Step-by-step bridge plug and de-encapsulation tool

Abstract

The present application relates to unconventional oil and gas reservoir completion engineering technical field, especially to a kind of step-by-step unblocking bridge plug and unblocking tool, to solve the risk problem caused by sudden release of pressure in plugging layer when bridge plug unblocking.The present application provides a kind of step-by-step unblocking bridge plug, including mandrel, packing mechanism and anchoring mechanism.Mandrel is inserted into anchoring mechanism, and packing mechanism is sleeved on anchoring mechanism;Packing mechanism includes upper cylinder assembly, rubber cylinder arranged below upper cylinder assembly and lower cylinder assembly arranged below rubber cylinder;Anchoring mechanism includes upper cone assembly and slip, and the lower side of upper cone assembly is inserted into the upper side of slip.When unblocking, mandrel is pulled up, and the upper end of mandrel is abutted on upper cylinder assembly and drives upper cylinder assembly to move upwards, so that rubber cylinder restores original state;Continue to pull up mandrel, and upper cylinder assembly is abutted on upper cone assembly and drives upper cone assembly to move upwards, and slip resets.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of unconventional oil and gas reservoir completion engineering, and particularly relates to a step-by-step unblocking bridge plug and unblocking tool. BACKGROUND

[0002] The fishable bridge plug is widely used as a downhole plugging tool in interlayer plugging construction of oil and gas wells. The fishable bridge plug currently in use achieves the whole bridge plug unblocking through the unblocking tool in one operation. The fishable bridge plug with such a structure may cause the sudden release of the plugging layer pressure at the unblocking moment when plugging the reservoir with high pressure, and the released pressure may bend the fishing oil pipe, causing the occurrence of downhole complex accidents. SUMMARY

[0003] The present application aims to provide a step-by-step unblocking bridge plug and unblocking tool, which first releases the plugging layer pressure and then releases the anchoring to eliminate the risk caused by the sudden release of the plugging layer pressure when the bridge plug is unblocked.

[0004] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0005] A step-by-step unblocking bridge plug comprises a mandrel, a sealing mechanism and an anchoring mechanism. The mandrel is inserted into the anchoring mechanism, and the sealing mechanism is sleeved on the anchoring mechanism. The sealing mechanism comprises an upper cylinder assembly, a rubber cylinder arranged below the upper cylinder assembly and a lower cylinder assembly arranged below the rubber cylinder. The anchoring mechanism comprises an upper cone assembly and a slip. The lower side of the upper cone assembly is inserted into the upper side of the slip.

[0006] When setting, the lower cylinder assembly moves upward, extruding the rubber cylinder with the upper cylinder assembly to make the rubber cylinder expand. At the same time, the upper cone assembly moves downward to push the slip to move outward. When unblocking, the mandrel is pulled up, the upper end of the mandrel abuts against the upper cylinder assembly and drives the upper cylinder assembly to move upward, so that the rubber cylinder returns to the original state.

[0007] The mandrel is continuously pulled up, the upper cylinder assembly abuts against the upper cone assembly and drives the upper cone assembly to move upward, and the slip resets.

[0008] Further, the anchoring mechanism further comprises a fixing sleeve. The fixing sleeve is sleeved on the mandrel, and the fixing sleeve is inserted into the upper cylinder assembly.

[0009] Further, the step-by-step unblocking bridge plug further comprises a first shear pin. The first shear pin is inserted into the fixing sleeve after penetrating through the side wall of the mandrel.

[0010] Further, the step-by-step unblocking bridge plug further comprises a first lock block. The first lock block penetrates through the side wall of the fixing sleeve. One end of the first lock block abuts against the mandrel, and the other end is inserted into the upper cylinder assembly.

[0011] Further, the anchoring mechanism further comprises a central pipe. The upper side of the central pipe is inserted into the lower side of the fixing sleeve and is screwed with the fixing sleeve.

[0012] Further, the anchoring mechanism further comprises a connecting shaft sleeved on the central pipe; the upper cone assembly is sleeved on the connecting shaft, and the lower part of the connecting shaft is connected with the upper cone assembly.

