Bridge plug for abandoned well operation

Abstract

The bridge plug comprises at least two setting assemblies and a locking assembly, each setting assembly comprises a mandrel, each mandrel is provided with a channel, and every two adjacent mandrels are connected in an inserted mode through the corresponding channel; each locking assembly is arranged between every two adjacent core shafts and comprises a matching part arranged on one core shaft and a locking part arranged on the other core shaft, and the locking parts are movably arranged in the directions close to and away from the matching parts. The locking state is close to the matching part and is matched with the matching part, and the unlocking state is far away from the matching part and is released from the matching part; wherein the setting assembly is used for sealing a shaft, and when the setting assembly seals the shaft, the locking part is in the unlocking state. The multiple setting assemblies are sequentially connected in series and put down into the shaft, continuous setting can be conducted on the shaft, operation is easy, the operation time is short, and the operation cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field exploitation operations, and in particular to a bridge plug for abandoned well operations. Background Art

[0002] In permanent well abandonment operations, the operation method is to use a drill bit to send a drillable bridge plug tool to the specified position, hydraulically seal the bridge plug tool, lift the drill bit and then start cementing operations. After the cementing operation is completed, the bridge plug setting tool is removed and maintenance is carried out before the next level bridge plug is lowered again and the above operations are repeated many times to achieve multiple cement plug operations.

[0003] Patent CN108868675A discloses a bridge plug hydraulic fluid sealing tool, including an upper joint, a shear pin a, a front drive device, a lower center rod, a push tube connecting sleeve, a sealing plug, a push ring, a composite ring, a shear pin b, a ball seat, and a conversion joint. The upper joint is connected to the front drive device through the shear pin a, and the push tube connecting sleeve and the lower center rod are placed on the front drive device. A accommodating sealing chamber for accommodating liquid is enclosed between the front drive device, the lower center rod and the push tube connecting sleeve. The push ring and the push tube connecting sleeve can move backward, and after movement, an annular sealing chamber will be formed between the front drive device and the lower center rod. The composite ring is connected to the lower center rod through the shear pin b, the sealing plug is arranged on the front drive device, the conversion joint is connected to the lower center rod, and the ball seat is arranged in the inner cavity of the conversion joint.

[0004] However, the above-mentioned prior art can only realize a single cement plug operation when a single tool enters the well. When multiple cement plugs are required for the entire wellbore, continuous operation cannot be realized, resulting in long operation time and high operation cost. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and propose a bridge plug for abandoned well operations, so as to solve the technical problem that in the prior art, only a single cement plug operation can be achieved when a single tool enters the well, and continuous operation cannot be achieved when multiple cement plugs are required for the entire wellbore, resulting in long operation time and high operation cost.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides a bridge plug for well abandonment operation, comprising: At least two setting assemblies, each of which comprises a core shaft, each of which is provided with a channel, and two adjacent core shafts are plug-connected through the channel; A locking assembly is provided between two adjacent spindles, the locking assembly comprising a matching portion provided on one of the spindles and a locking portion provided on the other spindle, the locking portion being movably arranged in a direction approaching and moving away from the matching portion, so as to have a locking state in which the matching portion is matched with the matching portion when the matching portion is approached, and an unlocking state in which the matching portion is released when the matching portion is moved away from the matching portion; Wherein, the sealing assembly is used to seal the wellbore, and when the sealing assembly seals the wellbore, the locking portion is in the unlocked state.

[0007] In some embodiments, a slot is provided on the outer periphery of one end of the mandrel, and the slot constitutes the matching portion; The locking portion is movably mounted on the side wall of the other end of the core shaft along the radial direction of the core shaft.

[0008] In some embodiments, the locking assembly further comprises a locking sleeve, which is axially movably sleeved on the outer periphery of the core shaft and arranged corresponding to the locking portion, and the locking sleeve is connected to the locking portion so that when the locking sleeve moves axially, it drives the locking portion to move radially.

[0009] In some embodiments, the inner side of the locking sleeve is wedge-fitted with the locking portion.

