A downhole isolation device

Abstract

The application belongs to the technical field of oil and gas well testing tools, and particularly relates to a downhole isolation device. The downhole isolation device comprises an outer cylinder, a switch valve and a switch sleeve arranged in the outer cylinder, and a plug-in connector. The upper end of the switch sleeve is connected with the lower end of the plug-in connector through elastic claws. In the initial state, the elastic claws are radially abutted by the outer cylinder. In the process of releasing the hand, the plug-in connector moves upward, driving the elastic claws and the switch sleeve to move upward. After the switch sleeve closes the switch valve, the elastic claws are separated from the abutment with the outer cylinder, so that the elastic claws can be radially expanded under the relative action of the plug-in connector, and then the plug-in connector is separated from the switch sleeve. The plug-in connector can be connected with the switch sleeve again through the reverse movement of the elastic claws. The application can repeatedly execute the closing and opening actions.

Description

Technical Field

[0001] This invention belongs to the technical field of oil and gas well testing tools, specifically relating to a downhole isolation device. Background Technology

[0002] After high-pressure oil and gas exploration wells achieve production, the method of killing the well and replacing the tubing string is generally used for secondary completion. However, due to the damage to the reservoir caused by well killing, the use of downhole isolation devices to temporarily seal the oil and gas well after the test is a new type of operation method for quickly converting exploration well tests into appraisal wells.

[0003] However, existing downhole isolation devices can only be closed and opened once, which cannot adapt to complex working conditions and require repeated closure and opening actions.

[0004] Furthermore, existing downhole isolation devices generally employ a mechanical opening and closing mechanism, where the tubing string drives a switching tool via lifting and lowering. Therefore, during the opening of the downhole isolation device, the entire tubing string driving the switching tool needs to move axially. Because sufficient axial movement space is required, the gas production tree cannot be directly installed during this process; a blowout preventer (BOP) must be installed at the wellhead to prevent downhole fluid from ejecting when the tubing string drives the switching tool to open the isolation device. Only after the isolation device is opened can the gas production tree be installed, allowing for further work. Summary of the Invention

[0005] In view of the technical problems mentioned above, the present invention aims to provide a downhole isolation device capable of repeatedly performing the closing and opening actions.

[0006] According to the present invention, a downhole isolation device is provided, comprising an outer cylinder, a switching valve disposed within the outer cylinder, and a switching sleeve, wherein the switching sleeve is located above the switching valve, and the upward or downward movement of the switching sleeve can cause the switching valve to close or open, characterized in that the downhole isolation device further comprises:

[0007] An insertion connector is provided, wherein the upper end of the switch sleeve is connected to the lower end of the insertion connector via a resilient claw.

[0008] In the initial state, the elastic claw is radially abutted by the outer cylinder.

[0009] During the release process, the insertion connector moves upward, causing the elastic claw and the switch sleeve to move upward. After the switch sleeve closes the switch valve, the elastic claw disengages from its contact with the outer cylinder, allowing it to expand radially under the relative action of the insertion connector, thereby separating the insertion connector from the switch sleeve.

[0010] The insertion connector can be reconnected to the switch sleeve via the elastic claw by reversing its movement.

[0011] In one specific embodiment, a sealing ball seat is provided inside the switch sleeve, and a sealing ring is provided between the switch sleeve and the outer cylinder.

[0012] In one specific embodiment, after the insertion connector is connected to the switch sleeve via the elastic claw, the insertion connector and the switch sleeve are able to move axially relative to each other within the length range of the elastic claw.

[0013] In one specific embodiment, the elastic claw is fixedly disposed at the upper end of the switch sleeve, and an inwardly protruding internal tooth is provided at the upper end of the elastic claw. An external tooth that mates with the elastic claw is provided at the lower end of the insertion connector. When the lower end of the insertion connector abuts against the upper end of the switch sleeve, the internal tooth is located above the external tooth.

[0014] In one specific embodiment, the outer cylinder is provided with a stepped hole. In the initial state, the elastic claw is located at the small diameter of the outer cylinder, thereby radially abutting against the elastic claw. In the released state, the elastic claw moves with the insertion connector to the large diameter of the outer cylinder, thereby releasing the radial abutment against the elastic claw.

