1, characterized in that: The sealing mechanism (5) comprises an annular expansion bag (51) bonded and fixed to the inner wall of the shell (1); the outer side of the annular expansion bag (51) is connected to a second electronic valve through a pipeline; the second electronic valve is connected to an external hydraulic station; the annular expansion bag (51) is equipped with a second pressure sensor for monitoring the hydraulic pressure in the annular expansion bag (51); an outer annular sealing block (52) is fixed to the inner side of the annular expansion bag (51); the inner wall of the outer annular sealing block (52) has an annular groove (57); an inner annular sealing block (54) is bonded and fixed to the outer wall of the oil layer casing (32); the inner annular sealing block (54) is adapted to the annular groove (57).

9. The casing head device based on the pressure control system according to claim 8, characterized in that: An annular plastic bag (55) is arranged on the outer side of the inner annular sealing block (54), and sealant is stored in the annular plastic bag (55). A plurality of annularly distributed piercing members (53) are fixed to the inner side wall of the annular groove (57). A plurality of grooves (56) are opened on the outer side of the inner annular sealing block (54), and the plurality of grooves (56) respectively correspond to the plurality of piercing members (53).

10. The casing head device based on the pressure control system according to claim 9, characterized in that: The piercing member (53) comprises a crossbar portion and a plurality of spike portions fixed to the end of the crossbar portion, wherein the plurality of spike portions are distributed in a ring shape and are arranged obliquely on the outside.

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