CN210068069U - Anti-leakage double-sealing well-flushing packer - Google Patents

Abstract

The utility model discloses a leak protection double containment well-flushing packer, including last outer tube (4), well center tube (56) and lower center tube (55) that from the top down connected gradually, go up outer tube (4) overcoat and be equipped with leather cup sealing mechanism, well center tube (56) overcoat is equipped with hydraulic pushing mechanism, and lower center tube (55) overcoat is equipped with packing element sealing mechanism and the slips anchor mechanism that sets up from top to bottom, packing element sealing mechanism contains sealed packing element, slips anchor mechanism contains slips (43), and this hydraulic pushing mechanism can make this sealed packing element axial compression, and this hydraulic pushing mechanism can also make slips (43) strut. The anti-leakage double-seal well-flushing packer can realize sealing at normal temperature and high temperature without increasing the operation cost, greatly enhances the stratigraphy degree for oil deposit, promotes the yield of crude oil, and enables air to enter the stratum according to the design requirement instead of entering the stratum in a general manner.

Description

Anti-leakage double-sealing well-flushing packer

Technical Field

The utility model relates to an oil development equipment field, specific is a leak protection double containment well-flushing packer.

Background

Any impediment to the ability of fluids to be produced or injected naturally in the near wellbore region of a reservoir when performing various operations such as drilling, completion, production, stimulation, workover, and the like, is collectively referred to as formation damage. The formation damage is caused by a plurality of reasons and forms a plurality of types. There are mainly capillarity, solid phase invasion, scaling and damage to the rock. American core companies summarize information about four thousand wells worldwide, summarizing the severity and prevalence of particle migration, wetting reversal, and scaling for reservoir damage. With well cleanout being most prominent during the workover phase and production. The well washing in the production process mainly aims at a high oil well containing wax and a thick oil well. At present, conventional hot washing and leakage-proof hot washing of a leather cup packer are mainly adopted.

Problems exist with conventional hot well cleanup processes:

because the formation pressure is low, in the hot washing process, mud and fine silt enter a near-wellbore zone of the formation along with the well washing liquid and are gradually deposited in the croup hole to block an oil layer to form a bottleneck and reverse bottleneck effect, the resistance is small when the mud and the fine silt leak to the oil layer, the mud and the fine silt enter the near-wellbore zone of the formation along with the well washing liquid, the mud and the fine silt leak to the oil layer. The blockage is difficult to eliminate in a short time under the condition of small pressure difference production, so that the pump is blocked when the pump is lowered for production along with the produced liquid flowing to a shaft, and the normal production of an oil well is influenced. Most wells are not washed thoroughly, and the purposes of well washing, paraffin removal, sand blockage removal, viscosity reduction and the like cannot be achieved. Theoretical analysis suggests that the initiation pressure for leak-off to the formation is: the starting pressure P is more than or equal to the cement truck pressure P + the well depth Hgamma/10-P stratum static pressure-frictional resistance loss P, and the well flushing fluid can be leaked to an oil layer to different degrees as long as the starting pressure P is more than or equal to 0. Forming a pollution zone. According to the research of American rock core company, the high-permeability layer can form about 1m of pollution zone, and the low-permeability layer can form 0.01m-0.3m of pollution zone. The formation of the pollution zone causes the diversification and the complication of the pollution types of the oil layer and brings difficulty to the blockage removal work of the oil layer.

Conventional leak-proof hot-wash wells have major problems:

the sealing structure is accelerated to wear along with the creeping of the oil pumping pipe column, the sealing effect is poor, and the effective time is short; when the pipe string is lifted out in operation, the sleeve is not provided with a pressure relief device, the leather cup is damaged in the process that the leather cup is lifted upwards in a pressing and opening state, residues of the leather cup are left in a well, and a pump valve is often clamped, so that the normal production of the oil well is influenced;

SUMMERY OF THE UTILITY MODEL

In order to improve the sealed effect of well-flushing packer, the utility model provides a leak protection double containment well-flushing packer, this leak protection double containment well-flushing packer can realize sealing under normal atmospheric temperature and high temperature, and does not increase the running cost, makes the oil reservoir use the stratification degree to strengthen greatly, makes the output of crude oil obtain promoting. Allowing air to enter the formation as designed rather than generally. The anti-leakage double-seal well-flushing packer has wide application prospect, is suitable for realizing seat sealing at different temperatures and achieves the purpose of sealing and isolating an oil layer.

