A self-balancing packer

Abstract

The present application provides a self-balancing packer, comprising: a central tube; an outer core tube sleeved on the middle part of the central tube, and a self-balancing assembly, a rubber barrel sealing assembly and a rubber barrel locking assembly are sequentially sleeved on the outside of the outer core tube from top to bottom; an outer tube assembly, hermetically sleeved on the central tube and at least part of the outer core tube, and forming a balance cavity with the central tube, and the self-balancing assembly is arranged in the balance cavity; the outer tube assembly is provided with at least a pair of balance holes communicating the outside and the balance cavity in the radial direction, and the at least a pair of balance holes are respectively located above and below the rubber barrel sealing assembly, and the pressure outside the outer tube assembly can enter the balance cavity through the at least a pair of balance holes respectively, so that the self-balancing assembly absorbs the pressure. The technical solution of the present application absorbs most of the pressure through the self-balancing assembly, thereby reducing the pressure-bearing burden of the rubber barrel sealing assembly and improving the pressure-bearing capacity of the packer.

Description

Technical Field

[0001] The present application relates to the technical field of oil wells, and in particular to a self-balancing packer. Background Art

[0002] In downhole operations, hydraulic fracturing, water injection, water control and other processes are becoming more and more common. During the operation of each process, packers are needed to isolate each reservoir for segmented operations. Common packers include permanent packers and recoverable packers. Among them, recoverable packers are unsealed by lifting the tubing string to shear the unsealing shear pins, and then extracted and recovered.

[0003] As the development of oil and gas wells becomes more and more difficult, such as fracturing operations, the packer needs to withstand a larger annular pressure difference. This retrievable packer withstands the annular pressure difference by setting a larger number of unsealing shear pins. However, too many unsealing shear pins will require a greater lifting force, which will have an adverse effect on the safety of the tubing. Therefore, the annular pressure bearing capacity of the packer can generally only reach 25-35MPa, which cannot better meet the development application conditions.

[0004] Therefore, a self-balancing packer is needed to solve the problem that the existing packers cannot withstand a large annular pressure difference. Summary of the invention

[0005] The main purpose of the present application is to provide a self-balancing packer to solve the problem that the existing packers cannot withstand a large annular pressure difference.

[0006] In order to solve the above technical problems, the embodiments of the present application provide the following technical solutions:

[0007] The present application provides a self-balancing packer, comprising:

[0008] Central tube;

[0009] An outer core tube, wherein the outer core tube is sleeved on the middle part of the central tube, and the outer part of the outer core tube is sleeved with a self-balancing component, a rubber tube sealing component and a rubber tube locking component in sequence from top to bottom;

[0010] in,

[0011] An outer tube assembly, wherein the outer tube assembly sealing sleeve is disposed on the central tube and at least a portion of the outer core tube, and forms a balancing cavity with the central tube, and the self-balancing assembly is disposed in the balancing cavity;

[0012] The outer tube assembly is provided with at least a pair of balance holes that communicate radially between the outside and the balance cavity. The at least a pair of balance holes are respectively located above and below the rubber cylinder sealing assembly. The pressure outside the outer tube assembly can enter the balance cavity through the at least a pair of balance holes respectively, so that the self-balancing assembly can absorb the pressure.

[0013] Preferably, the self-balancing assembly includes an upper balance piston and a lower balance piston, and the outer tube assembly includes:

[0014] A connecting cylinder, which is sleeved on the central tube and at least part of the outer core tube in a sealed manner;

[0015] A release shear outer cylinder, which is sleeved on the outer core tube and is located between the connecting cylinder and the rubber cylinder sealing assembly, and is hermetically connected to the outer core tube 7;

[0016] The connecting cylinder, the central tube, the outer core tube and the release shear outer cylinder form a first balance cavity. The upper balance piston is slidably and sealingly connected in the first balance cavity and is sealingly connected to the top end of the outer core tube;

[0017] The release shear outer cylinder, the outer core tube and the rubber cylinder sealing assembly form a second balance cavity. The lower balance piston is slidably and sealingly connected in the second balance cavity;

[0018] A locking outer cylinder, which is sleeved outside the rubber cylinder locking assembly and is connected to the rubber cylinder sealing assembly;

[0019] Wherein,

[0020] The connecting cylinder is provided with a first balance hole that communicates radially between its outside and the first balance cavity, and the first balance hole is located between one end of the upper balance piston and the release shear outer cylinder;

[0021] The release shear outer cylinder is provided with a second balance hole that is arranged radially and communicates between its outside and the second balance cavity. The second balance hole is located between one end of the lower balance piston and the rubber cylinder sealing assembly;

[0022] The locking outer cylinder is provided with a third balance hole. One end of the third balance hole communicates with the outside of the locking outer cylinder, and the other end communicates with the gap between the outer core tube and the central tube and respectively communicates with the first balance cavity where the other end of the upper balance piston is located and the second balance cavity where the other end of the lower balance piston is located.

[0023] Preferably, it further comprises a first joint, a second joint, an outer tube, and an interlocking assembly and an unsealing assembly sleeved on the outside of the central tube, the central tube comprises a first end and a second end, and the central tube is provided with a first pressure transmission hole, a second pressure transmission hole and a third pressure transmission hole radially penetratingly arranged from the first end to the second end in sequence;

[0024] The first joint is connected to the first end of the central tube, and the second joint is connected to the second end of the central tube;

[0025] The outer tube is sleeved on the outside of the interlocking assembly, and the two ends of the outer tube are respectively connected to the first joint and the connecting tube;

[0026] The unsealing assembly is arranged between the first joint and the rubber cylinder sealing assembly, and the interlocking assembly is arranged between the first joint and the unsealing assembly.

[0027] Preferably, one end of the outer tube is sleeved on the other end of the first joint and is threadedly connected to the first joint, and the other end of the outer tube is inserted into one end of the connecting tube and is sealed and connected to the connecting tube;

[0028] The interlocking assembly includes an upper locking slip, a disjointed sleeve, a disjointed sleeve shear pin, an upper interlocking stopper and an upper piston, wherein:

[0029] The outer wall of the central tube is provided with a first boss, the other end of the first joint can contact the upper surface of the first boss in a direction parallel to the axial direction, and a sliding gap is formed between the first joint and the outer tube, and the disengagement sleeve is slidably connected in the sliding gap;

[0030] A first tooth portion is provided on the inner wall of the outer cylinder, and the upper locking slip is connected to the outer periphery of the disengagement sleeve and can be engaged with the first tooth portion;

[0031] The disconnect sleeve shear pins are radially inserted into the disconnect sleeve and the first joint in sequence;

[0032] The outer wall of the center tube is provided with a first block groove, the upper interlocking block is radially penetrated into the first joint, and the inner edge of the upper interlocking block can be snapped into the first block groove; the disengagement sleeve, the outer tube, the connecting tube and the center tube form an upper piston cavity, the upper piston is slidingly and sealingly connected to the upper piston cavity, and the first pressure transmission hole is connected to the upper piston cavity.

[0033] Preferably, the interlocking assembly also includes an anti-rotation pin shaft, the outer wall of the center tube is provided with an anti-rotation long groove with one end opening parallel to the axial direction, the opening of the anti-rotation long groove is arranged toward the first joint, the anti-rotation pin shaft radially passes through the first joint, and is slidably connected in the anti-rotation long groove.

[0034] Preferably, a second boss is provided on the inner wall of the connecting cylinder, the second boss is sealingly connected to the central tube, and the other end of the outer cylinder is connected to the connecting cylinder on the side of the second boss facing the first joint;

[0035] A first clamping table is provided on the inner wall of the other end of the outer cylinder. The inner edge of the upper piston is slidably and sealingly connected to the central tube, the outer edge of the upper piston is slidably and sealingly connected to the outer cylinder, and the upper piston is located between the disconnection sleeve and the first clamping table. The first pressure transmission hole communicates between the upper piston and the second boss.

[0036] Preferably, the rubber cylinder sealing assembly includes, from top to bottom in sequence, a upper rubber cylinder seat, a main rubber cylinder, and a lower rubber cylinder pressing ring sleeved on the outer core tube;

[0037] Wherein, one end of the upper rubber cylinder seat is inserted into the release and shear outer cylinder, and the unsealing assembly includes an unsealing and shear pin. The unsealing and shear pin sequentially passes through the release and shear outer cylinder radially into the upper rubber cylinder seat;

[0038] The middle part of the inner circumference of the main rubber cylinder is sealingly clamped to the outer core tube through a main rubber cylinder support ring;

[0039] The inner circumference of the lower rubber cylinder pressing ring contacts the outer core tube. The lower rubber cylinder pressing ring is inserted into the locking outer cylinder and is connected to the locking outer cylinder through a first fixing member.

[0040] Preferably, the rubber cylinder sealing assembly further includes an upper auxiliary rubber cylinder, a pair of auxiliary rubber cylinder spacer rings, a lower auxiliary rubber cylinder, and a lower auxiliary rubber cylinder pushing ring; wherein,

[0041] The upper auxiliary rubber cylinder and the lower auxiliary rubber cylinder are respectively arranged on the upper and lower sides of the main rubber cylinder, and a pair of the auxiliary rubber cylinder spacer rings are respectively arranged between the upper auxiliary rubber cylinder and the main rubber cylinder, and between the main rubber cylinder and the lower auxiliary rubber cylinder;

[0042] The upper auxiliary rubber cylinder is clamped between the upper rubber cylinder seat and one of the auxiliary rubber cylinder spacer rings, and the lower auxiliary rubber cylinder is clamped between the other auxiliary rubber cylinder spacer ring and the lower rubber cylinder pressing ring;

[0043] Both ends of the lower auxiliary rubber cylinder pushing ring are respectively inserted into the lower auxiliary rubber cylinder and the lower rubber cylinder pressing ring, and the lower auxiliary rubber cylinder pushing ring is threadedly connected to the lower rubber cylinder pressing ring.