[0013] Further, the step-by-step unblocking bridge plug further comprises a second lock block penetrating through the sidewall of the central pipe; one end of the second lock block abuts against the mandrel, and the other end of the second lock block is inserted into the connecting shaft.

[0014] Further, the step-by-step unblocking bridge plug further comprises an unblocking lock block penetrating through the sidewall of the mandrel; one end of the unblocking lock block abuts against the central pipe, and the other end of the unblocking lock block protrudes from the inner wall of the mandrel.

[0015] In another aspect of the present application, an unblocking tool for the step-by-step unblocking bridge plug is provided, which comprises a split jaw unblocking sleeve provided with an unblocking head, and the upper end surface of the unblocking head can abut against the lower end surface of the unblocking lock block or the mandrel.

[0016] Further, the unblocking tool further comprises a guide sleeve inserted into the split jaw unblocking sleeve, and the guide sleeve abuts against the unblocking head.

[0017] The technical effects that can be achieved by the present application are summarized as follows:

[0018] The step-by-step unblocking bridge plug provided by the present application comprises a mandrel, a sealing mechanism and an anchoring mechanism. The mandrel is inserted into the anchoring mechanism, and the sealing mechanism is sleeved on the anchoring mechanism. The sealing mechanism comprises an upper cylinder assembly, a rubber cylinder arranged below the upper cylinder assembly and a lower cylinder assembly arranged below the rubber cylinder. The anchoring mechanism comprises an upper cone assembly and a slip, and the lower side of the upper cone assembly is inserted into the upper side of the slip.

[0019] When setting, the lower cylinder assembly moves upward, extrudes the rubber cylinder together with the upper cylinder assembly, and the rubber cylinder expands. At the same time, the upper cone assembly moves downward, pushes the slip to move outward.

[0020] When unblocking, the mandrel is pulled upward, the upper end of the mandrel abuts against the upper cylinder assembly and drives the upper cylinder assembly to move upward, so that the rubber cylinder returns to the original state. The mandrel is continuously pulled upward, the upper cylinder assembly abuts against the upper cone assembly and drives the upper cone assembly to move upward, and the slip is reset.

[0021] The step-by-step unblocking bridge plug provided by the present application first makes the rubber cylinder return to the original state to release the reservoir pressure when unblocking. At this time, the slip of the anchoring mechanism remains in the anchoring state, so that the step-by-step unblocking bridge plug is fixed. Therefore, the pipe string can be prevented from creeping when the pressure is released, the impact caused by the sudden release of pressure can be avoided, and the occurrence of complex accidents in the well can be avoided. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0023] Figure 1 A cross-sectional view of the step-by-step unblocking bridge plug provided by the embodiment of the present application;

[0024] Figure 2 A schematic view of the Figure 1 anchoring mechanism in the middle;

[0025] Figure 3 A schematic view of the step-by-step unblocking bridge plug provided by the embodiment of the present application;

[0026] Figure 4 A schematic view of the unblocking tool provided by the embodiment of the present application;

[0027] Figure 5 A schematic view of the Figure 4 split claw unblocking sleeve;

[0028] Figure 6 A schematic view of the step-by-step unblocking bridge plug provided by the embodiment of the present application;

[0029] Figure 7 A schematic view of the step-by-step unblocking bridge plug provided by the embodiment of the present application;

[0030] Figure legend: 100 - mandrel; 200 - pack-off mechanism; 300 - anchoring mechanism; 400 - first shear pin; 500 - first lock block; 600 - second lock block; 700 - unblocking lock block; 800 - second shear pin; 900 - shear piece; 1000 - running-in tool; 210 - upper cylinder assembly; 220 - rubber cylinder; 230 - lower cylinder assembly; 310 - upper cone assembly; 320 - slip; 330 - lower cone; 340 - fixing sleeve; 350 - central tube; 360 - connecting shaft; 370 - pressure cap; 380 - spring; 390 - slip cover; 3100 - pressure ring; 3120 - third lock block; 3130 - lower plug; 211 - support sleeve; 212 - upper joint; 231 - rubber cylinder seat; 232 - outer sleeve; 233 - first C-shaped lock ring; 311 - connecting sleeve; 312 - upper cone; 313 - second C-shaped lock ring; 1 - split claw unblocking sleeve; 2 - guide sleeve; 3 - connecting rod; 1-1, unlocking head; 1-2, split claw; A - pressure transmission hole. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0033] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0035] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0036] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] Some embodiments of the present application will be described in detail with reference to the drawings. The following embodiments and features of the embodiments described below can be combined with each other without conflict.

