Internal support type packer

Abstract

The utility model belongs to the field of oil exploitation equipment, and particularly discloses an inner supporting type packer which comprises a central pipe, a fixed ring and a movable ring are sleeved on the central pipe, a rubber sleeve is connected between the movable ring and the fixed ring, a plurality of elastic supporting strips are connected between the movable ring and the fixed ring, the elastic supporting strips are evenly and annularly distributed around the central pipe and located in the rubber sleeve, and the rubber sleeve is connected with the movable ring and the fixed ring. An annular piston cavity is formed in the position, located below the movable ring, outside the center pipe, an annular piston is inserted into the annular piston cavity, the upper end of the annular piston is connected with the movable ring, and a first through hole communicated with the annular piston cavity is formed in the pipe wall of the center pipe. The upper end and the lower end of the inner supporting type packer can be connected with a casing pipe, after hydraulic pressure is added into the casing pipe, the annular piston and the movable ring can be pushed to move upwards to enable the elastic supporting strips to be bent and deformed, so that the rubber barrel is opened outwards, the rubber barrel is internally supported by the elastic supporting strips and does not depend on compression deformation of the rubber barrel any more, and the packing strength between the rubber barrel and the well wall can be enhanced; good packing between the rubber sleeve and the well wall is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of oil exploitation equipment, concretely relates to an inner bracing packer. BACKGROUND

[0002] As a downhole tool, the packer is widely used in well completion and cementing operation in the process of oil exploitation. The working environment of the packer is in the open hole after drilling and completion, and the upper and lower parts of the packer are connected with the casing, and the isolation of the specific area in the wellbore is realized by changing the working state of the packer.

[0003] The existing packer comprises a center pipe, a fixed ring and a movable ring which are sleeved on the center pipe and are spaced apart from each other, the fixed ring is fixedly connected with the center pipe, the movable ring can slide up and down along the center pipe, a rubber sleeve is connected between the movable ring and the fixed ring, the rubber sleeve is extruded by moving the movable ring close to the fixed ring, the rubber sleeve is deformed and then contacts with the well wall to realize sealing, and then the floating valve connected to the lower end of the casing can be used to pour cement into the annular space below the sealing part to realize well completion or cementing operation.

[0004] The existing packer has the problem that the circumferential expansion of the rubber sleeve completely depends on the extrusion deformation of the movable ring and the fixed ring, which results in insufficient sealing strength between the rubber sleeve and the well wall. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing an inner bracing packer to solve the problem of insufficient sealing strength between the rubber sleeve and the well wall of the existing packer.

[0006] In order to achieve the above-mentioned purpose, the utility model discloses an inner bracing packer, which comprises a center pipe, a fixed ring and a movable ring which are sleeved on the center pipe and are spaced apart from each other, the fixed ring is fixedly connected with the center pipe, the movable ring can slide up and down along the center pipe, a rubber sleeve is connected between the movable ring and the fixed ring, characterized in that a plurality of elastic support strips are connected between the movable ring and the fixed ring, the elastic support strips are uniformly arranged around the center pipe, the elastic support strips are located in the rubber sleeve, an annular piston cavity with an opening facing upward is arranged at the part below the movable ring outside the center pipe, an annular piston is inserted into the annular piston cavity, the upper end of the annular piston is connected with the movable ring, and a first through hole which communicates with the annular piston cavity is arranged on the pipe wall of the center pipe. The inner bracing packer can be connected with the casing, and when working, the casing is lowered into the well, then the hydraulic medium is added into the casing and pressurized, the hydraulic medium can enter the annular piston cavity through the first through hole, and then the annular piston is pushed to move upward, the movable ring moves upward, the elastic support strips are bent and deformed, the rubber sleeve is expanded outward, the middle part of the rubber sleeve is expanded and contacts with the well wall to realize sealing. Since the rubber sleeve is supported by the elastic support strips inside, it no longer relies on the extrusion deformation of itself, and thus the sealing strength between the rubber sleeve and the well wall can be enhanced.

[0007] The movable cylinder is installed in the center tube, the pressure area of the upper end of the movable cylinder is smaller than that of the lower end, the movable cylinder and the center tube are provided with a shear pin, the movable cylinder is provided with a second through hole, and the movable cylinder can slide upward to align the second through hole with the first through hole after the shear pin is disconnected. Before the hydraulic force reaches the set value, the smaller pressure is not enough to push the movable cylinder to disconnect the shear pin, and the first through hole is in a closed state, so that early sealing can be prevented.