The utility model provides a technical scheme that its technical problem adopted is: the utility model provides a leak protection double containment well-flushing packer, includes from the last outer tube, well center tube and the lower center tube that connect gradually from the top down, goes up the outer tube overcoat and is equipped with leather cup sealing mechanism, and well center tube overcoat is equipped with hydraulic pushing mechanism, and the outer tube overcoat of lower center tube is equipped with packing element sealing mechanism and the slips anchor mechanism that sets up from top to bottom, packing element sealing mechanism contains sealed packing element, slips anchor mechanism contains the slips, and this hydraulic pushing mechanism can make this sealed packing element axial compression, and this hydraulic pushing mechanism can also make the slips strut.

Go up the endotheca and be equipped with the center tube, go up the lower extreme and the last outer tube threaded connection of center tube, the upper end of going up the center tube is located outside the outer tube, goes up the upper end of center tube and is equipped with the top connection outward, leather cup sealing mechanism contains the first leather cup and the second leather cup that set up from top to bottom.

Be equipped with the balance hole in the lower part lateral wall of going up the outer tube, first leather cup and second leather cup all are located the top in balance hole, and the upper portion of going up the outer tube is connected fixedly through first fixing pin and last center tube, and first leather cup endotheca is equipped with upper and lower first support sleeve and first bush, and second leather cup endotheca is equipped with upper and lower second support sleeve and second bush.

The upper end of the middle central tube is in threaded connection with the lower end of the upper outer tube, the lower end of the middle central tube is in threaded connection with the upper end of the lower central tube, the hydraulic pushing mechanism comprises a hydraulic cylinder barrel, the hydraulic cylinder barrel is sleeved outside the middle central tube, and an upper sealing sleeve, an upper piston, a lower sealing sleeve and a lower piston which are sequentially arranged from top to bottom are arranged between the hydraulic cylinder barrel and the middle central tube.

An upper liquid inlet hole and a lower liquid inlet hole which are arranged up and down are arranged in the side wall of the middle central tube, the upper liquid inlet hole corresponds to the upper piston, the lower liquid inlet hole corresponds to the lower piston, the upper outer tube, the upper sealing sleeve and the hydraulic cylinder barrel are fixedly connected through a second fastening pin, the upper piston is connected with the hydraulic cylinder barrel through a first shearing pin, and the lower piston is connected with the hydraulic cylinder barrel through a second shearing pin.

The rubber cylinder sealing mechanism further comprises a lower outer pipe, the lower outer pipe is sleeved outside the lower central pipe, a bushing and a locking ring which are arranged from top to bottom are sleeved between the lower outer pipe and the lower central pipe, the upper end of the lower outer pipe is fixedly connected with the bushing through a third fastening pin, the rubber cylinder comprises three rubber cylinders which are sequentially arranged from top to bottom, the three rubber cylinders are all sleeved outside the lower outer pipe, and a spacing ring is arranged between every two adjacent rubber cylinders.

The slip anchoring mechanism further comprises a cone and a slip seat, the cone, the slip and the slip seat are sequentially connected from top to bottom, the cone is connected with the rubber cylinder sealing mechanism through a tail end spacer ring, the cone and the slip seat are sleeved outside the lower central pipe, and a hoop spring is sleeved outside the slip.

Be equipped with the pressure release hole in the lateral wall of lower center tube, the position of pressure release hole corresponds with the slip seat, and the upper and lower both sides in pressure release hole all are equipped with the ninth sealing washer, and the ninth sealing washer cover is located between slip seat and the lower center tube.

