A step-by-step unsealing packer for water injection wells

Abstract

A step-by-step unsealing packer for a water injection well relates to the technical field of downhole tools in oil fields, and comprises an upper joint, a center pipe, an outer center pipe, a lower joint, a sealing mechanism, an unsealing mechanism and a rubber tube assembly. The sealing mechanism is located between the rubber tube assembly and the lower joint, and the unsealing mechanism is located between the rubber tube assembly and the upper joint. The rubber tube assembly sealing sleeve is mounted on the outer center pipe. The sealing mechanism compresses the rubber tube assembly from bottom to top, so that the rubber tube assembly expands and seals. The unsealing mechanism comprises an upper outer sleeve, an intermediate sleeve and a locking body. The locking body is locked on a step outside the center pipe. The intermediate sleeve limits the elastic sliding of the locking body. A locking block A is also provided on the intermediate sleeve. The locking block A limits the sliding range of the intermediate sleeve. When unsealing, the upper joint and the upper outer sleeve move upward at the same time, while the intermediate sleeve does not move upward. After the unsealing shear pins are cut off, step-by-step unsealing is achieved. Moreover, the sealing force of the present invention does not act on the unsealing shear pins, and the sealing stability is very high. After the well is sealed, there is no risk of accidental unsealing.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field downhole tools, and in particular relates to a step-by-step unsealing packer for a water injection well. Background Art

[0002] Stratified water injection refers to a water injection method in which a packer is placed in the injection well to separate oil layers with large differences, and then water is distributed in layers using a water distributor, so that the water injection volume of the high permeability layer is controlled, the water injection of the medium and low permeability oil layers is strengthened, and all types of oil layers can play a role.

[0003] In order to achieve differentiated stratified water injection for each oil layer, multiple packers need to be connected in series in the stratified water injection string. The commonly used method of unsealing the packers is mostly to lift the string. When unsealing, the unsealing shear pins of multiple packers are stressed at the same time, and the unsealing load acts on the string at the same time, resulting in excessive unsealing load and difficulty in unsealing successfully. In addition, the force of most packers after setting will act on the unsealing shear pins, so the unsealing shear pins are required to be able to withstand a large shear force, and the lifting force during unsealing also acts on the unsealing shear pins, so the unsealing shear pins are required not to have a large shear force, so the existing packers have serious conflicts. Summary of the invention

[0004] In order to solve the problem that the existing multi-stage packers have a large unsealing load and are difficult to unseal, the present invention provides a step-by-step unsealing packer for water injection wells. The present invention can easily achieve step-by-step unsealing, and the setting force of the present invention does not act on the unsealing shear pins. The setting stability is very high. After the well is lowered and sealed, there is no risk of accidental unsealing.

