CN214576889U

CN214576889U - Wellhead blowout prevention packer

Info

Publication number: CN214576889U
Application number: CN202022319249.2U
Authority: CN
Inventors: 张瑞霞; 刘永顺; 魏伟; 岳广韬; 朱瑛辉; 田浩然; 周景彩; 刘建新; 闫丽丽; 毛晓楠; 韩博
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering Shengli Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering Shengli Co
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2021-11-02
Anticipated expiration: 2030-10-16

Abstract

The utility model discloses a wellhead blowout prevention packer, which comprises an upper anchoring and sealing mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially sleeved on the outer wall of an outer central pipe from top to bottom; the lower end of the upper anchoring sealing mechanism is propped against the upper end surface of a circular bead of the outer wall of the outer central tube, and the upper end of the upper anchoring sealing mechanism is connected with a rotary setting/deblocking mechanism; the lower end of the lower anchoring mechanism is connected with the supporting mechanism, and the upper end of the lower anchoring mechanism is propped against the lower end face of the shoulder of the outer wall of the outer central tube. The utility model discloses can seal the sleeve pipe at the well head, hang the tubular column, have and prevent scurrying the function, the application of plug valve can be accomplished the pressure control in the well at the in-process of changing the well head in supporting oil pipe, reduces the construction risk, reduces worker intensity of labour, prevents that the blowout is out of control.

Description

Wellhead blowout prevention packer

Technical Field

The utility model belongs to the technical field of well head packer technique and specifically relates to a well head blowout prevention packer.

Background

At present, in the process of repairing a well in underground operation, the construction of replacing the well mouth is a more frequent construction procedure. The construction of well mouth replacement is needed in the hot production well steam injection circulation, sand prevention and fracturing construction, long-stop well old well construction and other special working conditions.

The well head replacement construction is relatively mature in process and flow, but has the following problems:

(1) the wellhead is not provided with a control device in the construction process and is in an uncontrollable state. Pressure change in the well cannot be measured in time in the process of replacing the well mouth, observation is not easy, if pressure in the well suddenly changes, the well mouth overflows, blowout accidents can not be controlled in time and even out of control occur, and a large well control risk exists;

(2) because the well head replacement process is complicated, especially when a large-scale high-pressure well head or a pipe column is replaced in a well, a special auxiliary tool is not used, the time is long, the efficiency is low, and well control and safety risks are invisibly increased.

The existing hydraulic setting packer needs a series of applications such as matching hydraulic pipelines, pump trucks and the like in wellhead application, is relatively complex to use and cannot be recycled; the conventional mechanical setting packers Y211, Y221 and the like cannot meet the application occasions that no production string is arranged at the lower part or the upper part of the string, and cannot realize the function of preventing the string from jacking.

Publication (bulletin) No.: CN107165600B, publication (public notice) day: 2018-04-17 is a high-efficiency environment-friendly wellhead sealing device for an oil well, which comprises a blowout preventer, a packing press sleeve, a packing barrel and a base, wherein the blowout preventer shell, the packing press sleeve, the packing barrel and the base are fixedly installed together from top to bottom in sequence, a base body through hole is formed in the middle of the base, a lower supporting ring seat is fixed on the inner side of the lower part of the packing barrel, a lower packing sealing ring sleeve with the top surface abutting against the lower supporting ring seat is installed below the lower supporting ring seat, an upper supporting ring seat is fixed on the inner side of the upper part of the packing press sleeve, and an upper packing sealing ring sleeve with the bottom surface seated on the upper supporting ring seat is installed above the upper supporting ring seat. The phenomenon of oil leakage and polluted environment can be avoided appearing, whole equipment can normally work is ensured, and the dismouting need not to shut down when maintaining and dismantle, only need open and close the plug can, can not cause the oil recovery to break, guaranteed production efficiency, still can prevent extravagant simultaneously, have high-efficient convenient, labour saving and time saving, characteristics that factor of safety is high.