[0044] Preferably, a piston sleeve lock nut is sleeved on the second joint, and the rubber cylinder locking assembly includes:

[0045] The upper setting packer piston has one end slidably and sealingly sleeved on the central tube, and forms a pressure chamber with the inner wall of the central tube;

[0046] The inner split sleeve of the setting packer piston is sleeved on the central tube and is located in the pressure chamber. One end outer wall of the inner split sleeve of the setting packer piston is sealingly connected to the inner wall of the upper setting packer piston;

[0047] The lower setting packer piston sleeve has one end sleeved on the upper setting packer piston 34 and the other end abutted against the piston sleeve lock nut;

[0048] The lower setting packer piston is sleeved on the inner split sleeve of the setting packer piston. One end of the lower setting packer piston is connected to the other end of the upper setting packer piston, and the other end of the lower setting packer piston is sealingly connected between the lower setting packer piston sleeve and the inner split sleeve of the setting packer piston;

[0049] The upper setting packer piston sleeve has one end sleeved on the outside of the upper setting packer piston and the other end inserted into the locking outer cylinder;

[0050] The rubber barrel setting shear pin passes radially through the upper setting packer piston sleeve into the upper setting packer piston; wherein,

[0051] On the inner wall of one end of the inner split sleeve of the setting packer piston close to the upper setting packer piston, there is a first groove communicating with the second pressure transmission hole. The first groove communicates with the pressure chamber. On the inner wall of the other end of the inner split sleeve of the setting packer piston, there is a second groove communicating with the third pressure transmission hole. The second groove communicates with the outside of the other end of the lower setting packer piston.

[0052] Preferably, the rubber barrel locking assembly further includes:

[0053] The interlock block support sleeve is sleeved on the central tube and is threadedly connected to the central tube. There is a third boss on the outer circumference of the interlock block support sleeve;

[0054] The interlock block support sleeve extension sleeve is sleeved on the outside of the interlock block support sleeve;

[0055] The interlock block limit sleeve has two ends respectively sleeved and connected to the outside of the outer core tube and the interlock block support sleeve extension sleeve, and there is a second block groove on the interlock block support sleeve;

[0056] The lower interlock block is arranged in the second block groove and is slidably connected to the outer wall of the interlock block support sleeve;

[0057] Slip seat lock nut, the slip seat lock nut is threadedly connected and sleeved on the outer periphery of the interlock block limiting sleeve;

[0058] Locking slip seat, the locking slip seat is sleeved radially between the interlock block limiting sleeve and the locking outer cylinder, and axially connected between the slip seat lock nut and the lower interlock block;

[0059] Lower locking slip, the lower locking slip is sleeved on the outer wall of the locking slip seat;

[0060] Anti-setting packer shear pin seat, the anti-setting packer shear pin seat is arranged radially between the interlock block limiting sleeve and the locking outer cylinder, and axially arranged on the side of the lower interlock block away from the locking slip seat;

[0061] Anti-setting packer shear pin, the anti-setting packer shear pin is sequentially inserted through the locking outer cylinder and the anti-setting packer shear pin seat.

[0062] Compared with the prior art, the self-balancing packer provided by the present application has at least the following beneficial effects: The packer of the present application is arranged in the wellbore and is set at the preset setting position of the oil and gas well casing through the rubber barrel sealing assembly. When the packer bears the upper annulus pressure difference, the balance hole above the rubber barrel sealing assembly transmits the larger pressure above to the balance cavity, and most of the pressure is absorbed by the self-balancing assembly, thereby reducing the pressure-bearing burden of the rubber barrel sealing assembly; When the packer bears the lower annulus pressure difference, the balance hole below the rubber barrel sealing assembly transmits the larger pressure below to the balance cavity, and most of the pressure is absorbed by the self-balancing assembly, thereby reducing the pressure-bearing burden of the rubber barrel sealing assembly and improving the pressure-bearing capacity of the packer; The technical solution of the present application absorbs the annulus pressure difference through the balance hole and the self-balancing assembly, and there is no need to set a large number of releasing shear pins, which will affect the safety of the pipe string. The self-balancing packer of the present application has a large annulus pressure-bearing capacity, can better meet the development and use conditions, and is applied to more development environments.

[0063] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly and implement it according to the content of the specification, the following takes the preferred embodiments of the present application and combines the drawings to describe in detail as follows. Brief Description of the Drawings

[0064] By referring to the drawings and reading the following detailed description, the above and other objects, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0065] Figure 1Shows a cross-sectional view of a self-balancing packer according to an exemplary embodiment of the present application;

[0066] Figure 2 Shows a cross-sectional view of a self-balancing component in a self-balancing packer according to an exemplary embodiment of the present application;

[0067] Figure 3 Shows a cross-sectional view of an interlock component in a self-balancing packer according to an exemplary embodiment of the present application;

[0068] Figure 4 Shows a cross-sectional view of a rubber barrel seal component in a self-balancing packer according to an exemplary embodiment of the present application;

[0069] Figure 5 Shows a cross-sectional view of a setting component in a rubber barrel locking component of a self-balancing packer according to an exemplary embodiment of the present application;

[0070] Figure 6 Shows a cross-sectional view of an anti-premature setting component in a rubber barrel locking group of a self-balancing packer according to an exemplary embodiment of the present application;

[0071] Figure 7a Shows a schematic structural view of a central tube in a self-balancing packer according to an exemplary embodiment of the present application, Figure 7b Shows a cross-sectional view of the central tube;

[0072] Figure 8 Shows a cross-sectional view of an outer core tube in a self-balancing packer according to an exemplary embodiment of the present application;

[0073] Figure 9a Shows a cross-sectional view of an upper locking slip in a self-balancing packer according to an exemplary embodiment of the present application, Figure 9b Shows Figure 9a An enlarged schematic view of part A in;

[0074] Figure 10a Shows a schematic structural view of a disconnect sleeve in a self-balancing packer according to an exemplary embodiment of the present application, Figure 10b Shows Figure 10a A-A cross-sectional view of, Figure 10c Shows Figure 10a B-B cross-sectional view of;

[0075] Figure 11 Shows a cross-sectional view of an outer cylinder in a self-balancing packer according to an exemplary embodiment of the present application;

[0076] Figure 12a Shows a schematic structural view of an upper interlock block in a self-balancing packer according to an exemplary embodiment of the present application, Figure 12b Shows a cross-sectional view of the upper interlock block;

[0077] Figure 13 Shows a schematic structural diagram of the main rubber cylinder in a self - balancing packer according to an exemplary embodiment of the present application;

[0078] Figure 14 Shows a cross - sectional view of the locking outer cylinder in a self - balancing packer according to an exemplary embodiment of the present application;

[0079] Figure 15a Shows a schematic structural diagram of the first joint in a self - balancing packer according to an exemplary embodiment of the present application, Figure 15b Shows Figure 15a Cross - sectional view in the A - A direction of Figure 15c Shows Figure 15a Cross - sectional view in the B - B direction of;

[0080] Figure 16a Shows a schematic structural diagram of the second joint in a self - balancing packer according to an exemplary embodiment of the present application, Figure 16b Shows a cross - sectional view of the second joint;

[0081] Figure 17a Shows a schematic diagram of the state at the pressure in the first stage during the setting process of a self - balancing packer according to an exemplary embodiment of the present application, Figure 17b Shows Figure 17a Partial enlarged schematic diagram of;

[0082] Figure 18 Shows a partial state schematic diagram at the pressure in the second stage during the setting process of a self - balancing packer according to an exemplary embodiment of the present application;

[0083] Figure 19 Shows a schematic diagram of the state at the pressure in the third stage during the setting process of a self - balancing packer according to an exemplary embodiment of the present application;

[0084] Figure 20 Shows a partial state schematic diagram of the shear of the unsealing shear pin during the unsealing process of a self - balancing packer according to an exemplary embodiment of the present application;

[0085] Figure 21 Shows a partial state schematic diagram of the complete release of the rubber cylinder locking assembly during the unsealing process of a self - balancing packer according to an exemplary embodiment of the present application;

[0086] Figure 22 Shows a partial state schematic diagram of the reset of the rubber cylinder sealing assembly during the unsealing process of a self - balancing packer according to an exemplary embodiment of the present application.

[0087] Explanation of the reference numerals in the drawings:

[0088] 1 First joint, 101 Interlock block mounting groove, 102 Shearing pin mounting threaded hole, 103 Anti-rotation pin shaft mounting threaded hole, 2 Central tube, 201 Anti-rotation long slot, 202 First boss, 203 First block slot, 3 Outer cylinder, 301 First tooth part, 302 First clamping table, 4 Connecting tube, 401 Second boss, 5 Upper rubber cylinder seat, 6 Upper balance piston, 7 Outer core tube, 8 Interlock block support sleeve, 9 Interlock block limit sleeve, 10 Upper piston, 11 Disconnecting sleeve, 111 Slip installation groove, 112 Pin threaded hole, 12 Upper locking slip, 121 Serrated thread, 13 Disconnecting sleeve shearing pin, 14 Anti-rotation pin shaft, 15 Upper interlock block, 16 Upper auxiliary rubber cylinder, 17 Auxiliary rubber cylinder spacer ring, 18 Main rubber cylinder, 19 Lower auxiliary rubber cylinder, 20 Lower auxiliary rubber cylinder push ring, 21 Lower rubber cylinder pressing ring, 22 Lower interlock block, 23 Locking slip seat, 24 Slip seat lock nut, 25 Locking outer cylinder, 26 Lower locking slip, 27 Anti-setting shear pin seat, 28 Anti-setting shear pin, 29 Interlock block support sleeve extension sleeve, 30 Main rubber cylinder support ring, 31 Setting piston inner split sleeve, 32 Second joint, 33 Lower setting piston, 34 Upper setting piston, 35 Upper setting piston sleeve, 36 Lower setting piston sleeve, 37 Piston sleeve lock nut, 38 First fixing piece, 39 Rubber cylinder setting shear pin, 40 Fourth fixing piece, 41 Third fixing piece, 42 Unsetting shear pin, 43 Second fixing piece, 44 Third seal, 45 Second seal, 46 Fifth seal, 47 Sixth seal, 48 Fourth seal, 49 Seventh seal, 50 First seal, 51 Ninth seal, 52 Tenth seal, 53 Eighth seal, 54 Lower balance piston, 55 Release shear outer cylinder, 56 First pressure transmission hole, 57 Second pressure transmission hole, 58 Third pressure transmission hole, 59 First balance hole, 60 Second balance hole, 61 Fourth pressure transmission hole, 62 Fifth pressure transmission hole, 63 Third balance hole. Detailed implementation mode

[0089] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be fully conveyed to those skilled in the art. It should be noted that unless otherwise specified, the technical terms or scientific terms used in the present application should have the ordinary meaning understood by those skilled in the art to which the present application belongs.

