Self-sealing packer for conventional well flushing
By designing a self-sealing sealer for the front well washing, the deformation of the vulcanized rubber cylinder assembly blocks the oil sleeve ring space, the problem of the backpressure formation of the well washing fluid is solved, and an energy-saving and efficient front well washing process is achieved, which extends the oil production time and reduces safety risks.
Patent Information
- Application Number
- CN202422245313.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-12
AI Technical Summary
The problem of backpressure formation of the well washing fluid in the existing regular well washing process has not been effectively solved, resulting in low well washing efficiency and safety hazards.
A self-sealed sealing packer for the front well was designed, including an upper joint, a central tube, a vulcanized rubber cylinder assembly, a thrust assembly and a pressure bearing sleeve. Through the cooperation of the pressure guide hole and a thrust assembly, the well washing fluid is prevented from entering the formation, and the deformation of the vulcanized rubber cylinder assembly is used to block the oil sleeve ring to avoid back pressure.
Effectively prevent the backpressure formation of the well washing fluid, save energy, extend oil production time, improve well washing efficiency, and reduce safety risks.
Smart Images
Figure CN223075515U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of oil production, in particular to a self-sealing packer for normal well flushing. Background Art
[0002] During the oil production process of oil wells, since there is a lot of paraffin in the crude oil, during the long-term oil production process, these paraffins will gradually precipitate and solidify inside the oil pipe in the shallow well section due to the decrease in temperature, resulting in a reduction in the effective flow area of the inner hole of the oil pipe. This leads to an increase in the load of the pumping unit, wasting electric energy, and may also cause wax sticking of the oil pump, safety accidents such as rod breakage, and environmental problems caused by oil spillage after rod breakage.
[0003] Generally, after oil production workers find serious wax deposition, they will arrange for hot flushing of the wax-deposited well. Hot flushing is to inject high-temperature hot water into the oil well to melt the paraffin and turn it back into a liquid state. The oil well hot flushing process is divided into two types. One is the reverse well flushing process - that is, hot water is injected into the annular space (annular space between the casing and the oil pipe) between the casing and the oil pipe and returns to the oil pipe through the suction of the oil pump; the other is the normal well flushing process - the flushing fluid is injected through the oil pipe, and then enters the annular space between the casing and the oil pipe through the normal well flushing valve and returns to the ground. Compared with the reverse well flushing process, the normal well flushing has many advantages. The flushing fluid directly enters the oil pipe and directly contacts the paraffin, with less heat loss. Generally, the well flushing time is two-thirds shorter than that of the reverse well flushing, and the well flushing efficiency is high. At the same time, like the reverse well flushing, there is also the problem that the flushing fluid back-presses into the formation during the well flushing process. At the same time, the normal well flushing operation is more troublesome, resulting in less application of the normal well flushing process. If the problem of the flushing fluid back-pressing into the formation during the normal well flushing process can be solved, the advantages of the normal well flushing can be better reflected. At present, the normal well flushing process has not solved the problem of the flushing fluid back-pressing into the formation. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a self-sealing packer for normal well flushing to solve the technical problem that the normal well flushing process in the prior art has not solved the problem of the flushing fluid back-pressing into the formation. The preferred technical solutions provided by the utility model can produce many technical effects, which will be elaborated below.
[0005] To achieve the above purpose, the utility model provides the following technical solutions:
[0006] A self-sealing packer for normal well flushing provided by the utility model comprises an upper joint, a central pipe, a vulcanized rubber cylinder assembly, a thrust assembly, a pressure-bearing sleeve and a lower joint. Among them, the inner wall of the lower end of the upper joint is connected to the upper end of the central pipe, the inner wall of the upper end of the lower joint is connected to the lower end of the central pipe, the vulcanized rubber cylinder assembly is sleeved on the central pipe and the upper end of the vulcanized rubber cylinder assembly is connected to the outer wall of the lower end of the upper joint, the lower end of the pressure-bearing sleeve is connected to the outer wall of the upper end of the lower joint and there is a receiving cavity between the pressure-bearing sleeve and the central pipe, the thrust assembly is installed in the receiving cavity, the upper end of the pressure-bearing sleeve is in contact with the vulcanized rubber cylinder assembly, and the lower end of the vulcanized rubber cylinder assembly is connected to the thrust assembly;
[0007] A pressure guiding hole is arranged on the central pipe, the pressure guiding hole is communicated with the receiving cavity, and the vulcanized rubber cylinder assembly can be deformed under the action of the thrust assembly.
