Underground cutting tool anchoring device

Abstract

The invention discloses an anchoring device for an underground cutting tool. The technical problem that the anchoring effect is poor is solved. The device comprises an anchoring shell, an upper connector, a lower bearing and an inner core pipe and further comprises a plurality of anchoring arms, the anchoring arms are hinged to the anchoring shell and distributed in the circumferential direction of the anchoring shell at equal intervals, the length direction of the anchoring arms is parallel to the axial direction of the anchoring shell, and the length direction of the anchoring arms is parallel to the axial direction of the anchoring shell. The axial direction of a hinge shaft on each anchoring arm is parallel to the axial direction of the anchoring shell, and the upper end and the lower end of the side, away from the hinge shaft, of each anchoring arm are each provided with an anchoring block used for abutting against the inner wall of a tubular column. And the control piece is arranged between the anchoring shell and the multiple anchoring arms and used for controlling the multiple anchoring arms to rotate synchronously. The anchoring effect can be improved, it is guaranteed that cutting operation is conducted smoothly, meanwhile, the anchoring arm can be automatically retracted, and the risk that a tool is clamped in the lifting process is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and in particular relates to a downhole cutting tool anchoring device. Background Art

[0002] With the continuous deepening of oil field development and exploitation, the deformation and breakage of downhole oil casing are increasing year by year. When the pipe string is stuck in the well and cannot be pulled out normally during operation, it is necessary to cut the pipe string first. In the Chinese waters alone, there are hundreds of well-times of cutting operations every year.

[0003] In the current context of cost reduction, efficiency improvement and green development, downhole oil casing cutting tools have become a more environmentally friendly and efficient cutting tool. The instrument uses cable transmission and is a domestically produced instrument that can cut oil and casing in deep wells. It can complete quantitative and multiple cutting in one trip down the well.

[0004] Compared with traditional cutting methods, downhole oil casing cutting tools do not require the use of explosives and other pyrotechnics and hazardous chemicals, are not affected by well inclination, liquid media in the well, and liquid flow in the well. The cutting process can be monitored from the ground, has high cutting accuracy, and a smooth cutting section. It can be flexibly applied to various pipe cutting operations and has extremely high flexibility and convenience in dealing with and solving complex well conditions.

[0005] However, downhole cutting in related technologies faces the following problems:

[0006] (1) The anchoring point setting of the anchoring device is too simple, that is, the anchoring device only sets three anchoring points on the same plane to ensure the stability of the instrument. This anchoring method is only applicable to the working condition where the wellbore is completely vertical. In a highly inclined well or horizontal well, the anchoring method of three anchoring points is not enough to stably support the instrument. The instrument will tilt under the action of gravity, and the unstable anchoring force will lead to operation failure.

[0007] (2) The anchoring arm lacks the automatic retraction function. When the cutting operation is completed or the instrument fails, the anchoring motor and pump stop working, and the anchoring arm is not retracted or is not retracted completely. It is easy for the anchoring arm to get stuck during the lifting process, causing great losses. Summary of the invention

[0008] In order to solve all or part of the above problems, the purpose of the present invention is to provide a downhole cutting tool anchoring device, which can improve the anchoring effect and ensure the smooth progress of the cutting operation. The anchoring arm of the anchoring device can be automatically retracted to effectively reduce the risk of getting stuck during the tool lifting process.

[0009] The present invention provides a downhole cutting tool anchoring device, comprising:

[0010] An anchor shell, arranged in a cylindrical shape;

[0011] An upper connector, disposed on the top of the anchor shell and used for connecting with external instruments;

[0012] A lower bearing, disposed at the bottom of the anchor shell and used for connecting with external instruments;

[0013] An inner core tube is coaxially arranged in the anchor shell, and the top of the inner core tube is connected to the upper joint, and the bottom is connected to the lower bearing;

[0014] A plurality of anchoring arms, each of which is hinged to the anchoring shell, and the plurality of anchoring arms are arranged at equal intervals along the circumference of the anchoring shell, and the length direction of the anchoring arm is parallel to the axial direction of the anchoring shell, the axial direction of the hinge axis on the anchoring arm is parallel to the axial direction of the anchoring shell, and each of the anchoring arms is provided with an anchor block for pressing against the inner wall of the pipe column at the upper and lower ends of the side away from the hinge axis;

[0015] The control component is arranged between the anchoring shell and the plurality of anchoring arms and is used for controlling the synchronous rotation of the plurality of anchoring arms.

