Shaft plugging device capable of being opened and closed repeatedly

Abstract

The utility model discloses a shaft plugging device capable of being opened and closed repeatedly, and belongs to the field of oil production engineering. The shaft plugging device comprises an upper connector and a sealing switch, the upper connector is sequentially connected with an outer cylinder and a transition connector and internally communicated with the outer cylinder and the transition connector to form an oil flow channel, and a conical surface valve seat is arranged in the upper connector; one end of the sealing switch is attached to the conical surface valve seat, the other end of the sealing switch penetrates through the spring seat, the spring seat is connected with the liquid inlet plate, the liquid inlet plate is arranged on the top of the transition connector, a nut is arranged on the sealing switch below the spring seat, and a spring is arranged on the sealing switch between one end of the sealing switch and the spring seat in a sleeved mode. No well control risk exists in the production operation process; after an oil well is produced, the problem that the switch is blocked by foreign matter is avoided, the switch can still be tightly sealed after being repeatedly opened and closed for multiple times in the process of tripping a tubular column in well repair, the well control risk and the potential safety hazard of production operation can be greatly reduced, and the conditions of later conventional well repair operation are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil production engineering, and particularly relates to a wellbore plugging device with repeated opening and closing. Background Technique

[0002] In the efficient development and operation of shale oil horizontal wells, the high energy of the formation and the characteristics of a large amount of produced fluid backflow pose severe challenges to the subsequent operation process. Especially in a series of key links such as wellbore cleaning, drill pipe pulling, wellhead replacement until production after well testing, the well control risk is particularly prominent, significantly affecting the production efficiency and economic benefits of the oilfield.

[0003] The following problems exist in the existing technologies and need to be solved urgently: (1) Due to the extremely high formation pressure of shale oil horizontal wells, the test tubing string is often blocked during the pulling-out process due to excessive pressure difference, and the wellhead disassembly work becomes extremely complex. The long blowdown process not only prolongs the operation cycle but also causes the well testing crew to stay on-site for a long time, severely restricting the production progress of the oilfield; (2) The unique high gas-liquid ratio, intermittent, and irregular liquid spraying phenomenon of shale oil horizontal wells make the well control difficulty increase sharply during sensitive operations such as wellhead replacement and blowout preventer installation; (3) Despite taking various environmental protection measures, during the operation process, if the produced fluid backflow is not properly treated, it may still cause on-site pollution, causing irreversible damage to the surrounding environment; (4) The currently widely used sliding sleeve type wellbore switcher indeed achieved the significant advantage of rapid production in two trips at the initial stage, that is, the production cycle was greatly shortened by temporarily plugging the wellbore under pressure and normal pressure production operations. However, with the increase in the number of uses, impurities such as scale and sand grains in the wellbore gradually accumulate, resulting in problems such as sticking and poor sealing of the sliding sleeve switch.

[0004] Therefore, aiming at the well control risk, environmental pollution, and reliability of the wellbore switcher during the period from well testing to production of shale oil horizontal wells, it is urgent to develop more advanced and reliable technologies and equipment to comprehensively improve the operation efficiency, ensure production safety, reduce environmental pollution, and promote the sustainable development of the shale oil development industry. Content of the Utility Model

[0005] The utility model provides a wellbore plugging device with repeated opening and closing to solve the problems existing in the prior art. It is used to control the pressure in the wellbore during the production after horizontal well fracturing, solve the problem of poor sealing, and reduce the well control risk and potential safety hazards.

[0006] To achieve the above object, the utility model provides the following technical solutions:

[0007] The utility model provides a wellbore plugging device with repeated opening and closing, which comprises an upper joint and a sealing switch. The upper joint is sequentially connected with an outer cylinder and a transition joint. An oil flow channel is formed by internal communication among the upper joint, the outer cylinder and the transition joint. At the connection between the upper joint and the outer cylinder, a conical valve seat is arranged inside the upper joint. One end of the sealing switch is attached to the conical valve seat, and the sealing switch can slide up and down relative to the conical valve seat. The other end of the sealing switch passes through a spring seat, and the spring seat is connected with a liquid inlet plate. The liquid inlet plate is arranged at the top of the transition joint. Below the spring seat, a nut is arranged on the sealing switch, and a spring is sleeved on the sealing switch between one end of the sealing switch and the spring seat.

[0008] The sealing switch comprises a switch head and a switch cylinder, which are integrally formed. The switch head is closely attached to both the conical valve seat and the inner wall of the outer cylinder, and the diameter of the switch cylinder is smaller than the inner diameter of the outer cylinder.