[0090] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application 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 should not be construed as a limitation to the present application.

[0091] To solve the problems existing in the prior art, the present application provides a self-balancing packer. Please refer to Figures 1 to 22 , the packer includes: a central tube 2; an outer core tube 7, the outer core tube 7 is sleeved on the middle part of the central tube 2, and a self-balancing assembly, a rubber barrel sealing assembly and a rubber barrel locking assembly are sequentially sleeved on the outside of the outer core tube 7 from top to bottom; an outer tube assembly, the outer tube assembly is hermetically sleeved on the central tube 2 and at least part of the outer core tube 7, and forms a balance cavity with the central tube 2, and the self-balancing assembly is arranged in the balance cavity; wherein, the outer tube assembly is provided with at least a pair of balance holes that communicate with the outside and the balance cavity in the radial direction, and at least a pair of balance holes are respectively located above and below the rubber barrel sealing assembly, and the pressure outside the outer tube assembly can enter the balance cavity through at least a pair of balance holes respectively, so that the self-balancing assembly absorbs the pressure.

[0092] The packer involved in the technical solution of the present application is arranged in a wellbore. The rubber barrel sealing assembly is used to set the setting position of the oil and gas well casing. When the packer bears the upper annulus pressure difference, the balance hole above the rubber barrel sealing assembly transmits the larger pressure above to the balance cavity, and most of the pressure is absorbed by the self-balancing assembly, thereby reducing the pressure-bearing burden of the rubber barrel sealing assembly; when the packer bears the lower annulus pressure difference, the balance hole below the rubber barrel sealing assembly transmits the larger pressure below to the balance cavity, and most of the pressure is absorbed by the self-balancing assembly, thereby reducing the pressure-bearing burden of the rubber barrel sealing assembly; the technical solution of the present application absorbs the annulus pressure difference through the balance hole and the self-balancing assembly, without the need to set a large number of release shear pins 42, which affects the safety of the pipe string. Therefore, the self-balancing packer of the present application has a large annulus pressure-bearing capacity and can better meet the development and use conditions and be applied to more development environments.

[0093] Specifically, please refer to Figure 2, the self-balancing component in the present application includes an upper balance piston 6 and a lower balance piston 54. The outer tube assembly includes: a connecting cylinder 4, which is hermetically sleeved on the central tube 2 and at least part of the outer core tube 7; a release shear outer cylinder 55, which is sleeved on the outer core tube 7 and is located between the connecting cylinder 4 and the rubber cylinder sealing assembly, and is hermetically connected to the outer core tube 7; the connecting cylinder 4, the central tube 2, the outer core tube 7 and the release shear outer cylinder 55 form a first balance cavity, the upper balance piston 6 is slidably and hermetically connected in the first balance cavity and is hermetically connected to the top end of the outer core tube 7; the release shear outer cylinder 55, the outer core tube 7 and the rubber cylinder sealing assembly form a second balance cavity, and the lower balance piston 54 is slidably and hermetically connected in the second balance cavity; a locking outer cylinder 25, which is sleeved outside the rubber cylinder locking assembly and is connected to the rubber cylinder sealing assembly; wherein, the connecting cylinder 4 is provided with a first balance hole 59 that radially communicates with its outside and the first balance cavity, and the first balance hole 59 is located between one end of the upper balance piston 6 and the release shear outer cylinder 55; the release shear outer cylinder 55 is provided with a second balance hole 60 that is radially arranged and communicates with its outside and the second balance cavity, and the second balance hole 60 is located between one end of the lower balance piston 54 and the rubber cylinder sealing assembly; the locking outer cylinder 25 is provided with a third balance hole 63, one end of the third balance hole 63 communicates with the outside of the locking outer cylinder 25, the other end communicates with the gap between the outer core tube 7 and the central tube 2, and respectively communicates with the first balance cavity where the other end of the upper balance piston 6 is located and the second balance cavity where the other end of the lower balance piston 54 is located.

[0094] It should be noted that the third balance hole 63 is provided on the locking outer cylinder 25, and the pressure is transmitted to the gap between the outer core tube 7 and the central tube 2 through the gaps between the parts. The pressure transmitted through the third balance hole 63 can also be realized by using the mounting holes of the various fixing parts below the rubber cylinder sealing assembly without the need for additional drilling.

[0095] Please refer to Figure 2 and Figure 8 , the outer core tube 7 is sleeved on the central tube 2. The top of the outer core tube 7 is provided with a first external thread for connecting with the upper balance piston 6. The middle part of the outer core tube 7 is provided with a fifth pressure transmission hole 62. The middle part of the outer core tube 7 is provided with an annular fourth boss. The fifth pressure transmission hole 62 penetrates through the fourth boss in the middle of the outer core tube 7 and is used to communicate with the second balance cavity to transmit pressure to the lower balance piston 54. The bottom of the outer core tube 7 is provided with a second external thread for connecting with the rubber cylinder locking assembly. The thread teeth of the first external thread and the second external thread can be trapezoidal.

[0096] Please refer to Figure 2, a first balance chamber is formed in such a way that the connecting cylinder 4 is located above and outside, the release shear outer cylinder 55 is located below, and the central tube 2 and the outer core tube 7 are located inside. The upper balance piston 6 is slidably connected in the first balance chamber in a direction parallel to the axial direction. Among them, the top end of the upper balance piston 6 contacts the outer wall of the central tube 2 and the inner wall of the connecting cylinder 4 respectively in the radial direction, and the top outer wall of the upper balance piston 6 is hermetically connected to the inner wall of the connecting cylinder 4 through the first seal 50. There is a gap between the bottom outer wall of the upper balance piston 6 and the inner wall of the connecting cylinder 4; the inner wall of the upper balance piston 6 is threadedly connected to the first external thread of the outer core tube 7, and the top of the upper balance piston 6 abuts against the top of the outer core tube 7. The bottom inner wall of the upper balance piston 6 is hermetically connected to the outer wall of the outer core tube 7 through the second seal 45. When pressure is applied above or below the upper balance piston 6, the upper balance piston 6 can drive the outer core tube 7 to move synchronously. Sealing grooves for installing the first seal 50 and the second seal 45 are respectively provided on the top outer wall and the bottom inner wall of the upper balance piston 6.

[0097] The top inner wall of the release shear outer cylinder 55 is hermetically connected to the outer wall of the outer core tube 7 through a seal. A sealing groove for installing the seal is provided on the top inner wall of the release shear outer cylinder 55. The top outer wall of the release shear outer cylinder 55 is connected to the inner wall of the connecting cylinder 4 through a thread. The bottom of the release shear outer cylinder 55 is sleeved on the rubber cylinder sealing assembly; a second balance chamber is formed in such a way that the release shear outer cylinder 55 is located above and outside, the rubber cylinder sealing assembly is located below, and the outer core tube 7 is located inside. The lower balance piston 54 is slidably connected in the second balance chamber in a direction parallel to the axial direction. Among them, the top outer wall of the lower balance piston 54 is slidably hermetically connected to the inner wall of the release shear outer cylinder 55 through a seal. A first gap is formed between the top inner wall of the lower balance piston 54 and the outer core tube 7. The first gap communicates with the fifth pressure transmission hole 62. The pressure introduced from the fifth pressure transmission hole 62 can enter above the top of the lower balance piston 54 through the first gap to push the lower balance piston 54 to move downward; the bottom inner wall of the lower balance piston 54 is slidably hermetically connected to the outer wall of the outer core tube 7 through a seal. A second gap is formed between the bottom outer wall of the lower balance piston 54 and the bottom inner wall of the release shear outer cylinder 55. The second gap communicates with the second balance hole 60. The pressure introduced from the second balance hole 60 can push the top of the lower balance piston 54 to move upward, and when the lower balance piston 54 abuts against the fourth boss of the outer core tube 7, it can drive the outer core tube 7 to move upward synchronously. Sealing grooves for installing seals are respectively provided on the top outer wall and the bottom inner wall of the lower balance piston 54

[0098] The self-balancing seal of the present application also includes a first joint 1, a second joint 32, an outer tube 3, and an interlocking assembly and an unsealing assembly sleeved on the outside of the center tube 2. The center tube 2 includes a first end and a second end, and the center tube 2 is provided with a first pressure transmission hole 56, a second pressure transmission hole 57 and a third pressure transmission hole 58 radially extending from the first end to the second end; the first joint 1 is sealed and connected to the first end of the center tube 2 through a third sealing member 44, and the second joint 32 is connected to the second end of the center tube 2; the outer tube 3 is sleeved on the outside of the interlocking assembly, and the two ends of the outer tube 3 are respectively connected to the first joint 1 and the connecting tube 4; the unsealing assembly is arranged between the first joint 1 and the rubber tube sealing assembly, and the interlocking assembly is arranged between the first joint 1 and the unsealing assembly.

[0099] The interlocking assembly also includes an anti-rotation pin shaft 14. The outer wall of the center tube 2 is provided with an anti-rotation long groove 201 with an opening at one end parallel to the axial direction. The opening of the anti-rotation long groove 201 is set toward the first joint 1. The anti-rotation pin shaft 14 radially passes through the first joint 1 and is slidably connected in the anti-rotation long groove 201.

[0100] Specifically, see Figure 7a and Figure 7b , wherein the center tube 2 can be made of 42CrMo / 35CrMo alloy steel material, the first end of the center tube 2 is a cylindrical tube, which is used for sliding and sealing connection with the first joint 1, and the first end of the center tube 2 is provided with two symmetrical anti-rotation long grooves 201, which are used to cooperate with the anti-rotation pin shaft 14; the first end of the center tube 2 is also provided with an annular first stopper groove 203, which is used to clamp with the upper interlocking stopper 15; the middle part of the center tube 2 is provided with an annular first boss 202, which is used to transmit the lifting and unsealing force of the upper piston 10; the center tube 2 is provided with three pressure transmission holes from the first end to the second end, which are the first pressure transmission hole 56, the second pressure transmission hole 57 and the third pressure transmission hole 58, which are used to transmit the pressure transmitted in the oil pipe; the second end of the center tube 2 is provided with a third external thread, which is used to connect with the second joint 32. The thread teeth of the third external thread can be trapezoidal.