Publication (bulletin) No.: CN111411914A, publication (public notice) day: 2020-07-14 discloses a shaft blowout prevention plug, which comprises an anchoring assembly, a plugging assembly and an anchor sealing operation assembly, wherein the lower end of the anchoring assembly is connected with the plugging assembly, the anchor sealing operation assembly is inserted into an inner cavity of the anchoring assembly and an inner cavity of the plugging assembly, the anchor sealing operation assembly is connected with an anchoring shifting fork of the anchoring assembly in a torque tube transmission mode, and the anchor sealing operation assembly is connected with a lower joint of the plugging assembly through a central pull tube. When the operation construction needs to change the well mouth operation, the blowout preventer is not required to be removed, the device is directly placed into a shaft through a derrick lifting system, and the shaft is quickly plugged through the rotation of the hydraulic clamp and the lifting compression setting. The blowout accident is prevented.

Publication (bulletin) No.: CN106939777B, publication (public notice) day: 2018-12-21 relates to a blowout prevention packer used in oil extraction engineering in the oil and gas industry. The method solves the problems of packing of an oil-gas production layer and underground blowout prevention. The technical scheme is as follows: the sliding pin is fixed in a pin hole at the lower part of the locking cylinder; the locking steel balls are arranged in the three through holes in the middle of the locking cylinder; the upper end of the connecting cylinder is connected with the lower end of the locking cylinder through screw threads, and the lower end of the connecting cylinder is connected with the upper end of the anchoring cylinder through screw threads; the upper spacing ring, the sealing rubber cylinder and the lower spacing ring are integrally sleeved on the excircle of the connecting cylinder; the flukes are arranged in the three groups of step through holes at the upper part of the anchoring cylinder; the upper end of the sealing mandrel is connected with the lower end of the oil sealing mandrel through a screw thread, the lower end of the sealing mandrel is connected with a ball seat through a screw thread, the ball seat is installed on a raised step surface at the lower part of the inner cavity of the lower joint, and the sealing steel ball is installed on a spherical surface at the center of the upper end surface of the ball seat. The setting and the unsealing are carried out by adopting a mode of injecting liquid into the pipe column, and the control is convenient and simple; and the underground high-pressure plugging is automatically realized under the blowout condition, so that the production safety is ensured.

In a word, above technical scheme of the disclosure and the technical problem that will solve and the beneficial effect who produces all with the utility model discloses inequality, perhaps technical field or application are different, are directed against the utility model discloses more technical problem and the beneficial effect that will solve, above all there is not technological inspiration in the technical document of disclosing.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a packer is prevented spouting by well head to the above-mentioned defect that prior art exists, can seal the sleeve pipe at the well head, hang the tubular column, have and prevent scurrying the function, the application of supporting oil pipe internal plug valve can be in the in-process completion of changing the well head to the pressure control in the well, reduces the construction risk, reduces worker intensity of labour, prevents that the blowout is out of control.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a wellhead blowout prevention packer comprises an upper anchoring and sealing mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially sleeved on the outer wall of an outer central pipe from top to bottom;

the lower end of the upper anchoring sealing mechanism is propped against the upper end surface of a circular bead of the outer wall of the outer central tube, and the upper end of the upper anchoring sealing mechanism is connected with a rotary setting/deblocking mechanism;

the lower end of the lower anchoring mechanism is connected with the supporting mechanism, and the upper end of the lower anchoring mechanism is propped against the lower end face of the shoulder of the outer wall of the outer central tube.

Furthermore, the upper anchoring sealing mechanism comprises an upper slip mechanism and a rubber cylinder mechanism which are connected, the rubber cylinder mechanism comprises a single rubber cylinder or a combination of a plurality of rubber cylinders, and a spacer ring is additionally arranged between every two rubber cylinders when the plurality of rubber cylinders are arranged.