[0009] The side surface of the switch head comprises a conical surface and a cylindrical surface. The conical surface of the switch head is attached to the conical surface of the conical valve seat, and the cylindrical surface of the switch head is attached to the inner wall of the outer cylinder.

[0010] A plurality of sealing rings are arranged at the joint where the cylindrical surface of the switch head is attached to the inner circumferential side surface of the outer cylinder.

[0011] The spring seat and the liquid inlet plate are connected by threads.

[0012] Below the nut, a split pin is arranged on the sealing switch.

[0013] A washer is arranged at the bottom of the nut.

[0014] The liquid inlet plate is provided with a plurality of liquid inlet holes.

[0015] One end of the upper joint is connected with one end of the outer cylinder by threads.

[0016] The other end of the outer cylinder is connected with one end of the transition joint by threads.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0018] The wellbore plugging device provided by the utility model is first lowered into the oil well under pressure during use. After setting and releasing the string, due to the sealing surface composed of the sealing switch, the conical valve seat and the outer cylinder, the wellbore can be temporarily sealed and controlled, and the wellhead of the oil well has no pressure. The high-pressure wellhead for well testing can be safely replaced with a production wellhead, and there is no well control risk during the production operation process. The conical valve seat provides an upper limit position for the sealing switch, and the spring can realize the function of repeatedly opening and closing the sealing switch. The spring seat and the liquid inlet plate provide a lower fixing position for the spring, and the liquid inlet plate is arranged to be flexibly disassembled. The nut is set to hold against the spring seat to maintain an appropriate spring compression state, so that the sealing switch and the conical valve seat are elastically closed. After the utility model is applied to oil well production, when the oil flow continuously flushes the sealing surface of the sealing switch, problems such as foreign object jamming of the switch can be prevented; during the process of pulling and running the pipe string during workover, the sealing switch can still be tightly sealed after repeatedly opening and closing many times. This wellbore plugging device can greatly reduce the well control risk and potential safety hazards during the production operation, and improve the conditions for conventional workover operations in the later stage. After being used in a shale oil horizontal well, the production operation can be completed within 2 days, shortening the interval between well testing and production by 13 days, achieving early oil production and increased oil production, and improving the annual crude oil contribution rate of new wells.

[0019] Further, the switch head is in close fit with the inner walls of both the conical valve seat and the outer cylinder, and a sealing ring is provided to ensure the sealing performance of the sealing switch and prevent gas and liquid leakage.

[0020] Further, a split pin is provided to hold against the nut to prevent the nut from loosening or falling off downward, playing a role in limiting. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Structural schematic diagram of the wellbore plugging device with repeated opening and closing of the present utility model;

[0023] Figure 2 Schematic diagram of the liquid inlet plate in the wellbore plugging device with repeated opening and closing of the present utility model;

[0024] Wherein: 1. upper sub; 2. conical valve seat; 3. sealing ring; 4. outer cylinder; 5. sealing switch; 51. switch head; 52. switch cylinder; 6. spring; 7. liquid inlet plate; 8. spring seat; 9. nut; 10. washer; 11. split pin; 12. transition sub; 13. lower sub. Detailed Embodiment

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts fall within the scope of protection of the present utility model.

[0027] It should be noted that: Similar reference numerals and letters denote similar items in the following accompanying drawings. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0028] In the description of the embodiments of the present utility model, it should be noted that if terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present utility model. In addition, terms such as "first" and "second" are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0029] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0030] In the description of the embodiments of the present utility model, it should also be noted that unless otherwise clearly specified and limited, if the terms "set", "installed", "connected", "connected" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0031] The following further describes the present utility model in detail with reference to the accompanying drawings:

[0032] As Figure 1 shown, the repeated opening and closing wellbore plugging device provided by the present utility model includes an upper joint 1, the upper joint 1 is sequentially connected to an outer cylinder 4, a transition joint 12, and a lower joint 13. The upper joint 1, the outer cylinder 4, the transition joint 12, and the lower joint 13 are internally connected to form an oil flow channel. A conical valve seat 2 is arranged inside one end where the upper joint 1 is connected to the outer cylinder 4. One end of a sealing switch 5 fits and slides on the conical valve seat 2. The conical valve seat 2 provides an upper limit position for the sealing switch 5. The other end of the sealing switch 5 slides through a spring seat 8. The spring seat 8 is threadedly connected to a liquid inlet plate 7. The liquid inlet plate 7 is arranged at the top of the transition joint 12. The liquid inlet plate 7 is provided with a plurality of liquid inlet holes. A spring 6 is sleeved on the sealing switch 5 between one end of the sealing switch 5 and the spring seat 8. Below the spring seat 8, a nut 9 is arranged on the sealing switch 5. The sealing switch 5 is threadedly connected to the nut 9. The nut 9 can move downward together with the downward-sliding sealing switch 5. When the sealing switch 5 is in the closed state, the nut 9 is arranged to press against the spring seat 8 to maintain an appropriate spring compression state, so that the sealing switch 5 and the conical valve seat 2 are elastically closed. Below the nut 9, a split pin 11 is arranged on the sealing switch 5. The split pin 11 can press against the nut 9 to prevent it from loosening or becoming loose downward, playing a role in limiting the position. A washer 10 is arranged at the bottom of the nut 9 to provide buffering for the closing of the sealing switch 5.

[0033] The sealing switch 5 includes a switch head 51 and a switch cylinder 52, and the switch head 51 and the switch cylinder 52 are integrally formed. The switch head 51 is in close fit with both the conical valve seat 2 and the inner wall of the outer cylinder 4. The side surface of the switch head 51 includes a conical surface and a cylindrical surface. The conical surface of the switch head 51 fits with the conical surface of the conical valve seat 2, and the cylindrical surface of the switch head 51 fits with the inner wall of the outer cylinder 4. A plurality of sealing rings 3 are arranged at the fitting position of the cylindrical surface of the switch head 51 and the inner wall of the outer cylinder 4. The sealing rings 3 can enhance the sealing performance of the sealing switch 5. The diameter of the switch cylinder 52 is smaller than the inner diameter of the outer cylinder 4. The switch cylinder 52 is a single-section cylinder or a two-section cylinder.

[0034] The outer side of the spring seat 8 is in a "convex" shape. One end of the spring 6 is arranged on the step of the spring seat 8, and the other end of the spring 6 is arranged at the bottom of the switch head 51.

[0035] Embodiment 1

[0036] As Figure 1 And as Figure 2 As shown, the repeatedly opening and closing wellbore seal of this embodiment includes an upper joint 1, an outer cylinder 4, a transition joint 12 and a lower joint 13 connected in sequence. The inside of the upper joint 1, the outer cylinder 4, the transition joint 12 and the lower joint 13 are internally connected to form an oil flow channel. A conical valve seat 2 is arranged inside one end where the upper joint 1 is connected to the outer cylinder 4. The conical surface of the switch head 51 of the sealing switch 5 fits with the conical surface of the conical valve seat 2. The cylindrical surface of the switch head 51 fits with the inner wall of the outer cylinder 4. Two sealing rings 3 are arranged at the place where the cylindrical surface of the switch head 51 fits with the inner wall of the outer cylinder 4. The diameter of the switch cylinder 52 is smaller than the inner diameter of the outer cylinder 4, and the switch cylinder 52 is a two-stage cylinder. One end of the switch cylinder 52 slides through the spring seat 8. The spring seat 8 is threadedly connected with the liquid inlet plate 7. The liquid inlet plate 7 is arranged at the top of the transition joint 12. The liquid inlet plate 7 is provided with 12 liquid inlet holes. Below the spring seat 8, the sealing switch 5 is threadedly connected with a nut 9, and a washer 10 is arranged at the bottom of the nut 9. Below the nut 9, a split pin 11 is arranged on the sealing switch 5. The outer side of the spring seat 8 is in a "convex" shape. One end of the spring 6 is arranged on the step of the spring seat 8, and the other end of the spring 6 is arranged at the bottom of the switch head 51.

[0037] The outer ring at the end of the upper joint 1 of the repeatedly opening and closing wellbore seal of this embodiment is threadedly connected with the inner ring at one end of the outer cylinder 4. The inner ring at the other end of the outer cylinder 4 is threadedly connected with the outer ring at one end of the transition joint 12. The inner ring at the other end of the transition joint 12 is threadedly connected with the outer ring of the lower joint 13.

[0038] The repeatedly opening and closing wellbore plugging device of this embodiment is made of steel.