[0008] The outer wall of the center tube is provided with a clamping block capable of moving radially along the center tube, the clamping block and the inner wall of the annular piston are provided with ratchets, and the center tube and the clamping block are provided with an elastic member. The elastic member is used to make the ratchet on the clamping block engage with the ratchet on the annular piston, so as to prevent the annular piston from sliding downward. During the upward movement of the movable ring, the ratchet on the clamping block can engage with the ratchet on the inner wall of the annular piston under the action of the elastic member, so as to prevent the elastic support strip from rebounding and realize stable sealing.

[0009] The upper part of the center tube is screwed with a first fixed sleeve, and the first fixed sleeve is screwed with the fixed ring. The first fixed sleeve is used to realize the fixed connection of the fixed ring on the center tube, and facilitates the installation of the fixed ring.

[0010] The upper end of the annular piston is provided with a connecting head and is screwed with the movable ring screwed therein through the connecting head. The annular piston is relatively fixed with the movable ring in a screwed manner, and facilitates the connection of the assembly formed by the fixed ring, the movable ring and the elastic support strip with the annular piston.

[0011] The movable cylinder is provided with a first pin hole, the center tube is provided with a second pin hole, the tail of the shear pin is located in the first pin hole, and the head of the shear pin is located in the second pin hole. In the initial state, the shear pin passes through the second pin hole and the first pin hole to relatively fix the movable cylinder and the center tube, so as to maintain the initial position of the movable cylinder.

[0012] The movable cylinder is provided with a long sliding hole extending in the axial direction thereof, and the center tube is provided with a guide pin inserted into the long sliding hole. The long sliding hole and the guide pin jointly act to ensure that the movable cylinder can slide up and down, and prevent the movable cylinder from rotating arbitrarily, so as to ensure that the second through hole can align with the first through hole when the movable cylinder reaches the upper stop point.

[0013] The first inner ring groove is provided on the center pipe, and the first inner ring groove comprises a first groove section and a second groove section connected in sequence, the inner diameter of the first groove section is smaller than the diameter of the groove bottom of the second groove section, the movable cylinder body comprises a first cylinder section and a second cylinder section connected in sequence, the inner diameters of the first cylinder section and the second cylinder section are equal, the outer diameter of the first cylinder section is smaller than the outer diameter of the second cylinder section, the first cylinder section is in sliding sealing connection with the first groove section, and the second cylinder section is in sliding sealing connection with the second groove section, the upper end surface of the first cylinder section is used for forming the upper end pressure receiving surface of the movable cylinder body, and the lower end surface of the second cylinder section is used for forming the lower end pressure receiving surface of the movable cylinder body, and since the inner diameters of the first cylinder section and the second cylinder section are equal and the outer diameter of the first cylinder section is smaller than the outer diameter of the second cylinder section, the upper end pressure receiving area of the movable cylinder body is smaller than the lower end pressure receiving area.

[0014] The outer wall of the center pipe is provided with a clamping groove, a clamping block is installed in the clamping groove, and the elastic member is a spring sheet installed in the clamping groove and used for applying an outward force to the clamping block. When the annular piston moves upwards, the clamping block can retract into the clamping groove, and when the annular piston stops moving, the clamping block extends outwards under the action of the spring sheet, so that the ratchet teeth on the clamping block are engaged with the ratchet teeth on the inner wall of the annular piston.

[0015] The lower end of the center pipe is screwed with a second fixed sleeve, the upper portion of the second fixed sleeve is provided with a second inner ring groove penetrating the upper end surface thereof, the groove wall of the second inner ring groove and the outer wall of the center pipe jointly form the annular piston cavity, and the inner and outer surfaces of the annular piston are in dynamic sealing cooperation with the center pipe and the second fixed sleeve respectively. The second fixed sleeve not only plays a role in forming the second inner ring groove, but also is used for connecting the sleeve, and the second groove section can be designed to penetrate the lower end surface of the center pipe, so that the installation of the movable cylinder body is facilitated.