[0101] See also Figure 1 and Figure 3, one end of the outer cylinder 3 is sleeved on the other end of the first joint 1 and is threadedly connected to the first joint 1. The other end of the outer cylinder 3 is inserted into one end of the connecting cylinder 4 and is sealingly connected to the connecting cylinder 4. The interlock assembly includes an upper locking slip 12, a disconnecting sleeve 11, a disconnecting sleeve shear pin 13, an upper interlock stop 15 and an upper piston 10. Among them, a first boss 202 is provided on the outer wall of the central tube 2. The other end of the first joint 1 can contact the upper surface of the first boss 202 in a direction parallel to the axial direction and form a sliding gap with the outer cylinder 3. The disconnecting sleeve 11 is slidably connected in the sliding gap. A first tooth portion 301 is provided on the inner wall of the outer cylinder 3. The upper locking slip 12 is connected to the outer periphery of the disconnecting sleeve 11 and can be engaged and clamped with the first tooth portion 301. The disconnecting sleeve shear pin 13 is sequentially inserted through the disconnecting sleeve 11 and the first joint 1 in the radial direction. A first stop groove 203 is provided on the outer wall of the central tube 2. The upper interlock stop 15 is inserted through the first joint 1 in the radial direction, and the inner edge of the upper interlock stop 15 can be clamped in the first stop groove 203. The disconnecting sleeve 11, the outer cylinder 3, the connecting cylinder 4 and the central tube 2 enclose an upper piston cavity. The upper piston 10 is slidably and sealingly connected in the upper piston cavity. The first pressure transmission hole 56 communicates with the upper piston cavity. The upper interlock stops 15 and the first stop grooves 203 are in one-to-one correspondence, and the upper interlock stops 15, the first stop grooves 203 and the disconnecting sleeve shear pins 13 are evenly distributed in a plurality along the radial direction of the central tube 2.

[0102] Please refer to Figure 1 , for the self-balancing packer involved in this application, during use, the first joint 1 is located at the top and is used to connect the setting and releasing tool of the tubing. The second joint 32 is located at the bottom and is used to connect the completed well string that has been run into the well. Multiple self-balancing packers of this application can be set according to requirements to isolate different reservoirs.

[0103] Please refer to Figure 3 , Figures 15a to 15c, the first joint 1 can be machined from 42CrMo / 35CrMo alloy steel. Both ends of the first joint 1 are penetrated. The middle part of the outer surface of the first joint 1 is provided with a fourth external thread. The outer cylinder 3 is sleeved from the bottom upwards to the middle part of the first joint 1 and is threadedly connected to the fourth external thread of the first joint 1. One end of the first joint 1 is provided with a tapered pipe internal thread for connecting with the downhole string. The other end of the first joint 1 is provided with a plurality of interlocking block mounting grooves 101, a plurality of shear pin mounting threaded holes 102 and a plurality of anti-rotation pin mounting threaded holes 103 that are circumferentially distributed and penetrate the inner wall and the outer wall. Each interlocking block mounting groove 101 is used to mount an upper interlocking block 15. Each shear pin mounting threaded hole 102 is used to mount a disconnect sleeve shear pin 13. Each anti-rotation pin mounting threaded hole 103 is used to mount an anti-rotation pin 14. The inner wall at the other end of the first joint 1 is a stepped hole for contacting and transmitting force with the first end of the central tube 2. A sealing groove for clamping the third seal 44 is provided on the inner wall of the first joint 1. The inner wall of the first joint 1 and the outer wall of the central tube 2 are sealed by the third seal 44.

[0104] Among them, please refer to Figure 3 , Figures 7a to 7b , the first block groove 203 on the central tube 2 is annular, and the cross-section of the first block groove 203 is an inverted trapezoid, and the groove wall is inclined. The upper interlocking block 15 is clamped in the interlocking block mounting groove 101 of the first joint 1. The inner edge of the upper interlocking block 15 can be clamped in the first block groove 203 and can slide out from the inclined groove wall of the first block groove 203.

[0105] Please refer to Figures 12a to 12b , the upper interlocking block 15 is machined from 42CrMo / 35CrMo alloy steel. The upper interlocking block 15 is an arc-shaped block. The upper interlocking block 15 can be cut into blocks from 1 whole ring and used in groups. The two sides of the inner edge of the upper interlocking block 15 are provided with 60° inclined surfaces for cooperating with the first block groove 203 of the central tube 2. The inclined surface angle of the upper interlocking block 15 can be not limited to 60°.

[0106] Please refer to Figure 3 , the shear pin mounting threaded hole 102 of the first joint 1 is circumferentially aligned with the anti-rotation long groove 201 of the central tube 2. One end of the disconnect sleeve shear pin 13 is provided with a fifth external thread for connecting to the shear pin mounting threaded hole 102. The other end of the disconnect sleeve shear pin 13 is slidably connected to the anti-rotation long groove 201, and the anti-rotation long groove 201 is used to perform anti-rotation limit on the disconnect sleeve shear pin 13.

[0107] Please refer to Figure 1 and Figure 3A second boss 401 is provided on the inner wall of the connecting tube 4, and the second boss 401 is sealed and connected to the center tube 2. The other end of the outer tube 3 is connected to the connecting tube 4 and is located on the side of the second boss 401 facing the first joint 1; a first clamping platform 302 is provided on the inner wall of the other end of the outer tube 3, and the inner edge of the upper piston 10 is slidingly and sealingly connected to the center tube 2 through the sixth sealing member 47, and the outer edge of the upper piston 10 is slidingly and sealingly connected to the outer tube 3 through the fifth sealing member 46, and the upper piston 10 is located between the disengaging sleeve 11 and the first clamping platform 302, and the first pressure transmission hole 56 is connected between the upper piston 10 and the second boss 401.

[0108] See also Figure 3 The two ends of the connecting tube 4 are respectively provided with internal threads for connecting with the outer tube 3 and the rubber tube sealing assembly, and the middle part of the connecting tube 4 is provided with a second boss 401, and the inner wall of the second boss 401 is connected with the central tube 2 in a sliding and sealing manner through the seventh sealing member 49. The second boss 401 is used to separate the chamber where the upper piston 10 is located and the first balancing chamber where the upper balancing piston 6 is located, and the inner wall of the second boss 401 is provided with a sealing groove for installing the seventh sealing member 49.

[0109] See also Figure 3 , Figure 11 The outer cylinder 3 is made of 42CrMo / 35CrMo alloy steel material, and a first clamping platform 302 is provided in the middle of the inner wall of the outer cylinder 3. The upper balance piston 6 can contact the first clamping platform 302, so that the outer cylinder 3 can transmit the lifting force to the upper balance piston 6 when unsealed; a first internal thread is provided at one end of the inner wall of the outer cylinder 3, which is used to connect with the fourth external thread in the middle of the first joint 1, and the outer cylinder 3 is locked at the threaded connection with the first joint 1 through the second fixing member 43; the outer wall of the other end of the outer cylinder 3 is provided with a first internal thread Six external threads and a sealing groove for installing the fourth seal 48. The outer tube 3 is connected and fixed to the inner wall of the connecting tube 4 through the sixth external thread, and is sealed to the inner wall of the connecting tube 4 through the fourth seal 48. The inner wall of the outer tube 3 is provided with a first tooth portion 301 between the first internal thread and the first clamping platform 302. The first tooth portion 301 is a first serrated locking thread for limiting the retreat of the upper locking cava 12. The first serrated locking thread adopts a climbing angle of 60° and a locking angle of -3° to make the locking more reliable.

[0110] See also Figure 3 , Figure 9a and Figure 9b, the upper locking slip 12 is made of 65Mn or 60Si2Mn spring steel. The upper locking slip 12 is annular with a notch in the circumferential direction for elastic assembly between the disconnect sleeve 11 and the outer cylinder 3. The outer periphery of the upper locking slip 12 is provided with serrated threads 121 with a 60° climbing angle and a -3° locking angle to make the locking more reliable. The serrated threads 121 of the upper locking slip 12 are arranged in the same direction as the inclination of the serrations of the first tooth part 301 of the outer cylinder 3. The upper locking slip 12 can move along the inclination direction of the serrations of the serrated threads 121 relative to the outer cylinder 3 and be clamped without being able to retract.

[0111] Please refer to Figure 3 , Figures 10a to 10c , the disconnect sleeve 11 is made of 42CrMo / 35CrMo alloy steel. The two ends of the disconnect sleeve 11 are through. There is a retaining ring installation groove 111 with a retaining strip on the outer wall at one end of the disconnect sleeve 11. The retaining ring installation groove 111 is integrally milled. The upper locking slip 12 is clamped in the retaining ring installation groove 111, and the retaining strip is placed at the notch of the upper locking slip 12. The middle part of the disconnect sleeve 11 is provided with a plurality of pin threaded holes 112 for installing the disconnect sleeve shear pin 13. Each disconnect sleeve shear pin 13 passes through a pin threaded hole 112 and is connected to a shear pin installation threaded hole 102 of the first joint 1. The inner diameter of the other end of the disconnect sleeve 11 is larger than the inner diameter of one end of the disconnect sleeve 11, providing a moving space for the upper interlocking block 15 after release.

[0112] Please refer to Figure 4 , the rubber cylinder seal assembly includes, from top to bottom, sleeved on the outer core tube 7 in sequence: the upper rubber cylinder seat 5, the main rubber cylinder 18 and the lower rubber cylinder pressing ring 21. Among them, one end of the upper rubber cylinder seat 5 is inserted into the release shear outer cylinder 55. The unsealing assembly includes a plurality of unsealing shear pins 42, and the unsealing shear pins 42 pass through the release shear outer cylinder 55 to the upper rubber cylinder seat 5 in the radial direction in sequence. The middle part of the inner circumference of the main rubber cylinder 18 is hermetically clamped with the outer core tube 7 through the main rubber cylinder support ring 30.