[0039] The working method of the repeatedly opening and closing wellbore plugging device provided by the present utility model includes:

[0040] After assembling the repeatedly opening and closing wellbore plugging device, connect the upper part of the upper joint 1 with an insertable releasing packer to form a combined tool, and then connect the tubing and lower it into the oil well. The sealing switch 5 in the wellbore plugging device is in a closed state under the action of the spring 6, temporarily plugging the internal flow channel of the wellbore plugging device;

[0041] When the wellbore plugging device reaches the predetermined position, after pressure is applied to the insertable releasing packer to set the packer and release the hand, the oil-casing annular space in the wellbore is plugged, and then the tubing is removed;

[0042] When installing the pump, connect the inserting pipe, the sucker rod pump and the tubing from bottom to top and lower them into the wellbore. The inserting pipe passes through the inside of the releasing packer and pushes the sealing switch 5 to move downward to compress the spring 6. At this time, the sealing switch 5 is opened, and the oil flow channel is opened. The oil flow passes through the lower joint 13 and the transition joint 12 in sequence, then enters the outer cylinder 4 and the upper joint 1 through the liquid inlet plate 7, and then enters the wellbore above the releasing packer. After the pump installation is completed, start the oil pumping equipment to produce oil.

[0043] Compared with the sliding sleeve type switch structure of the existing wellbore switch, the sliding sleeve type switch structure of the present invention is improved to a "conical surface + double rubber ring" type sealing switch. After the oil well is put into production, due to the continuous scouring of the sealing surface of the "conical surface + double rubber ring" type sealing switch by the oil flow, there will be no problem of foreign matter jamming the switch. During the process of pulling and running the tubing during workover, this tool can still be tightly sealed after repeated opening and closing for many times, and the reliability is greatly improved.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify or equivalently replace the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention is within the protection scope of the claims of the present invention pending approval.

Claims

1. A wellbore plugging device with repeated opening and closing, characterized in that, It includes an upper joint (1) and a sealing switch (5). The upper joint (1) is sequentially connected to an outer cylinder (4) and a transition joint (12). The inside of the upper joint (1), the outer cylinder (4), and the transition joint (12) is internally connected to form an oil flow channel. At the connection between the upper joint (1) and the outer cylinder (4), a conical valve seat (2) is arranged inside the upper joint (1); one end of the sealing switch (5) is in contact with the conical valve seat (2), and the sealing switch (5) can slide up and down relative to the conical valve seat (2). The other end of the sealing switch (5) passes through a spring seat (8). The spring seat (8) is connected to a liquid inlet plate (7). The liquid inlet plate (7) is arranged at the top of the transition joint (12). Below the spring seat (8), a nut (9) is arranged on the sealing switch (5), and a spring (6) is sleeved on the sealing switch (5) between one end of the sealing switch (5) and the spring seat (8).

2. The repeated opening and closing wellbore plugging device according to claim 1, wherein, The sealing switch (5) includes a switch head (51) and a switch cylinder (52), and the switch head (51) and the switch cylinder (52) are integrally formed; the switch head (51) is in close contact with both the conical valve seat (2) and the inner wall of the outer cylinder (4), and the diameter of the switch cylinder (52) is smaller than the inner diameter of the outer cylinder (4).

3. The repeated opening and closing wellbore plugging device according to claim 2, wherein, The side surface of the switch head (51) includes a conical surface and a cylindrical surface. The conical surface of the switch head (51) is in contact with the conical surface of the conical valve seat (2), and the cylindrical surface of the switch head (51) is in contact with the inner wall of the outer cylinder (4).

4. A repeated opening and closing wellbore plugging device according to claim 2, characterized in that, A plurality of sealing rings (3) are arranged at the contact between the cylindrical surface of the switch head (51) and the inner side surface of the outer cylinder (4).

5. The repeated opening and closing wellbore plugging device according to claim 2, characterized in that, The spring seat (8) and the liquid inlet plate (7) are connected by threads.

6. The repeated opening and closing wellbore plugging device according to claim 2, characterized in that, Below the nut (9), a split pin (11) is arranged on the sealing switch (5).

7. A repeated opening and closing wellbore plugging device according to claim 1, characterized in that, A washer (10) is arranged at the bottom of the nut (9).

8. A repeated opening and closing wellbore plugging device according to claim 1, characterized in that, The liquid inlet plate (7) is provided with a plurality of liquid inlet holes.

9. A repeated opening and closing wellbore plugging device according to claim 1, characterized in that, One end of the upper joint (1) is connected to one end of the outer cylinder (4) by threads.

10. A repeated opening and closing wellbore plugging device according to claim 1, wherein, The other end of the outer cylinder (4) is connected to one end of the transition joint (12) by threads.

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