[0038] The fishable bridge plug is widely used as a downhole plugging tool in interlayer plugging operation of oil and gas wells. In the present application, the fishable bridge plug is used to achieve the whole bridge plug unblocking by one operation of the unblocking tool. The fishable bridge plug with such structure will cause the sudden release of the plugging layer pressure at the unblocking moment when plugging the reservoir with high pressure, and the released pressure can bend the fishing oil pipe, causing the occurrence of downhole complex accidents.

[0039] Therefore, the present application provides a step-by-step unblocking bridge plug, which comprises a mandrel 100, a sealing mechanism 200 and an anchoring mechanism 300. The mandrel 100 is inserted into the anchoring mechanism 300, and the sealing mechanism 200 is sleeved on the anchoring mechanism 300. The sealing mechanism 200 comprises an upper cylinder assembly 210, a rubber cylinder 220 arranged below the upper cylinder assembly 210 and a lower cylinder assembly 230 arranged below the rubber cylinder 220. The anchoring mechanism 300 comprises an upper cone assembly 310 and a slip 320, and the lower side of the upper cone assembly 310 is inserted into the upper side of the slip 320.

[0040] When setting, the lower cylinder assembly 230 moves upward, extrudes the rubber cylinder 220 with the upper cylinder assembly 210, and expands the rubber cylinder 220. At the same time, the upper cone assembly 310 moves downward and pushes the slip 320 to move outward.

[0041] When unblocking, the mandrel 100 is pulled up, the upper end of the mandrel 100 abuts against the upper cylinder assembly 210 and drives the upper cylinder assembly 210 to move upward, so that the rubber cylinder 220 returns to the original state. The mandrel 100 is continuously pulled up, the upper cylinder assembly 210 abuts against the upper cone assembly 310 and drives the upper cone assembly 310 to move upward, and the slip 320 is reset.

[0042] The step-by-step unblocking bridge plug provided by the present application first makes the rubber cylinder 220 return to the original state to release the reservoir pressure when unblocking. At this time, the slip 320 of the anchoring mechanism 300 remains in the anchoring state, so that the step-by-step unblocking bridge plug is fixed. Therefore, the pipe string can be prevented from creeping when the pressure is released, the impact caused by the sudden release of the pressure can be avoided, and the occurrence of downhole complex accidents can be avoided.

[0043] The structure and shape of the step-by-step unblocking bridge plug and the unblocking tool provided by the present embodiment will be described in detail below. Figures 1-7 The structure and shape of the step-by-step unblocking bridge plug and the unblocking tool provided by the present embodiment will be described in detail below.

[0044] In an optional solution of the present embodiment, the anchoring mechanism 300 further comprises a fixing sleeve 340. As shown in Figure 1 Figure 2 The fixing sleeve 340 is sleeved on the mandrel 100 and inserted into the upper cylinder assembly 210.

[0045] ​In this embodiment, the anchoring mechanism 300 further comprises a lower cone 330, as shown in Figure 1 , The upper side of the lower cone 330 is inserted into the lower side of the slip 320, as shown in Figure 2 .

[0046] In this embodiment, the anchoring mechanism 300 further comprises a central pipe 350, the upper side of which is inserted into the lower side of the fixing sleeve 340 and is screwed with the fixing sleeve 340; the lower side of the central pipe 350 is fixedly connected with the lower cone 330.

[0047] In this embodiment, the anchoring mechanism 300 further comprises a compression ring 3100, which is sleeved on the lower side of the lower cone 330 and is screwed with the lower cone 330. Further, the anchoring mechanism 300 is provided with a third locking block 3120, which passes through the lower side of the lower cone 330 and is inserted into the sidewall of the central pipe 350, one end of the third locking block 3120 abutting against the inner wall of the compression ring 3100, so that the central pipe 350 and the lower cone 330 are fixedly connected.