The lower central tube jacket is also provided with a centering mechanism, the centering mechanism is positioned below the slip anchoring mechanism, the centering mechanism comprises a centering block seat and a centering block, the centering block seat is sleeved outside the lower central tube, and the centering block seat is connected with the centering block through a spring.

The lower end of the centering block seat is connected with the lower central tube through a third shearing pin, a sliding ring sleeve is sleeved outside the lower end of the centering block seat, a sliding ring is arranged in the sliding ring sleeve and connected with a sliding ring pin, and a slideway capable of guiding the sliding ring pin to slide is arranged outside the lower central tube.

The utility model has the advantages that: the anti-leakage double-seal well-flushing packer has a two-stage hydraulic seal structure, has the functions of hot anti-leakage hot well-flushing, improves the sealing effect and prolongs the service life; the automatic friction type sliding sleeve switch valve is lifted to a certain height to automatically open and release pressure, so that the control is flexible and reliable, and residues are prevented from falling into a well to block a pump after a leather cup is damaged; the construction process is simple, and no construction process and construction cost are increased when the pump is put into the well; the anti-leakage double-seal well-flushing plug removal device can be repeatedly used underground due to the special structure, and the use cost is low; in the normal production process, the side liquid level is not influenced; a one-way valve is designed at a flushing fluid inlet of the flushing plug removal device, so that formation fluid is prevented from entering a casing pipe, and a pipe column cannot be clamped by sand.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

Figure 1 is the overall schematic diagram of leak protection double seal well-flushing packer of the utility model.

Fig. 2 is an upper schematic view of a cup seal mechanism.

Fig. 3 is a lower schematic view of the cup seal mechanism.

Fig. 4 is an upper schematic view of the hydraulic pushing mechanism.

Fig. 5 is a lower schematic view of the hydraulic pushing mechanism.

Fig. 6 is a schematic view of the cartridge sealing mechanism.

FIG. 7 is a schematic view of a slip anchoring mechanism.

Figure 8 is an upper schematic view of the centralizer mechanism.

Figure 9 is a lower schematic view of the centralizer mechanism.

1. An upper joint; 2. an upper center tube; 3. a first fixing pin; 4. an upper outer tube; 5. a first support sleeve; 6. a second fixing pin; 7. a first leather cup; 8. a first bushing; 9. a first seal ring; 10. a first leather cup pressing cap; 11. a second support sleeve; 12. a second leather cup; 13. a second bushing; 14. a second leather cup pressing cap; 15. a second seal ring; 16. a balance hole; 17. a third seal ring; 18. pressing the cap; 19. a first locking pin; 20. a second locking pin; 21. an upper sealing sleeve; 22. a fourth seal ring; 23. a first shear pin; 24. an upper piston; 25. a fifth seal ring; 26. a lower piston; 27. a lower sealing sleeve; 28. a sixth seal ring; 29. a second shear pin; 30. a seventh seal ring; 31. a hydraulic cylinder barrel; 32. a coupling sleeve; 33. a lower outer tube; 34. a third locking pin; 35. a bushing; 36. a locking ring; 37. a rubber cylinder; 38. a spacer ring; 39. an annular groove; 40. an eighth seal ring; 41. a terminal spacer ring; 42. a cone; 43. slips; 44. a hoop spring; 45. a slip seat; 46. a ninth seal ring; 47. a pressure relief vent; 48. a righting block seat; 49. a righting block; 50. a spring; 51. a slip ring sleeve; 52. a third shear pin; 53. a slip ring; 54. a slip ring pin; 55. a lower center tube; 56. a center tube; 57. an upper feed hole; 58. and a lower liquid inlet hole.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The utility model provides a leak protection double containment well-flushing packer, includes from the last outer tube 4, well center tube 56 and the lower center tube 55 that connect gradually from the top down, goes up 4 overcoat of outer tube and is equipped with leather cup sealing mechanism, and the 56 overcoat of well center tube is equipped with hydraulic pushing mechanism, and the packing element sealing mechanism and the slips anchor mechanism that set up about the 55 overcoat of lower center tube is equipped with, packing element sealing mechanism contains sealed packing element, slips anchor mechanism contains slips 43, and this hydraulic pushing mechanism can make this sealed packing element axial compression, and this hydraulic pushing mechanism can also make slips 43 strut, as shown in figure 1.

