CN209838374U

CN209838374U - Self-sealing type washable well mechanism and packer using same

Info

Publication number: CN209838374U
Application number: CN201920204619.2U
Authority: CN
Inventors: 姜振海; 王文军; 于淼; 李春菊; 田晓龙; 丁相楠; 何山
Original assignee: Petrochina Co Ltd; Daqing Oilfield Co Ltd
Current assignee: Petrochina Co Ltd; Daqing Oilfield Co Ltd
Priority date: 2019-02-18
Filing date: 2019-02-18
Publication date: 2019-12-24
Anticipated expiration: 2029-02-18

Abstract

The utility model discloses a but proclaim oneself formula flushing mechanism and use its packer relates to the oil field, and wherein, a but proclaim oneself formula flushing mechanism and use its packer, include: a central tube (2); a well washing flow channel is arranged on the outer side of the central pipe (2), and the well washing flow channel is provided with a well washing switch control mechanism; and controlling the switch of the well washing switch control mechanism by the injection liquid pressure in the well washing flow channel to complete well washing and prevent the loss of the injection liquid. The problems that after the well is sealed or after the injection is stopped, when the pressure of an injection interval is high, a well flushing valve is opened, a large amount of injected liquid is lost, water resources are wasted, much useless work is done, water injection production is delayed, production cost is increased, and environmental protection is influenced are solved.

Description

Self-sealing type washable well mechanism and packer using same

Technical Field

The utility model relates to an oil field, but the packer of self-sealing flushing mechanism and use it specifically says so.

Background

Compression type washable well packers are commonly used in oilfield production of water flooding. The construction procedures are increased, the operation cost is increased, special professional equipment is increased, the water nozzle in the water distributor needs to be fished after operation construction, especially after setting or after stopping injection, the well washing valve is opened, a large amount of injection liquid is lost, waste of water resources is caused, much useless work is done, water injection production is delayed, the production cost is increased, and environmental protection is influenced.

Disclosure of Invention

In view of this, the utility model provides a but self-sealing flushing mechanism and use its packer to solve after the seat seals or when the injection zone interval pressure after stopping annotating is high, lead to well flushing valve to open, a large amount of injection liquid runs off, has caused the waste of water resource, has done a lot of idle work again, has delayed water injection production, has increased manufacturing cost, has influenced environmental protection's problem.

In a first aspect, the utility model provides a but proclaim oneself formula well-flushing mechanism, include:

a central tube;

a well washing flow channel is arranged on the outer side of the central pipe, and the well washing flow channel is provided with a well washing switch control mechanism;

and controlling the switch of the well washing switch control mechanism by the injection liquid pressure in the well washing flow channel to complete well washing and prevent the loss of the injection liquid.

Preferably, one end of the well washing flow channel is provided with a liquid inlet hole, one end of the well washing flow channel is provided with a liquid inlet and outlet hole, and the well washing switch control mechanism is arranged between the liquid inlet hole and the liquid inlet and outlet hole;

and the well washing switch control mechanism is used for controlling the liquid inlet hole and the liquid inlet and outlet hole to be communicated or not communicated.

Preferably, the outer side of the well washing flow passage is provided with a setting mechanism;

the setting mechanism is arranged between the liquid inlet hole and the liquid inlet and outlet hole, is in contact connection with the well wall and is used for preventing the injected liquid from flowing out from a space formed by the outer side of the central tube and the well wall.

Preferably, the well-flushing flow path comprises: an upper chamber, a middle chamber and a lower chamber;

one end of the upper cavity is provided with the liquid inlet hole, and the other end of the upper cavity is provided with the inner liquid outlet hole; the inner liquid outlet hole is communicated with an inlet of the middle cavity, an outlet of the middle cavity is communicated with the lower cavity, and the lower cavity is provided with the liquid inlet and outlet holes;

and the well washing switch control mechanism is arranged between the outlet of the middle chamber and the liquid inlet and outlet hole and is used for controlling the liquid inlet and outlet hole to be opened or closed.

Preferably, the setting mechanism comprises: a taper sleeve and a leather cup;

the taper sleeve is sleeved on the outer side of the well washing flow channel, a first recess is formed between the inner side of the taper sleeve and the outer side of the well washing flow channel, and one end of the leather cup is fixed in the first recess.

Preferably, the setting mechanism further comprises: sleeving;

the sleeve is sleeved on the outer side of the well washing flow passage and is connected with the inner side of the leather cup in a propping mode.