[0008] Optionally, the vulcanized rubber cylinder assembly includes an upper vulcanized body, a lower vulcanized body and a deformation rubber cylinder. The two ends of the deformation rubber cylinder are respectively connected to the upper vulcanized body and the lower vulcanized body. The upper vulcanized body is sleeved on the central pipe and the upper vulcanized body is connected to the outer wall of the lower end of the upper joint. The deformation rubber cylinder is sleeved on the central pipe, and the lower vulcanized body is sleeved on the central pipe and the lower vulcanized body can move along the axial direction of the central pipe.
[0009] Optionally, the lower vulcanized body includes a connecting seat and a casing. The inner ring end of the connecting seat is fixedly connected to the casing. Both the connecting seat and the casing are sleeved on the central pipe. The connecting seat is connected to the deformation rubber cylinder. The other end of the casing is connected to the thrust assembly, and the pressure-bearing sleeve is in contact with the outer wall of the casing.
[0010] Optionally, the pressure-bearing sleeve includes a limiting seat and an outer pipe. The outer ring end of the limiting seat is fixedly connected to one end of the outer pipe. The other end of the outer pipe is connected to the outer wall of the upper end of the lower joint. The limiting seat is sleeved on the casing. The end of the limiting seat can be in contact with the end of the connecting seat, and the receiving cavity exists between the outer pipe and the central pipe.
[0011] Optionally, the thrust assembly includes a piston and a compression spring. Both the compression spring and the piston are sleeved on the central pipe. The outer wall of the piston is in contact with the inner wall of the outer pipe. The lower end of the compression spring is in contact with the upper end of the piston. The upper end of the compression spring is in contact with the lower end of the limiting seat. The lower end of the casing is connected to the upper end of the piston.
[0012] Optionally, the thrust assembly further includes a limiting sleeve. The limiting sleeve is connected to the inner wall of the outer pipe, and there is a moving distance between the lower end of the limiting sleeve and the upper end of the lower joint.
[0013] Optionally, an annular clamping groove is provided on the inner circle of the upper end of the piston, and the lower end of the sleeve extends into the annular clamping groove.
[0014] Optionally, a communication groove is provided on the inner circle of the upper end of the lower joint, the positions of the communication groove and the pressure guiding hole correspond to each other and the communication groove is communicated with the pressure guiding hole, and the communication groove is communicated with the accommodating cavity.
[0015] Optionally, the upper vulcanized body includes a fixing seat and a threaded sleeve. The outer ring end of the fixing seat is fixedly connected to the threaded sleeve. The fixing seat is sleeved on the central tube. The threaded sleeve is threadedly connected to the outer wall of the lower end of the upper joint. The fixing seat is connected to the deformation rubber cylinder.
[0016] Optionally, a plurality of connection holes are provided on both the upper vulcanized body and the lower vulcanized body.
[0017] A positive flushing well self-sealing packer provided by the present utility model. The upper joint and the lower joint are respectively connected to two adjacent tubing strings. The positive flushing well valve is located above the upper joint, and the lower joint is located above the sucker rod pump. When positive flushing the well, the sucker rod pump stops operating. The flushing fluid (hot water) will be conveyed from the upper joint to the lower joint direction. The flushing fluid cannot pass through the sucker rod pump, and the pressure inside the central tube will increase. And part of the flushing fluid will enter below the thrust assembly through the pressure guiding hole. When the pressure of the flushing fluid on the thrust assembly is greater than the elastic force of the thrust assembly itself, it will push the thrust assembly to move upward, and then push the vulcanized rubber cylinder assembly to be compressed and expand and deform outward, so as to block the oil casing annulus, thereby preventing the flushing fluid from entering the formation, thus avoiding the phenomenon of the flushing fluid backpressure on the formation, achieving energy saving while eliminating the reservoir recovery period, extending the effective oil production time, and solving the technical problem that the positive flushing well process in the prior art does not solve the problem of the flushing fluid backpressure on the formation. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0019] Figure 1 is a schematic structural diagram of a positive flushing well self-sealing packer provided by an embodiment of the present utility model;
[0020] Figure 2 is a schematic structural diagram of a vulcanized rubber cylinder assembly of a positive flushing well self-sealing packer provided by an embodiment of the present utility model;
[0021] Figure 3 is Figure 2 the sectional view taken along A-A in
[0022] Figure 4 is Figure 2 the sectional view taken along B-B in
[0023] Figure 5 It is a schematic structural view of the connection of the central pipe, thrust assembly, pressure-bearing sleeve and lower joint of a positive flushing self-sealing packer provided by an embodiment of the present invention.