[0016] Optionally, the control element includes:

[0017] A control piston is slidably sleeved on the inner core tube, and a hydraulic ring cavity is formed between the control piston, the upper joint, the anchor shell and the inner core tube;

[0018] A hydraulic channel is provided on the upper joint, one end of the hydraulic channel is used to communicate with a hydraulic device of an external instrument, and the other end of the hydraulic channel is communicated with the hydraulic ring cavity;

[0019] A plurality of strip holes are respectively arranged on the anchor shell, the length direction of the strip holes is parallel to the axial direction of the anchor shell, and the plurality of strip holes are arranged in one-to-one correspondence with the plurality of anchor arms;

[0020] There are multiple guide blocks, which are fixed on the control piston respectively, and the multiple guide blocks are slidably connected with the corresponding strip holes respectively;

[0021] Control balls, which come in multiple groups and are respectively fixed on the corresponding guide blocks;

[0022] Each group of control grooves is arc-shaped, and each group of control balls is slidably matched with the corresponding control grooves. When the control piston drives the control balls to slide along the inner core tube, the anchoring arm can rotate under the action of the corresponding control balls and control grooves.

[0023] Optionally, the control element further includes:

[0024] The guide tube is sleeved on the inner core tube, and the bottom is connected to the lower bearing. The bottom of the control piston is slidably sleeved on the guide tube.

[0025] Optionally, the control element further includes:

[0026] A control spring is arranged between the control piston and the guide tube and is used to push the control piston to move toward the upper joint so that the plurality of anchoring arms can be smoothly retracted.

[0027] Optionally, the control spring is sleeved on the inner core tube, and a step groove is provided at the lower end of the inner wall side of the control piston. The bottom of the control spring is connected to the guide tube, the top is located in the step groove, and is connected to the bottom of the step groove.

[0028] Optionally, a seal is formed between the control piston and the anchor shell and the inner core tube respectively through a sealing ring.

[0029] Optionally, the outer surface of the anchor shell is provided with a clearance ring groove along its circumference, and the cross-section of each anchor arm is arc-shaped. When the anchor arm is retracted, the inner surface of the anchor arm is in close contact with the bottom of the clearance ring groove, and the outer surface is flush with the outer surface of the anchor shell.

[0030] Optionally, a plurality of pairs of articulated blocks are arranged in the yield ring groove, and the plurality of pairs of articulated blocks are arranged in one-to-one correspondence with the plurality of anchor arms, and each pair of articulated blocks are respectively located at the two end positions of the corresponding anchor arms, and two articulated shafts are respectively arranged on each anchor arm, and the articulated shafts are distributed at the two ends of the anchor arms, and are rotatably connected with the corresponding articulated blocks through rotating sleeves.

[0031] Optionally, multiple pairs of support blocks are arranged in the yield ring groove, and the multiple pairs of support blocks are arranged one-to-one corresponding to the multiple anchor arms, each of the anchor arms is respectively provided with two support notches, each pair of support blocks is respectively located in the corresponding support notches, and the end of the hinge axis on each hinge block away from the corresponding hinge block passes through the corresponding support block and is rotatably connected to the support block.

[0032] Optionally, a clearance groove is formed between two adjacent hinge blocks located on the same side of the clearance ring groove. When the anchor arm is retracted, multiple anchor blocks can enter the corresponding clearance grooves respectively, and the outer surface of the anchor block is flush with the outer surface of the anchor shell.

[0033] It can be seen from the above technical solution that the downhole cutting tool anchoring device provided by the present invention has the following advantages:

[0034] The device uses multi-point anchoring to effectively improve the anchoring effect, ensure the instrument is firmly connected to the wellbore, and thus ensure the smooth progress of the cutting operation. At the same time, when the cutting operation is completed, the anchoring arm can be smoothly retracted, reducing the risk of the tool getting stuck during the lifting process, thereby improving the stability of use.

[0035] Other features and advantages of the present invention will be set forth in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0037] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0038] Figure 2 is a cross-sectional view of an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of the structure when the anchoring arm is expanded in an embodiment of the present invention;

[0040] Figure 4 A bottom view of the anchor arm when it is spread out in the embodiment of the present invention;

[0041] Figure 5 1 is a side view of an anchoring arm in an embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 1. Anchor shell; 2. Upper joint; 3. Lower bearing; 4. Inner core tube; 5. Anchor arm; 6. Articulated shaft; 7. Anchor block; 8. Control member; 81. Control piston; 82. Hydraulic ring cavity; 83. Hydraulic channel; 84. Strip hole; 85. Control ball; 86. Control groove; 87. Guide tube; 88. Control spring; 89. Step groove; 90. Guide block; 9. Sealing ring; 10. Give way ring groove; 11. Articulated block; 12. Rotating sleeve; 13. Support block; 14. Give way groove; 15. Support notch. DETAILED DESCRIPTION

[0044] To make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other arbitrarily without conflict.

