A dissolvable variable-gauge tubing anchor and method of use

Abstract

The application discloses a soluble variable-diameter oil pipe anchoring device and a use method. The device comprises a body of a pipe body structure, a plurality of floating anchor seats are elastically connected to the outer circumferential side of the body in the radial direction, each floating anchor seat is provided with a ball tooth mounting sleeve, the outer end of the ball tooth mounting sleeve is open, the inner end is provided with a through hole connected with the through cavity of the body, the inner side sealing sleeve of the ball tooth mounting sleeve is provided with a ball tooth anchor shoe, and the ball tooth anchor shoe is detachably and fixedly installed with the floating anchor seat.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil exploration downhole operation tools, in particular to a soluble variable-diameter tubing anchoring device and a use method thereof. BACKGROUND

[0002] Well completion refers to the process of connecting the well bottom and the oil layer with a certain structure after the open hole is drilled to the designed well depth, and it is the last important link of drilling work and the beginning of oil production engineering, and is closely related to the subsequent oil production, water injection and the development of the whole oil and gas field. The quality of well completion directly affects the production capacity and economic life of the oil well, and even relates to whether the whole oil field can be developed reasonably.

[0003] The tubing anchoring device is a commonly used tool in well completion operation, mainly used for resisting upward or downward pressure of the pipe string to fix the pipe string, and is often used with a packer. The working principle is to push the anchor shoe radially by hydraulic pressure to make the anchor shoe press the inner wall of the casing, so as to fix the pipe string.

[0004] At present, with the development of tight oil and gas reservoirs such as shale gas, shale oil and coalbed methane, the amount of fracturing sand is increasing, and the matching hydraulic anchor is constantly encountering various problems. The common problems are as follows: 1. The gap between the hydraulic anchor and the casing is small, and the conventional hydraulic anchor cannot pass through the casing deformation section smoothly, causing the pipe string to be stuck, resulting in operation failure. 2. The sand particles are deposited in the inner cavity of the anchor shoe piston, and after the operation is completed, the anchor shoe cannot be effectively retracted due to pressure relief, so that the pipe string cannot be pulled out, causing a pipe sticking accident. 3. After the hydraulic anchor is used for a long time, the spring is prone to fatigue, resulting in insufficient spring force to release the anchoring, thereby causing a pipe sticking accident. SUMMARY

[0005] The purpose of the present application is to solve the problems existing in the prior art, and to provide a soluble variable-diameter tubing anchoring device and a use method thereof. A floating anchor seat is arranged on the body, and when the anchoring device passes through the casing deformation section, the floating anchor seat is retracted due to the extrusion of the inner wall of the casing, so as to adapt to the casing deformation section and ensure smooth running.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A soluble variable-diameter tubing anchoring device, comprising a body of a pipe body structure, a plurality of floating anchor seats are elastically connected to the outer circumferential side of the body in the radial direction, each floating anchor seat is provided with a ball tooth mounting sleeve, the outer end of the ball tooth mounting sleeve is open, and the inner end is provided with a through hole connected with the through cavity of the body, the inner side of the ball tooth mounting sleeve is provided with a ball tooth anchor shoe, and the ball tooth anchor shoe is detachably and fixedly installed with the floating anchor seat.

[0008] The outer periphery of the body is provided with a spring groove and a floating sealing hole, the spring groove is internally provided with a first elastic member, and the other end of the first elastic member is in abutment with the inner side surface of the floating anchor seat.

[0009] The two ends of the body are provided with annular bosses, the limiting pressure ring is sleeved on the outer side of the annular bosses and is fixedly installed with the annular bosses through screws, one end of the limiting pressure ring is staggered with the annular bosses to form a suspended end, the end edge of the floating anchor seat is sleeved on the inner side of the suspended end of the limiting pressure ring, and the end of the floating anchor seat is in abutment with the annular boss.