Preferably, the outer side of the central tube is also provided with an outer barrel;

a space formed by the inner side of the outer cylinder and the outer side of the central tube is the lower chamber;

the outer side of the outer barrel is provided with an opening, and the opening is the liquid inlet and outlet hole.

Preferably, the well-flushing switch control mechanism comprises: a shift switch and an elastic member;

the pressure generated by the injection liquid in the well washing flow channel enables the displacement switch to generate displacement and compress the elastic piece to deform, the displacement controls the liquid inlet and outlet holes of the well washing flow channel to be opened, and the injection liquid flows out from the liquid inlet and outlet holes; and the flushing flow channel is not filled with the injection liquid or the pressure, the elastic part restores to deform, and the elastic part controls the displacement switch to close the liquid inlet and outlet hole.

Preferably, the outer side of the central pipe is also provided with an outer cylinder, and a space formed by the inner side of the outer cylinder and the outer side of the central pipe is the well-flushing flow channel;

an opening is formed in the outer side of the outer barrel, and the opening is the liquid inlet and outlet hole;

the displacement switch is arranged on one side of the opening in the outer barrel, and the elastic piece is arranged on the other side of the opening in the outer barrel.

In a second aspect, the present invention provides a packer, comprising:

the self-sealing type well-flushing mechanism is characterized in that the self-sealing type well-flushing mechanism comprises a self-sealing type self-flushing mechanism;

one end of the central tube is connected with the outer tube, and the other end of the central tube is connected with the round nut;

the inside of the base pipe has an inner chamber for flushing the well.

The utility model discloses following beneficial effect has at least:

the utility model provides a but self-sealing flushing mechanism and use its packer to solve and sit behind the seat seal or when the injection zone section pressure after stopping annotating is high, lead to well flushing valve to open, a large amount of injection liquid runs off, has caused the waste of water resource, has done a lot of idle work again more, has delayed water injection production, has increased manufacturing cost, has influenced environmental protection's problem.

And simultaneously, the utility model discloses removed from and suppressed, thrown, dragged for processes such as water injection well choke, improved efficiency, practiced thrift the cost.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a half-section structure of a self-sealing type well-flushing mechanism and a packer using the same according to an embodiment of the present invention;

figure 2 is the utility model discloses and the well tubular column connection schematic diagram.

In figure 1, 1-outer tube, 2-central tube, 3-first sealing ring, 4-liquid inlet hole, 5-second sealing ring, 6-taper sleeve, 7-leather cup, 8-sleeve, 9-upper chamber, 10-outer tube, 11-inner liquid outlet hole, 12-middle chamber, 13-flushing valve, 14-third sealing ring, 15-fourth sealing ring, 16-liquid inlet and outlet hole, 17-lower chamber, 18-spring, 19-round nut and 20-inner chamber.

Detailed Description

The present invention will be described below based on examples, but it should be noted that the present invention is not limited to these examples. In the following detailed description of the present invention, certain specific details are set forth in detail. However, for parts not described in detail, those skilled in the art can fully understand the present invention.

Furthermore, those skilled in the art will appreciate that the drawings are provided for purposes of illustrating the objects, features, and advantages of the invention and are not necessarily drawn to scale.

Also, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, the meaning of "includes but is not limited to".

The utility model belongs to an used downhole tool in the oil field water injection specifically is a proclaim oneself formula washable well mechanism and use its packer.

The utility model aims at the above-mentioned technical problem provide a but proclaim oneself formula flushing mechanism and use its packer to the aforesaid technical problem, utilize and proclaim oneself formula flushing mechanism theory of operation and reverse well-flushing valve principle for water injection well packer application effect is better.

Fig. 1 is a schematic diagram of a half-section structure of a self-sealing type washable well mechanism and a packer using the same according to an embodiment of the present invention. As shown in fig. 1, a self-sealing type washable well mechanism and a packer using the same, comprises: a central tube 2; the outer side of the central pipe 2 is provided with a well washing flow channel which is provided with a well washing switch control mechanism; the injected hydraulic pressure in the well washing flow channel controls the switch of the well washing switch control mechanism to complete well washing and prevent the injected liquid from losing. The problems that after the well is sealed or after the injection is stopped, when the pressure of an injection interval is high, a well flushing valve is opened, a large amount of injected liquid is lost, water resources are wasted, much useless work is done, water injection production is delayed, production cost is increased, and environmental protection is influenced are solved.