In this embodiment, the inner sleeve of the upper outer tube 4 is provided with the upper central tube 2, the lower end of the upper central tube 2 is in threaded connection with the upper outer tube 4, the upper end of the upper central tube 2 is located outside the upper outer tube 4, the upper end of the upper central tube 2 is provided with the upper joint 1, and the leather cup sealing mechanism comprises the first leather cup 7 and the second leather cup 12 which are arranged up and down.

In this embodiment, a balance hole 16 is provided in a side wall of a lower portion of the upper outer tube 4, the first leather cup 7 and the second leather cup 12 are both located above the balance hole 16, the upper portion of the upper outer tube 4 is fixedly connected with the upper central tube 2 through the first fixing pin 3, the first leather cup 7 is provided with the upper and lower first supporting sleeves 5 and the first bushing 8 in an inner sleeve manner, and the second leather cup 12 is provided with the upper and lower second supporting sleeves 11 and the second bushing 13 in an inner sleeve manner, as shown in fig. 2 and 3.

Specifically, the upper joint 1 is connected with the upper central pipe 2 through screw threads and other fixedly connecting modes, the upper outer pipe 4 is sleeved outside the upper central pipe 2, and the upper outer pipe 4 is connected with the lower part of the upper central pipe 2 through trapezoidal threads. Third sealing rings 17 are arranged on two sides of the balance hole 16, which are in contact with the upper central pipe 2; the first supporting sleeve 5 is sleeved outside the upper outer pipe 4 and is connected with the upper outer pipe through a second fixing pin 6; the first leather cup 7 and the first bushing 8 as well as the second leather cup 12 and the second bushing 13 are connected together through vulcanization, the leather cups and the bushings are sleeved outside the upper outer tube 4, and the tail ends of the leather cups and the bushings are provided with a first leather cup pressing cap 10 and a second leather cup pressing cap 14; the contact parts of the first bushing 8 and the second bushing 13 and the upper outer pipe 4 are respectively provided with a first sealing ring 9 and a second sealing ring 15.

In this embodiment, the upper end of the middle central tube 56 is in threaded connection with the lower end of the upper outer tube 4, the lower end of the middle central tube 56 is in threaded connection with the upper end of the lower central tube 55, the hydraulic pushing mechanism includes a hydraulic cylinder 31, the hydraulic cylinder 31 is sleeved outside the middle central tube 56, and an upper sealing sleeve 21, an upper piston 24, a lower sealing sleeve 27 and a lower piston 26 are sequentially arranged between the hydraulic cylinder 31 and the middle central tube 56 from top to bottom, as shown in fig. 4 and 5.

In this embodiment, an upper liquid inlet hole 57 and a lower liquid inlet hole 58 are provided in the sidewall of the center tube 56, the upper liquid inlet hole 57 corresponds to the upper piston 24, the lower liquid inlet hole 58 corresponds to the lower piston 26, the upper outer tube 4, the upper sealing sleeve 21 and the liquid cylinder 31 are fixedly connected by the second fastening pin 20, the upper piston 24 and the liquid cylinder 31 are connected by the first shearing pin 23, and the lower piston 26 and the liquid cylinder 31 are connected by the second shearing pin 29.