[0010] The outer side of the floating anchor seat is provided with a pressing strip in the axial direction, and the two ends of the pressing strip are bolted with the floating anchor seat, and the pressing strip is in abutment with the outer side port of the ball tooth mounting sleeve.

[0011] The outer side surface of the floating anchor seat is provided with a sink groove matched with the pressing strip, the ball tooth anchor tile is provided with a strip-shaped groove in the axial direction, the pressing strip is inserted into the strip-shaped groove, and the second elastic member is arranged between the pressing strip and the groove bottom of the strip-shaped groove.

[0012] The two ends of the body are both provided with connecting threads, and one side of the connecting thread at one end is provided with an axially extending positioning groove.

[0013] The first sealing member is arranged between the outer side wall of the ball tooth mounting sleeve and the floating sealing hole, and the second sealing member is arranged between the outer side wall of the ball tooth anchor tile and the inner side wall of the ball tooth mounting sleeve.

[0014] The ball tooth anchor tile is made of a soluble metal material.

[0015] The outer side of the ball tooth anchor tile is provided with a hard alloy tooth.

[0016] A use method of a soluble variable-diameter tubing anchor device, comprising the following steps:

[0017] S1, lowering the anchor device into the well casing, and the floating anchor seat is radially expanded under the action of the elastic member;

[0018] S2, when encountering the deformation section of the casing, the floating anchor seat is radially retracted under the action of the casing wall of the deformation section, so that the anchor device can smoothly continue to be lowered;

[0019] S3, after the anchor device is lowered to the predetermined position, high-pressure liquid is injected into the inner cavity of the body, the high-pressure liquid enters the through hole of the ball tooth mounting sleeve, the ball tooth anchor tile is pushed to radially extend outward, and is clamped on the inner wall of the casing;

[0020] S4, after the construction work is completed, a liquid capable of accelerating the dissolution of the soluble metal material is injected into the casing, so that the ball tooth anchor tile is quickly dissolved.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The floating anchor seat is arranged on the body, and when the anchor device passes through the casing deformation section, the floating anchor seat is retracted due to the extrusion of the casing inner wall, so as to adapt to the casing deformation section and ensure smooth running;

[0023] 2. The ball tooth mounting sleeve is arranged on the floating anchor seat, and the ball tooth anchor shoe is mounted through the ball tooth mounting sleeve, that is, the floating adaptation function and the anchoring function are integrated, two functions are realized by using one mechanism, the ball tooth anchor shoe occupies extra space alone is avoided, the structure is simplified, and the overall size of the device is reduced;

[0024] 3. By integrating the ball tooth anchor shoe on the floating anchor seat, the ball tooth anchor shoe moves radially synchronously with the floating anchor seat during the running of the casing, so that the ball tooth anchor shoe always maintains the position closest to the casing wall, and after the hydraulic pressure is injected, the ball tooth anchor shoe directly extends from the floating anchor seat to clamp the casing wall, so that the anchoring is more firm, and the ball tooth anchor shoe is prevented from being stuck due to the long retraction path after pressure relief, so that the unblocking is more smooth. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a sectional view of the oil pipe anchor device of the present application;

[0026] Figure 2 is a perspective view of the body of the oil pipe anchor device of the present application;

[0027] Figure 3 is a perspective view of the floating anchor seat of the present application;

[0028] Figure 4 is a perspective view of the oil pipe anchor device of the present application;

[0029] Figure 5 is a perspective view of the ball tooth anchor shoe of the present application;

[0030] In the figure: 1, body; 101, spring groove; 102, floating sealing hole; 103, positioning groove; 2, limiting pressure ring; 3, screw; 4, floating anchor seat; 401, ball tooth mounting sleeve; 402, sink groove; 5, first elastic member; 6, first sealing member; 7, ball tooth anchor shoe; 701, hard alloy tooth; 702, strip-shaped groove; 8, second sealing member; 10, second elastic member; 11, pressing strip. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] In the description of the present application, it should be noted that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", "horizontal", "vertical" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0033] As shown in Figures 1 to 5 A soluble variable-diameter tubing anchoring device, comprising a body 1 of a tubular structure, a plurality of floating anchor seats 4 are connected to the outer periphery of the body 1 in the radial direction, each floating anchor seat 4 is provided with a ball tooth mounting sleeve 401, the outer end of the ball tooth mounting sleeve 401 is open, the inner end is provided with a through hole connected with the through cavity of the body 1, the inner side of the ball tooth mounting sleeve 401 is provided with a ball tooth anchor shoe 7, and the ball tooth anchor shoe 7 is detachably fixedly installed with the floating anchor seat 4.