[0016] In conclusion, the inner support type packer has the advantages that: 1. The rubber sleeve of the inner support type packer is internally supported by the elastic support strips, and the sealing strength between the rubber sleeve and the well wall is improved. 2. During the upward movement of the movable ring, the ratchet teeth on the clamping block can be engaged with the ratchet teeth on the inner wall of the annular piston under the action of the elastic member, so that the elastic support strips are prevented from rebounding, and the sealing stability is maintained. 3. Before the hydraulic force reaches the set value, the smaller pressure is insufficient to push the movable cylinder body to break the shear pin, and the first through hole is always in a closed state, so that the sealing is avoided in advance. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of an embodiment of the utility model;

[0018] Figure 2 is Figure 1 is a structural schematic diagram of another working state of the embodiment shown in the figure;

[0019] Figure 3 is Figure 2A part of the enlarged view in A of the figure;

[0020] Figure 4 is Figure 2 B part of the enlarged view in the figure;

[0021] Figure 5 is Figure 1 The structure schematic view of the assembly formed by the stationary ring, the movable ring and the elastic support strip in the embodiment shown.

[0022] In the figure: 1, the center tube, 2, the stationary ring, 3, the movable ring, 4, the rubber cylinder, 5, the elastic support strip, 6, the annular piston cavity, 7, the annular piston, 8, the first through hole, 9, the movable cylinder body, 901, the first cylinder section, 902, the second cylinder section, 10, the shear pin, 11, the second through hole, 12, the clamping block, 13, the ratchet, 14, the elastic member, 15, the first fixed sleeve, 16, the first pin hole, 17, the second pin hole, 18, the long sliding hole, 19, the guide pin, 20, the first inner ring groove, 201, the first groove section, 202, the second groove section, 21, the clamping groove, 22, the second fixed sleeve, 23, the second inner ring groove. DETAILED DESCRIPTION

[0023] The specific embodiments of the utility model are described in further detail below in combination with the drawings and examples. The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

[0024] The utility model provides a kind of inner bracing packer, to solve the problem that the rubber cylinder circumferential expansion of existing packer completely relies on the extrusion deformation of movable ring and stationary ring, leading to the insufficient sealing strength between rubber cylinder and well wall.

[0025] Therefore Figures 1 to 5 The structure of one embodiment of inner bracing packer is shown.

[0026] Refer to Figure 1 , Figure 2 , Figure 5In some embodiments of the utility model, inner support type packer includes center tube 1, the upper end part of center tube 1 is equipped with the inner taper thread for connecting casing. Center tube 1 is equipped with the fixed ring 2, movable ring 3 of spacing from top to bottom, fixed ring 2 is fixedly connected with center tube 1, and movable ring 3 can slide up and down along center tube 1. Movable ring 3 is connected with rubber cylinder 4 between fixed ring 2, and movable ring 3 is connected with multiple elastic support strips 5 between fixed ring 2, and elastic support strip 5 is evenly ringed around center tube 1, and elastic support strip 5 is located in rubber cylinder 4. The part of center tube 1 outside is located below movable ring 3 and is equipped with annular piston cavity 6 with the opening upwards, and annular piston 7 is inserted in annular piston cavity 6, and the upper end of annular piston 7 is connected with movable ring 3. The pipe wall of center tube 1 is equipped with the first through-hole 8 that communicates annular piston cavity 6. The inner support type packer is used for connecting casing, and when working, it is lowered into the well along with casing. In order to realize packing, hydraulic medium can be added to casing and pressurized. Hydraulic medium enters annular piston cavity 6 through first through-hole 8, and then pushes annular piston 7 to move upwards, and movable ring 3 moves upwards accordingly, so that multiple elastic support strips 5 between movable ring 3 and fixed ring 2 are deformed and bent, rubber cylinder 4 is expanded outward, the middle part of rubber cylinder 4 is in contact with the well wall after expansion, and packing is realized. In order to further improve the packing performance of the inner support type packer after packing, the number of elastic support strips 5 should be increased as much as possible, and the middle part of rubber cylinder 4 is thicker than other parts. After the above improvement, the inside of rubber cylinder 4 is supported by elastic support strip 5, and packing is no longer realized by the extrusion deformation of itself, so that the packing strength between rubber cylinder and well wall is enhanced, and reliable packing between rubber cylinder and well wall is realized.

[0027] In the embodiment, in order to realize the fixed connection of fixed ring 2 and center tube 1, the upper part of center tube 1 is screwed with first fixed sleeve 15, and first fixed sleeve 15 is screwed with fixed ring 2, so that the installation of fixed ring 2 is facilitated.

