CN217151876U - Sleeve centering assembly and sleeve supporting and centering device - Google Patents

Abstract

The utility model provides a sleeve pipe centering subassembly and sleeve pipe support centering device. The centering assembly comprises a top thread body, a fixed seat, a baffle, a screw and a centering chuck; the top thread body is provided with a baffle groove and a cavity penetrating through the inner end surface and the outer end surface, the fixed seat is arranged in the cavity, and the cavity can limit the fixed seat to rotate circumferentially and move inwards; the baffle can be inserted into the baffle slot and can limit the outward movement of the fixed seat; the screw rod penetrates through the threaded cavity, and the external thread of the screw rod is matched with the internal thread of the threaded cavity; the centering chuck is arranged at the inward end of the screw rod and can be attached to the sleeve. The sleeve supporting and centering device comprises at least three groups of supporting and centering units; each group of supporting and centering units comprises a centering assembly, a supporting assembly and a positioning assembly which are sequentially connected from bottom to top; the beneficial effects of the utility model include: the safety and the high efficiency are realized; the mounting failure caused by the solidification of cement paste due to long centering time is prevented; meanwhile, the safety of operators is guaranteed.

Description

Sleeve centering assembly and sleeve supporting and centering device

Technical Field

The utility model relates to an oil drilling field relates to a sleeve pipe centering subassembly and sleeve pipe support centering device very much.

Background

In oil and gas exploration drilling engineering, when a certain well depth is drilled, a casing with a certain depth needs to be put in to isolate a stratum so as to implement the next drilling engineering. The casing slips function as a key component to suspend the casing head at the surface of the casing and to form a seal at the casing head between the casing and the formation or casing. When the casing slip is installed, firstly, the connection between the lift-off casing head and the blowout preventer stack is disassembled; then, the casing and the casing head need to be centered before the cementing cement is solidified; and finally, placing the slips into a gap between the casing head and the casing and placing the slips on a step of the casing head, and completing the installation after the weight of the casing is suspended.

Two conditions must be met to complete the above three steps: 1. the weight of the upper blowout preventer stack needs to be suspended or supported to provide a safe personnel operating space; 2. the sleeve and the sleeve head are centered at a high speed, the coaxiality of the central lines is smaller than 0.2mm, and the slips can be smoothly placed into the step of the sleeve head.

At present, in actual operation, only two to three groups of chain blocks and steel wire ropes can be used for pulling the sleeve from two to three different directions to be centered, and the operation process is heavy. Especially in the second casing at the wellhead, there is no proper casing anchoring point in the round well and casing centering is difficult. According to statistics, in the last three years, an enterprise fails to center a casing before cement is solidified, so that the installation fails for 5 wells, and about 230 ten thousand yuan is directly lost. In the process of lifting the blowout preventer stack, the blowout preventer stack is fixed by using a mode of suspending the blowout preventer stack by using a steel wire rope after hoisting. Statistics shows that in recent three years, a blowout preventer stack falls for three times due to reasons such as improper lifting appliance selection and suspension modes of a certain enterprise, direct economic loss of 104 ten thousand yuan is caused, and great hidden dangers are caused to safety of operators. Moreover, the sleeve pipe is centered by the chain block and the steel wire rope sleeve, and is influenced by the precision of the chain block and the tension of the steel wire, so that the centering precision hardly meets the requirement of being less than 0.2mm, and the slips cannot smoothly enter the step position of the sleeve head after being placed into the sleeve head. At present, the slips are in place by adopting a knocking method, but the knocking effect is poor due to limited operation space, the installation time is wasted, and the safety problems that operators fall off and scrap iron splashes when knocking in narrow operation space exist.