[0034] The anchoring process is that the body 1 is lowered into the casing of the wellbore, the inner cavity of the body 1 is pressurized, the liquid enters the ball tooth mounting sleeve 401 through the through hole, the ball tooth anchor shoe 7 is pushed to move radially by using hydraulic pressure, so that the ball tooth anchor shoe 7 extrudes the inner wall of the casing, the body 1 is anchored with the casing, and the pipe string is resisted from being pulled up or pressed down, so as to achieve the purpose of fixing the pipe string.

[0035] The floating anchor seat 4 is also arranged on the body 1, and under normal circumstances, the floating anchor seat 4 is in a radially expanded state, when the anchoring device passes through the casing deformation section, the floating anchor seat 4 is retracted due to being extruded by the inner wall of the casing, so as to adapt to the casing deformation section and ensure smooth further lowering.

[0036] The ball tooth mounting sleeve 401 is arranged on the floating anchor seat 4, the ball tooth anchor shoe 7 is installed through the ball tooth mounting sleeve 401, that is, the floating adaptation function and the anchoring function are integrated, one mechanism is used to realize two functions, the ball tooth anchor shoe 7 avoids occupying extra space alone, the structure is simplified, and the overall size of the device is reduced.

[0037] By integrating the ball tooth anchor shoe 7 on the floating anchor seat 4, the ball tooth anchor shoe 7 moves radially synchronously with the floating anchor seat 4 during the casing running process, so that the ball tooth anchor shoe 7 always maintains the closest position to the casing wall. After the hydraulic pressure is injected, the ball tooth anchor shoe 7 directly extends from the floating anchor seat 4 to clamp the casing wall, so that the anchoring is more firm, and the retraction path of the ball tooth anchor shoe 7 is long after the pressure is released, so that the ball tooth anchor shoe 7 is clamped, and the unclamping is more smooth.

[0038] As shown in Figure 2 , the outer periphery of the body 1 is provided with a spring groove 101 and a floating sealing hole 102, the first elastic member 5 is arranged in the spring groove 101, and the other end of the first elastic member 5 abuts against the inner side surface of the floating anchor seat 4; the outer side wall of the ball tooth mounting sleeve 401 is provided with the first sealing member 6 between the floating sealing hole 102, and the outer side wall of the ball tooth anchor shoe 7 is provided with the second sealing member 8 between the inner side wall of the ball tooth mounting sleeve 401. The first elastic member 5 elastically supports the floating anchor seat 4 in the radial direction, and when the deformed section of the casing wall presses the floating anchor seat 4, the floating anchor seat 4 retracts against the elastic force of the first elastic member 5 to avoid being clamped; the first sealing member 6 is used to prevent the pressurized liquid from leaking out of the floating sealing hole 102, and the second sealing member is used to prevent the pressurized liquid from leaking out of the ball tooth mounting sleeve 401, thereby ensuring the pressurizing effect on the ball tooth anchor shoe 7.

[0039] The body 1 is provided with an annular boss at both ends, the limiting pressure ring 2 is sleeved outside the annular boss, and the limiting pressure ring 2 is fixedly installed with the annular boss through the screw 3. One end of the limiting pressure ring 2 is offset from the annular boss to form a suspended end; the end edge of the floating anchor seat 4 is sleeved inside the suspended end of the limiting pressure ring 2, and the end of the floating anchor seat 4 abuts against the annular boss. By sleeving the suspended end of the limiting pressure ring 2 with the end edge of the floating anchor seat 4, the radial displacement of the floating anchor seat 4 is limited by the limiting pressure ring 2; by abutting the end of the floating anchor seat 4 with the annular boss, the axial displacement of the floating anchor seat 4 is limited.