[0113] The inner circumference of the lower rubber cylinder pressing ring 21 contacts the outer core tube 7. The lower rubber cylinder pressing ring 21 is inserted into the locking outer cylinder 25 and is connected to the locking outer cylinder 25 through the first fixing member 38.

[0114] Please refer to Figure 13 , the main rubber cylinder 18 can be made of hydrogenated nitrile or AFLAS material. There is an annular support ring installation groove in the middle of the inner wall of the main rubber cylinder 18. When the main rubber cylinder 18 is compressed, the main rubber cylinder 18 can only start to deform according to the set position to ensure reliable sealing. The main rubber cylinder support ring 30 is adapted to the support ring installation groove, and its cross-section is preferably trapezoidal. The inner wall of the main rubber cylinder support ring 30 is flush with the inner wall of the main rubber cylinder 18 and is hermetically connected to the outer core tube 7 through the second sealing member 45.

[0115] The rubber barrel sealing assembly further includes an upper auxiliary rubber barrel 16, a pair of auxiliary rubber barrel spacer rings 17, a lower auxiliary rubber barrel 19, and a lower auxiliary rubber barrel pushing ring 20; wherein,

[0116] The upper auxiliary rubber barrel 16 and the lower auxiliary rubber barrel 19 are respectively arranged on the upper and lower sides of the main rubber barrel 18, and a pair of auxiliary rubber barrel spacer rings 17 are respectively arranged between the upper auxiliary rubber barrel 16 and the main rubber barrel 18, and between the main rubber barrel 18 and the lower auxiliary rubber barrel 19;

[0117] The upper auxiliary rubber barrel 16 is clamped between the upper rubber barrel seat 5 and an auxiliary rubber barrel spacer ring 17, and the lower auxiliary rubber barrel 19 is clamped between the other auxiliary rubber barrel spacer ring 17 and the lower auxiliary rubber barrel pressing ring 21;

[0118] Both ends of the lower auxiliary rubber barrel pushing ring 20 are respectively inserted into the lower auxiliary rubber barrel 19 and the lower rubber barrel pressing ring 21, and the lower auxiliary rubber barrel pushing ring 20 is threadedly connected to the lower rubber barrel pressing ring 21.

[0119] Since the packer seals by squeezing the rubber barrel, the rubber barrel part is subjected to greater pressure. In this application, the upper auxiliary rubber barrel 16 and the lower auxiliary rubber barrel 19 can improve the pressure-bearing effect. Among them, the hardness of the upper auxiliary rubber barrel 16 and the lower auxiliary rubber barrel 19 can reach 90-95 Shore hardness, and their hardness is higher than that of the main rubber barrel 18, so as to protect the main rubber barrel 18, with good pressure-bearing effect and low requirements for the main rubber barrel 18.

[0120] Please refer to Figure 1 and Figure 5, a piston sleeve lock nut 37 is sleeved on the second joint 32. The rubber cylinder locking assembly includes: an upper setting piston 34, one end of the upper setting piston 34 is slidably and sealingly sleeved on the central tube 2 and forms a pressure chamber with the inner wall of the central tube 2; an inner setting piston sleeve 31, the inner setting piston sleeve 31 is sleeved on the central tube 2 and is located in the pressure chamber, and the outer wall of one end of the inner setting piston sleeve 31 is sealingly connected to the inner wall of the upper setting piston 34; a lower setting piston sleeve 36, one end of the lower setting piston sleeve 36 is sleeved on the upper setting piston 34, and the other end abuts against the piston sleeve lock nut 37; a lower setting piston 33, the lower setting piston 33 is sleeved on the inner setting piston sleeve 31, one end of the lower setting piston 33 is connected to the other end of the upper setting piston 34, and the other end of the lower setting piston 33 is sealingly connected between the lower setting piston sleeve 36 and the inner setting piston sleeve 31; an upper setting piston sleeve 35, one end of the upper setting piston sleeve 35 is sleeved on the outside of the upper setting piston 34, and the other end is inserted into the locking outer cylinder 25; a rubber cylinder setting shear pin 39, the rubber cylinder setting shear pin 39 passes through the upper setting piston sleeve 35 radially into the upper setting piston 34; wherein, a first groove communicating with the second pressure transmission hole 57 is provided on the inner wall of one end of the inner setting piston sleeve 31 close to the upper setting piston 34, the first groove communicates with the pressure chamber, and a second groove communicating with the third pressure transmission hole 58 is provided on the inner wall of the other end of the inner setting piston sleeve 31, and the second groove communicates with the outside of the other end of the lower setting piston 33. The above structure constitutes a setting assembly for setting and locking the rubber cylinder sealing assembly.

[0121] Please refer to Figure 5 , Figure 16a and Figure 16b , the second joint 32 can be processed from 42CrMo / 35CrMo alloy steel material; wherein, a sealing groove for installing the eighth seal 53 is provided at one end of the second joint 32, and the eighth seal 53 is clamped in the sealing groove to achieve the seal between the lower setting piston sleeve 36 and the second joint 32; a seventh external thread is provided in the middle of the second joint 32 for installing the piston sleeve lock nut 37, and a third fixing member 41 is connected to the piston sleeve lock nut 37 radially, and the third fixing member 41 abuts against the second joint 32 to press the piston sleeve lock nut 37 against the second joint 32; a tapered trapezoidal pipe external thread is provided at the other end of the second joint 32 for connecting with the lower pipe string; a second internal thread is provided at one end of the second joint 32 for connecting with the second end of the central tube 2. At the same time, a plurality of threaded holes are also provided at this end of the second joint 32 for installing the fourth fixing member 40, and the fourth fixing member 40 abuts against the central tube 2 to make the connection between the second joint 32 and the central tube 2 more firm.

[0122] Please refer to Figure 5, one end inner wall of the upper setting piston 34 is sealingly connected to the central tube 2 through the ninth seal 51. A seal groove for installing the ninth seal 51 is provided on the inner wall of the upper setting piston 34. The other end is threadedly connected to the lower setting piston 33. The lower setting piston 33 is respectively sealingly connected to the lower setting piston sleeve 36 through the eighth seal 53 and sealingly connected to the inner split sleeve 31 of the setting piston through the tenth seal 52. A plurality of rubber cylinder setting shear pins 39 are provided between the upper setting piston 34 and the upper setting piston sleeve 35. Among them, the pressure introduced through the second pressure transmission hole 57 acts on the lower part of the upper setting piston 34 through the first groove of the inner split sleeve 31 of the setting piston to push the upper setting piston 34 to move upward. The pressure introduced through the third pressure transmission hole 58 acts on the lower part of the lower setting piston 33 through the second groove of the inner split sleeve 31 of the setting piston to push the lower setting piston 33 to move upward. When the pressure is large enough, the upper setting piston 34 and the lower setting piston 33 move upward, causing the rubber cylinder setting shear pins 39 to shear. The upper setting piston 34 and the lower setting piston 33 move upward to generate a thrust on the rubber cylinder seal assembly, causing the lower auxiliary rubber cylinder 19, the main rubber cylinder 18, and the upper auxiliary rubber cylinder 16 to be compressed to achieve sealing. Through the double hydraulic drive mode of the upper setting piston 34 and the lower setting piston 33, the pressure transmission of the packer can be made more stable.

[0123] Please refer to Figure 6 , the rubber cylinder locking assembly further includes:

[0124] The interlocking block support sleeve 8. There is a thread in the middle of the central tube 2. The interlocking block support sleeve 8 is sleeved on the central tube 2 and is threadedly connected to the central tube 2. A third boss is provided on the outer periphery of the interlocking block support sleeve 8. The interlocking block support sleeve extension sleeve 29. The interlocking block support sleeve extension sleeve 29 is sleeved on the outside of the interlocking block support sleeve 8. The interlocking block limiting sleeve 9. The two ends of the interlocking block limiting sleeve 9 are respectively sleeved and connected to the outside of the outer core tube 7 and the interlocking block support sleeve extension sleeve 29, and a second block groove is provided on the interlocking block limiting sleeve 9. The lower interlocking block 22. The lower interlocking block 22 is arranged in the second block groove and is slidably connected to the outer wall of the interlocking block support sleeve 8. The slip joint seat lock nut 24. The slip joint seat lock nut 24 is threadedly connected and sleeved on the outer periphery of the interlocking block limiting sleeve 9. The locking slip joint seat 23. The locking slip joint seat 23 is sleeved radially between the interlocking block limiting sleeve 9 and the locking outer cylinder 25 and is axially connected between the slip joint seat lock nut 24 and the lower interlocking block 22. The lower locking slip joint 26. The lower locking slip joint 26 is sleeved on the outer wall of the locking slip joint seat 23. The anti-setting shear pin seat 27. The anti-setting shear pin seat 27 is arranged radially between the interlocking block limiting sleeve 9 and the locking outer cylinder 25 and is axially arranged on the side of the lower interlocking block 22 away from the locking slip joint seat 23. The anti-setting shear pin 28. The anti-setting shear pin 28 is sequentially inserted into the locking outer cylinder 25 and the anti-setting shear pin seat 27.

[0125] The above structure constitutes an anti-premature setting component for initially sealing and locking the rubber barrel sealing component. Through the linkage and self-locking of the setting component and the rubber barrel sealing component, the downward pressure acting on the rubber barrel after the rubber barrel expands can be decomposed, further improving the annular space pressure-bearing capacity.

[0126] Please refer to Figure 14 , the locking outer cylinder 25 can be machined from 42CrMo / 35CrMo alloy steel material; multiple shear pin threaded holes are provided in the middle of the locking outer cylinder 25 for installing the anti-setting shear pins 28; a shoulder is provided on the inner wall of one end of the locking outer cylinder 25 facing the second joint 32 for connecting with the upper setting piston sleeve 35 and bearing the setting force; a second serrated locking thread is also provided on the inner wall of the locking outer cylinder 25 for restricting the backward movement of the lower locking slip 26; the second serrated locking thread has a climbing angle of 60° and a locking angle of -3°, making the locking more reliable; a threaded mounting hole is provided at the other end of the locking outer cylinder 25 for installing the first fixing member 38, and a fixing member mounting hole corresponding to the first fixing member 38 is provided on the lower rubber barrel pressing ring 21, and the first fixing member 38 passes through the threaded mounting hole and is connected in the fixing member mounting hole. Similar to the structure of the upper locking slip 12, the lower locking slip 26 is also an annular shape with a notch, and the outer wall of the lower locking slip 26 is provided with a serrated external thread, which is adapted and clamped with the second serrated locking thread of the locking outer cylinder 25, and the serrated external thread of the lower locking slip 26 and the second serrated locking thread of the locking outer cylinder 25 are arranged in the same direction of the inclination of the serrations. When the locking outer cylinder 25 moves upward relative to the lower locking slip 26, it can move to be clamped with the lower locking slip 26 and cannot move backward.