[0005] The technical solution provided by the present invention is: a step-by-step unsealing packer for water injection wells, comprising an upper joint, a central tube, an outer central tube, a lower joint, a sealing mechanism, an unsealing mechanism and a rubber tube assembly, wherein the sealing mechanism is located between the rubber tube assembly and the lower joint, and the unsealing mechanism is located between the rubber tube assembly and the upper joint, the rubber tube assembly sealing sleeve is sleeved on the outer central tube, and the sealing mechanism compresses the rubber tube assembly from bottom to top so that the rubber tube assembly expands and seals; the unsealing mechanism comprises an upper outer sleeve, an intermediate sleeve and a locking body, the locking body is fixedly connected to the upper end of the outer central tube, the upper end of the rubber tube assembly abuts against the locking body, the locking body comprises a main sleeve and elastic limiting teeth annularly spaced and distributed at the upper end of the main sleeve, the outer side of the central tube comprises a constant diameter section and an expanded diameter section A, and the initial state The lower elastic limiting teeth are against the step between the constant diameter section and the expanded diameter section A, and the middle sleeve is slidably arranged between the locking body and the upper outer sleeve. Under the restriction of the middle sleeve, the upper part of the inner side of the middle sleeve is the constant diameter cavity, and the constant diameter cavity limits the elastic limiting teeth from bouncing radially in the main sleeve. The lower part of the inner side of the middle sleeve is the expanded diameter cavity, and the expanded diameter cavity allows the elastic limiting teeth to bounce outward. In the initial state, the elastic limiting teeth are located in the constant diameter cavity section. To unseal, the middle sleeve must slide upward until the entire constant diameter cavity has passed the elastic limiting teeth. A locking hole is processed radially in the constant diameter cavity, and a locking block A is slidably inserted in the lock hole. The inner side of the locking block A corresponds to the elastic limiting teeth and a groove is processed on the outer side of the elastic limiting teeth at this location, and the inner side of the locking block A is against the groove. The outer side of the locking block A is against the upper outer sleeve, and the inner side of the upper outer sleeve below the groove is processed with an expanded diameter section B for the locking block A to extend into. When the locking block A enters the expanded diameter section B, the locking of the locking block A and the elastic limit tooth is released; a tension spring is arranged between the lower end of the intermediate sleeve and the locking body. Under the elastic force of the tension spring, the intermediate sleeve has a downward sliding movement tendency. In the initial state, the tension spring is in a tensioned state. A shearing pin is arranged between the intermediate sleeve and the upper outer sleeve. Under the action of the shearing pin, the tension spring cannot be reset. An unsealing shearing pin is arranged between the upper joint and the center tube. A locking hole is radially processed on the upper joint, and a locking block B is slidably inserted in the lock hole. A slot is processed on the center tube corresponding to the locking block B. There is an annular limit groove with a strong magnetic block in it. In the initial state, the inner side of the locking block B is against the slot, and the outer side of the locking block B is against the middle sleeve. At this time, the annular limit groove is located above the locking block B. Only when the middle sleeve slides downward to the bottom dead center of the groove, the annular limit groove is aligned with the locking block B. At this time, the strong magnetic block sucks the locking block B into the annular limit groove. However, if the middle sleeve still wants to slide upward, the locking block B can be pushed into the slot again. The upper end of the upper outer sleeve is fixedly connected to the upper joint, and the lower end of the upper outer sleeve is matched with the main sleeve sliding seal. There is a liquid gap between the outer center tube and the center tube, and the liquid inlet of the sealing assembly reaches the lower end of the middle sleeve and the upper joint through the liquid gap.

[0006] A further technical solution is that a stopper is fixedly connected to the lower end of the intermediate sleeve, and the stopper abuts against the constant diameter section of the central tube.

[0007] A further technical solution is that the length of the locking block A in the circumferential direction of the intermediate sleeve is greater than the distance between the two elastic limiting teeth.

[0008] A further technical solution is: the sealing mechanism includes a sealing piston, a retaining spring and a tooth sleeve, the upper end of the tooth sleeve is located between the center tube and the outer center tube, the inner side of the outer center tube is provided with a step, the upper end of the tooth sleeve is against the step on the inner side of the outer center tube, the lower end of the tooth sleeve is against the lower joint, the tooth sleeve is provided with a one-way tooth, the upper end of the sealing piston is located outside the upper center tube and against the rubber cylinder assembly, the retaining spring is arranged on the inner side of the sealing piston, the tooth limits the retaining spring in one direction, and only allows the retaining spring and the sealing piston to slide upward, the tooth sleeve and the corresponding center tube are both processed with liquid inlet pressure transmission holes, and the outer center tube between the sealing piston and the tooth sleeve is processed with a liquid hole.

[0009] Compared with the prior art, the beneficial effects of the present invention are:

[0010] 1. The present invention can realize step-by-step unblocking, thus avoiding unblocking failure caused by excessive unblocking load.

[0011] 2. The setting force of the rubber cartridge assembly of the present invention does not act on the unsealing shear pins, thereby resolving the conflicts when the existing packers use unsealing shear pins. After the present invention is set, no accidental unsealing will occur.

[0012] 3. The shear force of the unsealing shear nail of the present invention can be designed to be minimal, making it easier to lift and unseal. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 yes Figure 1 Schematic diagram of the structure of the upper middle part.

[0015] Figure 3 yes Figure 1 Schematic diagram of the structure of the lower middle part.

[0016] Figure 4 It is a schematic diagram of the structure after the upper part of the present invention is pushed by the setting hydraulic pressure, the middle sleeve moves upward, and the shear pins are sheared off.

[0017] Figure 5 It is a structural schematic diagram of the present invention when the upper part is not pushed by the setting hydraulic pressure and the intermediate sleeve is pulled to the bottom dead center by the tension spring.