[0010] In some embodiments, the length of the slot along the axial direction is greater than the length of the locking portion along the axial direction, so that in the locked state, two adjacent core shafts can be movably arranged; A boss is provided on the outer periphery of one end of the core shaft close to the slot, and the boss abuts against the end of the locking sleeve, so that the locking sleeve is driven to move in a direction away from the locking portion through the boss.

[0011] In some embodiments, the outer periphery of the mandrel is provided with a limiting groove; The locking assembly further comprises a limiting member, which is movably arranged on the locking sleeve in a radial direction, so that when the locking sleeve drives the locking portion to be in the locking state, the limiting member extends into the limiting groove to limit the movement of the locking sleeve.

[0012] In some embodiments, the sealing assembly includes a sealing component and a sealing component, which are axially arranged in sequence on the outer periphery of the core shaft, and the sealing component is axially movably arranged to squeeze the sealing component when the sealing component moves toward the sealing component, so that the sealing component is in sealing contact with the wellbore.

[0013] In some embodiments, the locking assembly further includes a release cylinder, which is sleeved on the outer periphery of the locking sleeve and arranged corresponding to the limiting member, the release cylinder is wedge-fitted with the limiting member, and one end of the release cylinder is connected to the sealing component.

[0014] In some embodiments, one end of the release tube is threadedly connected to the setting component.

[0015] In some embodiments, the bridge plug for well abandonment operations further includes a joint assembly, the joint assembly is connected to a sealing assembly, and a locking assembly is provided between the joint assembly and the sealing assembly.

[0016] Compared with the prior art, the bridge plug for abandoned well operation provided by the present invention, each of the sealing assemblies can seal the wellbore, so as to achieve the purpose of blocking the wellbore. When it is necessary to seal the entire wellbore continuously, the core shafts of the plurality of sealing assemblies are first plugged and connected in sequence along the axial direction, and between two adjacent core shafts, the locking portion moves toward the matching portion so that the locking portion and the matching portion are matched in the locking state to achieve the connection and locking of the two adjacent core shafts. The plurality of core shafts are connected and locked in sequence according to the above method, and then the plurality of sealing assemblies are lowered into the wellbore. When the sealing assembly at the lowest end is lowered to the set position, the sealing assembly abuts against the side wall of the wellbore to achieve sealing. At the same time, the sealing assembly at the lowest end The locking portion in the sealing assembly moves in the direction away from the matching portion in the sealing assembly above it and is in the unlocked state. At this time, the locking portion and the matching portion are released, and the sealing assembly at the lower end is separated from the sealing assembly above, so that the seal is released. After the release is completed, the cement plugging operation is carried out on the spot. After the operation is completed, the remaining sealing assemblies are continued to be lifted until they are moved to another set position, and the sealing and release are carried out again. The above steps are repeated to perform the sealing, release and cement plugging operations until the operations of all the sealing assemblies are completed and the single-well continuous abandonment operation is completed. The present application can continuously seal the wellbore by serially lowering multiple sealing assemblies into the wellbore in sequence. The operation is simple, the operation time is short, and the operation cost is low.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows with reference to the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a bridge plug for well abandonment operation provided by the present invention; Figure 2 yes Figure 1 Partial schematic diagram of the middle joint assembly and the setting assembly; Figure 3 yes Figure 1 A partial schematic diagram of the middle joint assembly and the locking assembly; Figure 4 yes Figure 1A partial cross-sectional view of the middle setting component; Figure 5 yes Figure 1 Partial cross-sectional view of the middle seal.

[0019] Description of reference numerals: 1-sealing assembly, 11-core shaft, 111-channel, 112-pressure transmission hole, 12-sealing component, 121-sealing cylinder, 1211-stopper, 1212-hydraulic chamber, 122-ball seat, 123-sealing ball, 124-shear ring, 13-seal, 131-upper slip, 132-upper cone, 133-rubber cylinder, 134-lower cone, 135-lower slip, 14-end ring, 2-locking assembly, 21-locking part, 22-slot, 23-locking sleeve, 24-limiting member, 25-release cylinder, 3-joint assembly. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In order to solve the technical problem that in the prior art, only a single cement plug operation can be performed when a single tool is entered into the well, and continuous operation cannot be performed when multiple cement plugs are required for the entire wellbore, resulting in long operation time and high operation cost, the present invention provides a bridge plug for abandoned well operation, which can continuously seal the wellbore by serially lowering multiple sealing assemblies into the wellbore, with simple operation, short operation time and low operation cost.