[0048] In this embodiment, the anchoring mechanism 300 further comprises a connecting shaft 360, which is sleeved on the central pipe 350; the upper cone assembly 310 is sleeved on the connecting shaft 360, and the lower part of the connecting shaft 360 is connected with the upper cone assembly 310. Specifically, as shown in Figure 1 , the step-by-step unblocking bridge plug further comprises a second locking block 600, which passes through the sidewall of the central pipe 350; one end of the second locking block 600 abutting against the mandrel 100, and the other end being inserted into the connecting shaft 360, so that the central pipe 350 and the connecting shaft 360 are connected.

[0049] Further, the upper cone assembly 310 comprises a connecting sleeve 311, an upper cone 312 and a second C-shaped locking ring 313. As shown in Figure 2 , the second C-shaped locking ring 313 is clamped on the inner wall of the connecting sleeve 311, and the upper side of the upper cone 312 is inserted into the inner wall of the connecting sleeve 311 and is screwed with the connecting sleeve 311. The lower side of the connecting shaft 360 is provided with a groove, and after the upper cone assembly 310 moves downward relative to the connecting shaft 360, the second C-shaped locking ring 313 is clamped into the groove, so that the connecting shaft 360 and the upper cone assembly 310 are connected. Further, a sealing ring is arranged between the connecting sleeve 311 and the central pipe 350 to ensure the sealing performance.

[0050] In this embodiment, the anchoring mechanism 300 further comprises a slip cover 390 and a spring 380. The slip cover 390 is used to limit the slip 320 on the central pipe 350, and the spring 380 abuts against the slip 320 to apply a force to the slip 320 pointing to the central pipe 350, so that the slip 320 is contracted.

[0051] In this embodiment, the anchoring mechanism 300 further comprises a lower plug 3130. As shown in Figure 2As shown, the lower plug 3130 is inserted into the lower part of the central pipe 350 and is screwed with the central pipe 350, for plugging the lower end of the central pipe 350. Further, a sealing ring is arranged between the lower plug 3130 and the central pipe 350, for improving the sealing performance.

[0052] In the embodiment, the upper cylinder assembly 210 comprises a support sleeve 211 and an upper joint 212. As shown, the upper side of the support sleeve 211 is inserted into the lower side of the upper joint 212 and is screwed with the upper joint 212. Further, the anchoring mechanism 300 further comprises a pressing cap 370, which is sleeved on the upper side of the connecting shaft 360 and is screwed with the connecting shaft 360. After the upper cylinder assembly 210 moves upward, the support sleeve 211 abuts against the pressing cap 370, thereby driving the connecting shaft 360 to move upward. Figure 1

[0053] Further, the lower cylinder assembly 230 comprises a rubber cylinder seat 231, an outer sleeve 232 and a first C-shaped locking ring 233. As shown, the upper end of the rubber cylinder seat 231 abuts against the lower end of the rubber cylinder 220, and the lower side of the rubber cylinder seat 231 is sleeved on the upper side of the outer sleeve 232 and is screwed with the outer sleeve 232. After the rubber cylinder seat 231 and the outer sleeve 232 are connected, a groove is formed in the inner wall, and the first C-shaped locking ring 233 is clamped in the groove. Meanwhile, a groove is formed in the middle part of the connecting shaft 360, and after the lower cylinder assembly 230 moves upward relative to the connecting shaft 360, the first C-shaped locking ring 233 is clamped in the groove in the middle part of the connecting shaft 360, so as to connect the lower cylinder assembly 230 with the connecting shaft 360. Optionally, a sealing ring is arranged between the upper cylinder assembly 210 and the connecting shaft 360, and a sealing ring is arranged between the lower cylinder assembly 230 and the connecting shaft 360, for improving the sealing performance. Figure 1 In the optional scheme of the embodiment, the step-by-step unblocking bridge plug further comprises a second shear pin 800. Specifically, the lower side of the outer sleeve 232 is sleeved on the upper side of the connecting sleeve 311, and the second shear pin 800 is inserted into the sidewall of the connecting sleeve 311 after penetrating through the sidewall of the outer sleeve 232, so as to connect the lower cylinder assembly 230 with the upper cone assembly 310.