Chinese patent publication No. CN202483472U provides a casing centralizer. The casing centralizing tool comprises a base, wherein the base is of a through structure, two groups of adjusting devices are vertically arranged on the base, and the two groups of adjusting devices are matched with each other to centralize a casing. The invention discloses a wellhead auxiliary casing centering slip seating device and an application method thereof, and the device comprises bolts, pile legs, pile leg sleeves, connecting pieces, quick connecting buckles, a jack, two half casing sleeves and an arc-shaped centering block, wherein the two half casing sleeves are buckled and connected through the quick connecting buckles at two butt ends to form a complete circular casing sleeve, 4 connecting pieces are uniformly distributed and connected at intervals of 90 degrees outside the circular casing sleeve, the other end of each connecting piece is welded on the pile leg sleeve, the pile legs are inserted into the pile leg sleeves, the upper ends of the pile legs are movably connected with the jack through the bolts, and the telescopic rod ends of the jack are connected with the arc-shaped centering block. Neither of the above patents can achieve the following effects: the blowout preventer is supported or suspended, and a safe operation space is provided. Secondly, the sleeve is centered quickly, and the coaxiality of the central line is smaller than 0.2 mm.

There is therefore a need for a casing support centering device that addresses the safety, economic and efficiency issues in casing installation.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to solve the above-mentioned not enough at least one item that prior art exists, one of the purpose of the utility model is to realize supporting and quick centering to the sheathed tube.

In order to achieve the above object, one aspect of the present invention provides a bushing centering assembly.

The sleeve centering assembly can comprise a top thread body, a fixed seat, a baffle plate, a screw rod and a centering chuck; the top thread body is provided with a baffle groove and a cavity penetrating through the inner end face and the outer end face, wherein the baffle groove is formed on the inner wall of the cavity and is communicated with the outside; the fixing seat is arranged in the cavity, the cavity can limit the fixing seat to rotate circumferentially and move inwards, the fixing seat is provided with a through threaded cavity, and one opening of the threaded cavity faces the sleeve; the baffle can be inserted into the baffle slot and can limit the outward movement of the fixed seat; the screw rod penetrates through the threaded cavity, and the external thread of the screw rod is matched with the internal thread of the threaded cavity; the centering chuck is arranged at the inward end of the screw rod and can be attached to the sleeve.

Optionally, the central axis of the threaded cavity of the fixing base is perpendicular to the central axis of the sleeve.

Optionally, the cavity body can comprise a screw rod cavity and a fixing cavity which are communicated from inside to outside; wherein the radial dimension of the lead screw cavity is smaller than that of the fixed cavity; the fixing cavity is matched with the fixing seat.

Optionally, the fixing cavity may be a rectangular cavity, and the fixing seat may be a rectangular parallelepiped.

Alternatively, the centering collet may comprise an arc-shaped collet.

Alternatively, the flapper may have a U-shaped opening in which the screw is located with the flapper inserted into the flapper slot.

Optionally, the U-shaped open end of the baffle can be provided with a limiting block, and one end of the baffle, which deviates from the U-shaped open end, can be provided with a handle ring.

On the other hand, the utility model provides a sleeve pipe supports centering device.

The apparatus may comprise at least three sets of support centering units; each group of supporting and centering units comprises a centering component, a supporting component and a positioning component which are sequentially connected from bottom to top. The centering assembly comprises a bushing centering assembly as described above; the support assembly comprises a support rod; the positioning assembly comprises a positioning jackscrew and a jackscrew seat which are matched with each other, and the jackscrew seat is connected with the upper end of the supporting rod.

Optionally, the upper end and the lower end of the supporting rod can be respectively provided with a fixing hole; the upper end of the top thread body can be provided with a first fixing rod extending upwards, the lower end of the top thread body can be provided with a second fixing rod extending downwards, and the first fixing rod is inserted into a fixing hole at the lower end of the supporting rod; the upper end of the jackscrew seat can be provided with a third fixing rod extending upwards, the lower end of the jackscrew seat can be provided with a fourth fixing rod extending downwards, and the fourth fixing rod is inserted into the fixing hole at the upper end of the supporting rod.