[0022] See also Figure 1 , Figure 1 It is a schematic diagram of the structure of a bridge plug for well abandonment operation in one embodiment of the present invention.

[0023] The present invention provides a bridge plug for well abandonment operation, comprising at least two sealing assemblies 1 and locking assemblies 2, wherein the sealing assembly 1 comprises a core shaft 11, wherein the core shaft 11 is provided with a channel 111, and two adjacent core shafts 11 are plug-connected through the channel 111; the locking assembly 2 is arranged between two adjacent core shafts 11, wherein the locking assembly 2 comprises a mating portion arranged on one of the core shafts 11 and a locking portion 21 arranged on the other core shaft 11, wherein the locking portion 21 is movably arranged in a direction approaching and moving away from the mating portion, so as to have a locking state in which the sealing assembly 1 is mated with the mating portion and an unlocking state in which the sealing assembly 1 is released from mating with the mating portion. wherein the sealing assembly 1 is used for sealing a wellbore, and when the sealing assembly 1 seals the wellbore, the locking portion 21 is in the unlocking state.

[0024] In this example, see Figures 1 to 3 Each of the sealing assemblies 1 can seal the wellbore, thereby achieving the purpose of plugging the wellbore. When the entire wellbore needs to be sealed continuously, the core shafts 11 of the plurality of sealing assemblies 1 are first plugged and connected in sequence along the axial direction. Between two adjacent core shafts 11, the locking portion 21 moves toward the matching portion, so that the locking portion 21 cooperates with the matching portion in the locking state to achieve the connection and locking of the two adjacent core shafts 11. The plurality of core shafts 11 are connected and locked in sequence according to the above method, and then the plurality of sealing assemblies 1 are lowered into the wellbore. When the sealing assembly 1 at the lowermost end is lowered to the set position, the sealing assembly 1 abuts against the side wall of the wellbore to achieve sealing. At the same time, the sealing assembly 1 at the lowermost end The locking portion 21 moves toward the direction away from the matching portion in the sealing assembly 1 located above it and is in the unlocked state. At this time, the locking portion 21 is released from the matching portion, and the lowermost sealing assembly 1 is separated from the upper sealing assembly 1 to achieve release. After the release is completed, the cement plugging operation is carried out on the spot. After the operation is completed, the remaining sealing assemblies 1 are continued to be lifted until they are moved to another set position, and the sealing and release are carried out again. The above steps are repeated to perform the sealing, release, and cement plugging operations until the operation of all the sealing assemblies 1 is completed, and the single-well continuous abandonment operation is completed. The present application can continuously seal the wellbore by serially lowering multiple sealing assemblies 1 into the wellbore in sequence. The operation is simple, the operation time is short, and the operation cost is low.

[0025] In this example, see Figure 3 A slot 22 is provided on the outer periphery of one end of the core shaft 11 , and the slot 22 constitutes the matching portion; the locking portion 21 is movably installed on the side wall of the other end of the core shaft 11 along the radial direction of the core shaft 11 .

[0026] Specifically, the core shaft 11 has a first end and a second end that are relatively arranged. The outer diameter of the first end is smaller than the inner diameter of the channel 111 at the second end, so that the first end can be inserted into the channel 111 of the second end of the adjacent core shaft 11 to achieve the plug-in connection of the two core shafts 11. The card slot 22 is arranged on the outer side wall of the first end, and the side wall of the second end is provided with a first mounting hole connected to the channel 111. The first mounting hole is adapted to the locking portion 21, and the locking portion 21 is slidably installed in the first mounting hole. After the two core shafts 11 are plug-in connected, the lock The stop portion 21 corresponds to the slot 22 of the adjacent core shaft 11. When the locking portion 21 is driven to move toward the slot 22, the locking portion 21 can extend into the slot 22. The slot 22 limits the locking portion 21, thereby realizing the axial and circumferential limitation of the core shaft 11 and realizing the series connection of multiple sealing assemblies 1. When the sealing assembly 1 is lowered to the set position, the locking portion 21 is driven to move toward the direction away from the slot 22, so that the locking portion 21 exits the slot 22, thereby realizing the separation of the two adjacent core shafts 11 and achieving release.