In fig. 1, one end of the well-flushing flow passage is provided with a liquid inlet hole 4, one end of the well-flushing flow passage is provided with a liquid inlet and outlet hole 16, and a well-flushing switch control mechanism is arranged between the liquid inlet hole 4 and the liquid inlet and outlet hole 16; and the well washing switch control mechanism is used for controlling the communication or non-communication of the liquid inlet hole 4 and the liquid inlet and outlet hole 16. When injection liquid is filled in the well washing flow channel, the injection liquid generates injection liquid pressure, and the hydraulic pressure controls the opening of the well washing switch control mechanism; and when no injection liquid and pressure exist in the well washing flow channel, the well washing switch control mechanism is controlled to be closed.

In fig. 1, the outside of the well-flushing flow channel is provided with a setting mechanism; the setting mechanism is arranged between the liquid inlet hole 4 and the liquid inlet and outlet hole 16, is in contact connection with the well wall and is used for preventing the injected liquid from flowing out from a space formed by the outer side of the central tube 2 and the well wall.

In fig. 1, a well-flushing flow path includes: upper chamber 9, middle chamber 12 and lower chamber 17; one end of the upper cavity 9 is provided with a liquid inlet hole 4, and the other end of the upper cavity 9 is provided with an inner liquid outlet hole 11; the inner liquid outlet hole 11 is communicated with the inlet of the middle cavity 12, the outlet of the middle cavity 12 is communicated with the lower cavity 17, and the lower cavity 17 is provided with a liquid inlet and outlet hole 16; and the well washing switch control mechanism is arranged between the outlet of the middle chamber 12 and the liquid inlet and outlet hole 16 and is used for controlling the liquid inlet and outlet hole 16 to be opened or closed.

In fig. 1, a setting mechanism comprises: a taper sleeve 6 and a leather cup 7; the taper sleeve 6 is sleeved on the outer side of the well washing flow channel, a first recess is formed between the inner side of the taper sleeve 6 and the outer side of the well washing flow channel, and one end of the leather cup 7 is fixed in the first recess.

In fig. 1, the setting mechanism further includes: a sleeve 8; the sleeve 8 is sleeved outside the well washing flow passage and is connected with the inner side of the leather cup 7 in a propping mode.

In fig. 1, the outside of the central tube 2 also has an outer cylinder 10; the space formed by the inner side of the outer cylinder 10 and the outer side of the central tube 2 is a lower chamber 17; the outer side of the outer cylinder 10 has an opening which is a liquid inlet/outlet hole 16.

In fig. 1, a well-flushing switch control mechanism comprises: a shift switch and an elastic member; the pressure generated by the injection liquid in the well washing flow channel enables the displacement switch to generate displacement and compress the elastic part to deform, the displacement controls the opening of the liquid inlet and outlet hole 16 of the well washing flow channel, and the injection liquid flows out from the liquid inlet and outlet hole 16; when no injection liquid or pressure is injected into the well washing flow channel, the elastic part recovers deformation, and the elastic part controls the displacement switch to close the liquid inlet and outlet hole 16. Specifically, the shift switch is a flushing valve 13, and the flushing valve 13 is a spring 18.

In fig. 1, the outer side of the central pipe 2 is also provided with an outer cylinder 10, and a space formed by the inner side of the outer cylinder 10 and the outer side of the central pipe 2 is a well-flushing flow channel; the outer side of the outer cylinder 10 is provided with an opening which is a liquid inlet and outlet hole 16; one side in the outer cylinder 10 of the opening is a shift switch, and the other side in the outer cylinder 10 of the opening is an elastic part.

The utility model also provides a packer, include: the self-sealing type well-flushing mechanism; one end of the central tube 2 is connected with the outer tube 1, and the other end of the central tube 2 is connected with the round nut 19; the inside of the base pipe 2 has an inner chamber 20, the inner chamber 20 being used for flushing the well.

In fig. 1, that is, the present invention provides a self-sealing type well-flushing mechanism, including: the outer pipe 1 is in threaded connection with the central pipe 2 and is sealed by the sealing ring 3, the taper sleeve 6, the leather cup 7, the sleeve 8, the outer pipe 10, the well flushing valve 13 and the spring 18 are arranged on the outer pipe 1 and the central pipe 2 and are respectively sealed by the second sealing ring 5, the third sealing ring 14 and the fourth sealing ring 15, and the round nut 19 is in threaded connection with the central pipe 2 into a whole.

In FIG. 1, that is, the packing tubing and casing annulus mechanism, comprises: taper sleeve 6, sealing washer 5, leather cup 7, cover 8, outer tube 1.