Alternatively, the second fixing rod may be fixedly connected to a casing head flange, and the third fixing rod may be fixedly connected to a four-way or wire-cutting flange provided above the casing head.

Optionally, the support rod may be further provided with a pull ring.

Optionally, the device can comprise 3-6 groups of the supporting and centering units.

Compared with the prior art, the beneficial effects of the utility model include at least one of following content:

(1) the potential safety hazard of falling of the heavy object is eliminated.

The utility model discloses take supporting component and centering subassembly integrated design, both alleviateed instrument weight, reached the purpose of support and centering again, eliminated the safe risk of former operation mode heavy object whereabouts again simultaneously.

(2) The centering efficiency is greatly increased.

The utility model discloses can save the installation time of well drilling well head blowout preventer stack, make efficiency increase substantially, stop the installation failure because of the centering failure leads to.

(3) After the centering is finished, the centering assembly can be quickly withdrawn, so that the slips can be conveniently lowered.

The utility model discloses design slidable baffle on the centering subassembly, after the centering was ended, the pulling baffle then can withdraw from the centering subassembly fast, makes things convenient for the slips to transfer.

(4) The centering accuracy is high.

The utility model discloses can make the central line axiality reach the requirement that is less than 0.2mm for the slips can put into casing head step department smoothly.

Drawings

Fig. 1 shows a schematic view of the overall installation of a casing support centering device in an exemplary embodiment of the invention;

fig. 2 shows a schematic structural view of a support centering unit in an exemplary embodiment of the invention;

fig. 3 shows a schematic structural view of a bushing centering assembly in an exemplary embodiment of the present invention;

fig. 4 shows a cross-sectional view of a jackscrew in an exemplary embodiment of the invention;

fig. 5 shows a left side view of the jackscrew body in an exemplary embodiment of the present invention;

fig. 6 shows a schematic structural view of a baffle in an exemplary embodiment of the invention;

figure 7 shows a cross-sectional view of a support bar in an exemplary embodiment of the invention;

fig. 8 shows a top view of a support bar in an exemplary embodiment of the invention;

fig. 9 shows a schematic structural diagram of a positioning assembly in an exemplary embodiment of the invention.

Description of reference numerals:

1-centering component, 11-top thread body, 111-cavity body, 111 a-fixed cavity; 111 b-the shaft lumen; 112-baffle slot; 12-a fixed seat; 13-baffle, 131-stopper, 132-handle ring; 14-a screw; 15-centering the chuck; 16-a first fixing bar; 17-a second fixation bar;

2-support assembly, 21-support bar; 22-a tab; 23-a fixation hole;

3-positioning component, 31-positioning jackscrew; 32-a jackscrew seat; 33-a third fixing bar; 34-a fourth fixing bar;

4-four-way or wire cutting flanges;

5-a sleeve head flange;

6-sleeve.

Detailed Description

The present invention is described in further detail below with reference to the attached drawings and specific embodiments so that those skilled in the art can better understand the present invention.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Exemplary embodiment 1

The present exemplary embodiment provides a casing centering assembly.

The present ferrule centering assembly is described below in conjunction with fig. 3-6.

As shown in fig. 3, the ferrule centering assembly may include: the device comprises a jackscrew body 11, a fixed seat 12, a baffle 13, a screw 14 and a centering chuck 15.

As shown in fig. 3 and 4, a cavity 111 penetrating through the inner and outer end surfaces is formed in the jackscrew 11, the fixing base 12 is installed in the cavity 111, and the cavity 111 can limit the circumferential rotation and inward movement of the fixing base 12.

In the present embodiment, as shown in fig. 4 and 5, the cavity 111 includes a screw cavity 111b and a fixing cavity 111a communicating from inside to outside. The radial dimension of the lead screw lumen 111b is smaller than the radial dimension of the fixation lumen 111 a; the screw cavity 111b is a cavity to which the screw 14 is screwed.