[0028] In the embodiment, the upper end of annular piston 7 is provided with a connector and is screwed with movable ring 3 screwed therein through the connector. Specifically, the lower part of movable ring 3 is provided with external threads, and the connector of annular piston 7 is provided with internal threads, and the screwing of annular piston 7 and movable ring 3 is realized by the cooperation of external threads and internal threads. After adopting this mode, the connection of the assembly formed by fixed ring 2, movable ring 3 and elastic support strip 5 and annular piston 7 is more convenient.

[0029] Referring to Figure 2 , Figure 4In order to prevent the internal support packer from being sealed in advance, in some embodiments of the utility model, a movable cylinder 9 is installed in the center tube 1, the upper end pressure area of the movable cylinder 9 is less than the lower end pressure area. A shear pin 10 is arranged between the movable cylinder 9 and the center tube 1. The movable cylinder 9 is provided with a second through hole 11, and the movable cylinder 9 can slide upwards to align the second through hole 11 with the first through hole 8 after the shear pin 10 is broken. Because the upper end pressure area of the movable cylinder 9 is less than the lower end pressure area, the movable cylinder 9 is subjected to upward force after being pressurized, and when the force acting on the movable cylinder 9 reaches a certain value, the shear pin 10 can be sheared off, the movable cylinder 9 moves upwards, and the second through hole 11 is aligned with the first through hole 8. At this time, the hydraulic medium can enter the annular piston cavity 6 through the second through hole 11 and the first through hole 8, and then push the annular piston 7 and the fixed ring 2 to move, so as to realize sealing. Before the hydraulic pressure reaches the set value, the smaller pressure is not enough to push the movable cylinder 9 to break the shear pin 10, and the first through hole 8 is always in a closed state, so that the annular piston cavity 6 is prevented from moving due to smaller pressure, and the situation of early sealing is avoided.

[0030] In the embodiment, in order to install the shear pin 10, the movable cylinder 9 is provided with a first pin hole 16, the center tube 1 is provided with a second pin hole 17, the tail of the shear pin 10 is located in the first pin hole 16, and the head of the shear pin 10 is located in the second pin hole 17. In the initial state, the shear pin 10 passes through the second pin hole 17 and the first pin hole 16 to fix the movable cylinder 9 relative to the center tube 1, so as to maintain the initial position of the movable cylinder 9.

[0031] In the embodiment, in order to prevent the movable cylinder 9 from rotating randomly, the movable cylinder 9 is provided with a long sliding hole 18 extending in the axial direction, and the center tube 1 is provided with a guide pin 19 inserted into the long sliding hole 18. The long sliding hole 18 and the guide pin 19 jointly act to ensure that the movable cylinder 9 can slide up and down, and prevent the movable cylinder 9 from rotating randomly, so as to ensure that the second through hole 11 can be aligned with the first through hole 8 when the movable cylinder 9 reaches the upper stop point.

[0032] In this embodiment, in order to install the movable cylinder 9, the first inner annular groove 20 is arranged on the center pipe 1, the first inner annular groove 20 comprises the first groove section 201 and the second groove section 202 which are connected in sequence, the inner diameter of the first groove section 201 is smaller than the groove bottom diameter of the second groove section 202, the movable cylinder 9 comprises the first cylinder section 901 and the second cylinder section 902 which are connected in sequence, the inner diameters of the first cylinder section 901 and the second cylinder section 902 are equal, the outer diameter of the first cylinder section 901 is smaller than the outer diameter of the second cylinder section 902, the first cylinder section 901 is in sliding sealing connection with the first groove section 201, and the second cylinder section 902 is in sliding sealing connection with the second groove section 202. The upper end surface of the first cylinder section 901 is used to form the upper end pressure receiving surface of the movable cylinder 9, and the lower end surface of the second cylinder section 902 is used to form the lower end pressure receiving surface of the movable cylinder 9. Since the inner diameters of the first cylinder section 901 and the second cylinder section 902 are equal and the outer diameter of the first cylinder section 901 is smaller than the outer diameter of the second cylinder section 902, the upper end pressure receiving area of the movable cylinder 9 is smaller than the lower end pressure receiving area.