Specifically, an upper sealing sleeve 21, an upper piston 24, a lower sealing sleeve 27 and a lower piston 26 are sequentially sleeved outside a middle central tube 56, and a hydraulic cylinder barrel 31 is sleeved outside the piston and the sealing sleeves; the upper sealing sleeve 21 is connected with the upper outer tube 4 through a second fastening pin 20; the upper piston 24 and the lower piston 26 are fixed with a hydraulic cylinder 31 through a first shear pin 23 and a second shear pin 29 respectively; the pressing cap 18 is screwed to the upper outer tube 4 and is fixed to the upper outer tube 4 by a first fastening pin 19.

In this embodiment, the rubber sleeve sealing mechanism further includes a lower outer tube 33, the lower outer tube 33 is sleeved outside the lower center tube 55, a bushing 35 and a locking ring 36 which are vertically arranged are sleeved between the lower outer tube 33 and the lower center tube 55, the upper end of the lower outer tube 33 is connected and fixed with the bushing 35 through a third fastening pin 34, the rubber sleeve includes three rubber sleeves 37 which are sequentially arranged from top to bottom, the three rubber sleeves 37 are all sleeved outside the lower outer tube 33, and a spacer ring 38 is disposed between two adjacent rubber sleeves 37, as shown in fig. 6.

In this embodiment, the slip anchoring mechanism further includes a cone 42 and a slip seat 45, the cone 42, the slip 43 and the slip seat 45 are sequentially connected from top to bottom, the cone 42 is connected with the rubber tube sealing mechanism through a terminal spacer ring 41, the cone 42 and the slip seat 45 are both sleeved outside the lower central tube 55, and a hoop spring 44 is sleeved outside the slip 43, as shown in fig. 7.

In this embodiment, a pressure relief hole 47 is formed in a side wall of the lower central tube 55, the position of the pressure relief hole 47 corresponds to the slip seat 45, ninth sealing rings 46 are respectively disposed on upper and lower sides of the pressure relief hole 47, and the slip seat 45 and the lower central tube 55 are sleeved with the ninth sealing rings 46.

Specifically, the coupling sleeve 32 is connected with the bushing 35 through threads; the tail end spacer ring 41 and the rubber cylinder 37 are sequentially sleeved outside the lower outer pipe 33, and the lower outer pipe 33 is sleeved outside the lower central pipe 55; the cone 42 is connected with the end spacer ring 41 through threads; the lock ring 36 is in threaded connection with the lower center tube 55; the locking ring 36 is a split ring, the inner diameter of the locking ring 36 can be enlarged or reduced, and the locking ring 36 can be clamped at the upper end of the main annular groove 39 when moving downwards, so that the locking and fixing effects are achieved. The slips 43 are placed inside the slip bowl 45 and the slips are externally bound with a garter spring 44 to the outside of the lower center tube 55.

In this embodiment, a centering mechanism is further disposed outside the lower central tube 55, the centering mechanism is located below the slip anchoring mechanism, the centering mechanism includes a centering block seat 48 and a centering block 49, the centering block seat 48 is sleeved outside the lower central tube 55, and the centering block seat 48 is connected to the centering block 49 through a spring 50.

In this embodiment, the lower end of the centering block seat 48 is connected to a lower center tube 55 through a third shear pin 52, a slip ring sleeve 51 is sleeved outside the lower end of the centering block seat 48, a slip ring 53 is arranged inside the slip ring sleeve 51, the slip ring 53 is connected to a slip ring pin 54, and a slide way for guiding the slip ring pin 54 to slide is arranged outside the lower center tube 55, as shown in fig. 8 and 9.

Specifically, the centering block seat 48 is sleeved outside the lower central tube 55, and the upper part of the centering block seat 48 is connected with the lower part of the slip seat 45 through threads; the centering block 49 is seated in the centering block seat 48, and a spring 50 is arranged between the centering block 49 and the centering block seat 48 for supporting; the sliding ring sleeve 51 is connected with the centering block seat 48 through threads, and the centering block seat 48 is connected with the lower central pipe 55 through a third shear pin 52; the outside of the slip ring pin 54 is provided with a slip ring sleeve 51, the slip ring pin 54 and the slip ring sleeve are positioned inside the slip ring sleeve 51, and the lower part of the slip ring pin is positioned inside the slideway of the lower central pipe 55.