The fixing cavity 111a is adapted to the fixing base 12, and the fixing cavity 111a can limit the circumferential rotation and inward movement of the fixing base 12.

In this embodiment, the central axis of the threaded cavity of the anchor block 12 is perpendicular to the central axis of the cannula 6, ensuring that the centering assembly 1 is able to push the cannula 6 to a centered position.

In this embodiment, the fixing cavity 111a is a rectangular parallelepiped cavity, and the fixing base 12 is a rectangular parallelepiped. Of course, the present invention is not limited thereto, and the fixing cavity 111a and the fixing base 12 may also be in other shapes, such as an oval shape, a prism shape, etc.; as long as the fixing cavity 111a is matched with the fixing seat 12, it is ensured that the fixing seat 12 can be installed in the fixing cavity 111a without rotating, and the screw 14 can be installed in the fixing seat 12.

The fixed seat 12 is provided with a through threaded cavity, and one opening of the threaded cavity faces the sleeve; the screw 14 passes through the threaded cavity and the external thread of the screw 14 is matched with the internal thread of the threaded cavity.

A centering collet 15 is mounted on the inward end of the screw 14 and is able to engage the sleeve 6.

In this embodiment, the centering collet 15 may comprise an arc-shaped collet. The arc-shaped interface of the arc-shaped chuck can simultaneously meet the fitting requirements of the outer diameter sizes of various (such as seven) sleeves of an oil field, namely the fitting area of the arc-shaped chuck with each sleeve is not less than 3 square centimeters, so that the influence of stress concentration on the sleeves is avoided.

In this embodiment, the centering collet 15 can be replaced and selected to have a suitable size according to the size of the jacked pipe 6.

In this embodiment, as shown in fig. 4, the jackscrew 11 is further provided with a baffle slot 112, and the baffle slot 112 is formed on the inner wall of the cavity 111 and is communicated with the outside. The flapper 13 can be inserted into the flapper slot 112 and can limit outward movement of the fixed base 12.

In the present embodiment, as shown in fig. 6, the baffle 13 has a U-shaped opening. With the flapper 13 inserted into the flapper slot 112, the screw 14 is located in the U-shaped opening, the fixed base 12 abuts against the body of the flapper 13, and the flapper 13 can restrict the rearward movement of the fixed base 12.

In this embodiment, as shown in fig. 6, the U-shaped opening end of the baffle 13 is provided with a stopper 131. Stops 131 on the flapper 13 allow the flapper 13 to be installed in the flapper channel 112. After the centering assembly 1 is adopted for centering, the sleeve slips can be quickly lowered only by withdrawing the screw 14 and the fixing seat 12, the slidable baffle 13 is designed, and after the centering is finished, the baffle 13 is pulled, so that the screw 14 and the fixing seat 12 can be quickly withdrawn. The flap 13 provides a reaction force by bearing against the anchor 12 and the screw 14.

In this embodiment, as shown in fig. 6, one end of the baffle 13 facing away from the U-shaped opening is provided with a handle ring 132 to facilitate sliding and pulling of the baffle 13.

Exemplary embodiment 2

The present exemplary embodiment provides a casing support centering device. The device can save the installation time and avoid the installation failure caused by the centering failure; the potential safety hazard of falling of the heavy object can be eliminated.

The present casing support centering device is described below in conjunction with fig. 1-9.

In this embodiment, the apparatus may include at least three sets of support centering units. As shown in fig. 1, the apparatus comprises three sets of supporting and centering units evenly spaced at 120 ° intervals around the circumference of the flange (only two sets of supporting and centering units are shown in the figure for the sake of view). The device can support a space between the blowout preventer stack and the casing head, provides conditions for subsequent work, and facilitates subsequent operation.

In this embodiment, as shown in fig. 2, each group of supporting and centering units may include a centering component 1, a supporting component 2, and a positioning component 3, which are connected in sequence from bottom to top.