[0033] With reference to Figure 2 , Figure 3 In order to prevent the elastic supporting strip 5 from rebounding after sealing, in some embodiments of the utility model, the outer wall of the center pipe 1 is provided with the clamping block 12 which can move radially along the center pipe 1, the clamping block 12 and the inner wall of the annular piston 7 are both provided with the ratchet 13, and the elastic member 14 is arranged between the center pipe 1 and the clamping block 12. The elastic member 14 is used to make the ratchet 13 on the clamping block 12 mesh with the ratchet 13 on the annular piston 7, thereby preventing the annular piston 7 from sliding downward. In the process of moving the movable ring 3 upward, the ratchet 13 on the clamping block 12 can mesh with the ratchet 13 on the inner wall of the annular piston 7 under the action of the elastic member 14, thereby preventing the elastic supporting strip 5 from rebounding and realizing stable sealing.

[0034] In this embodiment, in order to install the clamping block 12, the outer wall of the center pipe 1 is provided with the clamping groove 21, the clamping block 12 is installed in the clamping groove 21, and the elastic member 14 is the spring sheet which is installed in the clamping groove 21 and is used to apply outward force to the clamping block 12. When the annular piston 7 moves upward, the clamping block 12 can retract into the clamping groove 21, and when the annular piston 7 stops moving, the clamping block 12 extends outward under the action of the spring sheet, thereby ensuring that the ratchet 13 on the clamping block 12 meshes with the ratchet 13 on the inner wall of the annular piston 7.

[0035] With reference to Figure 1 , Figure 2 , Figure 4In the embodiment, in order to form the second inner ring groove 23, the lower end of the central pipe 1 is screwed with the second fixed sleeve 22, and the second fixed sleeve 22 is provided with an outer tapered thread for connecting the sleeve pipe. The upper part of the second fixed sleeve is provided with the second inner ring groove 23 penetrating the upper end face thereof, and the groove wall of the second inner ring groove 23 and the outer wall of the central pipe 1 jointly form the annular piston cavity 6, and the inner and outer surfaces of the annular piston 7 are in dynamic sealing cooperation with the central pipe 1 and the second fixed sleeve 22 respectively.

[0036] The working mode of the utility model is as follows:

[0037] Figure 1 It is the initial state of the inner support packer, the upper end of the central pipe 1 and the lower end of the second fixed sleeve 22 are connected with the sleeve pipe, and are lowered into the well along with the sleeve pipe, and after reaching the preset position, hydraulic pressure is added into the sleeve pipe, because the pressure area of the upper end of the movable cylinder 9 is smaller than that of the lower end, the movable cylinder 9 as a whole is subjected to upward force, the shear pin 10 is broken, the movable cylinder 9 slides upward, and enters Figure 2 The working state shown in the figure.

[0038] Figure 2 It is the formal working state of the inner support packer, in this state, the movable cylinder 9 slides to the upper stop point, the first through hole 8 is aligned with the second through hole 11, the hydraulic medium enters the annular piston cavity 6 through the second through hole 11 and the first through hole 8, the annular piston cavity 6 slides upward under the action of pressure, the movable ring 3 slides upward along with it, the elastic supporting strip 5 between the movable ring 3 and the fixed ring 2 is bent and deformed, thereby supporting the middle part of the rubber cylinder 4 outward, so that it is in contact with the well wall, the rubber cylinder 4 itself has a certain thickness, and after being pressed, it can be well sealed with the well wall, and sealing is realized.

[0039] It can be seen from the description of the use mode of the inner support packer that the rubber cylinder 4 of the inner support packer is supported by the elastic supporting strip 5 inside, and the sealing strength between the rubber cylinder and the well wall is improved. In the process of upward movement of the movable ring 3, the ratchet teeth 13 on the clamping block 12 can be engaged with the ratchet teeth 13 on the inner wall of the annular piston 7 under the action of the elastic member 14, thereby preventing the elastic supporting strip 5 from rebounding. Before the hydraulic pressure reaches the set value, the smaller pressure is not enough to push the movable cylinder 9 to break the shear pin 10, and the first through hole 8 is always in a closed state, thereby preventing the annular piston cavity 6 from moving due to the smaller pressure, and avoiding the situation of early sealing.

[0040] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0041] The terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] The above is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and substitutions can be made, and these improvements and substitutions should also be considered as the protection scope of the present application.