[0054] In the embodiment, the step-by-step unblocking bridge plug further comprises a first shear pin 400, which is inserted into the fixed sleeve 340 after penetrating through the sidewall of the mandrel 100, so as to connect the mandrel 100 with the anchoring mechanism 300.

[0055] Further, the step-by-step unblocking bridge plug further comprises a first locking block 500, which penetrates through the sidewall of the fixed sleeve 340. One end of the first locking block 500 abuts against the mandrel 100, and the other end is inserted into the sidewall of the upper joint 212, so as to connect the upper cylinder assembly 210 with the anchoring mechanism 300.

[0056]

[0057] ​​The step-by-step unblocking bridge plug in the embodiment further comprises a second locking block 600 which penetrates the sidewall of the central pipe 350; one end of the second locking block 600 abuts against the mandrel 100, and the other end is inserted into the connecting shaft 360, so that the central pipe 350 and the connecting shaft 360 are connected.

[0058] In the embodiment, the unblocking bridge plug further comprises an unblocking locking block 700 which penetrates the sidewall of the mandrel 100; one end of the unblocking locking block 700 abuts against the central pipe 350, and the other end protrudes from the inner wall of the mandrel 100. Further, the unblocking locking block 700 is provided with a step on the side abutting against the central pipe 350, so as to prevent the unblocking locking block 700 from moving to the inner side of the mandrel 100 and falling off.

[0059] In the embodiment, the step-by-step unblocking bridge plug further comprises a shear piece 900 which is annular and has an L-shaped cross section; the sidewall of the shear piece 900 is open, so as to facilitate installation. As shown in Figure 1 、 Figure 2 , the shear piece 900 is sleeved on the pressure cap 370 and abuts against the lower end surface of the pressure cap 370. The shear piece 900 is clamped into the upper side of the connecting shaft 360, so that the shear piece 900 is connected with the connecting shaft 360 and is prevented from falling off. The shear piece 900 is sheared off after the upper cylinder assembly 210 is moved upward, so as to offset a part of the impact of the upward movement of the upper cylinder assembly 210 and prevent the upper cylinder from being impacted too much during the upward movement.

[0060] In the embodiment, the step-by-step unblocking bridge plug further comprises a running tool 1000. As shown in Figure 1 , the running tool 1000 is inserted into the upper joint 212 and is screwed with the upper side of the upper joint 212. Meanwhile, the running tool 1000 is inserted into the mandrel 100. Further, the step-by-step unblocking bridge plug is provided with a pressure transmission hole A which penetrates the sidewall of the running tool 1000, the mandrel 100, the central pipe 350 and the connecting shaft 360 in sequence. Specifically, the upper end surface of the connecting sleeve 311 abuts against the step of the inner wall of the outer sleeve 232, and the gap between the connecting sleeve 311 and the outer sleeve 232 is connected with the pressure transmission hole A. Optionally, sealing rings are arranged between the running tool 1000, the mandrel 100, the central pipe 350 and the connecting shaft 360, so as to improve the sealing performance of the pressure transmission hole A and prevent pressure leakage.

[0061] The connection relationship of the step-by-step unblocking bridge plug provided in the embodiment is as follows: as shown in Figure 1 、 Figure 2 , the running tool 1000 is screwed with the upper cylinder assembly 210, the upper cylinder assembly 210 is connected with the anchoring mechanism 300 through the first locking block 500, and the upper cone assembly 312 of the anchoring mechanism 300 is connected with the lower cylinder assembly 230 through the second shear pin 800. The spring 380 keeps the slips 320 contracted, so as to keep the position of the upper cone assembly 312 and the lower cylinder assembly 230. The rubber sleeve 220 is supported by the lower cylinder assembly 230.

[0062] Correspondingly, the embodiment also includes a de-encapsulating tool suitable for step-by-step de-encapsulating the bridge plug. As shown in Figure 4 、 Figure 5 、 Figure 7 The de-encapsulating tool includes a split jaw de-encapsulating sleeve 1, which is provided with an unlocking head 1-1, the upper end surface of the unlocking head 1-1 being capable of abutting against the lower end surface of the de-encapsulating block 700 or the mandrel 100. Specifically, the split jaw de-encapsulating sleeve 1 further includes a split jaw 1-2, the lower end of the split jaw 1-2 being provided with the unlocking head 1-1.