[0018] Figure 6 It is a structural schematic diagram of the upper joint driving the locking block B and the middle sleeve upward when the upper part of the present invention is unsealed.

[0019] Figure 7It is a schematic diagram of the structure of the upper part of the present invention after being completely unsealed.

[0020] In the figure: 1, upper joint; 2, shear pin; 3, middle sleeve; 4, locking block A; 5, groove; 6, elastic limit tooth; 7, stopper; 8, tension spring; 9, main sleeve; 10, upper outer sleeve; 11, outer center tube; 12, center tube; 13, setting piston; 14, liquid hole; 15, tooth sleeve; 16, liquid inlet pressure transmission hole; 17, tooth; 18, retaining spring; 19, slot; 20, lower joint; 21, annular limit groove; 22, strong magnetic block; 23, locking block B; 24, unsealing shear pin; 25, liquid gap; 301, constant diameter cavity; 302, expanded diameter cavity; 1001, expanded diameter section B; 1201, constant diameter section; 1202, expanded diameter section A. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] like Figure 1 As shown, this embodiment includes an upper joint 1, a center tube 12, an outer center tube 11, a lower joint 20, a sealing mechanism, an unsealing mechanism and a rubber cartridge assembly. The sealing mechanism is located between the rubber cartridge assembly and the lower joint 20, the unsealing mechanism is located between the rubber cartridge assembly and the upper joint 1, the rubber cartridge assembly sealing sleeve is on the outer center tube 11, the sealing mechanism compresses the rubber cartridge assembly from bottom to top, so that the rubber cartridge assembly is expanded and sealed; the above is a structure that already exists in the prior art and will not be repeated here.

[0023] The innovation of this embodiment is: Figure 2As shown, the unsealing mechanism includes an upper sleeve 10, an intermediate sleeve 3 and a locking body, the locking body is fixedly connected to the upper end of the outer center tube 11, the upper end of the rubber cylinder assembly abuts against the locking body, the locking body includes a main sleeve 9 and elastic limiting teeth 6 annularly spaced and distributed at the upper end of the main sleeve 9, the outer side of the center tube 12 includes a constant diameter section 1201 and an expanded diameter section A1202, the elastic limiting teeth 6 in the initial state abut on the step between the constant diameter section 1201 and the expanded diameter section A1202, the intermediate sleeve 3 is slidably arranged between the locking body and the upper sleeve 10, under the restriction of the intermediate sleeve 3, the upper part of the inner side of the intermediate sleeve 3 is a constant diameter cavity 301, the constant diameter cavity 301 limits the elastic limiting teeth 6 from the radial bounce of the main sleeve 9, and the lower part of the inner side of the intermediate sleeve 3 is an expanded diameter cavity 3 02, the expanded diameter cavity 302 allows the elastic limiting tooth 6 to bounce outward. In the initial state, the elastic limiting tooth 6 is located in the section of the normal diameter cavity 301. To unseal, the middle sleeve 3 must slide upward until the entire normal diameter cavity 301 has completely passed over the elastic limiting tooth 6; a locking hole is processed radially in the normal diameter cavity 301, and a locking block A4 is slidably inserted in the lock hole. The inner side of the locking block A4 corresponds to the elastic limiting tooth 6 and a groove 5 is processed on the outer side of the elastic limiting tooth 6 at this location. The inner side of the locking block A4 abuts against the groove 5, and the outer side of the locking block A4 abuts against the upper sleeve 10. The inner side of the upper sleeve 10 below the groove 5 is processed with an expanded diameter section B1001 for the locking block A4 to extend into. When the locking block A4 enters the expanded diameter section B1001, the locking block A4 and the elastic limiting The lock of tooth 6 is released; a tension spring 8 is arranged between the lower end of the middle sleeve 3 and the locking body. Under the elastic force of the tension spring 8, the middle sleeve 3 has a downward sliding movement tendency. In the initial state, the tension spring 8 is in a tensioned state. A shearing nail 2 is arranged between the middle sleeve 3 and the upper outer sleeve 10. Under the action of the shearing nail 2, the tension spring 8 cannot be reset. An unsealing shearing nail 24 is arranged between the upper joint 1 and the central tube 12. A locking hole is radially processed on the upper joint 1, and a locking block B23 is slidably inserted in the locking hole. A card groove 19 is processed on the central tube 12 corresponding to the locking block B23. An annular limiting groove 21 is processed on the inner side of the middle sleeve 3, and a strong magnetic block 22 is provided in the annular limiting groove 21. In the initial state, the inner side of the locking block B23 is against the card groove. 19, the outer side of the locking block B23 is against the middle sleeve 3, and the annular limit groove 21 is now located above the locking block B23. Only when the middle sleeve 3 slides downward to the bottom dead center of the locking block A4 at the groove 5, the annular limit groove 21 is aligned with the locking block B23. At this time, the strong magnetic block 22 sucks the locking block B23 into the annular limit groove 21. However, if the middle sleeve 3 still wants to slide upward, the locking block B23 can be pushed into the slot 19 again. The upper end of the upper sleeve 10 is fixedly connected to the upper joint 1, and the lower end of the upper sleeve 10 is slidably sealed with the main sleeve 9. There is a liquid gap 25 between the outer center tube 11 and the center tube 12, and the liquid inlet of the sealing assembly reaches the lower end of the middle sleeve 3 and the upper joint 1 through the liquid gap 25.