[0040] As shown in Figure 4 , the outer side of the floating anchor seat 4 is provided with a pressing strip 11 in the axial direction, the two ends of the pressing strip 11 are bolted with the floating anchor seat 4, and the pressing strip 11 abuts against the outer side port of the ball tooth mounting sleeve 401. After the casing is run in, the pressing strip 11 seals the ball tooth anchor shoe 7 to prevent it from coming out, and when the ball tooth anchor shoe 7 is pressurized, the ball tooth anchor shoe 7 is displaced radially outward, and the pressing strip 11 limits the maximum displacement of the ball tooth anchor shoe 7.

[0041] As shown in Figure 5As shown, the outer side of the floating anchor seat 4 is provided with a sink groove 402 matched with the pressing strip 11, the ball tooth anchor shoe 7 is provided with a strip-shaped groove 702 in the axial direction, the pressing strip 11 is inserted into the strip-shaped groove 702, and the second elastic member 10 is arranged between the pressing strip 11 and the groove bottom of the strip-shaped groove 702; when no hydraulic pressure is injected, the ball tooth anchor shoe 7 is always in a contracted state under the action of the second elastic member 10, so that the ball tooth anchor shoe 7 can avoid rubbing the inner wall of the casing; after the hydraulic pressure is injected, the ball tooth anchor shoe 7 is radially displaced outward against the elastic force of the second elastic member 10, the second elastic member 10 is compressed, and the pressing strip 11 is inserted into the strip-shaped groove 702; after the pressure is released, the ball tooth anchor shoe 7 is retracted under the elastic force of the second elastic member 10, and the unblocking is realized.

[0042] Both ends of the body 1 are provided with connecting threads, and one side of one of the connecting threads is provided with an axially extending positioning groove 103. The connecting threads are used for being connected with other tools for use, and the positioning groove 103 is used for controlling the direction when being connected with other tools. In some embodiments, a plurality of anchor devices can be used in series, and the phase control of the tools can be realized through the positioning groove 103.

[0043] A plurality of floating anchor seats 4 are arranged in a circumferential array on the outer circumferential side of the body 1. The force on the circumferential side of the body 1 is more balanced, the inclination is avoided, and the anchoring is more stable.

[0044] The ball tooth anchor shoe 7 is made of a soluble metal material. After the construction work is completed, a liquid that can accelerate the dissolution of the soluble metal material is injected into the casing, so that the ball tooth anchor shoe 7 is quickly dissolved, the unblocking is realized, and the unblocking difficulty caused by the fatigue of the elastic member or the sand blocking is avoided.

[0045] As shown in the figure, Figure 5 The outer side of the ball tooth anchor shoe 7 is provided with a hard alloy tooth 701. The number of hard alloy teeth on a single ball tooth anchor shoe 7 is 8, which is used to firmly grasp the casing wall.

[0046] A use method of a soluble variable-diameter tubing anchor device, comprising the following steps:

[0047] S1, the anchor device is lowered into the casing in the well, and the floating anchor seat 4 is radially expanded under the action of the elastic member;

[0048] S2, when the deformation section of the casing is encountered, the floating anchor seat 4 is retracted along the radial direction under the action of the casing wall of the deformation section, so that the anchor device can continue to be lowered smoothly;

[0049] S3, after the anchor device is lowered to the predetermined position, high-pressure liquid is injected into the inner cavity of the body 1, the high-pressure liquid enters the through hole of the ball tooth mounting sleeve 401, pushes the ball tooth anchor shoe 7 to extend radially outward, and clamps the inner wall of the casing;

[0050] S4, after the construction operation is completed, inject into the sleeve a liquid that can accelerate the dissolution of the soluble metal material, so that the ball anchor shoe 7 is quickly dissolved.