Furthermore, the lower anchoring mechanism is a lower slip mechanism, and the lower slip mechanism comprises a first lower cone, a first lower slip holder, a first cone connecting sleeve, a sheath and a ball locking mechanism;

the first lower cone is sleeved on the outer wall of the first cone connecting sleeve, and the first cone connecting sleeve is sleeved on the outer wall of the outer central pipe;

the first lower cone is provided with a mounting groove for mounting a first lower slip, and the bottom of the mounting groove of the first lower cone is in conical surface connection with the lower slip;

the upper end of the first slip support props against the first slip, the lower end of the first slip support is connected with a sheath, and a ball locking mechanism is arranged in the sheath.

Furthermore, the upper end of the first lower cone is connected with a lower cone cap, and the upper end of the lower cone cap is propped against the lower end face of the shoulder of the outer wall of the outer central tube; the lower end of the ball locking mechanism is connected with the upper end of the top sleeve.

Furthermore, the supporting mechanism is a lower slip supporting mechanism, and the lower slip supporting mechanism comprises a friction block, a spring, a centering body, a pressing ring, a retaining ring and a track pin;

the lower end of the top sleeve is in threaded fit with the outer wall of the centralizing body, the pressure ring is in threaded fit with the outer wall of the centralizing body, and the centralizing body is in threaded fit with the outer wall of the outer central tube;

the lower end part of the friction block is radially limited between the inner wall of the pressing ring and the outer wall of the righting body, the upper end part of the friction block is radially limited between the inner wall of the top sleeve and the outer wall of the righting body, and the pressing ring and the top sleeve both axially limit the outer wall steps of the friction block;

the inner end of the spring props against the outer wall of the centralizing body, and the outer end of the spring props against the friction block;

the lower end of the compression ring is in threaded connection with the baffle ring, and the outer wall of the lower end part of the outer central tube is provided with a convex baffle table for axial limiting, namely the outer diameter of the baffle table is larger than the inner diameter of the baffle ring;

radial track pins are installed on the inner wall of the baffle ring, tracks are formed on the outer wall of the outer central pipe, and the track pins are inserted into the tracks and move relatively to the tracks.

Further, the upper slip mechanism comprises a second upper slip holder, a second upper slip and a second cone;

the second cone is sleeved on the outer wall of the outer central pipe, the lower end of the second cone props against the rubber cylinder mechanism, and the lower end of the rubber cylinder mechanism props against the upper end face of the shoulder of the outer wall of the outer central pipe;

the second cone is provided with an installation groove for installing a second upper slip, and the bottom of the installation groove of the second cone is in conical surface connection with the second upper slip;

the lower end of the second upper slip support props against the second upper slip, and the upper end of the second upper slip support is connected with a moving block of the rotary setting/unsetting mechanism through a transmission nail.

Furthermore, the upper slip mechanism comprises a transmission sleeve, a third upper cone connecting sleeve, a third upper cone, a slip sleeve, a plate spring, a third upper slip and a third lower cone;

the third upper slip, the third upper cone, the third lower cone and the third upper cone connecting sleeve are all sleeved on the outer wall of the outer central pipe, the upper end of the third upper slip is connected with the lower end of the third upper cone in a conical surface manner, the lower end of the third upper slip is connected with the upper end of the third lower cone in a conical surface manner, the upper end of the third upper cone is connected with the third upper cone connecting sleeve, and the lower end of the third lower cone is propped against the upper end surface of a shoulder of the outer wall of the outer central pipe;

the plate spring is fixed on the outer wall of the third upper slip, the slip sleeve is sleeved outside the third upper slip, and a window used for exposing the plate spring is formed in the slip sleeve;

the rubber cylinder mechanism is sleeved on the outer wall of the third upper cone connecting sleeve, and the lower end of the rubber cylinder mechanism is propped against the upper end face of the third upper cone;

the lower end of the transmission sleeve props against the upper end of the rubber cylinder mechanism, and the transmission sleeve is connected with a moving block of the rotary setting/unsealing mechanism through a transmission nail.