[0015] In one specific embodiment, a first circulation hole is provided on the wall of the switch sleeve, and a second circulation hole is provided on the wall of the outer cylinder. In the initial state, the first circulation hole and the second circulation hole are misaligned. After the insertion connector drives the switch sleeve to move upward through the elastic claw, the first circulation hole and the second circulation hole coincide.

[0016] In one specific embodiment, at least two sealing rings for sealing with the outer cylinder are provided on the outer wall of the switch sleeve, and the two sealing rings are respectively provided on the upper and lower sides of the first circulation hole.

[0017] In one specific embodiment, a protrusion is provided on the inner wall of the outer cylinder to prevent the switch sleeve from detaching from the outer cylinder from above.

[0018] In one specific embodiment, the outer wall of the insertion connector is provided with threads for connection with the outer cylinder.

[0019] In one specific embodiment, a sealing ring is provided between the insertion connector and the outer cylinder.

[0020] Compared with the prior art, the advantages of this application are as follows.

[0021] The insertion connector of the present invention, through the cooperation of the elastic claw and the switch sleeve, can realize multiple switching actions of the valve, thereby adapting to various complex working conditions.

[0022] This invention features a sealing ball seat on the switch sleeve, enabling the switch sleeve to open the valve by dropping the ball and pressurizing it. This keeps the tubing string connected above the insertion joint stationary during the process, allowing the gas production tree to be installed in advance. This meets the well control requirements during testing and tool operation of high-pressure and sulfur-containing oil and gas wells, and simplifies the operation procedures. Attached Figure Description

[0023] The present invention will now be described with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram showing the initial state of an embodiment of the downhole isolation device according to the present invention is provided.

[0025] Figure 2 A schematic diagram of the release process of an embodiment of the downhole isolation device according to the present invention is shown;

[0026] Figure 3 A schematic diagram showing the separation of the insertion connector of the downhole isolation device according to the present invention is displayed;

[0027] Figure 4 A schematic diagram of the insertion connector of the downhole isolation device according to the present invention being re-inserted is shown;

[0028] Figure 5 A schematic diagram of the opening of the switching valve after the downhole isolation device according to the present invention has been used to pressurize the well by dropping a ball is shown.

[0029] In the diagram: 1. Outer cylinder; 11. Second circulation hole; 12. Connecting short section; 13. Connecting main cylinder; 2. Switch valve; 21. Ball valve; 22. Upper ball seat; 23. Lower ball seat; 24. Ball cage; 25. Operating pin; 3. Switch sleeve; 31. Sealing ball seat; 32. First circulation hole; 4. Insertion connector; 41. External teeth; 6. Elastic claw; 61. Internal teeth; 7. Lower connector; 8. Limiting sleeve; 100. Downhole isolation device.

[0030] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0031] The invention will now be described with reference to the accompanying drawings.

[0032] It should be noted that in this application, the direction closer to the wellhead according to the present invention is described as "up" or a similar term, while the direction farther from the wellhead is described as "down" or a similar term.

[0033] They are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0034] In existing technology, a downhole isolation device includes an outer cylinder 1, a switching valve 2, and a switching sleeve 3, both of which are located within the inner cavity of the outer cylinder 1. When the switching valve 2 is closed, it seals the inner cavity of the outer cylinder 1. The switching sleeve 3 is cylindrical and located above the switching valve 2, with its lower end connected to the operating pin 25 of the switching valve 2. Initially, the switching valve 2 is open, allowing fluid to flow within both the valve and the sleeve. When the switching sleeve 3 moves upward, it moves the operating pin 25, thereby closing the switching valve 2 and sealing the outer cylinder 1.

[0035] Figure 1 The structure of the downhole isolation device 100 according to the present invention is shown. For example... Figure 1 As shown, the downhole isolation device 100, in addition to the outer cylinder 1, switching valve 2, and switching sleeve 3 as in the prior art, also includes an insertion connector 4. The insertion connector 4 is generally cylindrical and located above the switching sleeve 3, with the two connected by a resilient claw 6. Figure 1 and Figure 2 As shown, in the process of transitioning from the initial state to the release state, that is, from... Figures 1 to 2 During the process, the elastic claw 6 is radially blocked by the outer cylinder 1, and the elastic claw 6 cannot perform radial expansion. Therefore, the insertion connector 4 can drive the switch sleeve 3 to move upward together through the elastic claw 6, thereby causing the switch sleeve 3 to close the switch valve 2.