[0051] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A dissolvable variable diameter liner anchoring device, comprising: The body (1) comprising a pipe body structure, the outer periphery of the body (1) is elastically connected with a plurality of floating anchor seats (4) in the radial direction, each of the floating anchor seats (4) is provided with a ball tooth mounting sleeve (401), the outer end of the ball tooth mounting sleeve (401) is open, the inner end is provided with a through hole connected with the through cavity of the body (1), the inner side of the ball tooth mounting sleeve (401) is provided with a ball tooth anchor tile (7), the ball tooth anchor tile (7) is detachably fixedly installed with the floating anchor seat (4); The outer periphery of the body (1) is provided with a spring groove (101) and a floating sealing hole (102), the first elastic member (5) is arranged in the spring groove (101), and the other end of the first elastic member (5) abuts against the inner side of the floating anchor seat (4); The both ends of the body (1) are provided with annular bosses, the limiting pressure ring (2) is sleeved on the outer side of the annular boss, is fixedly installed with the annular boss through the screw (3), and the one end of the limiting pressure ring (2) is staggered with the annular boss to form a suspended end; the end edge of the floating anchor seat (4) is sleeved on the inner side of the suspended end of the limiting pressure ring (2), and the end of the floating anchor seat (4) abuts against the annular boss.

2. The dissolvable variable diameter liner anchor of claim 1, wherein, The outer side of the floating anchor seat (4) is provided with a pressing strip (11) in the axial direction, the both ends of the pressing strip (11) are bolted with the floating anchor seat (4), and the pressing strip (11) abuts against the outer open end of the ball tooth mounting sleeve (401).

3. A dissolvable variable diameter liner anchor as defined in claim 2, wherein, The outer side of the floating anchor seat (4) is provided with a sunken groove (402) matched with the pressing strip (11), the ball tooth anchor tile (7) is provided with a strip-shaped groove (702) in the axial direction, the pressing strip (11) is inserted into the strip-shaped groove (702), and the second elastic member (10) is arranged between the pressing strip (11) and the groove bottom of the strip-shaped groove (702).

4. The dissolvable variable diameter liner anchor of claim 1, wherein, The both ends of the body (1) are provided with connecting threads, and one side of the connecting thread is provided with an axially extending positioning groove (103).

5. The dissolvable variable diameter liner anchor of claim 1, wherein, The first sealing member (6) is arranged between the outer side wall of the ball tooth mounting sleeve (401) and the floating sealing hole (102); and the second sealing member (8) is arranged between the outer side wall of the ball tooth anchor tile (7) and the inner side wall of the ball tooth mounting sleeve (401).

6. The dissolvable variable diameter liner anchor of claim 1, wherein, The ball tooth anchor tile (7) is made of a soluble metal material.

7. The dissolvable variable diameter liner anchor of claim 1, wherein, The outer side of the ball tooth anchor tile (7) is provided with a hard alloy tooth (701).

8. A method of using a dissolvable variable diameter liner anchor as claimed in any one of claims 1 to 7, wherein, The method comprises the following steps: S1, the anchor device is lowered into the casing in the well, and the floating anchor seat (4) is expanded in the radial direction under the action of the elastic member; S2, when the deformed section of the casing is encountered, the floating anchor seat (4) is retracted in the radial direction under the action of the casing wall of the deformed section, so that the anchor device can continue to be lowered smoothly; S3, after the anchor device is lowered to the predetermined position, high-pressure liquid is injected into the inner cavity of the body (1), the high-pressure liquid enters the through hole of the ball tooth mounting sleeve (401), the ball tooth anchor tile (7) is pushed to stretch out in the radial direction, and the inner wall of the casing is clamped; S4, after the construction operation is completed, inject the liquid which can accelerate the dissolution of the soluble metal material into the sleeve, so that the ball anchor shoe (7) is quickly dissolved.

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