[0063] Further, the de-encapsulating tool further includes a guide sleeve 2, which is inserted into the split jaw de-encapsulating sleeve 1, and the guide sleeve 2 is used to support the unlocking head 1-1.

[0064] In the embodiment, the de-encapsulating tool further includes a connecting rod 3, the lower side of the connecting rod 3 being inserted into the upper side of the guide sleeve 2 and being threadedly connected with the guide sleeve 2.

[0065] The working process of the step-by-step de-encapsulating bridge plug and the de-encapsulating tool provided by the embodiment is as follows:

[0066] During setting, as shown in Figure 1 、 Figure 3 , a setting ball is put into the running tool 1000, and then the setting ball is pressed after the lower end of the running tool 1000 is blocked, at this time, the high-pressure liquid enters the gap between the outer sleeve 232 and the connecting sleeve 311 through the pressure transmission hole A, under the action of pressure, the second shear pin 800 is sheared off, then the lower cylinder assembly 230 moves upward, extruding the rubber cylinder 220, so that the rubber cylinder 220 expands, and finally the reservoir is sealed, at this time, the first C-shaped locking ring 233 is clamped into the groove in the middle of the connecting shaft 360, preventing the lower cylinder assembly 230 from moving downward, resulting in the release of the sealing. At the same time, the upper cone assembly 310 moves downward and pushes the slips 320 to move outward, completing the anchoring with the casing, at this time, the second C-shaped locking ring 313 is clamped into the groove on the lower side of the connecting shaft 360, preventing the upper cone assembly 310 from moving upward, resulting in the release of the anchoring. After the setting is completed, the running tool 1000 is taken out.

[0067] When the unblocking is completed, the unblocking tool is continuously lifted, and at this time, the unblocking block 700 loses the support of the central pipe 350 and is squeezed out of the mandrel 100 by the unlocking head 1-1, and no longer protrudes from the inner wall of the mandrel 100, so that the unblocking tool is separated from the step-by-step unblocking bridge plug. It should be noted that the side of the unblocking block 700 abutting against the unlocking head 1-1 is provided with a chamfer, so as to prevent the unlocking head 1-1 from only providing upward force to the unblocking block 700 and failing to move the unblocking block 700. Similarly, the first lock block 500 and the second lock block 600 are both provided with chamfers, so as to be able to receive horizontal force during the unblocking process and achieve unblocking.

[0068] When the unblocking is completed, the unblocking tool is continuously lifted, and at this time, the unblocking block 700 loses the support of the central pipe 350 and is squeezed out of the mandrel 100 by the unlocking head 1-1, and no longer protrudes from the inner wall of the mandrel 100, so that the unblocking tool is separated from the step-by-step unblocking bridge plug. It should be noted that the side of the unblocking block 700 abutting against the unlocking head 1-1 is provided with a chamfer, so as to prevent the unlocking head 1-1 from only providing upward force to the unblocking block 700 and failing to move the unblocking block 700. Similarly, the first lock block 500 and the second lock block 600 are both provided with chamfers, so as to be able to receive horizontal force during the unblocking process and achieve unblocking.