[0024] A stopper 7 is fixedly connected to the lower end of the intermediate sleeve 3, and the stopper 7 abuts against the constant diameter section 1201 of the central tube 12. After unsealing, the stopper 7 abuts against the step between the constant diameter section 1201 and the expanded diameter section A1202, thereby preventing this embodiment from disintegrating into two sections.

[0025] The length of the locking block A4 in the circumferential direction of the intermediate sleeve 3 is greater than the distance between the two elastic limiting teeth 6 , so that the locking block A4 is guaranteed to fall into the groove 5 .

[0026] As one of the embodiments of the setting mechanism, the setting mechanism includes a setting piston 13, a retaining spring 18 and a tooth sleeve 15. The upper end of the tooth sleeve 15 is located between the center tube 12 and the outer center tube 11. The inner side of the outer center tube 11 has a step. The upper end of the tooth sleeve 15 abuts against the step on the inner side of the outer center tube 11. The lower end of the tooth sleeve 15 abuts against the lower joint 20. The tooth sleeve 15 has a one-way tooth 17. The upper end of the setting piston 13 is located outside the upper center tube 12 and abuts against the rubber cylinder assembly. The retaining spring 18 is arranged on the inner side of the setting piston 13. The tooth limits the retaining spring 18 in one direction, and only allows the retaining spring 18 and the setting piston 13 to slide upward. The tooth sleeve 15 and the corresponding center tube 12 are both machined with a liquid inlet pressure transmission hole 16, and the outer center tube 11 between the setting piston 13 and the tooth sleeve 15 is machined with a liquid hole 14.

[0027] Figure 2 The initial state of the unsealing mechanism in this embodiment when it is lowered into the well is shown. In the initial state, the tension spring 8 is under tension, and the middle sleeve 3 is connected to the upper outer sleeve 10 through the shear pins 2. Under the limitation of the shear pins 2, the tension spring 8 cannot pull the middle sleeve 3 downward to reset.

[0028] Figure 4 The state of the unsealing mechanism in this embodiment when the central tube 12 is pressurized and sealed is shown. When the seal is pressurized and sealed, the hydraulic pressure enters the sealing mechanism through the liquid inlet pressure transmission hole 16, on the one hand, it pushes the sealing piston 13 to squeeze the rubber cylinder assembly to seal, and on the other hand, it reaches the bottom of the unsealing mechanism from the liquid gap between the outer central tube 11 and the central tube 12. The hydraulic pressure acts on the lower ends of the middle sleeve 3 and the upper joint 1 respectively. Since the locking block B23 connects the upper joint 1 with the central tube 12, the upper joint 1 cannot slide upward, and after the middle sleeve 3 is subjected to the upward hydraulic thrust, the shear pin 2 is cut off, reaching Figure 4 In the position shown, the tension spring 8 at this moment has stored up the tension potential energy. In this position, the locking block A4 reaches the top of the groove 5, and under the restriction of the locking block A4, the intermediate sleeve 3 cannot continue to slide upwards.