The centering assembly 1 may comprise a bushing centering assembly as described in exemplary embodiment 1. The support assembly 2 may include a support rod 21. The positioning assembly 3 may include a positioning jack screw 31 and a jack screw seat 32, which are matched, and the jack screw seat 32 is connected with the upper end of the support rod 21.

In this embodiment, as shown in fig. 7, the upper and lower ends of the support rod 21 are respectively provided with fixing holes 23.

In this embodiment, as shown in fig. 4, the top thread body 11 has a first fixing rod 16 extending upward at an upper end thereof and a second fixing rod 17 extending downward at a lower end thereof, and the first fixing rod 16 is inserted into a fixing hole 23 at a lower end of a support rod 21 to connect the centering assembly 1 with the support assembly 2. Of course, the present invention is not limited thereto, and the centering assembly 1 can also be fixed on the supporting assembly 2 in other manners, such as welding.

In this embodiment, as shown in fig. 9, the top thread seat 32 has a third fixing rod 33 extending upward at an upper end thereof and a fourth fixing rod 34 extending downward at a lower end thereof, and the fourth fixing rod 34 is inserted into the fixing hole 23 at the upper end of the supporting rod 21 to connect the supporting member 2 and the positioning member 3. Of course, the present invention is not limited thereto, and the positioning component 3 can also be fixed on the supporting component 2 in other manners, such as welding.

In this embodiment, the second fixing rod 17 is fixedly connected to the casing head flange 5, and the third fixing rod 33 is fixedly connected to the four-way or wire-cutting flange 4 above the casing head. The second and third fixing rods 17 and 33 secure the support centralizing unit between the blowout preventer and the casing head, supporting an operating space.

In this embodiment, as shown in fig. 7 and 8, a pull ring 22 may be further disposed on the support rod 21 to facilitate the carrying and installation of the support rod.

In this embodiment, in order to avoid the influence of uncertain factors in the stability test of the pressing rod, the utility model discloses design two-part combination to supporting component 2 and centering component 1. Wherein, fixed centering subassembly 1, the stability that can avoid long thin pole is verified.

In the present embodiment, as shown in fig. 9, the positioning assembly 3 includes a top thread seat 32 and a positioning top thread 31, wherein the top thread seat 32 is fixed on the supporting assembly 2 and has a through threaded hole; the positioning jackscrew 31 penetrates through the threaded hole, and the external thread of the positioning jackscrew 31 is matched with the internal thread of the threaded hole; the head of the positioning jackscrew 31 can clamp the pipeline. After the centering assembly 1 is withdrawn, the positioning assembly 3 can fix the position of the sleeve 6, so that the subsequent operation is facilitated, and the position change of the sleeve 6 after the centering assembly 1 is withdrawn is avoided.

In the embodiment, the casing supporting and centering device can comprise 3-6 groups of supporting and centering units. 3 ~ 6 support centering units can guarantee the intensity of support and sufficient operating space.

The installation of the casing support centering device of the present exemplary embodiment includes the steps of:

(1) the lower sleeve centering component 1, the upper positioning component 3 and the support component 2 form a support centering unit to support between the sleeve head flange 5 and the four-way or wire cutting flange 4.

(2) Three sets of supporting and centering units are placed on the circumference of the flange at 120 degrees.

(3) The lower sleeve centering component 1 performs centering operation on the sleeve 6 through a screw rod, so that the requirement that the central axis of the sleeve 6 is centered towards the central axis of the sleeve head quickly and the centering error is less than 0.2mm is met.

(4) After the casing 6 is centered, casing slips are assembled and placed on the centering assembly 1.

(5) After the positioning assembly 3 fixes the casing 6, the baffle 13 is moved to rapidly withdraw from the screw rod and the fixed seat in the centering assembly 1, so that the slip assembly falls onto the casing head step, and finally the casing is lowered to finish the suspension of the casing.

For a better understanding of the above exemplary embodiments, the design of the casing support centering device is further explained below with reference to specific examples.