[0027] In this example, see Figure 3 Since the locking part 21 moves in the radial direction, and the device is located in the wellbore, the wellbore has a small diameter, resulting in a relatively narrow space inside the wellbore, which is not conducive to driving the locking part 21. Therefore, the locking assembly 2 also includes a locking sleeve 23, which is axially movable and sleeved on the outer periphery of the core shaft 11 and corresponding to the locking part 21. The locking sleeve 23 is connected to the locking part 21 so that when the locking sleeve 23 moves axially, the locking part 21 is driven to move radially. The locking sleeve 23 drives the locking part 21 by driving the locking part 21 axially, and the locking sleeve 23 is driven axially instead of radially driving the locking part 21. The locking sleeve 23 then drives the locking part 21, which is simple to operate and solves the problem that the space inside the wellbore is relatively narrow and not conducive to driving the locking part 21.

[0028] In this example, see Figure 3 The inner side of the locking sleeve 23 is wedge-fitted with the locking portion 21 .

[0029] Specifically, the inner diameter of the locking sleeve 23 is gradually reduced from top to bottom. When the locking sleeve 23 moves downward, the distance between the inner side of the locking sleeve 23 and the locking portion 21 increases, thereby reserving a space for the locking portion 21 to withdraw from the slot 22, so that the locking portion 21 can withdraw from the slot 22. When the locking sleeve 23 moves upward, the inner side of the locking sleeve 23 abuts against the locking portion 21 and gradually pushes the locking portion 21 into the slot 22 to achieve locking cooperation.

[0030] Furthermore, the inner side surface of the locking sleeve 23 is divided into a first section, a second section and a third section in the radial direction, the first section, the second section and the third section are sequentially connected from top to bottom, the first section and the third section are straight sections, the diameter of the first section is larger than the diameter of the third section, the second section is a gradient section, the diameter of the second section gradually decreases from top to bottom, when the first section corresponds to the locking portion 21, the locking portion 21 can withdraw from the slot 22, when the third section abuts against the locking portion 21, the locking portion 21 can be pressed tightly into the slot 22, the second section is wedge-shaped with the locking portion 21, and plays a guiding role.

[0031] In this example, see Figure 3 In order to facilitate driving the locking sleeve 23 to move downward, the axial length of the slot 22 is greater than the axial length of the locking portion 21, so that in the locked state, the two adjacent core shafts 11 can be movably arranged; a boss is provided on the outer periphery of one end of the core shaft 11 close to the slot 22, and the boss abuts against the end of the locking sleeve 23, so that the locking sleeve 23 is driven to move in a direction away from the locking portion 21 through the boss.

[0032] Specifically, the boss is provided on the outer periphery of the core shaft 11 near one end, the boss is arranged in an annular shape, and its diameter is larger than the outer diameter of the locking sleeve 23, the boss and the slot 22 are arranged at intervals from top to bottom, and the length of the slot 22 along the axial direction is larger than the length of the locking portion 21 along the axial direction, so that the two adjacent core shafts 11 can move slightly in the axial direction even in the locked state. In the initial state, the locking portion 21 corresponds to the lower section of the slot 22, and the boss abuts against the end of the locking sleeve 23. When the sealing assembly 1 at the lower end is sealed, At this time, the sealing assembly 1 at the lowest end is relatively fixed against the wellbore, and the core shaft 11 located above the sealing assembly 1 at the lowest end moves downward, thereby pushing the locking sleeve 23 downward through the boss, so that the first section corresponds to the locking portion 21, leaving space for the locking portion 21 to move outward, and then the core shaft 11 is pulled upward to force the locking portion 21 to withdraw from the slot 22, thereby completing the unlocking, and utilizing the relative movement of the two adjacent core shafts 11 to drive the locking sleeve 23, without the need to set up an additional driving member, with a simple structure and convenient operation.