The working process of the leak-proof double-seal well-flushing packer is described below.

When in work, the anti-leakage double-seal well-flushing packer is lowered to a downhole design position along with a pipe column, pressure fluid is pumped into the upper central pipe 2, the pressure fluid enters through the fluid inlet holes (the upper fluid inlet hole 57 and the lower fluid inlet hole 58) of the central pipe 56, when the pressure reaches the shearing pressure of the first shearing pin 23 and the second shearing pin 29, the shearing pins are sheared, the upper piston 24 and the lower piston 26 sequentially push the connecting sleeve 32, the lower outer pipe 33 and the cone 42 downwards, the slips 43 are further pushed open, the casing wall which is contacted with the slips 43 is tightly contacted, the lower outer pipe 33 further continues to move downwards, the rubber sleeve 37 is further compressed, the annular space between the packer and the casing is further sealed, when the lower outer pipe 33 reaches a preset position, the locking ring 36 interacts with the annular groove 39 to achieve a backstop effect, namely the rubber sleeve 37 can still be kept in a compressed state after the liquid pressure disappears; at the moment, due to the interference fit of the first leather cup 7 and the second leather cup 12 with the casing wall, the double sealing effect is achieved.

When the pipe column needs to be taken out, the upper central pipe 2 is rotated anticlockwise, trapezoidal threads between the upper central pipe 2 and the upper outer pipe 4 are disengaged, the upper central pipe 2 is further lifted, the balance hole 16 is exposed, the upper central pipe 2 drives the upper outer pipe 4, the third shearing pin 52 is further driven to be sheared, the cone 42 is further driven to move upwards, the pressure relief hole 47 is further exposed, the upper and lower pressure differences of the rubber barrel 37 are further equalized, the deblocking is facilitated, and the centering block seat is kept still under the action of the centering block 49 due to the action of the slip ring pin 54; and further completing the unsealing operation.

The above description is only for the specific embodiments of the present invention, and the scope of the present invention can not be limited by the embodiments, so that the replacement of the equivalent components or the equivalent changes and modifications made according to the protection scope of the present invention should still belong to the scope covered by the present patent. In addition, the utility model provides an between technical feature and the technical feature, between technical feature and technical scheme, technical scheme and the technical scheme all can the independent assortment use.

Claims (10)

1. The utility model provides a leak protection double containment well-flushing packer, a serial communication port, leak protection double containment well-flushing packer includes from last outer tube (4), well center tube (56) and lower center tube (55) that connect gradually down, goes up outer tube (4) overcoat and is equipped with leather cup sealing mechanism, and well center tube (56) overcoat is equipped with hydraulic pushing mechanism, and lower center tube (55) overcoat is equipped with packing element sealing mechanism and slips anchor mechanism that sets up from top to bottom, packing element sealing mechanism contains sealed packing element, slips anchor mechanism contains slips (43), and this hydraulic pushing mechanism can make this sealed packing element axial compression, and this hydraulic pushing mechanism can also make slips (43) strut.

2. The leak-proof double-seal well-flushing packer as claimed in claim 1, wherein an upper central tube (2) is sleeved in the upper outer tube (4), the lower end of the upper central tube (2) is in threaded connection with the upper outer tube (4), the upper end of the upper central tube (2) is positioned outside the upper outer tube (4), an upper joint (1) is arranged outside the upper end of the upper central tube (2), and the cup seal mechanism comprises a first cup (7) and a second cup (12) which are arranged up and down.

3. The leak-proof dual-seal well-flushing packer as claimed in claim 2, wherein a balance hole (16) is formed in a side wall of a lower portion of the upper outer tube (4), the first cup (7) and the second cup (12) are both located above the balance hole (16), the upper portion of the upper outer tube (4) is fixedly connected with the upper central tube (2) through the first fixing pin (3), the first cup (7) is internally sleeved with the upper and lower first support sleeves (5) and the first bushing (8), and the second cup (12) is internally sleeved with the upper and lower second support sleeves (11) and the second bushing (13).