Further, the rotary setting/unsetting mechanism comprises a transmission nut, a transmission block, an inner central tube, an outer central tube and a transmission nail;

the transmission nut thread buckle type is sleeved on the outer wall of the inner central pipe, the inner central pipe extends into the outer central pipe, and the inner wall of the outer central pipe and the outer wall of the lower end of the inner central pipe are simultaneously provided with adaptive axial limiting steps to limit the inner central pipe to move upwards;

the outer central tube is provided with a stroke groove used for the transmission block to move up and down, the upper end of the transmission block is provided with an inner plug, the inner plug penetrates through the stroke groove to be inserted into an outer clamping groove formed in the outer wall of the transmission nut, the transmission nut and the inner central tube rotate relatively, and the transmission nut can drive the transmission block to move up and down in the stroke groove.

Compared with the prior art, the utility model following beneficial effect has:

firstly, the setting and the unsetting of the packer can be realized by mechanical means such as lifting/lowering, rotation and the like only by depending on the elevator and the hydraulic tongs without hydraulic power, and the packer is light, simple to operate, safe and reliable;

secondly, the packer can be repeatedly utilized, so that the operability and the economy are better;

and thirdly, the packer has more application occasions, and can be applied to occasions involving well mouth replacement construction without a production pipe column or with a production pipe column in the well, so that the application prospect is wide.

Drawings

FIG. 1 is a schematic structural view of a wellhead blowout preventer packer;

FIG. 2 is an enlarged partial view of the setting/unsetting mechanism of the wellhead blowout preventer packer of FIG. 1;

FIG. 3 is a half sectional view of a combination type of the glue cartridge mechanism of FIG. 1;

FIG. 4 is a schematic view of one construction of the drive nut of FIG. 1;

FIG. 5 is a schematic structural view of the drive block of FIG. 1;

FIG. 6 is a schematic structural view of the outer center tube of FIG. 1;

FIG. 7 is a schematic view of another preferred embodiment of a wellhead blowout preventer packer;

FIG. 8 is an enlarged partial view of the upper slip mechanism and the packing element mechanism of another preferred embodiment of the wellhead blowout preventer packer of FIG. 7.

In the figure: 100-rotary setting/unsetting mechanism, 101-inner central tube, 102-outer central tube, 103-drive nut, 104-drive block, 105-shoulder;

200-upper slip mechanism, 201-second upper slip bowl, 202-second upper slip, 203-second cone, 204-shoulder;

300-a glue cylinder mechanism; 301-rubber cylinder, 302-spacer ring;

400-lower slip mechanism, 401-lower cone cap, 402-first lower cone, 403-first lower slip, 404-first lower slip holder, 405-first cone connecting sleeve, 406-ball locking sleeve, 407-spring, 408-ball blocking sleeve, 409-steel ball, 410-sheath, 411-top sleeve;

500-lower slip supporting mechanism, 501-friction block, 502-spring, 503-centralizing body, 504-pressing ring, 505-rail pin and 506-retaining ring;

601-a transmission sleeve, 602-a spacer ring, 603-a third upper cone connecting sleeve, a third upper cone-604, a shear pin-605, 606-a slip sleeve, a plate spring-607, a third upper slip-608, a baffle ring-609 and a third lower cone-610.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1:

referring to fig. 1 to 6, the present invention provides a technical solution:

Further, the upper anchoring and sealing mechanism comprises an upper slip mechanism 100 and a rubber cylinder mechanism 300 which are connected, the rubber cylinder mechanism comprises a single rubber cylinder or a combination of a plurality of rubber cylinders, and when the plurality of rubber cylinders are arranged, a spacing ring is additionally arranged between every two rubber cylinders.

Further, the lower anchoring mechanism is a lower slip mechanism 400, and the lower slip mechanism comprises a first lower cone 402, a first lower slip 403, a first lower slip holder 404, a first cone connecting sleeve 405, a sheath 410 and a ball locking mechanism;

the first lower cone is provided with a mounting groove for mounting a first lower slip, and the bottom of the mounting groove of the first lower cone is in conical surface connection with the first lower slip;

The lower slip mechanism is well known in the art, and can be directly applied, and the more specific structural connection relation and the operation process thereof are not described in detail. As will be clear to the person skilled in the art.