[0029] Figure 5 The state of the unsealing mechanism in this embodiment after the pressure in the central tube 12 is removed is shown. When there is no pressure in the central tube 12, the hydraulic thrust at the lower end of the unsealing mechanism disappears. At this time, under the tension of the tension spring 8, the intermediate sleeve 3 is pulled out. Figure 4 Location reached Figure 5 The locking block A4 reaches the bottom of the groove 5. Under the restriction of the locking block A4, the intermediate sleeve 3 cannot slide down further. At this time, the lower part of the annular limiting groove 21 is aligned with the locking block B23. Under the adsorption of the strong magnetic block 22, the locking block B23 can enter the annular limiting groove 21.

[0030] When the packer has been set, during the stratified water injection process, if the central pipe 12 is reloaded with hydraulic pressure, the hydraulic pressure will reach the lower end of the unsealing mechanism again. Figure 5 When the hydraulic pressure is applied again, the upper joint 1 and the middle sleeve 3 are simultaneously pushed upward. When the hydraulic pressure is still small, since the unsealing shearing nail 24 is provided between the upper joint 1 and the center tube 12, the hydraulic pressure is very small under the connection of the unsealing shearing nail 24, and the upper joint 1 will not slide. However, the middle sleeve 3 will slide upward after being subjected to a small hydraulic thrust. After the middle sleeve 3 slides upward a small distance, the locking block will be pushed back into the card slot 19, so that the connection between the upper joint 1 and the center tube 12 becomes reliable again. At this time, the unsealing shearing nail 24 will no longer be subjected to shearing force. Therefore, the unsealing shearing nail 24 in the present invention does not need to bear a large shearing force, so it will be easier to unseal later.

[0031] Figure 6 The initial state of the unsealing mechanism in this embodiment is shown. When unsealing, the pressure in the central tube 12 is removed and the pipe string returns to Figure 5 The pipe column is lifted, the upper joint 1 and the upper sleeve 10 move upward, and the middle sleeve 3 does not move under the action of the tension spring 8, and reaches Figure 6 After reaching the position shown in the figure, driven by the locking block B23, the upward movement of the upper joint 1 will drive the upward movement of the intermediate sleeve 3 until Figure 7 Completely unblocked.

[0032] Figure 7 The unsealing mechanism in this embodiment is shown in a completely unsealed state, where the unsealing shear pins 24 are pulled off, the elastic limiting teeth 6 are bounced outward, and the rubber cylinder assembly pushes the locking body to slide upward, thereby achieving complete unsealing.

[0033] As can be seen from the above, the shear resistance of the unsealing shear pin 24 of the present invention does not need to be designed to be very large. On the one hand, the unsealing shear pin 24 does not bear the expansion force of the rubber cylinder assembly. On the other hand, as long as there is a slight hydraulic thrust, the intermediate sleeve 3 will move upward, and the lower outer side of the locking block has an inclined surface. The intermediate sleeve 3 pushes the locking block B23 into the slot 19 again. At this time, the unsealing shear pin 24 will no longer bear the shear force. Therefore, compared with any previous packer, the shear resistance of the unsealing shear pin 24 of the present invention can be designed to be the smallest, and the ease of unsealing is naturally the highest.