[0033] In this example, see Figure 3After the plurality of sealing assemblies 1 are connected in series in sequence, in order to put the locking portion 21 in the locked state, the third section of the locking sleeve 23 needs to abut against the locking portion 21. Since the entire device needs to be vertically lowered into the well, in order to prevent the locking sleeve 23 from moving downward under its own gravity, causing the locking portion 21 to accidentally exit the slot 22, a limiting groove is provided on the outer periphery of the core shaft 11. The locking assembly 2 also includes a limiting member 24, which is movably arranged on the locking sleeve 23 in the radial direction, so that when the locking sleeve 23 drives the locking portion 21 to be in the locked state, the limiting member 24 extends into the limiting groove to limit the movement of the locking sleeve 23.

[0034] Specifically, a second mounting hole is provided on the side wall of the locking sleeve 23, and the second mounting hole is connected to the internal cavity of the locking sleeve 23. The second mounting hole is adapted to the limiting member 24, and the limiting member 24 is slidably installed in the second mounting hole. When the locking sleeve 23 drives the locking portion 21 to be in the locking state, the third section abuts against the locking portion 21. At this time, the limiting member 24 corresponds to the limiting groove, and then the limiting member 24 is driven to extend into the limiting groove, so as to limit the axial movement of the locking sleeve 23 and avoid accidental unlocking.

[0035] In this example, see Figure 1 , Figure 4 and Figure 5 The sealing assembly 1 includes a sealing component 12 and a sealing member 13, which are sequentially sleeved on the outer periphery of the core shaft 11 along the axial direction. The sealing component 12 is movably arranged along the axial direction to squeeze the sealing member 13 when the sealing component 12 moves toward the sealing member 13, so that the sealing member 13 is in sealing contact with the wellbore.

[0036] Specifically, the sealing component 12 is axially slidably installed on the outer periphery of the core shaft 11, and the sealing component 13 is also sleeved on the outer periphery of the core shaft 11, and the sealing component 13 can be radially deformed, so that the sealing component 13 can be radially deformed and abut against the wellbore to form a seal under the action of external force. The sealing component 12 and the sealing component 13 are arranged in sequence from top to bottom. When the sealing component 12 moves downward, the sealing component 12 squeezes the sealing component 13 to deform it to complete the sealing.

[0037] For further information, see Figure 4The core shaft 11 is also provided with a pressure transmission hole 112 connected to the channel 111. The sealing component 12 includes a sealing cylinder 121, a ball seat 122 and a sealing ball 123. The sealing cylinder 121 is slidably sleeved on the outer periphery of the core shaft 11. The sealing cylinder 121 and the sealing member 13 are arranged in sequence along the axial direction. There is a gap between the sealing cylinder 121 and the core shaft 11. A stopper 1211 is convexly provided on the inner side of the sealing cylinder 121. The stopper 1211 is sealed and matched with the core shaft 11. A hydraulic chamber 1212 is formed between the sealing cylinder 121, the core shaft 11 and the stopper 1211. The hydraulic chamber 1212 is connected to the pressure hole. The ball seat 122 is radially slidably installed in the channel 111, and its outer diameter is adapted to the channel 111, so as to have a first state of moving downward to open the pressure hole and a second state of moving upward to block the pressure hole. State, a through hole is provided in the middle of the ball seat 122, and the through hole is adapted to the sealing ball 123. During specific use, the ball seat 122 of the sealing assembly 1 at the lowest end is initially in the second state. When the sealing assembly 1 is lowered to the set position, the sealing ball 123 is inserted from the upper end of the channel 111, and the sealing ball 123 is sealed and matched with the ball seat 122. At this time, the lower end of the entire channel 111 is blocked, and then a medium is injected into the channel 111. The pressure generated by the medium pushes the ball seat 122 to move downward in the first state. At this time, the hydraulic chamber 1212 is connected with the channel 111 through the pressure transmission hole 112, and the medium enters the hydraulic chamber 1212 from the pressure penetration hole. The medium in the hydraulic chamber 1212 pushes the stopper 1211 and the sealing cylinder 121 to move downward, thereby squeezing the seal 13 to complete the sealing.