Further, the supporting mechanism is a lower slip supporting mechanism, and the lower slip supporting mechanism comprises a friction block 501, a spring 502, a righting body 503, a pressing ring 504, a baffle ring 506 and a track pin 505;

The lower slip supporting mechanism and the track of the outer central pipe matched with the lower slip supporting mechanism are well known in the art and can be directly applied, and the more specific structural connection relation and the operation process are not described in detail. As will be clear to the person skilled in the art.

Further, the upper slip mechanism comprises a second upper slip holder 201, a second upper slip 202, a second cone 203;

the second cone is provided with an installation groove for installing a second upper slip, and the bottom of the second cone installation groove is in conical surface connection with the second upper slip;

Further, the rotary setting/unsetting mechanism comprises a transmission nut 103, a transmission block 104 and an inner central tube 101;

FIG. 1 is a schematic diagram of a wellhead blowout preventer with one-way slips as upper slips, and an embodiment of the wellhead blowout preventer shown in FIG. 1 is described below. The wellhead blowout preventer mainly comprises a rubber barrel mechanism 300, an upper slip mechanism 200, a lower slip mechanism 400, a rotary setting/unsetting mechanism 100 and the like.

The glue cartridge mechanism 300 comprises 301 a glue cartridge and 302 a spacer ring. The rubber cylinder can be a single rubber cylinder, a double rubber cylinder, a triple rubber cylinder and the like, as shown in fig. 3.

Fig. 2 is an enlarged partial schematic view of a packer setting/unsetting mechanism 100, comprising an inner base pipe 101, an outer base pipe 102, a drive nut 103, a drive block 104, and a drive pin 106. The inner central tube 101 is a structure with a small upper end and a large lower end, and the shoulder 105 is hung on the reducing shoulder of the outer central tube 102 to realize vertical connection of the inner central tube and the outer central tube and string bearing and pulling transmission.

A bearing may be added at the shoulder between the inner center tube 101 and the outer center tube 102 to reduce rotational friction between the inner center tube 101 and the outer center tube 102.

The inner central tube 101 is in threaded connection with the drive nut 103.

The outer part of the inner center tube 103 is designed with a longer transmission thread to realize the downward movement of the transmission nut 103 along the inner center tube 101. The drive threads may be triangular threads, rectangular threads, trapezoidal threads, etc.

The inner center tube 101 and the drive nut 103 may be either left-handed or right-handed threaded. When the threads are in left-handed thread connection, the outer center tube 102 is fixed by the backup wrench, the inner center tube 101 is rotated forward, and the transmission nut 103 moves downward along the inner center tube 101. When the threads are right-handed threaded, the outer center tube 102 is secured with backup tongs, the inner center tube 101 is reversed, and the drive nut 103 moves down the inner center tube 101.

Fig. 4 shows a schematic view of the drive nut 103. The middle of the driving nut 103 is provided with 4 grooves for connecting the driving block 104. The number of the grooves of the driving nut 103 can be 1, 2, 3, 4, 5, 6 … …, the groove bottom can be arc, flat or inclined, and fig. 4 is just one embodiment structure of the driving nut.

Fig. 5 is a schematic structural diagram of the driving block 104, the internal structure of the driving block 104 corresponds to the bottom structure of the slot of the driving nut 103, and the number of the driving blocks 104 is the same as the number of the slots of the driving nut 103. Drive block 104 is externally slotted for attachment of drive pin 106.

A plurality of elongated slots 205 (shown in fig. 6) are formed in the outer center tube 102, and the number of the slots is the same as that of the slots of the transmission nut 103. The slots are used to provide axial movement space for the drive block 104 to move down the outer center tube 102. The length of the slot is larger than the setting distance between the rubber cylinder and the upper slip.

The outer center tube 102 has a shoulder 204 in the middle, and the shoulder 204 supports its upper rubber cylinders, slips, etc.