4. The leak-proof double-seal well-flushing packer as claimed in claim 1, wherein the upper end of the middle central tube (56) is in threaded connection with the lower end of the upper outer tube (4), the lower end of the middle central tube (56) is in threaded connection with the upper end of the lower central tube (55), the hydraulic pushing mechanism comprises a hydraulic cylinder (31), the hydraulic cylinder (31) is sleeved outside the middle central tube (56), and an upper sealing sleeve (21), an upper piston (24), a lower sealing sleeve (27) and a lower piston (26) are sequentially arranged between the hydraulic cylinder (31) and the middle central tube (56) from top to bottom.

5. The leak-proof dual-seal well-flushing packer as claimed in claim 4, wherein an upper liquid inlet hole (57) and a lower liquid inlet hole (58) are vertically arranged in the side wall of the central tube (56), the upper liquid inlet hole (57) corresponds to the upper piston (24), the lower liquid inlet hole (58) corresponds to the lower piston (26), the upper outer tube (4), the upper seal sleeve (21) and the liquid cylinder barrel (31) are fixedly connected through the second fastening pin (20), the upper piston (24) is connected with the liquid cylinder barrel (31) through the first shearing pin (23), and the lower piston (26) is connected with the liquid cylinder barrel (31) through the second shearing pin (29).

6. The leak-proof dual-seal well-flushing packer as claimed in claim 1, wherein the packing element sealing mechanism further comprises a lower outer tube (33), the lower outer tube (33) is sleeved outside the lower central tube (55), a bushing (35) and a locking ring (36) are sleeved between the lower outer tube (33) and the lower central tube (55), the upper end of the lower outer tube (33) and the bushing (35) are fixedly connected through a third fastening pin (34), the packing element comprises three packing elements (37) which are sequentially arranged from top to bottom, the three packing elements (37) are all sleeved outside the lower outer tube (33), and a spacer ring (38) is arranged between two adjacent packing elements (37).

7. The leak-proof dual-seal well-flushing packer as claimed in claim 1, wherein the slip anchoring mechanism further comprises a cone (42) and a slip seat (45), the cone (42), the slip (43) and the slip seat (45) are sequentially connected from top to bottom, the cone (42) is connected with the rubber barrel sealing mechanism through a tail end spacer ring (41), the cone (42) and the slip seat (45) are both sleeved outside the lower central tube (55), and a hoop spring (44) is sleeved outside the slip (43).

8. The leak-proof dual-seal well-flushing packer as claimed in claim 7, wherein a pressure relief hole (47) is formed in a side wall of the lower central tube (55), the pressure relief hole (47) corresponds to the slip seat (45), ninth sealing rings (46) are respectively disposed on upper and lower sides of the pressure relief hole (47), and the ninth sealing rings (46) are sleeved between the slip seat (45) and the lower central tube (55).

9. The leak-proof double-seal well-flushing packer as claimed in claim 1, wherein a centering mechanism is further provided outside the lower central tube (55), the centering mechanism is located below the slip anchoring mechanism, the centering mechanism comprises a centering block seat (48) and a centering block (49), the centering block seat (48) is sleeved outside the lower central tube (55), and the centering block seat (48) is connected with the centering block (49) through a spring (50).

10. The leak-proof dual-seal well-flushing packer as claimed in claim 9, wherein the lower end of the centering block seat (48) is connected to the lower central tube (55) through a third shear pin (52), a slip ring sleeve (51) is sleeved outside the lower end of the centering block seat (48), a slip ring (53) is arranged in the slip ring sleeve (51), the slip ring (53) is connected to a slip ring pin (54), and a slideway capable of guiding the slip ring pin (54) to slide is arranged outside the lower central tube (55).

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