[0127] Please refer to Figure 6, the locking slip seat 23 is annular. The lower locking slip 26 is fixed in the annular slip mounting groove on the outer wall of the locking slip seat 23. The groove wall of the slip mounting groove facing away from the rubber barrel sealing assembly is beveled, so that the lower locking slip 26 can slide out of the locking slip seat 23 along this bevel. The interlocking block support sleeve 8 is sleeved on the central tube 2 and is threadedly connected to the outer wall of the central tube 2 at the top. The top of the interlocking block support sleeve 8 is provided with a third boss. The interlocking block limiting sleeve 9 is annular. The inner wall of the top of the interlocking block limiting sleeve 9 is provided with a third internal thread, and the outer wall is provided with an eighth external thread. The third internal thread is threadedly connected to the bottom of the outer core tube 7, so that the top of the interlocking block limiting sleeve 9 is sleeved and connected to the bottom of the outer core tube 7. The eighth external thread at the top of the interlocking block limiting sleeve 9 is fixedly connected to the slip seat lock nut 24. The interlocking block limiting sleeve 9 is provided with a plurality of second block grooves for clamping the lower interlocking block 22. Each lower interlocking block 22 is clamped in a second block groove, and the top of the lower interlocking block 22 protrudes from the outer wall of the interlocking block limiting sleeve 9. The slip seat lock nut 24 and the lower interlocking block 22 fix the locking slip seat 23 therebetween. The anti-setting shear pin seat 27 contacts below the lower interlocking block 22 and is connected to the locking outer cylinder 25 through the anti-setting shear pin 28. When not set, the anti-setting shear pin seat 27 is located above the serrated locking thread on the inner wall of the locking outer cylinder 25. During the setting process, the locking outer cylinder 25 is pushed upward by the upper setting piston sleeve 35. The anti-setting shear pin seat 27 is blocked by the lower interlocking block 22 and does not move, causing the anti-setting shear pin 28 to shear. The locking outer cylinder 25 pushes the lower rubber barrel pressing ring 21 upward to squeeze the main rubber barrel 18, the upper auxiliary rubber barrel 16 and the lower auxiliary rubber barrel 19 for setting. In the fully set state, the locking outer cylinder 25 and the lower locking slip 26 are locked to lock the rubber barrel sealing assembly.

[0128] In this application, each sealing member can be an O-ring, and each fixing member can be a screw. The upper interlocking block 15, the disconnecting sleeve shear pin 13, the lower interlocking block 22, the anti-setting shear pin 28, the rubber barrel setting shear pin 39, and each fixing member are all a plurality of circumferentially evenly distributed. The specific quantity can be set according to the force condition. It is clear that the more the number of shear pins, the greater the pressure-bearing capacity of the packer. In this application, each piston is annular; the locking slip and its corresponding serrated thread both adopt a climbing angle of 60° and a locking angle of -3°, making the locking more reliable.

[0129] The assembly process of the self-balancing packer involved in this application is as follows:

[0130] Please refer to Figure 1, install two third seals 44 into the corresponding seal grooves at the lower part of the first joint 1 respectively, then install the first joint 1 onto the first end of the central tube 2, and make the lower end face of the first joint 1 press against the first boss 202 of the central tube 2. At the same time, align the anti-rotation pin installation threaded hole 103 of the first joint 1 with the anti-rotation long groove 201 of the central tube 2, install two anti-rotation pins 14 into the anti-rotation pin installation threaded holes 103, install six upper interlock blocks 15 into the corresponding interlock block installation grooves 101 below the first joint 1, install the disconnecting sleeve 11 below the first joint 1, align the pin threaded hole 112 on the disconnecting sleeve 11 with the shear pin installation threaded hole 102 on the first joint 1, and then install four disconnecting sleeve shear pins 13 onto the disconnecting sleeve 11.

[0131] Install one upper locking slip 12 into the slip installation groove 111 on the disconnecting sleeve 11, and note that the sawtooth direction of the serrated thread 121 of the upper locking slip 12 faces downward; install two fifth seals 46 and two sixth seals 47 onto the outer wall and inner wall of the upper piston 10 respectively, and then install the upper piston 10 onto the central tube 2, making the upper end face of the upper piston 10 close to the lower end face of the disconnecting sleeve 11. Install the outer cylinder 3 onto the first joint 1 and connect them by thread. Install four second fixing parts 43 into the four threaded holes at the upper part of the outer cylinder 3 and tighten them. Thus, the assembly of the interlock assembly is completed.

[0132] Install two fourth seals 48 into the corresponding seal grooves at the upper part of the outer cylinder 3, install two seventh seals 49 into the corresponding seal grooves of the connecting cylinder 4, and sleeved the connecting cylinder 4 onto the central tube 2 and connect it with the outer cylinder 3 through the internal thread at the upper part.

[0133] Install two seals into the corresponding seal grooves on the upper inner wall of the release shear outer cylinder 55, and then install the release shear outer cylinder 55 onto the outer core tube 7, making its top closely adhere to the upper part of the fourth boss of the outer core tube 7; install two first seals 50 and two second seals 45 into the corresponding seal grooves on the outer wall and inner wall of the upper balance piston 6 respectively, and then install the upper balance piston 6 onto the upper part of the outer core tube 7 and connect and tighten it with the outer core tube 7 by thread. Install this outer core tube 7 onto the central tube 2 and connect and tighten it with the connecting cylinder 4 through the external thread at the top of the release shear outer cylinder 55.

[0134] Install four seals into the corresponding inner and outer seal grooves of the lower balance piston 54 respectively, and then install the lower balance piston 54 onto the upper part of the outer core tube 7, making the lower end face of the top inner wall of the lower balance piston 54 align with the lower part of the fourth boss of the outer core tube 7. Install the upper rubber cylinder seat 5 onto the outer core tube 7, making it closely adhere to the lower end face of the release shear outer cylinder 55. Install six unsealing shear pins 42 into the corresponding threaded holes of the release shear outer cylinder 55. Thus, the assembly of the self-balancing assembly and the unsealing assembly is completed.

[0135] Install the main rubber cylinder support ring 30 into the main rubber cylinder 18, and install one second seal 45 into the main rubber cylinder support ring 30. Install the upper auxiliary rubber cylinder 16, one auxiliary rubber cylinder spacer ring 17, the main rubber cylinder 18, one auxiliary rubber cylinder spacer ring 17, and the lower auxiliary rubber cylinder 19 onto the outer core tube 7 in sequence, making the upper auxiliary rubber cylinder 16 close to the upper rubber cylinder seat 5. Install the lower auxiliary rubber cylinder push ring 20 onto the lower rubber cylinder pressing ring 21 and connect them by threading, then install them onto the outer core tube 7, and push the upper part of the lower auxiliary rubber cylinder push ring 20 into the lower auxiliary rubber cylinder 19.

[0136] Install the interlock block support sleeve 8 onto the middle thread of the central tube 2 and tighten it; first install the lower locking slip 26 into the locking slip seat 23, then install the locking slip seat 23 onto the eighth external thread of the interlock block limit sleeve 9, and install the slip seat lock nut 24 onto the eighth external thread at the top of the interlock block limit sleeve 9; then install the interlock block limit sleeve 9 onto the second external thread at the bottom of the outer core tube 7 and tighten it. Install the lower interlock block 22 into the corresponding second block groove of the interlock block limit sleeve 9, then limit it with the locking slip seat 23, and install it onto the eighth external thread at the top of the interlock block limit sleeve 9 through the slip seat lock nut 24 to lock the locking slip seat 23; install the anti-setting shear pin seat 27 onto the interlock block limit sleeve 9 and make it close to the interlock block 22. Install the interlock block support sleeve extension sleeve 29 onto the lower part of the interlock block limit sleeve 9, install the locking outer cylinder 25 onto the lower rubber cylinder pressing ring 21 and fix it with 4 first fixing parts 38, and then install 6 anti-setting shear pins 28 into the corresponding shear pin threaded holes of the locking outer cylinder 25 and connect them to the anti-setting shear pin seat 27 at the same time. Thus, the assembly of the rubber cylinder locking component is completed.

[0137] Install 2 ninth seals 51 into the corresponding seal grooves of the upper setting piston 34, install the upper setting piston sleeve 35 onto the upper setting piston 34, and fix it with 6 rubber cylinder setting shear pins 39. Then install the upper setting piston sleeve 35 and the upper setting piston 34 together onto the locking outer cylinder 25 and the central tube 2. Install 2 seventh seals 49 onto the inner split sleeve 31 of the setting piston, then install it onto the central tube 2, and push the inner split sleeve 31 of the setting piston into the upper setting piston 34. Install 2 tenth seals 52 and 2 eighth seals 53 into the corresponding seal grooves of the lower setting piston 33 respectively, and then install the lower setting piston 33 onto the central tube 2 to make it threadedly connected to the top of the upper setting piston 34. Install the second joint 32 onto the third external thread at the second end of the central tube 2 and tighten it, and fix it with 4 fourth fixing parts 40; install the lower setting piston sleeve 36 onto the second joint 32 and push it in place, and finally install the lower setting piston sleeve lock nut 37 onto the second joint 32 and fix it with 4 third fixing parts 41.

[0138] Thus, the assembly of the entire packer is completed.

[0139] During the above assembly process, the fixing member can be a set screw, and the sealing member can be an O-ring. The quantities of the various components listed during the assembly process are only exemplary descriptions in the embodiments. The technical solution of the present application is not limited thereto. For example, components such as shear pins can be set to different quantities according to actual requirements such as setting packer pressure requirements.