In fig. 1, that is, the well-flushing mechanism, comprises: the device comprises an outer pipe 1, a central pipe 2, an outer cylinder 10, a well washing valve 13, a third sealing ring 14, a fourth sealing ring 15, a spring 18 and a round nut 19.

In FIG. 1, that is, a self-sealing type well cleanable mechanism has an upper chamber 9, a middle chamber 12, a lower chamber 17, and an inner chamber 20.

In fig. 1, that is, the upper and lower parts of the outer tube 1 are respectively provided with a liquid inlet hole 4 and an inner liquid outlet hole 11. The middle upper part of the outer cylinder 10 is provided with a liquid inlet and outlet hole 16. The inner side of the outer tube 1 is an upper chamber 9, and two ends of the upper chamber 9 are respectively communicated with the liquid inlet hole 4 and the inner liquid outlet hole 11.

In fig. 1, specifically, the outer pipe 1 is in threaded connection with one end of a central pipe 2, the other end of the central pipe 2 is in threaded connection with a round nut 19, the round nut 19 is used for connecting the central pipe 2 and an outer cylinder 10, the central pipe 2 is provided with an inner chamber 20, the inner chamber 20 is used for injecting water to a bottom layer, the outer side of one end of the central pipe 2 is provided with a liquid inlet hole 4, and the liquid inlet hole 4 and a liquid outlet hole 11 are used for well washing. The outside of the inner chamber 20 has a well-flushing flowpath.

In fig. 1, in particular, a well-flushing flow channel, comprises: an upper chamber 9, a middle chamber 12 and a lower chamber 17. Go up 9 one end of cavity and have feed liquor hole 4, go up cavity 9's the other end and have interior play liquid hole 11, feed liquor hole 4, interior play liquid hole 11 and last cavity 9 intercommunication, 4 downside in feed liquor hole have taper sleeve 6, taper sleeve 6 cup joints the outside at last cavity 9, taper sleeve 6 is sealed through the outside of first sealing washer 3 with last cavity 9, the inboard of taper sleeve 6 and the outside of last cavity 9 form first recess, leather cup 7 is fixed in the outside at last cavity 9 through first recess, cover 8 cup joints the outside at last cavity 9, the outside of cover 8 and the inboard (as 2 leather cups 7 in fig. 1) apical grafting of leather cup 7, cover 8 seals leather cup 7. The first sealing ring 3, the liquid inlet hole 4, the second sealing ring 5, the taper sleeve 6, the leather cup 7 and the sleeve 8 are arranged on the outer side of the upper cavity 9, the inner side of the outer cylinder 10 and the outer side of the central tube 2 form a middle cavity 12 and a lower cavity 17, namely, the inner side of the outer cylinder 10 is provided with a second groove (namely, the middle cavity 12 and the lower cavity 17), and the inner liquid outlet hole 11 is communicated with the middle cavity 12 and the lower cavity 17.

In fig. 1, in particular, between the middle chamber 12 and the lower chamber 17 there is a well-flushing valve 13 (switch assembly or displacement switch) from the inlet orifice 4 to the middle chamber 12. And the third sealing ring 14 and the fourth sealing ring 15 are used for sealing the well-flushing valve 13, the outer side of the central pipe 2 and the inner side of the outer cylinder 10, the outer side of the outer cylinder 10 is provided with a liquid inlet and outlet hole 16, the well-flushing valve 13 is opened, and water can flow out from the liquid inlet and outlet hole 16 to flush the well. That is, the pressure of water is utilized to displace the well-flushing valve 13, the well-flushing valve 13 enters the lower chamber 17, the liquid inlet and outlet hole 16 is communicated with the middle chamber 12, and water can flow out from the liquid inlet and outlet hole 16 to flush the well; when there is no water in the middle chamber 12, the spring 18 in the lower chamber 17 pushes the flushing valve 13 back to the original position, i.e. the flushing valve 13 closes the inlet and outlet holes 16.

The utility model has the advantages of simple and reasonable structure, the packing is reliable, well-flushing valve 13 is nimble good to be used. Use the utility model discloses can reduce construction process, operation construction cost low, need not suppress the special type professional equipment of setting (promptly, 7 leather cups) and throw the water injection well choke construction in the water injection mandrel.