The lower end of the outer base pipe 102 may be threaded to allow for the hooking of a tubular string downhole.

The outer center tube 102 may be formed by connecting and sealing 1, 2 or more pieces.

A drive pin 106 connects the rotary setting/unsetting mechanism 100 and the upper slip mechanism 200.

The upper slip mechanism 200 comprises a second upper slip bowl 201, a second upper slip 202, a second cone 203. The outer central tube 102 is fixed, the inner central tube 101 is rotated, the transmission nut 103 moves downwards along the inner central tube 101, the transmission nut 103 drives the transmission block 104 to move downwards, the transmission block 104 pushes the second upper slip holder 201 to move downwards through the transmission nail 106, the second upper slip holder 201 pushes the second upper slip 202, the second cone 203 and the rubber cylinder 300 to move downwards, and the lower end of the rubber cylinder is fixed on the shoulder 204 on the outer wall of the outer central tube 102. And the downward movement of the transmission nut realizes the setting of the rubber cylinder and the second upper slip. The second upper slip 202 is a one-way slip, one possible slip tooth angle is 60 °, 30 °, and other tooth angles that can satisfy the function of a one-way slip are still possible.

The lower slip mechanism 400 and the lower slip supporting mechanism 500 realize setting and unsetting of the lower slip by lifting and lowering by utilizing the principle of the Y211 packer, and the pipe column suspension is realized, which is not described in detail herein.

The setting of the lower slip can realize the suspension of the pipe column under the condition that the pipe column exists in the well when the well mouth is changed.

The steps of the embodiment of performing wellhead blowout prevention by the wellhead blowout prevention packer shown in FIG. 1 are as follows:

a wellhead blowout prevention packer is put into the well mouth to a certain distance below the well mouth;

lifting the wellhead blowout prevention packer, and replacing the track pin of the lower slip supporting mechanism with a track;

lowering the wellhead blowout prevention packer and setting a first lower slip;

the outer central tube of the backup tong of the hydraulic tong is utilized, the inner central tube is rotated by the main tong of the hydraulic tong, the second upper slip and the rubber cylinder mechanism are sealed, and the annular space of the oil sleeve is sealed;

the upper end of the inner central tube is connected with a plug valve to seal the inner space of the oil tube;

removing the existing old wellhead;

replacing a new wellhead;

the outer central tube of the backup tong of the hydraulic tong is utilized, the inner central tube is reversely rotated by the main tong of the hydraulic tong, and the second upper slips and the rubber cylinder are unsealed;

lifting the wellhead blowout prevention packer and unsealing the first lower slip;

installing a blowout preventer;

and (5) pulling out the wellhead blowout prevention packer to finish wellhead replacement construction.

Example 2:

of course, the embodiments with more specific components are only the preferred embodiments, and the embodiments with less specific components are the basic embodiments, but the basic objects of the present invention can also be achieved, so all of these modified embodiments are within the scope of the present invention.

Referring to fig. 1 to 6, the present invention provides a technical solution:

Example 3:

the embodiment 3 was obtained by slightly modifying a part of the mechanism of the embodiment 1.

Fig. 7 is a schematic view of a wellhead blowout preventer with upper slips being bidirectional slips, and a partial enlarged schematic view of a bidirectional slip mechanism and a rubber barrel mechanism of the wellhead blowout preventer is shown in fig. 8. The outer center tube 201 is provided with a driving sleeve 601, a rubber sleeve 300, a spacer ring 602, a third upper cone 604, a third upper slip 608 and a third lower cone 610 from top to bottom.

The upper slip mechanism comprises a transmission sleeve 601, a third upper cone connecting sleeve 603, a third upper cone 604, a slip sleeve 606, a plate spring 607, a third upper slip 608 and a third lower cone 610;

the rubber cylinder mechanism is sleeved on the outer wall of the upper cone connecting sleeve, and the lower end of the rubber cylinder mechanism is propped against the upper end face of the third upper cone;

A plate spring 607 and a slip sleeve 606 are sequentially arranged on the outer side of the third upper slip 608 from inside to outside;

a shear pin 605 is provided between the third upper cone 604 and the slip sleeve 606.