[0036] like Figure 3 As shown, after the switch valve 2 is closed, the elastic claw 6 disengages from the radial contact of the outer cylinder 1. In this case, if the insertion connector 4 continues to move upward, the elastic claw 6 can expand radially, thereby causing the insertion connector 4 to disengage from the elastic claw 6 and complete the release.

[0037] According to the present invention, a protrusion is provided on the inner wall of the outer cylinder 1 to prevent the switch sleeve 3 from detaching from the outer cylinder 1 from above. Specifically, to facilitate the installation of the downhole isolation device 100, the outer cylinder 1 includes a connecting short section 12 and a connecting main cylinder 13 fixedly connected from top to bottom. The lower end of the connecting short section 12 extends into the connecting main cylinder 13 and is connected to each other by a threaded connection, that is, the inner diameter of the lower end of the connecting short section 12 is smaller than the inner diameter of the connecting main cylinder 13. The switch sleeve 3 is slidably disposed in the connecting main cylinder 13 along the axial direction, and the maximum outer diameter of the switch sleeve 3 is larger than the inner diameter of the lower end of the connecting short section 12. The switch valve 2 is disposed in the connecting main cylinder 13, located below the switch sleeve 3. In this way, the lower end of the connecting short section 12 is equivalent to a protrusion provided on the inner wall of the outer cylinder 1, used to prevent the switch sleeve 3 from detaching from the outer cylinder 1 from above. The switch valve 2 is disposed in the connecting main cylinder 13, and the switch sleeve 3 is slidably disposed in the connecting main cylinder 13 along the axial direction.

[0038] According to the present invention, the elastic claw 6 includes a plurality of circumferentially evenly distributed ribs. The lower end of the elastic claw 6 is fixedly connected to the switch sleeve 3, and the upper inner wall of the elastic claw 6 is provided with internal teeth 61 for connecting with the insertion connector 4. The lower outer wall of the insertion connector 4 is provided with external teeth 41 for engaging with the internal teeth 61. Specifically, the top outer diameter of the switch sleeve 3 is equal to the inner diameter of the connecting short section 12, and the two are in a sealed sliding fit. The bottom outer diameter of the elastic claw 6 is equal to the top outer diameter of the switch sleeve 3, that is, under no external force, the outer wall of the elastic claw 6 contacts the inner wall of the connecting short section 12 within the normal tolerance range. The bottom inner diameter of the elastic claw 6 is larger than the inner diameter of the switch sleeve 3. After the lower end of the insertion connector 4 is inserted into the elastic claw 6, the insertion connector 4 and the elastic claw 6 can move axially relative to each other within the length range of the elastic claw 6, that is, from the position where the lower end of the insertion connector 4 abuts against the switch sleeve 3 to the position where the external teeth 41 of the insertion connector 4 abut against the internal teeth 61 of the elastic claw 6.

[0039] In this embodiment, the insertion connector 4 and the connecting short section 12 are connected to each other by a threaded connection, and the upper end of the insertion connector 4 is fixedly connected to the tubing string (not shown in the figure). When it is necessary to activate the downhole isolation device 100, the insertion connector 4 is first disconnected from the connecting short section 12 by rotation. Since the insertion connector 4 and the switch sleeve 3 are connected by an elastic claw 6, the rotation of the insertion connector 4 will not affect the switch sleeve 3. Furthermore, in Figure 1 In the initial state shown, there is a certain distance between the inner teeth 61 of the elastic claw 6 and the outer teeth 41 of the insertion connector 4. Therefore, during the process of the insertion connector 4 moving upward due to the rotation of the thread, the outer teeth 41 of the insertion connector 4 have not yet contacted the inner teeth 61 of the elastic claw 6.

[0040] After the insertion connector 4 is disengaged from the connecting short section 12, the insertion connector 4 is moved to the point where the outer teeth 41 and the inner teeth 61 abut against each other by lifting the oil pipe column connected to the insertion connector 4. If the insertion connector 4 continues to move upward, since the part of the elastic claw 6 with the inner teeth 61 is still in radial contact with the connecting short section 12, the elastic claw 6 will not expand radially. The insertion connector 4 can drive the elastic claw 6 and the switch sleeve 3 fixedly connected to the lower part of the elastic claw 6 to move upward through the connection relationship between the outer teeth 41 and the inner teeth 61, thereby closing the switch valve 2.