Figure 2 is the utility model discloses and the well tubular column connection schematic diagram. As shown in figure 2, the utility model provides a but, self-sealing well-flushing mechanism and packer S1 of simple structure, easy construction, do benefit to the environmental protection. The utility model discloses but from formula of sealing well-flushing mechanism and packer S1, include: the outer pipe 1 is in threaded connection with the central pipe 2 and is sealed by the sealing ring 3, the taper sleeve 6, the leather cup 7, the sleeve 8, the outer pipe 10, the well flushing valve 13 and the spring 18 are arranged on the outer pipe 1 and the central pipe 2 and are respectively sealed by the second sealing ring 5, the third sealing ring 14 and the fourth sealing ring 15, and the round nut 19 is in threaded connection with the central pipe 2 into a whole.

When the packer S1 is used, the lower part of the central pipe 2 is in threaded connection with a well-flushing check valve S3 and a water distributor S2, and after the upper part of the outer pipe 1 of the packer S1 is in threaded connection with a water injection pipe column and is lowered into a designed well depth, the leather cup 7 completes initial oil layer packing under the self elasticity; after water injection, the injection liquid of the injection layer passes through the liquid inlet and outlet hole 16 and the lower cavity 17 from the annular space of the oil casing to push the well-flushing valve 13, meanwhile, the liquid also enters the flaring at the lower end of the leather cup 7, and the pressure of the injection liquid of the injection layer section is higher than that of the non-injection layer section when the injection liquid is injected or stopped, so that the effect of the leather cup isolation layer section is good, and the well-flushing valve 13 is tightly closed under the double actions of the elastic force of the spring 18 and the liquid pressure; when a well is washed, well washing liquid pushes a well washing valve 13 to go downwards from the annular space of the oil casing through a liquid inlet hole 4, an upper chamber 9, an inner liquid outlet hole 11 and a middle chamber 12 at the middle upper part of the outer pipe 1, and the well washing liquid enters an inner chamber 20 and a water injection pipe column through a lower chamber 17, a liquid inlet and outlet hole 16 and other well-descending tools and then returns to a ground container; when the sealing is not performed, the water injection pipe column is lifted upwards, the lifting force overcomes the mass of the underground pipe column and the friction force between the leather cup 7 and the inner diameter of the shaft and moves upwards, and all underground tools and the water injection pipe column are taken out.

The utility model discloses the theory of operation as follows:

1. setting and water injection: the packer S1 is connected with a well-flushing check valve S3 and a water distributor S2, and after the packer S1 and a water injection pipe column are lowered to a designed well depth, a cup 7 (the cup 7 is a rubber part, and the outer diameter of the cup is larger than the inner diameter of a shaft) completes initial oil layer packing under the self elasticity; after water injection, when liquid pressure exists at the flaring opening at the lower end of the leather cup 7, the packing of the leather cup 7 is enhanced along with the increase of the liquid pressure; the well-flushing valve 13 has better closing effect under the action of the elastic force of the spring 18 and the pressure of the injected liquid.

2. Stopping injection: both the packing and the flushing valves 13 close tightly due to the injection interval fluid pressure being higher than the non-injection interval pressure.

3. Well flushing: well-flushing liquid (namely injection liquid) passes through the liquid inlet hole 4 at the middle upper part of the outer pipe, the upper chamber 9, the inner liquid outlet hole 16 and the middle chamber 12 from the annular space of the oil jacket to push the well-flushing valve 13 to move downwards, and the well-flushing liquid enters the inner chamber and the water injection pipe column through the lower chamber 17, the liquid inlet and outlet holes 16, the annular space of the lower oil casing pipe and the well-flushing check valve S3 and then returns to the ground container.

4. Deblocking: and lifting the water injection pipe column, wherein the lifting force overcomes the mass of the underground pipe column and the friction force between the leather cup 8 and the inner diameter of the shaft and goes up until all underground tools and the water injection pipe column are lifted out.

The utility model discloses use 11 wells in the extension oil field, on average every well operation instrument expense 1.8 ten thousand yuan. Water injection of the 11 wells is 1.584 ten thousand in 180 days of adjustment period, and oil extraction is 3981 tons according to the injection-extraction ratio of 1.16, so that economic benefits are created: 3981 x (1812.12-686.48) -18000 x 11=4283172 yuan. (1) The cost of a pump truck and a water tank truck is saved, and the construction of a water throwing and fishing nozzle is avoided. By applying 11 wells, the seal checking is reduced for 22 times, and the pressing cost is saved by 9.9 ten thousand yuan. (2) The well-flushing valve 13 is reasonable in position, and opening of the well-flushing valve 13 when stopping injection is avoided. (3) 428.3172 ten thousand yuan.