[0140] The packer of the present application is a retrievable packer, which is used to connect with the tubing to seal the annulus between the oil and gas pipe casings. One or more packers can be used to seal different reservoirs during use. Among them, the second joint 32 at the bottom of the packer is used to connect with the upper female thread of the completion string that has been lowered into the well, and is tightened according to the first preset torque. Then, the setting and releasing tool is connected to the first joint 1 and tightened according to the second preset torque. The central pipe 2 is communicated with the tubing, and the rubber barrel sealing assembly is used to seal the annulus between the tubing and the casing. The tool string connected with one or more self-balancing packers of the present application is lowered into the predetermined setting position in the oil and gas well casing. Different self-balancing packers are used to seal different reservoirs. A wellbore isolation valve or a shear ball seat is provided at the lower part of the string. When the wellbore isolation valve or the shear ball seat is activated, the annulus inside the tubing is closed. By gradually pressurizing the tubing, the setting of the packer can be completed. At the same time, the interlock assemblies of the respective self-balancing packers are gradually opened. After completing various downhole operation tasks, when recovery is required, the string is directly lifted. When the lifting force reaches the releasing force, the interlock assembly of the packer absorbs the lifting force and transmits the lifting force to the releasing assembly, causing the releasing shear pin 42 to shear, so as to achieve retrievability.

[0141] When there are multiple packers in the string lowered into the well, the lifting force needs to act on the releasing shear pins 42 of the releasing assemblies of all the packers. This requires a large lifting force, which may cause the string to rupture and be damaged. However, by using the self-balancing packer of the present application, the interlock assemblies of the respective packers can gradually absorb the lifting force, so that the packers of the entire string can be released step by step from top to bottom in sequence. The entire string can be retrieved under the condition of a relatively small lifting force.

[0142] Taking the lower part of the string as the bottom and the upper part of the string as the top, the specific working process of the self-balancing packer involved in the present application is as follows:

[0143] Please refer to Figure 17a and Figure 17b , when starting to pressurize the tubing, the pressure is transmitted to the lower part of the upper setting piston 34 through the second pressure transmission hole 57 of the central pipe 2, and is transmitted to the lower part of the lower setting piston 33 through the third pressure transmission hole 58. The upper setting piston 34 and the lower setting piston 33 generate an upward force under the action of the force, and this upward force is transmitted to the upper setting piston sleeve 35 and further transmitted to the locking outer cylinder 25.

[0144] Since the shear force of the anti-setting shear pin 28 is smaller than the shear force of the rubber tube setting shear pin 39, when the pressure reaches the predetermined first stage pressure (the first stage pressure is generally set to about 11-12MPa), the anti-setting shear pin 28 is sheared first, and the locking outer cylinder 25 is pushed to act on the rubber tube sealing assembly, and the upper auxiliary rubber tube 16, the main rubber tube 18 and the lower auxiliary rubber tube 19 are compressed and deformed by extrusion to achieve preliminary setting. In this state, the rubber tube sealing assembly is almost in contact with, partially in contact with, or even completely in contact with the inner wall of the wellbore outside the oil pipe.

[0145] See also Figure 18 , continue to pressurize until the pressure reaches the predetermined second stage pressure (the second stage pressure is generally set to about 15-16MPa), the pressure will be transmitted to the bottom of the upper piston 10 through the first pressure transmission hole 56 of the central tube 2, the upper piston 10 moves upward and pushes the disjointed sleeve 11 to move upward, under this pressure, the disjointed sleeve shear pin 13 is sheared, the disjointed sleeve 11 moves upward, and is locked by the upper locking slip 12 and the serrated thread on the inner wall of the outer tube 3 and cannot retreat, the upper interlocking stopper 15 slides out of the first stopper groove 203 of the central tube 2 due to the friction force, so that the first joint 1 can move upward relative to the central tube 2, reserving space for the release of the unsealing component.

[0146] See also Figure 19 , continue to increase the pressure in the tubing to the predetermined third stage pressure (the third stage pressure is generally set to about 18-19MPa). Under this pressure, the upper sealing piston 34 and the lower sealing piston 33 are forced to move upward, so that the rubber cylinder sealing shear pin 39 is sheared, and the upper sealing piston 34 moves up to abut against the interlocking block support sleeve 8 and the interlocking block support sleeve extension sleeve 29, and transmits the pressure to the interlocking block limit sleeve 9, and squeezes the lower rubber cylinder pressure ring 21, so that the lower auxiliary rubber cylinder 19, the main rubber cylinder 18 and the upper auxiliary rubber cylinder 16 are completely squeezed. At this time, the lower locking slip 26 and the locking outer cylinder 25 are locked and stuck, and the rubber cylinder sealing assembly is locked. At this point, the packer is completely sealed, and the unsealing assembly is released to wait for unsealing. And the unsealing assemblies of the respective balanced packers of the entire pipe string are released step by step. At this time, various downhole operations such as fracturing and water injection can be carried out.

[0147] During the operation, since the pressures of various reservoirs may be different, there will be an annular pressure difference above and below the self-balancing packer.

[0148] See also Figure 2 When the self-balancing packer is subjected to the upper annulus pressure difference, the pressure is transmitted to the upper balancing piston 6 through the first balancing hole 59 and to the lower balancing piston 54 through the second balancing hole 60, so that the upper balancing piston 6 and the lower balancing piston 54 move upward, driving the outer core tube 7 to move upward, thereby generating downward pressure on the rubber sleeve sealing assembly, so that the upper and lower pressures acting on the rubber sleeve sealing assembly are balanced.

[0149] Please refer to Figure 2 and Figure 6 When the self-balancing packer bears the differential pressure in the lower annulus, the pressure can enter the space between the outer core tube 7 and the central tube 2 through the third balance hole 63, and is transmitted to the fourth pressure transmission hole 61 and the fifth pressure transmission hole 62 through the space between them. The pressure makes the upper balance piston 6 move downward through the fourth pressure transmission hole 61, and makes the lower balance piston 54 move downward through the fifth pressure transmission hole 62, so as to generate a downward pressure on the rubber barrel sealing assembly and balance the upper and lower pressures acting on the rubber barrel sealing assembly.

[0150] Through the self-balancing packer of the present application, the upper and lower pressures acting on the rubber barrel of the rubber barrel sealing assembly can be only a very small 10 - 20 kN, greatly shearing the pressure-bearing burden of the rubber barrel sealing assembly to ensure the sealing effect. The self-balancing packer of the present application can increase the pressure-bearing capacity by 2 - 3 times and can withstand a pressure of up to 70 Mpa, greatly reducing the pressure on the rubber barrel locking assembly.

[0151] Please refer to Figure 20 When it is necessary to release and recover, the pipe string is lifted by the releasing tool. Since the rubber barrel is tightly attached to the inner wall of the casing after expansion, a frictional resistance will be generated between the rubber barrel and the casing wall, making the expanded rubber barrel and the outer core tube 7 unable to move temporarily. The lifting force passes through the first joint 1 of the packer, drives the outer cylinder 3, and drives the connecting cylinder 4 through the outer cylinder 3, generating an upward acting force on the releasing shear pin 42. When the shear force is reached (generally 30 - 40 kN), the releasing shear pin 42 is sheared. The first joint 1 pushes the upper piston 10 through the outer cylinder 3, and the upper piston 10 drives the central tube 2 to move upward by pushing the first boss 202 of the central tube 2. The interlocking block 15 slides along the central tube 2, and the rubber barrel sealing assembly is no longer pressurized, so that the rubber barrel locking assembly is released.

[0152] Please refer to Figure 21 When continuing to lift, the first joint 1 acts on the first boss 202 through the outer cylinder 3 and the upper piston 10, so that the central tube 2 moves upward. The central tube 2 drives the interlocking block support sleeve 8 to move upward. Due to the resistance of the rubber barrel sealing assembly, the outer core tube 7 cannot move temporarily. The upward movement of the interlocking block support sleeve 8 causes the lower interlocking block 22 to slide off the third boss at the top of the interlocking block support sleeve 8, so that it no longer clamps and locks the slip seat 23, and the rubber barrel locking assembly is completely released and no longer presses the rubber barrel sealing assembly. Please refer to Figure 22 At this time, the lower auxiliary rubber barrel 19, the main rubber barrel 18 and the upper auxiliary rubber barrel 16 return to their original positions under the action of the resilience force, and push the locking outer cylinder 25 downward. The self-balancing packer located above is released and can be lifted with the tubing string. The lifting force continues to be transmitted to the next self-balancing packer for step-by-step release. After all the self-balancing packers are released, the entire pipe string can be taken out of the wellbore casing.

[0153] The self-balancing packer involved in this application improves the pressure-bearing difference capacity between the upper and lower annuli of the packer through the self-balancing component; enables each packer to be gradually unsealed through the action of the interlock component, thereby realizing the independent unsealing of each packer; through the interlock component, the step-by-step actions of setting and gradually unsealing can be realized; the rubber barrel locking component adopts the linkage self-locking of the setting component and the component to prevent premature setting, so that the downward pressure acting on the rubber barrel after the rubber barrel expands can be decomposed, further improving the annulus pressure-bearing capacity; this application adopts the structural design of an inner split sleeve of the piston to achieve the function of a one-way two-stage hydraulic cylinder with a simple structure; through the component to prevent premature setting, the accidental setting of the packer can be effectively prevented; each stage of the hydraulic cylinder is started separately according to the stepped pressure, improving the controllability of operation safety; this application has a simple structure, low processing difficulty, and reduces the tool cost.

[0154] It can be understood that the relevant features in the above devices can be referred to each other. In addition, the "first", "second", etc. in the above embodiments are used to distinguish each embodiment, and do not represent the advantages and disadvantages of each embodiment.

[0155] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known structures and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0156] As described above, it is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed in this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claimed rights.