Claims

1. An internally supported packer, comprising a central tube (1), wherein a fixed ring (2) and a movable ring (3) spaced vertically are fitted onto the central tube (1), the fixed ring (2) is fixedly connected to the central tube (1), the movable ring (3) is capable of sliding up and down along the central tube (1), and a rubber sleeve (4) is connected between the movable ring (3) and the fixed ring (2), characterized in that, A plurality of elastic supporting strips (5) are connected between the movable ring (3) and the fixed ring (2), the elastic supporting strips (5) are uniformly arranged around the central pipe (1), the elastic supporting strips (5) are located in the rubber cylinder (4), the part of the central pipe (1) below the movable ring (3) is provided with an annular piston cavity (6) with an opening upward, the annular piston cavity (6) is inserted with an annular piston (7), the upper end of the annular piston (7) is connected with the movable ring (3), and the pipe wall of the central pipe (1) is provided with a first through hole (8) communicating with the annular piston cavity (6).

2. The internal-shouldered packer of claim 1, wherein, The central pipe (1) is provided with a movable cylinder body (9), the upper end of the movable cylinder body (9) has a smaller pressure area than the lower end, a shear pin (10) is arranged between the movable cylinder body (9) and the central pipe (1), the movable cylinder body (9) is provided with a second through hole (11), and the movable cylinder body (9) can slide upward to align the second through hole (11) with the first through hole (8) after the shear pin (10) is broken.

3. The internal-shouldered packer of claim 1, wherein, The outer wall of the central pipe (1) is provided with a clamping block (12) capable of moving radially along the central pipe (1), the clamping block (12) and the inner wall of the annular piston (7) are both provided with ratchets (13), and the clamping block (12) and the central pipe (1) are provided with an elastic element (14), which is used for meshing the ratchets (13) on the clamping block (12) with the ratchets (13) on the annular piston (7) to prevent the annular piston (7) from sliding downward.

4. The internal-shouldered packer of claim 1, wherein, The upper part of the central pipe (1) is screwed with a first fixed sleeve (15), and the first fixed sleeve (15) is screwed with the fixed ring (2).

5. The internal-shouldered packer of claim 1, wherein, The upper end of the annular piston (7) is provided with a connecting head and is screwed with the movable ring (3) screwed therein.

6. The internal-shouldered packer of claim 2, wherein, The movable cylinder body (9) is provided with a first pin hole (16), the central pipe (1) is provided with a second pin hole (17), the tail of the shear pin (10) is located in the first pin hole (16), and the head of the shear pin (10) is located in the second pin hole (17).

7. The inner-arch packer of claim 2, wherein, The movable cylinder body (9) is provided with a long sliding hole (18) extending along the axial direction thereof, and the central pipe (1) is provided with a guide pin (19) inserted into the long sliding hole (18).

8. The inner-arch packer of claim 2, wherein, The central pipe (1) is provided with a first inner ring groove (20), the first inner ring groove (20) comprises a first groove section (201) and a second groove section (202) connected in sequence, the inner diameter of the first groove section (201) is smaller than the groove bottom diameter of the second groove section (202), the movable cylinder body (9) comprises a first cylinder section (901) and a second cylinder section (902) connected in sequence, the inner diameters of the first cylinder section (901) and the second cylinder section (902) are equal, the outer diameter of the first cylinder section (901) is smaller than the outer diameter of the second cylinder section (902), the first cylinder section (901) is in sliding sealing connection with the first groove section (201), and the second cylinder section (902) is in sliding sealing connection with the second groove section (202).

9. The inner-arch packer of claim 3 wherein, The outer wall of the central pipe (1) is provided with a clamping groove (21), and the clamping block (12) is installed in the clamping groove (21), and the elastic element (14) is a spring sheet installed in the clamping groove (21) and used for applying an outward force to the clamping block (12).

10. The internal-shouldered packer of any one of claims 1 to 9, wherein, The lower end of the center pipe (1) is screwed with a second fixing sleeve (22), the upper part of the second fixing sleeve is provided with a second inner annular groove (23) penetrating the upper end face, the groove wall of the second inner annular groove (23) and the outer wall of the center pipe (1) jointly form the annular piston cavity (6), the inner and outer surfaces of the annular piston (7) are respectively in dynamic sealing cooperation with the center pipe (1) and the second fixing sleeve (22).

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