[0069] Then the unblocking tool is lowered below the mandrel 100, and then the unblocking tool is lifted, at this time, the guide sleeve 2 spreads the unblocking sleeve 1, so that the upper end surface of the unlocking head 1-1 abuts against the lower end surface of the mandrel 100, and as the unblocking tool continues to be lifted, the upper end surface of the mandrel 100 abuts against the upper joint 212, and the first lock block 500 loses the support of the mandrel 100 and is separated from the upper joint 212, so that the upper barrel body assembly 210 is separated from the anchoring mechanism 300. Figure 7As shown. Then, the unsealing tool is lifted further, causing the mandrel 100 to move the upper cylinder assembly 210, cutting the shear blade 900. After the shear blade 900 is cut, the upper cylinder assembly 210 can continue to move upward by one stroke, so that the support sleeve 211 abuts against the pressure cap 370. During this movement, the second locking block 600 loses the support of the mandrel 100 and disengages from the connecting shaft 360. The disengagement of the second locking block 600 causes the connecting shaft 360 and the central tube 350 to separate. Continue lifting the unsealing tool, causing the mandrel 100, the upper rubber sleeve assembly 210, the pressure cap 370, and the connecting shaft 360 to move upwards. Since the connecting shaft 360 and the upper cone assembly 310 are connected by the second C-shaped locking ring 313, and the central tube 350 and the lower cone 330 are connected, the connecting shaft 360 drives the upper cone assembly 310 upwards, while the lower cone 330 remains stationary. This causes the slip 320 to lose support and retract under the action of the spring 380, releasing the anchor. Continue lifting the unsealing tool, and finally remove the step-by-step unsealing bridge plug from the well.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A staged de-bridging bridge plug, comprising: It comprises a mandrel (100), a sealing mechanism (200) and an anchoring mechanism (300); The mandrel (100) is inserted into the anchoring mechanism (300), and the sealing mechanism (200) is sleeved on the anchoring mechanism (300); The sealing mechanism (200) comprises an upper cylinder assembly (210), a rubber cylinder (220) arranged below the upper cylinder assembly (210), and a lower cylinder assembly (230) arranged below the rubber cylinder (220); The anchoring mechanism (300) comprises an upper cone assembly (310) and a slip (320), and the lower side of the upper cone assembly (310) is inserted into the upper side of the slip (320); When setting, the lower cylinder assembly (230) moves upward, and the rubber cylinder (220) is extruded by the upper cylinder assembly (210) and the rubber cylinder (220) expands, while the upper cone assembly (310) moves downward and pushes the slip (320) to move outward; When unsetting, the mandrel (100) is lifted, the upper end of the mandrel (100) abuts against the upper cylinder assembly (210) and drives the upper cylinder assembly (210) to move upward, so that the rubber cylinder (220) returns to its original state; Continuing to lift the mandrel (100), the upper cylinder assembly (210) abuts against the upper cone assembly (310) and drives the upper cone assembly (310) to move upward, and the slip (320) resets; The anchoring mechanism (300) further comprises a fixing sleeve (340), the fixing sleeve (340) is sleeved on the mandrel (100), and the fixing sleeve (340) is inserted into the upper cylinder assembly (210); It further comprises a first lock block (500), the first lock block (500) penetrates the side wall of the fixing sleeve (340); One end of the first lock block (500) abuts against the mandrel (100), and the other end is inserted into the upper cylinder assembly (210); The anchoring mechanism (300) further comprises a central pipe (350), the upper side of the central pipe (350) is inserted into the lower side of the fixing sleeve (340) and is screwed with the fixing sleeve (340); The anchoring mechanism (300) further comprises a connecting shaft (360), the connecting shaft (360) is sleeved on the central pipe (350); The upper cone assembly (310) is sleeved on the connecting shaft (360), and the lower part of the connecting shaft (360) is connected with the upper cone assembly (310); It further comprises a second lock block (600), the second lock block (600) penetrates the side wall of the central pipe (350); One end of the second lock block (600) abuts against the mandrel (100), and the other end is inserted into the connecting shaft (360); It further comprises an unsetting lock block (700), the unsetting lock block (700) penetrates the side wall of the mandrel (100); One end of the unsetting lock block (700) abuts against the central pipe (350), and the other end protrudes from the inner wall of the mandrel (100).

2. The staged de-encapsulation bridge plug of claim 1, wherein Also comprise a first shear nail (400), the first shear nail (400) is inserted into the fixed sleeve (340) through the side wall of the mandrel (100).

3. A debridement tool for debridement of a bridge plug in steps as claimed in claim 2, characterized in that, The split claw unlocking sleeve (1) is provided with an unlocking head (1-1), and the upper end surface of the unlocking head (1-1) can abut against the unlocking block (700) or the lower end surface of the mandrel (100).

4. The deblocking tool of claim 3, wherein, Also comprise a guide sleeve (2), the guide sleeve (2) is inserted into the split claw unlocking sleeve (1), and the guide sleeve (2) abuts against the unlocking head (1-1).

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