[0041] According to the present invention, a stepped hole is provided in the connecting short section 12, the lower part of the connecting short section 12 is the small-diameter portion of the stepped hole, and the upper part of the connecting short section 12 is the large-diameter portion of the stepped hole. For example... Figure 1 As shown, in the absence of external force, the outer diameter of the elastic claw 6 is equal to the inner diameter of the smaller diameter portion of the connecting stub 12. When the insertion connector 4 moves to... Figure 2 At the indicated position, the switch valve 2 is closed, and the portion of the elastic claw 6 with internal teeth 61 at its upper end has disengaged from the small diameter of the connecting stub 12 and moved to the large diameter of the connecting stub 12. In this situation, continuing to move the insertion connector 4 upwards, since the portion of the elastic claw 6 with internal teeth 61 no longer has radial resistance from the connecting stub 12, the external teeth 41 of the insertion connector 4 can cause the portion of the elastic claw 6 with internal teeth 61 to expand radially outwards, such as... Figure 3 As shown, at this point, the insertion connector 4 can separate from the elastic claw 6, completing the release.

[0042] It is easy to understand that a guide slope is provided on the relative contact surface of the outer tooth 41 of the insertion connector 4 and the inner tooth 61 of the elastic claw 6, so that the axial force of the outer tooth 41 of the insertion connector 4 relative to the inner tooth 61 of the elastic claw 6 is converted into a radial force.

[0043] According to the present invention, a sealing ball seat 31 is provided inside the switch sleeve 3, a sealing ring is provided between the switch sleeve 3 and the outer cylinder 1, and a sealing ring is provided between the insertion connector 4 and the connecting short section 12 of the outer cylinder 1. Specifically, the upper end of the switch sleeve 3 is always in contact with the connecting short section 12 throughout the entire axial movement range of controlling the switch valve 2 to close or open. Therefore, a sealing ring for sealing with the connecting short section 12 is provided on the outer wall of the upper end of the switch sleeve 3.

[0044] With this setup, when the downhole isolation device 100 needs to be reopened, the insertion connector 4 is first reinserted into the elastic claw 6 under the drive of the tubing string. The length of the insertion connector 4 can be changed according to actual needs. At this time, the portion of the elastic claw 6 with internal teeth 61 at its upper end is still in the large-diameter portion of the connecting sub 12. When the insertion connector 4 is inserted into the elastic claw 6, the external teeth 41 at the lower end of the insertion connector 4 can cause the elastic claw 6 to expand radially outward, thereby allowing the insertion connector 4 to enter the elastic claw 6. Figure 4 As shown, after the insertion connector 4 enters the elastic claw 6 and is connected to the connecting short section 12 by means of threaded connection, the lower end face of the insertion connector 4 abuts against the upper end face of the switch sleeve 3.

[0045] Then, by inserting a ball into the switch sleeve 3, a seal is formed between the pressure ball and the sealing ball seat 31 of the switch sleeve 3. By inserting the oil pipe connected to the upper end of the connector 4 to pressurize the switch sleeve 3, the switch sleeve 3 moves downward, thereby opening the switch valve 2.

[0046] In this embodiment, the switch sleeve 3 is moved by pressurization to open the switch valve 2. This process eliminates the need for the mechanical lowering of the tubing string, as is common in existing technologies, to push the switch sleeve 3 to open the valve. Therefore, in this embodiment, after the insertion connector 4 is connected to the connecting section 12 via a threaded connection, the gas production tree can be installed at the wellhead, and then the switch sleeve 3 can be lowered by the aforementioned pressurization method to open the switch valve 2, thus simplifying the operation.

[0047] In this embodiment, if it is necessary to shut down the downhole isolation device 100 again due to the needs of complex working conditions, the above-mentioned related operations can be performed again. The tubing string drives the insertion joint 4 to move upward, and then the elastic claw 6 drives the switch sleeve 3 to move upward, and closes the switch valve 2.

[0048] According to a specific embodiment of the present invention, a first circulation hole 32 is provided on the wall of the switch sleeve 3. The first circulation hole 32 is located below the sealing ball seat 31, and a plurality of such holes are evenly distributed along the circumferential direction of the switch sleeve 3. A second circulation hole 11 corresponding to the first circulation hole 32 is provided on the wall of the outer cylinder 1. Figure 1 As shown, in the initial state, the first circulation hole 32 is located below the second circulation hole 11 and is offset from the second circulation hole 11, preventing fluid from entering the switch sleeve 3 through the wall of the outer cylinder 1. Furthermore, to enhance the sealing effect, at least two sealing rings for sealing with the outer cylinder 1 are provided on the outer wall of the switch sleeve 3. The two sealing rings are respectively located on the upper and lower sides of the first circulation hole 32. In the initial state, the sealing ring above the first circulation hole 32 is located below the second circulation hole 11.