The above-mentioned embodiments are merely embodiments for expressing the invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several changes, substitutions, modifications, etc. can be made without departing from the spirit of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A self-sealing washable well mechanism, comprising:

a central tube (2);

a well washing flow channel is arranged on the outer side of the central pipe (2), and the well washing flow channel is provided with a well washing switch control mechanism;

and the injected liquid pressure in the well washing flow channel controls the switch of the well washing switch control mechanism to complete well washing and prevent the injected liquid from losing.

2. The self-sealing washable well mechanism of claim 1, wherein:

one end of the well washing flow channel is provided with a liquid inlet hole (4), one end of the well washing flow channel is provided with a liquid inlet and outlet hole (16), and a well washing switch control mechanism is arranged between the liquid inlet hole (4) and the liquid inlet and outlet hole (16);

and the well washing switch control mechanism is used for controlling the communication or non-communication of the liquid inlet hole (4) and the liquid inlet and outlet hole (16).

3. The self-sealing washable well mechanism of claim 2, wherein:

the outer side of the well washing flow passage is provided with a setting mechanism;

the setting mechanism is arranged between the liquid inlet hole (4) and the liquid inlet and outlet hole (16), is in contact connection with a well wall, and is used for preventing the injected liquid from flowing out of a space formed by the outer side of the central pipe (2) and the well wall.

4. The self-sealing washable well mechanism of claim 2, wherein:

the well-flushing flow passage comprises: an upper chamber (9), a middle chamber (12) and a lower chamber (17);

one end of the upper cavity (9) is provided with the liquid inlet hole (4), and the other end of the upper cavity (9) is provided with an inner liquid outlet hole (11); the inner liquid outlet hole (11) is communicated with an inlet of the middle chamber (12), an outlet of the middle chamber (12) is communicated with the lower chamber (17), and the lower chamber (17) is provided with the liquid inlet and outlet hole (16);

the well washing switch control mechanism is arranged between the outlet of the middle chamber (12) and the liquid inlet and outlet hole (16) and is used for controlling the liquid inlet and outlet hole (16) to be opened or closed.

5. The self-sealing washable well mechanism of claim 3, wherein:

the setting mechanism includes: a taper sleeve (6) and a leather cup (7);

the taper sleeve (6) is sleeved on the outer side of the well washing flow channel, a first recess is formed between the inner side of the taper sleeve (6) and the outer side of the well washing flow channel, and one end of the leather cup (7) is fixed in the first recess.

6. The self-sealing washable well mechanism of claim 5, wherein:

the setting mechanism still includes: a sleeve (8);

the sleeve (8) is sleeved on the outer side of the well washing flow channel and is connected with the inner side of the leather cup (7) in a jacking mode.

7. The self-sealing washable well mechanism of claim 4, wherein:

the outer side of the central tube (2) is also provided with an outer cylinder (10);

the space formed by the inner side of the outer cylinder (10) and the outer side of the central tube (2) is the lower chamber (17);

the outer side of the outer cylinder (10) is provided with an opening which is the liquid inlet and outlet hole (16).

8. The self-sealing washable well unit of any one of claims 1-7, wherein:

well-flushing switch control mechanism includes: a shift switch and an elastic member;

the pressure generated by the injection liquid in the well washing flow channel enables the displacement switch to generate displacement and compress the elastic piece to deform, the displacement is used for controlling the opening of a liquid inlet and outlet hole (16) of the well washing flow channel, and the injection liquid flows out from the liquid inlet and outlet hole (16); the well washing flow channel is not filled with the injection liquid or the pressure, the elastic piece recovers deformation, and the elastic piece controls the displacement switch to close the liquid inlet and outlet hole (16).

9. The self-sealing washable well mechanism of claim 8, wherein:

an outer cylinder (10) is further arranged on the outer side of the central pipe (2), and a space formed by the inner side of the outer cylinder (10) and the outer side of the central pipe (2) is the well washing flow channel;

the outer side of the outer cylinder (10) is provided with an opening which is the liquid inlet and outlet hole (16);

the displacement switch is arranged on one side in the outer barrel (10) of the opening, and the elastic piece is arranged on the other side in the outer barrel (10) of the opening.

10. A packer, comprising:

a self-sealing washable well unit as defined in any one of claims 1-9;

one end of the central tube (2) is connected with the outer tube (1), and the other end of the central tube (2) is connected with the round nut (19);

the inside of the base pipe (2) has an inner chamber (20), the inner chamber (20) being used for flushing the well.