[0024] In the figure, 1 is the upper joint; 11 is the internal thread;
[0025] 2 is the central pipe; 21 is the pressure guiding hole;
[0026] 3 is the vulcanized rubber cylinder assembly; 31 is the upper vulcanized body; 311 is the fixed seat; 312 is the threaded sleeve; 313 is the connection hole; 32 is the lower vulcanized body; 321 is the connection seat; 322 is the casing; 33 is the deformed rubber cylinder;
[0027] 4 is the thrust assembly; 41 is the piston; 411 is the annular clamping groove; 42 is the compression spring; 43 is the limit sleeve;
[0028] 5 is the pressure-bearing sleeve; 51 is the limit seat; 52 is the outer pipe;
[0029] 6 is the lower joint; 61 is the communication groove; 62 is the external thread;
[0030] 7 is the accommodation cavity. Detailed implementation manners
[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative effort belong to the scope protected by the present invention.
[0032] In the description of the present utility model, it should be noted that unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0033] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0034] The present utility model provides a forward flushing well self-sealing packer, which includes an upper joint 1, a central pipe 2, a vulcanized rubber cylinder assembly 3, a thrust assembly 4, a pressure-bearing sleeve 5, and a lower joint 6. Among them, the inner wall of the lower end of the upper joint 1 is connected to the upper end of the central pipe 2, and a sealing ring is provided between the upper joint 1 and the central pipe 2. The inner wall of the lower end of the upper joint 1 and the upper end of the central pipe 2 can be threadedly connected. The inner wall of the upper end of the lower joint 6 is connected to the lower end of the central pipe 2, and the inner wall of the upper end of the lower joint 6 and the lower end of the central pipe 2 can be threadedly connected. The vulcanized rubber cylinder assembly 3 is sleeved on the central pipe 2, and the upper end of the vulcanized rubber cylinder assembly 3 is connected to the outer wall of the lower end of the upper joint 1. The lower end of the pressure-bearing sleeve 5 is connected to the outer wall of the upper end of the lower joint 6, and there is a receiving cavity 7 between the pressure-bearing sleeve 5 and the central pipe 2. The thrust assembly 4 is installed in the receiving cavity 7. The upper end of the pressure-bearing sleeve 5 is in contact with the vulcanized rubber cylinder assembly 3, and the lower end of the vulcanized rubber cylinder assembly 3 is connected to the thrust assembly 4;
[0035] The central pipe 2 is provided with pressure guiding holes 21 which are communicated with the accommodating cavity 7. The vulcanized rubber cylinder assembly 3 can be deformed under the action of the thrust assembly 4. A positive flushing well self-sealing packer provided by the utility model, an upper joint 1 and a lower joint 6 are respectively connected to two adjacent tubing strings. The positive flushing well valve is located above the upper joint 1, and the lower joint 6 is located above the sucker rod pump. When positive flushing the well, the sucker rod pump stops operating. The flushing fluid (hot water) will be conveyed from the upper joint 1 towards the lower joint 6. The flushing fluid cannot pass through the sucker rod pump, and the pressure inside the central pipe 2 will increase. And part of the flushing fluid will enter below the thrust assembly 4 through the pressure guiding holes 21. When the pressure of the flushing fluid on the thrust assembly 4 is greater than the elastic force of the thrust assembly 4 itself, it will push the thrust assembly 4 to move upward, and then push the vulcanized rubber cylinder assembly 3 to be compressed and expand outwards, so as to block the annulus between the tubing and the casing, and further prevent the flushing fluid from entering the formation, thus avoiding the phenomenon of the flushing fluid counterpressure on the formation, achieving energy saving while eliminating the reservoir recovery period, prolonging the effective oil production time, and solving the technical problem that the positive flushing well process in the prior art does not solve the problem of the flushing fluid counterpressure on the formation.