[0049] When the insertion connector 4 moves the switch sleeve 3 upward via the elastic claw 6, the first circulation hole 32 coincides with the second circulation hole 11, as shown. Figure 2 As shown. At this time, the fluid can flow between the outside and inside of the downhole isolation device 100 through the first circulation hole 32 and the second circulation hole 11, thereby facilitating the relevant procedures for drilling fluid circulation.

[0050] In one specific embodiment, the switching valve 2 includes a ball cage 24, a ball valve 21, an upper ball seat 22, a lower ball seat 23, and an operating pin 25. The ball cage 24 is generally cylindrical and coaxially fixed inside the connecting main cylinder 13, with a sealing ring between the outer wall of the ball cage 24 and the connecting main cylinder 13. The ball valve 21 has a through hole and is rotatably mounted inside the ball cage 24. By rotating the ball valve 21, the position of the through hole on the ball valve 21 changes, thereby achieving the effect of closing or opening. The upper ball seat 22 and the lower ball seat 23 are respectively located at the upper and lower ends of the ball valve 21 and coaxially sleeved inside the ball cage 24. The operating pin 25 is used to connect the ball valve 21 and the switching sleeve 3. When the switching sleeve 3 moves axially, it can drive the ball valve 21 to rotate through the operating pin 25, thereby opening or closing the switching valve 2.

[0051] The switching valve 2 can also use other structures in the prior art. The specific structure of the switching valve 2 is not the technical point of this invention and will not be described in detail here.

[0052] According to the present invention, a lower connector 7 is further provided at the lower part of the connecting main barrel 13. The lower connector 7 extends into the interior of the connecting main barrel 13, and its top abuts against the switching valve 2. This arrangement serves two purposes: firstly, it limits the movement of the switching valve 2, and secondly, it connects to other downhole tools below. A sealing ring for sealing with the connecting main barrel 13 is provided on the outer wall of the lower connector 7. In this embodiment, the lower connector 7 is connected to the connecting main barrel 13 via a limiting sleeve 8 using a threaded connection. The specific structure of the limiting sleeve 8 is prior art and not a key feature of this invention, and will not be described further here.

[0053] The operating steps of this invention are as follows.

[0054] The downhole isolation device 100 is inserted into the well along with the tubing string (not shown in the figure), the RDS valve (a commonly used downhole valve in the prior art, not shown in the figure), and the completion packer (not shown in the figure), wherein the downhole isolation device 100 is located above the completion packer, and the RDS valve is located above the downhole isolation device 100.

[0055] At this time, the internal state of the downhole isolation device 100 is as follows: Figure 1As shown, with switch valve 2 in the open state, the downhole isolation device 100 is essentially equivalent to a normal tubing string, allowing for normal acid fracturing and production testing operations. Acid fracturing and production testing operations are existing technologies and will not be described in detail here.

[0056] After the production test is completed, the downhole is shut in via the RDS valve, and upper formation kill is performed. Because the downhole packer is sealed, kill fluid will not enter the formation below the packer during the upper formation kill process, thus preventing the kill from affecting the reservoir. This part of the operation is the same as existing technology.

[0057] After well control, the gas production tree is removed, and a blowout preventer is installed. Then, following the procedures described in this embodiment, the tubing string is rotated to insert connector 4, disengaging it from the threaded connection at the connecting sub 12. The tubing string is then pulled up, and the ball valve 21 is closed via insert connector 4, elastic claw 6, switch sleeve 3, and operating pin 25. Figure 2 As shown. The gas-producing tree and blowout preventer are both existing technologies.

[0058] Continue to pull the tubing string upwards, separating the insertion connector 4 from the elastic claw 6, thus releasing the connector and separating the tubing string above the insertion connector 4, as well as various downhole tools, from the switch valve 2 of the downhole isolation device 100. The specific working principle has been described in detail above and will not be repeated here.