[0038] For further information, see Figure 4 The channel 111 is provided with a step at a position corresponding to the ball seat 122, and correspondingly, the ball seat 122 is also provided with a step, so that the step of the ball seat 122 and the step of the channel 111 are arranged at intervals in the vertical direction, and the sealing component 12 also includes a shear ring 124 and a shear pin, and the shear ring 124 is installed on the outer periphery of the ball seat 122 through the shear pin, and in the second state, the shear ring 124 abuts against the step of the channel 111, thereby limiting the ball seat 122, and when the medium is introduced, the shear pin is sheared off by the pressure of the medium, so that the ball seat 122 moves down its step until it abuts against the shear ring 124 to be in the first state.

[0039] Furthermore, the diameters of the setting balls 123 in the plurality of setting assemblies 1 are successively reduced in the downward direction, and such an arrangement can ensure that the setting balls 123 can pass through the ball seats 122 in the setting assemblies 1 above.

[0040] For further information, see Figure 5 The sealing member 13 comprises an upper slip 131, an upper cone 132, a rubber cylinder 133, a lower cone 134 and a lower slip 135. The upper slip 131, the upper cone 132, the rubber cylinder 133, the lower cone 134 and the lower slip 135 are sequentially sleeved on the outer periphery of the core shaft 11 from top to bottom. The upper slip 131 abuts against the lower end of the sealing cylinder 121, and the lower slip abuts against the boss. The inner diameter of the upper slip 131 is gradually expanded from top to bottom, and the outer diameter of the upper cone 132 is gradually expanded from top to bottom. The upper slip 131 and the upper cone 132 is wedge-shaped, the outer diameter of the lower cone 134 is gradually reduced from top to bottom, and the inner diameter of the lower slip 135 is gradually reduced from top to bottom. The lower slip 135 is wedge-shaped with the lower cone 134. When in use, the hydraulic pressure drives the sealing cylinder 121 downward, thereby pushing the upper slip 131 and the upper cone 132 to squeeze the rubber cylinder 133 to complete the sealing. After the rubber cylinder 133 is sealed, under the squeezing of the sealing cylinder 121, the upper slip 131 and the lower slip 135 will be evenly cracked along the axial stress groove position and eat into the wellbore wall to achieve permanent isolation.

[0041] Furthermore, in order to prevent the upper cone 132 and the rubber cylinder 133 from moving, the seal 13 also includes a shear pin, and the upper cone 132 is installed on the core shaft 11 through the shear pin. When the sealing cylinder 121 moves downward, the upper cone 132 can be pushed to shear the shear pin.

[0042] It can be understood that the upper slip 131, the upper cone 132, the rubber cylinder 133, the lower cone 134 and the lower slip 135 are all prior arts and will not be described in detail here.

[0043] Furthermore, the setting assembly 1 further comprises an end ring 14, wherein the end ring 14 is threadedly connected to the core shaft 11, and the end ring 14 constitutes the boss.

[0044] In this example, see Figure 3 In order to drive the limiting member 24 to move, the locking assembly 2 also includes a release cylinder 25, which is sleeved on the outer periphery of the locking sleeve 23 and corresponding to the limiting member 24. The release cylinder 25 is wedge-fitted with the limiting member 24, and one end of the release cylinder 25 is connected to the sealing component 12.

[0045] Specifically, the release cylinder 25 is connected to the sealing cylinder 121. When the sealing cylinder 121 moves downward, the release cylinder 25 is driven to move downward, so that the wedge-shaped cooperation between the release cylinder 25 and the limiting member 24 is utilized to unlock the limiting member 24, so that the limiting member 24 withdraws from the limiting groove, thereby unlocking the locking sleeve 23, so that the locking sleeve 23 can move axially.

[0046] In this embodiment, one end of the release tube 25 is threadedly connected to the setting member 12. When the core shaft 11 is connected in series in this way, the positional relationship between the release tube 25 and the stopper 24 can be adjusted to facilitate assembly.