[0036] As an optional implementation manner, the vulcanized rubber cylinder assembly 3 includes an upper vulcanized body 31, a lower vulcanized body 32 and a deformable rubber cylinder 33. The two ends of the deformable rubber cylinder 33 are respectively connected to the upper vulcanized body 31 and the lower vulcanized body 32. The upper vulcanized body 31 is sleeved on the central pipe 2 and the upper vulcanized body 31 is connected to the outer wall of the lower end of the upper joint 1. The deformable rubber cylinder 33 is sleeved on the central pipe 2. The lower vulcanized body 32 is sleeved on the central pipe 2 and the lower vulcanized body 32 can move along the axial direction of the central pipe 2. When positive flushing the well, the pressure of the flushing fluid will push the thrust assembly 4 to move upward, and then will push the lower vulcanized body 32 to move upward, so that the deformable rubber cylinder 33 is compressed, and the outer wall of the deformable rubber cylinder 33 expands outwards; when the positive flushing of the well ends, the pressure of the flushing fluid will be cancelled, and the deformable rubber cylinder 33 will return to its original state under the action of its own stress and the compression elastic force of the thrust assembly 4.
[0037] As an optional implementation manner, the lower vulcanized body 32 includes a connecting seat 321 and a sleeve 322. The inner ring end of the connecting seat 321 is fixedly connected to the sleeve 322. Both the connecting seat 321 and the sleeve 322 are sleeved on the central pipe 2. Both the connecting seat 321 and the sleeve 322 can move along the axial direction of the central pipe 2. A sealing ring is arranged between the connecting seat 321 and the central pipe 2. The connecting seat 321 is connected to the deformable rubber cylinder 33. The other end of the sleeve 322 is connected to the thrust assembly 4. The pressure-bearing sleeve 5 is in contact with the outer wall of the sleeve 322. A sealing ring is arranged between the pressure-bearing sleeve 5 and the sleeve 322.
[0038] As an alternative embodiment, the pressure-bearing sleeve 5 includes a limit seat 51 and an outer tube 52. The outer ring end of the limit seat 51 is fixedly connected to one end of the outer tube 52. The other end of the outer tube 52 is connected to the outer wall of the upper end of the lower joint 6. A sealing ring is provided between the outer tube 52 and the lower joint 6. The outer tube 52 and the lower joint 6 can be connected by threads. The limit seat 51 is sleeved on the casing 322, that is, the inner ring of the limit seat 51 is in contact with the outer wall of the casing 322 and a sealing ring is provided between the inner ring of the limit seat 51 and the casing 322. The end of the limit seat 51 can be in contact with the end of the connecting seat 321 to limit the further downward movement of the lower vulcanizate 32 and also for connecting the compression spring 42. There is an accommodation cavity 7 between the outer tube 52 and the central tube 2.
[0039] As an alternative embodiment, the thrust assembly 4 includes a piston 41 and a compression spring 42. Both the compression spring 42 and the piston 41 are sleeved on the central tube 2. The piston 41 can move along the axial direction of the central tube 2. A sealing ring is provided between the inner wall of the piston 41 and the outer wall of the central tube 2. The outer wall of the piston 41 is in contact with the inner wall of the outer tube 52, and a sealing ring is provided between the outer wall of the piston 41 and the inner wall of the outer tube 52. The lower end of the compression spring 42 is in contact with the upper end of the piston 41, and the upper end of the compression spring 42 is in contact with the lower end of the limit seat 51. The lower end of the casing 322 is connected to the upper end of the piston 41. When the pressure of the washing fluid on the piston 41 is greater than the elastic force of the compression spring 42 on the piston 41, the piston 41 will move upward, thereby driving the casing 322 to move upward, and at the same time causing the compression spring 42 to be compressed until the compression elastic force of the compression spring 42 on the piston 41 is consistent with the pressure of the washing fluid on the piston 41, or when the piston 41 abuts against the limit sleeve 43, the piston 41 will stop moving upward.