[0059] When a secondary well completion is required, insert the insertion connector 4 back into the connecting sub 12 and reconnect it to the elastic claw 6. Then, rotate the insertion connector 4 to establish the threaded connection between the insertion connector 4 and the connecting sub 12. After installing the gas production tree, as follows... Figure 4 As shown, a ball is thrown into the switch sleeve 3 to press down, causing the switch sleeve 3 to move downwards, eventually reaching... Figure 5 At the indicated location, open switch valve 2 to open the well. Production operations can then commence after the well is opened.

[0060] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A downhole isolation device, comprising an outer cylinder (1), a switching valve (2) disposed within the outer cylinder (1), and a switching sleeve (3), wherein the switching sleeve (3) is located above the switching valve (2), and the upward or downward movement of the switching sleeve (3) can cause the switching valve (2) to close or open, characterized in that, The downhole isolation device also includes: Insert connector (4), the upper end of the switch sleeve (3) is connected to the lower end of the insert connector (4) by an elastic claw (6), A sealing ball seat (31) is provided inside the switch sleeve (3), and a sealing ring is provided between the switch sleeve (3) and the outer cylinder (1). In the initial state, the elastic claw (6) is radially abutted by the outer cylinder (1). During the release process, the insertion connector (4) moves upward, causing the elastic claw (6) and the switch sleeve (3) to move upward. After the switch sleeve (3) closes the switch valve (2), the elastic claw (6) disengages from the outer cylinder (1), allowing the elastic claw (6) to expand radially under the relative action of the insertion connector (4), thereby separating the insertion connector (4) from the switch sleeve (3). The insertion connector (4) can be reconnected to the switch sleeve (3) via the elastic claw (6) by reversing its movement. After the lower end of the insertion connector is inserted into the elastic claw, the insertion connector can move axially relative to the elastic claw within the length range of the elastic claw. After the insertion connector enters the elastic claw and is connected to the connecting short section (12) of the outer cylinder (1) by threaded connection, the pressure ball is pressed into the switch sleeve (3) to form a seal with the sealing ball seat (31), and pressure is pressed into the switch sleeve, thereby causing the switch sleeve to move downward and opening the switch valve.

2. The downhole isolation device according to claim 1, characterized in that, After the insertion connector (4) is connected to the switch sleeve (3) via the elastic claw (6), the insertion connector (4) and the switch sleeve (3) can move relative to each other within the length range of the elastic claw (6).

3. The downhole isolation device according to claim 2, characterized in that, The elastic claw (6) is fixedly disposed on the upper end of the switch sleeve (3). An inwardly protruding inner tooth (61) is provided on the upper end of the elastic claw (6). An outer tooth (41) that cooperates with the elastic claw (6) is provided on the lower end of the insertion connector (4). When the lower end of the insertion connector (4) abuts against the upper end of the switch sleeve (3), the inner tooth (61) is located above the outer tooth (41).

4. The downhole isolation device according to claim 1, characterized in that, The outer cylinder (1) is provided with a stepped hole. In the initial state, the elastic claw (6) is located at the small diameter of the outer cylinder (1), thereby radially abutting the elastic claw (6). In the release state, the elastic claw (6) moves with the insertion connector (4) to the large diameter of the outer cylinder (1), thereby releasing the radial abutment of the elastic claw (6).

5. The downhole isolation device according to any one of claims 1 to 4, characterized in that, A first circulation hole (32) is provided on the wall of the switch sleeve (3), and a second circulation hole (11) is provided on the wall of the outer cylinder (1). In the initial state, the first circulation hole (32) and the second circulation hole (11) are misaligned. When the insertion connector (4) drives the switch sleeve (3) to move upward through the elastic claw (6), the first circulation hole (32) and the second circulation hole (11) coincide.

6. The downhole isolation device according to claim 5, characterized in that, At least two sealing rings for sealing with the outer cylinder (1) are provided on the outer wall of the switch sleeve (3), and the two sealing rings are respectively provided on the upper and lower sides of the first circulation hole (32).

7. The downhole isolation device according to any one of claims 1 to 4, characterized in that, The inner wall of the outer cylinder (1) is provided with a protrusion to prevent the switch sleeve (3) from detaching from the outer cylinder (1) from above.

8. The downhole isolation device according to any one of claims 1 to 4, characterized in that, The outer wall of the insertion connector (4) is provided with threads for connection with the outer cylinder (1).

9. The downhole isolation device according to any one of claims 1 to 4, characterized in that, A sealing ring is provided between the insertion connector (4) and the outer cylinder (1).

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