[0047] Furthermore, in order to prevent the release cylinder 25 from accidentally rotating, the release cylinder 25 and the setting cylinder 121 are connected via a fastening pin.

[0048] In this embodiment, in order to facilitate the connection of the sealing assembly 1 with external equipment, the bridge plug for well abandonment operation also includes a joint assembly 3, and the joint assembly 3 is connected to the sealing assembly 1. A locking assembly 2 is provided between the joint assembly 3 and the sealing assembly 1.

[0049] In order to better understand the present invention, the following Figures 1 to 5 The technical solution of the present invention is described in detail: The assembly process of the sealing assembly 1 is as follows: the sealing cylinder 121 is installed along the lower end of the core shaft 11 and is limited by the axial step of the core shaft 11 to form a sealed hydraulic chamber 1212, and then the upper slip 131, the upper cone 132, the rubber cylinder 133, the lower cone 134 and the lower slip 135 are installed in sequence from the lower end of the core shaft 11, the upper slip 131 is limited by the axial step of the core shaft 11 and abuts against the sealing cylinder 121, the upper slip 131 is connected to the core shaft 11 through a shear pin, and finally the end ring 14 is threadedly connected to the core shaft 11 and abutted against the lower slip 135, the ball seat 122 and the shear ring 124 are connected and positioned by the shear pin, and then the ball seat 122 is placed to the channel 111. The upper end is installed and limited by the axial step of the side wall of the channel 111, the side wall of the ball seat 122 is sealed with the channel 111, the release cylinder 25 is threadedly connected with the sealing cylinder 121 along the upper end of the core shaft 11, the locking portion 21 is installed in the first mounting hole, the limiting member 24 and the locking sleeve 23 are installed and inserted along the upper end of the core shaft 11, the release cylinder 25 is rotated to make the release cylinder 25 move upward, and the limiting member 24 and the locking sleeve 23 move upward together. When the limiting member 24 is aligned with the limiting groove, the limiting member 24 extends into the limiting groove and axially locks the locking sleeve 23, and the release cylinder 25 is continued to be rotated to align the fixing pin hole on its body with the fixing pin groove of the sealing cylinder 121, and the fixing pin is installed to complete the installation.

[0050] The process of connecting multiple sealing assemblies 1 in series: first, connect the joint assembly 3 with the drilling tool or oil pipe, loosen the fixing screws on the release cylinder 25, screw the release cylinder 25 and the sealing cylinder 121 together, unlock the limit piece 24, push the locking sleeve 23 axially downward, unlock the locking part 21, insert and connect the core shaft 11 with the joint assembly 3, and after insertion, rotate the release cylinder 25 in the opposite direction to push the locking sleeve 23 and the limit piece 24 upward until the locking sleeve 23 and the release cylinder 25 are in contact with the end face of the joint assembly 3 and the limit piece 24 is locked. The next-level sealing assembly 1 is connected and locked with the lower end of the core shaft 11 of the previous-level sealing assembly 1 according to the above steps, and is installed step by step and then put into the well.

[0051] Usage process (taking the three-stage sealing component 1 as an example): connect the three-stage sealing component 1 as needed and then lower it into the designated position of the first-stage bridge plug. First, put in the special sealing ball 123 of the first-stage sealing component 1. After sending the sealing ball 123 into the ball seat 122, the pressure is pressed to cut off the shear pin. The ball seat 122 moves downward to the limit position in contact with the end face of the shear ring 124. The pressure transmission hole 112 is opened, and the hydraulic pressure drives the sealing cylinder 121 downward to push the upper slip 131 and the upper cone 132, and after cutting off the shear pin, it moves downward to squeeze the rubber cylinder 133 to complete the sealing. After the rubber cylinder 133 is sealed, under the squeezing of the sealing cylinder 121, the upper slip 131 and the lower slip 135 will be evenly cracked along the axial stress groove position and eat into the casing wall to achieve permanent isolation. During the bridge plug setting process, The sealing cylinder 121 moves downward, driving the release cylinder 25 to move downward, unlocking the limiter 24. After the sealing is completed, the tubing is lowered, and the end ring 14 of the previous sealing assembly 1 moves downward to push the locking sleeve 23 of the already sealed shrinkage joint assembly downward, unlocking the locking portion 21. After unlocking, the remaining sealing assemblies 1 are lifted up to separate the lower end of the core shaft 11 of the previous sealing assembly 1 from the upper end of the core shaft 11 of the already sealed sealing assembly 1, thereby achieving release. After the release is completed, cement plugging operation is performed on site. After the operation is completed, the tubing is lifted up, the remaining sealing assemblies 1 are strung together to the designed position, and the sealing ball 123 of the next sealing assembly 1 is put in again. The above steps are repeated to perform the sealing, release, and cement plugging operations until all cement plug operations are completed and the wellhead is pulled out to complete the single well continuous abandonment operation.