[0040] As an alternative embodiment, the thrust assembly 4 further includes a limit sleeve 43. The limit sleeve 43 is connected to the inner wall of the outer tube 52. There is a moving distance between the lower end of the limit sleeve 43 and the upper end of the lower joint 6. The limit sleeve 43 is used to limit the further upward movement of the piston 41 and also to prevent the compression spring 42 from being compressed to a large extent. The lower joint 6 is used to limit the further downward movement of the piston 41.
[0041] As an alternative embodiment, an annular groove 411 is provided in the inner ring of the upper end of the piston 41. The lower end of the casing 322 extends into the annular groove 411. The annular groove 411 is used to connect with the casing 322 so that the piston 41 and the casing 322 can move synchronously.
[0042] As an optional implementation manner, a communication groove 61 is provided in the inner ring at the upper end of the lower joint 6. The positions of the communication groove 61 and the pressure guiding hole 21 correspond to each other and the communication groove 61 is communicated with the pressure guiding hole 21. The communication groove 61 is communicated with the accommodation cavity 7. The communication groove 61 is located at the lower end of the piston 41, so as to enable the washing fluid to pass through the pressure guiding hole 21, enter the communication groove 61, and apply pressure to the piston 41.
[0043] As an optional implementation manner, the upper vulcanized body 31 includes a fixed seat 311 and a threaded sleeve 312. The outer ring end of the fixed seat 311 is fixedly connected to the threaded sleeve 312. The fixed seat 311 is sleeved on the central tube 2. The threaded sleeve 312 is threadedly connected to the outer wall at the lower end of the upper joint 1. The fixed seat 311 is connected to the deformable rubber cylinder 33.
[0044] As an optional implementation manner, a plurality of connection holes 313 are provided on both the upper vulcanized body 31 and the lower vulcanized body 32. Manufacturing process of the vulcanized rubber cylinder assembly 3: The upper vulcanized body 31 and the lower vulcanized body 32 are both placed in a mold, then rubber is introduced into the mold, and part of the rubber will fill into the connection holes 313. After solidification, the solidified rubber will be connected to the connection holes 313. This connection method ensures the integrity of the vulcanized rubber cylinder assembly 3, making it not easy for the deformable rubber cylinder 33 to fall off from the upper vulcanized body 31 and the lower vulcanized body 32.
[0045] Internal threads 11 are provided on the inner wall at the upper end of the upper joint 1. The internal threads 11 are threadedly connected to the outer wall of the oil pipe. External threads 62 are provided on the outer wall at the lower end of the lower joint 6. The external threads 62 are threadedly connected to the inner wall of the oil pipe.
[0046] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of changes or substitutions, which should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.
Claims
1. A positive flushing well self-sealing packer, characterized in that, It includes an upper joint (1), a central tube (2), a vulcanized rubber cylinder assembly (3), a thrust assembly (4), a pressure-bearing sleeve (5) and a lower joint (6). Among them, The inner wall of the lower end of the upper joint (1) is connected to the upper end of the central tube (2), the inner wall of the upper end of the lower joint (6) is connected to the lower end of the central tube (2), the vulcanized rubber cylinder assembly (3) is sleeved on the central tube (2) and the upper end of the vulcanized rubber cylinder assembly (3) is connected to the outer wall of the lower end of the upper joint (1), the lower end of the pressure-bearing sleeve (5) is connected to the outer wall of the upper end of the lower joint (6) and there is a receiving cavity (7) between the pressure-bearing sleeve (5) and the central tube (2), the thrust assembly (4) is installed in the receiving cavity (7), the upper end of the pressure-bearing sleeve (5) is in contact with the vulcanized rubber cylinder assembly (3), and the lower end of the vulcanized rubber cylinder assembly (3) is connected to the thrust assembly (4); A pressure guiding hole (21) is provided on the central tube (2), the pressure guiding hole (21) communicates with the receiving cavity (7), and the vulcanized rubber cylinder assembly (3) can be deformed under the action of the thrust assembly (4).