In this example, the anchor block 12 is a square nut. The nut height may be 50 mm; the nut outer diameter may be 70 mm.

Calculating the size of the nut:

by looking up a table to know

Design of trapezoidal thread

The working height h of the thread ridge is 0.5P; allowable stress [ p ]]21Mpa

Major diameter and bottom diameter:

looking up the table, d is 40mm, d ₂ Taking 36.5mm, P is 7mm

Height of nut

H' is an integer of 50mm

The outer diameter of the nut is as follows: d ₃ ＝1.7×d＝1.7×40＝68mm，d ₃ Taking the integer as 70mm

In the above-mentioned formula, the compound has the following structure,

representing the tooth form factor; h represents the working height of the thread; p represents the pitch; [ p ]]Representing allowable stress; h' represents the nut height; d represents the nominal diameter of the jackscrew; d ₂ Representing the thread root diameter; d ₃ Representing the outer diameter of the nut.

In this example, the material of the fixing base 12 may be a bronze material.

In the present example, the length of the screw 14 is designed according to: and calculating and optimizing the length required when the slip is installed by subtracting the outer diameter of the casing commonly used by the casing head from the diameter of the bolt distribution circle of the current maximum casing head and the minimum casing head, wherein the total length is 300 mm. In the present example, 45 steel is selected as the material of the screw.

In this example, the overall length of the centering assembly 1 may be 300mm and the height may be 126 mm. The length design of the centering assembly 1: and (3) calculating the length of the centering component required when the slip is installed and optimizing by subtracting the common sleeve outer diameter of the sleeve head from the bolt distribution circle diameter of the current maximum sleeve head and the minimum sleeve head, wherein the total length is 300mm by calculation. The height of the centering assembly 1 is 126mm, depending on the requirements of the support assembly 2, the positioning assembly 3 and the operating space. The material selected by the centering assembly 1 is 45 steel, so that the safety of wellhead operation can be ensured.

In this example, the holder 12 and the screw 14 may be replaced with a screw jack. The centering chuck 15 is fixed at the output end of the jack and can receive the driving force of the jack to push the sleeve 6 to move. The maximum jacking force of the jackscrew is 5.8 tons. The jacking force design basis of the screw jack is as follows: at present, the manual block centering sleeve is used on site, and the success rate is over 98 percent. The maximum pulling force of the chain block is 5 tons, and considering that the acting point of the chain block has component force, the maximum force actually acting on the sleeve is not more than 4.5 tons. The maximum jacking force of the screw jack is designed to be 5.8 tons according to the design of 30 percent of additional jacking force.

The support rod 21 provides enough support strength of more than 4 times of safety factor; the safety of the support is ensured. The appearance design accords with the requirement of little compliance pole, conveniently carries and carries.

The height of the support rod 21 is more than 80mm, and 280mm is taken in the example; the diameter ranges between 56mm and 140mm, with a diameter of 70mm being taken for this example.

In the present example, the support bar 21 is designed to be high (in the present example, the operating space is set to 200 mm):

H＝H1+H2-H3-H4＝286+200-126-80＝280mm

in the above formula, H1 is the highest slip height; h2 is an operation space; h3 is the centering assembly height; h4 is the registration assembly height.

In this example, the support rod 21 is designed with a diameter: considering only the case where λ < λ 0, i.e., the length divided by the cross-sectional area is less than the range of the material's low compliance rod, (< phi > < L/2) is a short thick rod and < phi > < L/5 is a low compliance rod ((S))

Representing the length divided by the cross-sectional area) to yield a diameter range for the support rod 21 of between 56mm and 140mm, in this example 70mm diameter. The material of the support rod 21 is 45 steel which is commonly used for well control.

In the present example, the height of the positioning assembly 3 may be 80 mm. The height of the positioning assembly 3 is 80mm, depending on the slip height, operating space, requirements of the centering assembly 1 and the support assembly 2.