The upper part of the third upper cone 604 is connected with a third upper cone connecting sleeve 603, and the third upper cone connecting sleeve 603 is arranged at the inner sides of the transmission sleeve 601, the rubber cylinder 300 and the spacer ring 602; on the outside of the third lower cone a baffle ring 609 is arranged.

When the transmission sleeve 601 moves downwards, the rubber sleeve 300 is sequentially compressed, the third upper slip 608 moves downwards, the lower end of the third lower cone 610 is a shoulder 204 of the outer central tube 201, in the setting and unsetting processes, the shoulder 204 is fixed, the third upper slip 608 is completely set firstly, and the rubber sleeve 300 is set sequentially.

The third upper slip 608 is a bi-directional slip, one possible slip tooth angle is 45 ° and other tooth angle angles that can satisfy the bi-directional slip function are still possible.

The steps of the embodiment of performing wellhead blowout prevention by the wellhead blowout prevention packer shown in FIG. 7 are as follows:

lowering the wellhead blowout prevention packer and setting a first lower slip;

the outer central tube of the backup tong of the hydraulic tong is utilized, the inner central tube is rotated by the main tong of the hydraulic tong, the third upper slip and the rubber cylinder are sealed, and the annular space of the oil sleeve is sealed;

removing the existing old wellhead;

replacing a new wellhead;

the outer central tube of the backup tong of the hydraulic tong is utilized, the inner central tube is reversely rotated by the main tong of the hydraulic tong, and the third upper slips and the rubber cylinder are unsealed;

installing a blowout preventer;

All parts and parts which are not discussed in the present application and the connection mode of all parts and parts in the present application belong to the known technology in the technical field, and are not described again. Such as welding, threaded connections, etc.

In the present application, the term "plurality" means two or more unless expressly defined otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or unit indicated must have a specific direction, be constructed and operated in a specific orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present specification, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wellhead blowout prevention packer is characterized by comprising an upper anchoring and sealing mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially sleeved on the outer wall of an outer central pipe from top to bottom;

2. The wellhead blowout prevention packer according to claim 1, wherein the upper anchoring and sealing mechanism comprises an upper slip mechanism and a rubber sleeve mechanism which are connected, the rubber sleeve mechanism comprises a single rubber sleeve or a combination of a plurality of rubber sleeves, and a spacer ring is additionally arranged between every two rubber sleeves when the rubber sleeves are in a plurality.

3. A wellhead blowout preventer packer according to claim 1 or 2, wherein the lower anchoring mechanism is a lower slip mechanism, the lower slip mechanism comprising a first lower cone, a first lower slip shoe, a first cone connection sleeve, a jacket, a ball locking mechanism;

4. The wellhead blowout preventer packer according to claim 3, wherein the upper end of the first lower cone is connected with a lower cone cap, and the upper end of the lower cone cap is supported on the lower end surface of the shoulder of the outer wall of the outer center pipe; the lower end of the ball locking mechanism is connected with the upper end of the top sleeve.

5. The wellhead blowout prevention packer according to claim 4, wherein the support mechanism is a lower slip support mechanism, and the lower slip support mechanism comprises a friction block, a spring, a centralizer, a pressure ring, a baffle ring and a rail pin;

6. The wellhead blowout preventer packer according to claim 2, wherein the upper slip mechanism comprises a second upper slip shoe, a second upper slip, and a second cone;

7. The wellhead blowout prevention packer according to claim 2, wherein the upper slip mechanism comprises a transmission sleeve, a third upper cone connecting sleeve, a third upper cone, a slip sleeve, a plate spring, a third upper slip and a third lower cone;

8. A wellhead blowout preventer packer according to claim 6 or 7, wherein the rotary setting/unsetting mechanism comprises a drive nut, a drive block, an inner base pipe, an outer base pipe, a drive pin;