2. The positive flushing self-sealing packer according to claim 1, characterized in that, The vulcanized rubber cylinder assembly (3) includes an upper vulcanized body (31), a lower vulcanized body (32) and a deformable rubber cylinder (33). The two ends of the deformable rubber cylinder (33) are respectively connected to the upper vulcanized body (31) and the lower vulcanized body (32). The upper vulcanized body (31) is sleeved on the central tube (2) and the upper vulcanized body (31) is connected to the outer wall of the lower end of the upper joint (1). The deformable rubber cylinder (33) is sleeved on the central tube (2), and the lower vulcanized body (32) is sleeved on the central tube (2) and the lower vulcanized body (32) can move along the axial direction of the central tube (2).
3. The positive flushing self-sealing packer according to claim 2, characterized in that, The lower vulcanized body (32) includes a connecting seat (321) and a sleeve (322). The inner ring end of the connecting seat (321) is fixedly connected to the sleeve (322). Both the connecting seat (321) and the sleeve (322) are sleeved on the central tube (2). The connecting seat (321) is connected to the deformable rubber cylinder (33). The other end of the sleeve (322) is connected to the thrust assembly (4), and the pressure-bearing sleeve (5) is in contact with the outer wall of the sleeve (322).
4. The positive flushing well self-sealing packer according to claim 3, characterized in that, The pressure-bearing sleeve (5) includes a limiting seat (51) and an outer tube (52). The outer ring end of the limiting seat (51) is fixedly connected to one end of the outer tube (52). The other end of the outer tube (52) is connected to the outer wall of the upper end of the lower joint (6). The limiting seat (51) is sleeved on the sleeve (322). The end of the limiting seat (51) can be in contact with the end of the connecting seat (321), and there is the receiving cavity (7) between the outer tube (52) and the central tube (2).
5. The positive flushing self-sealing packer according to claim 4, characterized in that, The thrust assembly (4) includes a piston (41) and a compression spring (42). Both the compression spring (42) and the piston (41) are sleeved on the central tube (2). The outer wall of the piston (41) is in contact with the inner wall of the outer tube (52). The lower end of the compression spring (42) is in contact with the upper end of the piston (41). The upper end of the compression spring (42) is in contact with the lower end of the limit seat (51). The lower end of the sleeve (322) is connected to the upper end of the piston (41).
6. The positive flushing self-sealing packer according to claim 5, characterized in that, The thrust assembly (4) further includes a limit sleeve (43). The limit sleeve (43) is connected to the inner wall of the outer tube (52). There is a moving distance between the lower end of the limit sleeve (43) and the upper end of the lower joint (6).
7. The positive flushing self-sealing packer according to claim 5, characterized in that, An annular groove (411) is provided in the inner circle of the upper end of the piston (41). The lower end of the sleeve (322) extends into the annular groove (411).
8. A normal flushing self-sealing packer according to claim 5, characterized in that, A communication groove (61) is provided in the inner circle of the upper end of the lower joint (6). The positions of the communication groove (61) and the pressure guiding hole (21) correspond to each other and the communication groove (61) is communicated with the pressure guiding hole (21). The communication groove (61) is communicated with the accommodating cavity (7).
9. A normal flushing well self-sealing packer according to claim 2, characterized in that, The upper vulcanizate (31) includes a fixed seat (311) and a threaded sleeve (312). The outer ring end of the fixed seat (311) is fixedly connected to the threaded sleeve (312). The fixed seat (311) is sleeved on the central tube (2). The threaded sleeve (312) is threadedly connected to the outer wall of the lower end of the upper joint (1). The fixed seat (311) is connected to the deformable rubber cylinder (33).
10. The positive flushing self-sealing packer according to claim 2, characterized in that, A plurality of connection holes (313) are provided on both the upper vulcanizate (31) and the lower vulcanizate (32).