Claims

1. A self-balancing packer, characterized in that, Comprising: Central tube; Outer core tube, the outer core tube is sleeved on the middle part of the central tube, and a self-balancing assembly, a rubber barrel sealing assembly and a rubber barrel locking assembly are sequentially sleeved on the outside of the outer core tube from top to bottom; Outer tube assembly, the outer tube assembly is hermetically sleeved on the central tube and at least part of the outer core tube, and forms a balance cavity with the central tube, and the self-balancing assembly is arranged in the balance cavity; Wherein, The outer tube assembly is provided with at least a pair of balance holes that communicate the outside and the balance cavity in the radial direction, and at least a pair of balance holes are respectively located above and below the rubber barrel sealing assembly, and the pressure outside the outer tube assembly can enter the balance cavity through at least a pair of the balance holes respectively, so that the self-balancing assembly absorbs the pressure; The self-balancing assembly includes an upper balance piston and a lower balance piston, and the outer tube assembly includes: Connection cylinder, the connection cylinder is hermetically sleeved on the central tube and at least part of the outer core tube; Release shear outer cylinder, the release shear outer cylinder is sleeved on the outer core tube, and is located between the connection cylinder and the rubber barrel sealing assembly, and is hermetically connected to the outer core tube; The connection cylinder, the central tube, the outer core tube and the release shear outer cylinder form a first balance cavity, the upper balance piston is slidably and hermetically connected in the first balance cavity, and is hermetically connected to the top end of the outer core tube; The release shear outer cylinder, the outer core tube and the rubber barrel sealing assembly form a second balance cavity, and the lower balance piston is slidably and hermetically connected in the second balance cavity; Locking outer cylinder, the locking outer cylinder is sleeved on the outside of the rubber barrel locking assembly, and is connected to the rubber barrel sealing assembly; A fifth pressure transmission hole is provided in the middle part of the outer core tube for communicating with the second balance cavity to transmit pressure to the lower balance piston.

2. The self-balancing packer according to claim 1, wherein The connection cylinder is provided with a first balance hole that communicates with its outside and the first balance cavity in the radial direction, and the first balance hole is located between one end of the upper balance piston and the release shear outer cylinder; The release shear outer cylinder is provided with a second balance hole that is arranged in the radial direction and communicates with its outside and the second balance cavity, and the second balance hole is located between one end of the lower balance piston and the rubber barrel sealing assembly; The locking outer cylinder is provided with a third balance hole, one end of the third balance hole communicates with the outside of the locking outer cylinder, the other end communicates with the gap between the outer core tube and the central tube, and respectively communicates with the first balance cavity where the other end of the upper balance piston is located and the second balance cavity where the other end of the lower balance piston is located.

3. The self-balancing packer according to claim 2, wherein, It further includes a first joint, a second joint, an outer cylinder, and an interlock assembly and an unlocking assembly sleeved on the outside of the central tube. The central tube includes a first end and a second end, and the central tube is sequentially provided with a first pressure transmission hole, a second pressure transmission hole and a third pressure transmission hole that penetrate through in the radial direction from the first end to the second end; The first joint is connected to the first end of the central tube, and the second joint is connected to the second end of the central tube; The outer cylinder is sleeved outside the interlocking assembly, and both ends of the outer cylinder are respectively connected to the first joint and the connecting cylinder; The unsealing assembly is arranged between the first joint and the rubber barrel sealing assembly, and the interlocking assembly is arranged between the first joint and the unsealing assembly.

4. The self-balancing packer according to claim 3, wherein One end of the outer cylinder is sleeved on the other end of the first joint and is threadedly connected to the first joint. The other end of the outer cylinder is inserted into one end of the connecting cylinder and is hermetically connected to the connecting cylinder; The interlocking assembly includes an upper locking slip, a disconnecting sleeve, a disconnecting sleeve shear pin, an upper interlocking stop block, and an upper piston. Among them, A first boss is provided on the outer wall of the central tube. The other end of the first joint can contact the upper surface of the first boss in a direction parallel to the axial direction and form a sliding gap with the outer cylinder. The disconnecting sleeve is slidably connected in the sliding gap; A first tooth portion is provided on the inner wall of the outer cylinder. The upper locking slip is connected to the outer periphery of the disconnecting sleeve and can be engaged and clamped with the first tooth portion; The disconnecting sleeve shear pin is sequentially inserted through the disconnecting sleeve and the first joint in the radial direction; A first stop block groove is provided on the outer wall of the central tube. The upper interlocking stop block is inserted through the first joint in the radial direction, and the inner edge of the upper interlocking stop block can be clamped in the first stop block groove. The disconnecting sleeve, the outer cylinder, the connecting cylinder, and the central tube enclose an upper piston cavity. The upper piston is slidably and hermetically connected in the upper piston cavity, and the first pressure transmission hole communicates with the upper piston cavity.

5. The self-balancing packer according to claim 4, wherein, The interlocking assembly further includes an anti-rotation pin shaft. A longitudinally open anti-rotation long groove parallel to the axial direction is provided on the outer wall of the central tube. The opening of the anti-rotation long groove faces the first joint. The anti-rotation pin shaft passes through the first joint in the radial direction and is slidably connected in the anti-rotation long groove.

6. The self-balancing packer according to claim 4, wherein A second boss is provided on the inner wall of the connecting cylinder. The second boss is hermetically connected to the central tube. The other end of the outer cylinder is connected to the connecting cylinder on the side where the second boss faces the first joint; A first clamping table is provided on the inner wall of the other end of the outer cylinder. The inner edge of the upper piston is slidably and hermetically connected to the central tube, and the outer edge of the upper piston is slidably and hermetically connected to the outer cylinder. The upper piston is located between the disconnecting sleeve and the first clamping table, and the first pressure transmission hole communicates between the upper piston and the second boss.

7. The self-balancing packer according to claim 3, wherein The rubber barrel sealing assembly includes, from top to bottom in sequence, sleeved on the outer core tube: an upper rubber barrel seat, a main rubber barrel, and a lower rubber barrel pressing ring; Among them, one end of the upper rubber barrel seat is inserted into the release shear outer cylinder. The unsealing assembly includes a release shear pin. The release shear pin sequentially passes through the release shear outer cylinder into the upper rubber barrel seat in the radial direction; The middle part of the inner circumference of the main rubber barrel is hermetically clamped with the outer core tube through a main rubber barrel support ring; The inner circumference of the lower rubber barrel pressing ring contacts the outer core tube. The lower rubber barrel pressing ring is inserted into the locking outer cylinder and is connected to the locking outer cylinder through a first fixing member.

8. The self-balancing packer according to claim 7, wherein The rubber barrel sealing assembly further includes an upper auxiliary rubber barrel, a pair of auxiliary rubber barrel spacer rings, a lower auxiliary rubber barrel, and a lower auxiliary rubber barrel pushing ring. Among them, The upper auxiliary rubber cylinder and the lower auxiliary rubber cylinder are respectively arranged on the upper and lower sides of the main rubber cylinder, and a pair of auxiliary rubber cylinder spacer rings are respectively arranged between the upper auxiliary rubber cylinder and the main rubber cylinder, and between the main rubber cylinder and the lower auxiliary rubber cylinder; The upper auxiliary rubber cylinder is clamped between the upper rubber cylinder seat and one of the auxiliary rubber cylinder spacer rings, and the lower auxiliary rubber cylinder is clamped between the other auxiliary rubber cylinder spacer ring and the lower auxiliary rubber cylinder pressing ring; Both ends of the lower auxiliary rubber cylinder pushing ring are respectively inserted into the lower auxiliary rubber cylinder and the lower rubber cylinder pressing ring, and the lower auxiliary rubber cylinder pushing ring is threadedly connected to the lower rubber cylinder pressing ring.

9. The self-balancing packer according to claim 7, wherein, A piston sleeve lock nut is sleeved on the second joint, and the rubber cylinder locking assembly includes: An upper setting piston, one end of the upper setting piston is slidably and sealingly sleeved on the central tube, and a pressure chamber is formed with the inner wall of the central tube; An inner sleeve of the setting piston is sleeved on the central tube and is located in the pressure chamber. One end outer wall of the inner sleeve of the setting piston is sealingly connected to the inner wall of the upper setting piston; A lower setting piston sleeve, one end of the lower setting piston sleeve is sleeved on the upper setting piston, and the other end abuts against the piston sleeve lock nut; A lower setting piston, the lower setting piston is sleeved on the inner sleeve of the setting piston. One end of the lower setting piston is connected to the other end of the upper setting piston, and the other end of the lower setting piston is sealingly connected between the lower setting piston sleeve and the inner sleeve of the setting piston; An upper setting piston sleeve, one end of the upper setting piston sleeve is sleeved on the outside of the upper setting piston, and the other end is inserted into the locking outer cylinder; A rubber cylinder setting shear pin, the rubber cylinder setting shear pin radially penetrates through the upper setting piston sleeve into the upper setting piston; wherein, A first groove communicated with the second pressure transmission hole is arranged on the inner wall of one end of the inner sleeve of the setting piston close to the upper setting piston. The first groove is communicated with the pressure chamber. A second groove communicated with the third pressure transmission hole is arranged on the inner wall of the other end of the inner sleeve of the setting piston. The second groove is communicated with the outside of the other end of the lower setting piston.

10. The self-balancing packer according to claim 9, wherein, The rubber cylinder locking assembly further includes: An interlock block support sleeve, the interlock block support sleeve is sleeved on the central tube and is threadedly connected to the central tube. A third boss is arranged on the outer periphery of the interlock block support sleeve; An extended sleeve of the interlock block support sleeve, the extended sleeve of the interlock block support sleeve is sleeved on the outside of the interlock block support sleeve; An interlock block limiting sleeve, both ends of the interlock block limiting sleeve are respectively sleeved and connected to the outside of the outer core tube and the extended sleeve of the interlock block support sleeve, and a second block groove is arranged on the interlock block support sleeve; A lower interlock block, the lower interlock block is arranged in the second block groove and is slidably connected to the outer wall of the interlock block support sleeve; A slip seat lock nut, the slip seat lock nut is threadedly connected and sleeved on the outer periphery of the interlock block limiting sleeve; A locking slip seat, the locking slip seat is radially sleeved between the interlock block limiting sleeve and the locking outer cylinder, and is axially connected between the slip seat lock nut and the lower interlock block; Lower locking slips, the lower locking slips are sleeved on the outer wall of the locking slips seat; Anti-setting shear pin seat, the anti-setting shear pin seat is arranged radially between the interlocking block limiting sleeve and the locking outer cylinder, and axially arranged on the side of the lower interlocking block away from the locking slips seat; Anti-setting shear pin, the anti-setting shear pin is sequentially inserted into the locking outer cylinder and the anti-setting shear pin seat.

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