Claims

1. A step-by-step unsealing packer for a water injection well, comprising an upper joint (1), a central tube, an outer central tube (11), a lower joint (20), a sealing mechanism, an unsealing mechanism and a rubber cartridge assembly, wherein the sealing mechanism is located between the rubber cartridge assembly and the lower joint (20), the unsealing mechanism is located between the rubber cartridge assembly and the upper joint (1), the rubber cartridge assembly is sealingly sleeved on the outer central tube (11), the sealing mechanism compresses the rubber cartridge assembly from bottom to top so that the rubber cartridge assembly expands and seals, and the invention is characterized in that: The unsealing mechanism comprises an upper outer sleeve (10), an intermediate sleeve (3) and a locking body, wherein the locking body is fixedly connected to the upper end of the outer central tube (11), the upper end of the rubber sleeve assembly abuts against the locking body, the locking body comprises a main sleeve (9) and elastic limiting teeth (6) annularly spaced and distributed at the upper end of the main sleeve (9), the outer side of the central tube (12) comprises a constant diameter section (1201) and an expanded diameter section A (1202), the elastic limiting teeth (6) in an initial state abut against a step between the constant diameter section (1201) and the expanded diameter section A (1202), the intermediate sleeve (3) is slidably arranged between the locking body and the upper outer sleeve (10), and the upper part of the inner side of the intermediate sleeve (3) is a constant diameter cavity (301). The constant diameter cavity (301) limits the elastic limiting tooth (6) from bouncing radially of the main sleeve (9). The lower part of the inner side of the intermediate sleeve (3) is the enlarged diameter cavity (302). The enlarged diameter cavity (302) allows the elastic limiting tooth (6) to bounce outward. In the initial state, the elastic limiting tooth (6) is located in the constant diameter cavity (301) section. The constant diameter cavity (301) is processed with a locking hole in the radial direction. A locking block A (4) is slidably inserted in the locking hole. The inner side of the locking block A (4) corresponds to the elastic limiting tooth (6) and the outer side of the elastic limiting tooth (6) at this location is processed with a groove (5). The inner side of the locking block A (4) abuts against the groove (5), and the outer side of the locking block A (4) abuts against the upper sleeve (10). The groove (5) The inner side of the upper outer sleeve (10) at the lower side is processed with an expanded diameter section B (1001) for the locking block A (4) to extend into, a tension spring (8) is arranged between the lower end of the middle sleeve (3) and the locking body, and the middle sleeve (3) has a tendency to slide downward under the elastic force of the tension spring (8), a shearing nail (2) is arranged between the middle sleeve (3) and the upper outer sleeve (10), an unsealing shearing nail (24) is arranged between the upper joint (1) and the center tube (12), a locking hole is processed in the radial direction of the upper joint (1), a locking block B (23) is slidably inserted in the locking hole, a slot (19) is processed on the center tube (12) corresponding to the locking block B (23), and the middle sleeve (3) An annular limiting groove (21) is machined on the inner side, and a strong magnetic block (22) is provided in the annular limiting groove (21). In the initial state, the inner side of the locking block B (23) abuts against the slot (19), and the outer side of the locking block B (23) abuts against the intermediate sleeve (3). At this time, the annular limiting groove (21) is located above the locking block B (23). The upper end of the upper outer sleeve (10) is fixedly connected to the upper joint (1), and the lower end of the upper outer sleeve (10) is slidably sealed with the main sleeve (9). A liquid gap (25) is provided between the outer center tube (11) and the center tube (12), and the liquid inlet of the setting seal assembly reaches the lower end of the intermediate sleeve (3) and the upper joint (1) through the liquid gap (25).

2. A step-by-step unsealing packer for water injection wells according to claim 1, characterized in that: A stopper (7) is fixedly connected to the lower end of the intermediate sleeve (3), and the stopper (7) abuts against the constant diameter section (1201) of the central tube (12).

3. A step-by-step unsealing packer for water injection wells according to claim 1, characterized in that: The length of the locking block A (4) in the circumferential direction of the intermediate sleeve (3) is greater than the distance between the two elastic limiting teeth (6).

4. A step-by-step unsealing packer for water injection wells according to claim 1, characterized in that: The sealing mechanism comprises a sealing piston (13), a retaining spring (18) and a tooth sleeve (15), wherein the upper end of the tooth sleeve (15) is located between the center tube and the outer center tube (11), the inner side of the outer center tube (11) is provided with a step, the upper end of the tooth sleeve (15) abuts against the step on the inner side of the outer center tube (11), the lower end of the tooth sleeve (15) abuts against the lower joint (20), the tooth sleeve (15) is provided with a one-way retaining tooth (17), the upper end of the sealing piston (13) is provided with a retaining spring (18), the upper end of the tooth sleeve (15) is provided with a retaining spring (18), the upper end of the sealing piston (13) is provided with a retaining spring (18), the upper end of the tooth sleeve (15) is provided with a retaining spring (18), the upper end of the sealing piston (13) is provided with a retaining spring (18), the upper end of the sealing sleeve (15 ... Located on the outside of the upper center tube (12) and against the rubber cylinder assembly, the retaining spring (18) is arranged on the inside of the setting piston (13), and the retaining teeth (17) limit the retaining spring (18) in one direction, allowing only the retaining spring (18) and the setting piston (13) to slide upward, and the retaining teeth sleeve (15) and the corresponding center tube (12) are processed with a liquid inlet pressure transmission hole (16), and the outer center tube (11) between the setting piston (13) and the retaining teeth sleeve (15) is processed with a liquid hole (14).

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