Checking the strength of the supporting rod: the maximum weight of the well head is set to be 700KN, and 3 supporting rods are used for supporting the well head.

Then:

looking up a table [ sigma ] ═ 150 MPa; sigma < [ sigma ]

In the above formula, σ represents the actual compressive stress to which the support rod is subjected in this example; a represents the cross-sectional area of the support rod; f _N Representing the magnitude of the compressive stress applied to each supporting rod; d represents the strut diameter; [ sigma ]]Representing the allowable stress of the strut material.

According to the formula, the stress intensity of the support rod is enough.

Although the present invention has been described above in connection with exemplary embodiments, it will be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (12)

1. The sleeve centering assembly is characterized by comprising a top thread body, a fixed seat, a baffle plate, a screw and a centering chuck; wherein the content of the first and second substances,

the top thread body is provided with a baffle groove and a cavity penetrating through the inner end surface and the outer end surface, wherein the baffle groove is formed on the inner wall of the cavity and is communicated with the outside;

the fixing seat is arranged in the cavity, the cavity can limit the fixing seat to rotate circumferentially and move inwards, the fixing seat is provided with a through threaded cavity, and one opening of the threaded cavity faces the sleeve;

the baffle can be inserted into the baffle slot and can limit the outward movement of the fixed seat;

the screw rod penetrates through the threaded cavity, and the external thread of the screw rod is matched with the internal thread of the threaded cavity;

the centering chuck is arranged at the inward end of the screw rod and can be attached to the sleeve.

2. The cannula centering assembly of claim 1, wherein a central axis of the threaded cavity of the anchor block is perpendicular to a central axis of the cannula.

3. The cannula centering assembly of claim 1, wherein said cavity comprises a stem cavity and a fixation cavity communicating from inside to outside; wherein the content of the first and second substances,

the radial dimension of the lead screw cavity is smaller than that of the fixed cavity;

the fixing cavity is matched with the fixing seat.

4. The cannula centering assembly of claim 3, wherein the fixation cavity is a cuboid cavity and the fixation seat is a cuboid.

5. The cannula centering assembly of claim 1, wherein the centering collet comprises an arc-shaped collet.

6. The cannula centering assembly of claim 1, wherein the flapper has a U-shaped opening in which the screw is located with the flapper inserted into the flapper slot.

7. The bushing centering assembly of claim 6, wherein the U-shaped open end of the baffle is provided with a stop block, and an end of the baffle facing away from the U-shaped open end is provided with a handle ring.

8. The casing supporting and centering device is characterized by comprising at least three groups of supporting and centering units; wherein the content of the first and second substances,

each group of supporting and centering units comprises a centering component, a supporting component and a positioning component which are sequentially connected from bottom to top;

the centering assembly comprises the ferrule centering assembly of any one of claims 1-7;

the support assembly comprises a support rod;

the positioning assembly comprises a positioning jackscrew and a jackscrew seat which are matched with each other, and the jackscrew seat is connected with the upper end of the supporting rod.

9. The casing supporting and centering device according to claim 8, wherein the upper and lower ends of the supporting rod are respectively provided with a fixing hole;

the upper end of the top thread body is provided with a first fixing rod extending upwards, the lower end of the top thread body is provided with a second fixing rod extending downwards, and the first fixing rod is inserted into a fixing hole at the lower end of the supporting rod;

the upper end of the jackscrew seat is provided with a third fixing rod extending upwards, the lower end of the jackscrew seat is provided with a fourth fixing rod extending downwards, and the fourth fixing rod is inserted into a fixing hole at the upper end of the supporting rod.

10. The casing support centering device of claim 9, wherein the second retaining bar is fixedly connected to a casing head flange, and the third retaining bar is fixedly connected to a four-way or wire-cutting flange on the casing head.

11. The cannula support centering device of claim 8, wherein a pull ring is further disposed on the support rod.

12. The casing supporting and centering device of claim 8, wherein the device comprises 3-6 sets of the supporting and centering units.

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