[0052] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A bridge plug for well abandonment operation, characterized in that: It includes: At least two setting assemblies, each of which comprises a core shaft, each of which is provided with a channel, and two adjacent core shafts are plug-connected through the channel; A locking assembly is provided between two adjacent spindles, the locking assembly comprising a matching portion provided on one of the spindles and a locking portion provided on the other spindle, the locking portion being movably arranged in a direction approaching and moving away from the matching portion, so as to have a locking state in which the matching portion is matched with the matching portion when the matching portion is approached, and an unlocking state in which the matching portion is released when the matching portion is moved away from the matching portion; Wherein, the sealing assembly is used to seal the wellbore, and when the sealing assembly seals the wellbore, the locking portion is in the unlocked state.

2. The bridge plug for well abandonment operation according to claim 1, characterized in that: A slot is provided on the outer periphery of one end of the mandrel, and the slot constitutes the matching portion; The locking portion is movably mounted on the side wall of the other end of the core shaft along the radial direction of the core shaft.

3. The bridge plug for well abandonment operation according to claim 2, characterized in that: The locking assembly also includes a locking sleeve, which is axially movable and sleeved on the outer periphery of the core shaft and corresponding to the locking portion. The locking sleeve is connected to the locking portion so that the locking portion is driven to move radially when the locking sleeve moves axially.

4. The bridge plug for well abandonment operation according to claim 3, characterized in that: The inner side of the locking sleeve is wedge-matched with the locking portion.

5. The bridge plug for well abandonment operation according to claim 3, characterized in that: The length of the slot in the axial direction is greater than the length of the locking portion in the axial direction, so that in the locked state, two adjacent core shafts can be movably arranged; A boss is provided on the outer periphery of one end of the core shaft close to the slot, and the boss abuts against the end of the locking sleeve, so that the locking sleeve is driven to move in a direction away from the locking portion through the boss.

6. The bridge plug for well abandonment operation according to claim 5, characterized in that: The outer periphery of the mandrel is provided with a limiting groove; The locking assembly further comprises a limiting member, which is movably arranged on the locking sleeve in a radial direction, so that when the locking sleeve drives the locking portion to be in the locking state, the limiting member extends into the limiting groove to limit the movement of the locking sleeve.

7. The bridge plug for well abandonment operation according to claim 6, characterized in that: The sealing assembly includes a sealing component and a sealing member, which are axially sleeved on the outer circumference of the core shaft in sequence. The sealing component is axially movably arranged to squeeze the sealing member when the sealing component moves toward the sealing member, so that the sealing member is in sealing contact with the wellbore.

8. The bridge plug for well abandonment operation according to claim 7, characterized in that: The locking assembly also includes a release cylinder, which is sleeved on the outer circumference of the locking sleeve and arranged corresponding to the limiting member. The release cylinder is wedge-matched with the limiting member, and one end of the release cylinder is connected to the sealing component.

9. The bridge plug for well abandonment operation according to claim 8, characterized in that: One end of the release tube is threadedly connected to the setting component.

10. The bridge plug for well abandonment operation according to claim 1, characterized in that: The bridge plug for well abandonment operation also includes a joint assembly, which is connected to a sealing assembly, and a locking assembly is provided between the joint assembly and the sealing assembly.

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