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5The embodiment of the present invention is shown in the figure, which discloses a downhole cutting tool anchoring device, including a cylindrical anchoring shell 1, the top of which is fixedly connected to an upper joint 2, and the bottom of which is fixedly connected to a lower bearing 3, a wiring terminal is arranged in the upper joint 2 so that the upper joint 2 can be electrically connected to an external instrument, and the lower bearing 3 is used to connect to an external instrument that needs to rotate. An inner core tube 4 is coaxially arranged in the anchoring shell 1, the top of the inner core tube 4 is connected to the upper joint 2, and the bottom is connected to the lower bearing 3, and the inner core tube 4 mainly plays the role of passing the line or oil.

[0046] In one embodiment, Figure 1 , Figure 3 , Figure 4 As shown, multiple anchor arms 5 are hinged on the outer side of the anchor shell 1, and the multiple anchor arms 5 are arranged at equal intervals along the circumference of the anchor shell 1, and the length direction of the anchor arms 5 is parallel to the axial direction of the anchor shell 1. The axial direction of the hinge shaft 6 on the anchor arm 5 is parallel to the axial direction of the anchor shell 1, and each anchor arm 5 is integrally formed with an anchor block 7 for pressing against the inner wall of the pipe column at the upper and lower ends of the side away from the hinge shaft 6. A control member 8 is provided between the anchor shell 1 and the multiple anchor arms 5, and the control member 8 is used to control the synchronous rotation of the multiple anchor arms 5 so that the multiple anchor arms 5 are synchronously expanded or retracted.

[0047] The downhole cutting tool anchoring device in this embodiment adopts multi-point anchoring. Compared with the traditional three-point anchoring, this design can effectively improve the anchoring effect and ensure a firm connection between the instrument and the wellbore, thereby ensuring the smooth progress of the cutting operation.

[0048] In this embodiment, three anchoring arms 5 are provided, and the three anchoring arms 5 are arranged at intervals of 120°. Therefore, the anchoring device has a total of six anchoring points, which effectively improves the anchoring effect.

[0049] In one embodiment, Figure 1 , Figure 2 , Figure 3 As shown, the control member 8 includes a control piston 81 slidably sleeved on the inner core tube 4, the inner side wall of the control piston 81 is tightly abutted against the inner core tube 4, the outer side wall is tightly abutted against the anchor shell 1, and a hydraulic ring cavity 82 is formed between the top of the control piston 81, the inner side wall of the anchor shell 1 and the outer side wall of the inner core tube 4. A hydraulic channel 83 is provided on the upper joint 2, one end of the hydraulic channel 83 is used to communicate with the hydraulic device of the external instrument, and the other end is communicated with the hydraulic ring cavity 82. When the hydraulic medium enters the hydraulic ring cavity 82 through the hydraulic channel 83, the control piston 81 can move downward under the action of the hydraulic medium.

[0050] In one embodiment, Figure 1 , Figure 2 , Figure 3As shown, the anchor shell 1 is provided with a plurality of strip holes 84, which are arranged one by one corresponding to the plurality of anchor arms 5, and the length direction of the strip holes 84 is parallel to the axial direction of the anchor shell 1. A plurality of guide blocks 90 are fixedly connected to the control piston 81, and the plurality of guide blocks 90 are respectively vertically slidably matched with the corresponding strip holes 84, and a group of control balls 85 are respectively fixedly connected to each guide block 90.

[0051] In one embodiment, Figure 2 , Figure 3 , Figure 5 As shown, each anchor arm 5 is provided with a group of arc-shaped control grooves 86 on one side close to its hinge shaft 6, and each group of control balls 85 slides with the corresponding control grooves 86. When the control piston 81 drives the control balls 85 to slide along the inner core tube 4, the anchor arm 5 can rotate under the action of the corresponding control balls 85 and the control grooves 86.

[0052] In one embodiment, Figure 2 As shown, the control member 8 also includes a guide tube 87 sleeved on the inner core tube 4, the bottom of the guide tube 87 is fixedly connected to the lower bearing 3, and the bottom of the control piston 81 is slidably sleeved on the guide tube 87 to improve the guiding effect on the control piston 81, so that the control piston 81 can slide smoothly.

[0053] In one embodiment, Figure 2 As shown, the control member 8 further includes a control spring 88 sleeved on the inner core tube 4, and a step groove 89 is provided at the lower end of the inner wall side of the control piston 81. The bottom of the control spring 88 is connected to the guide tube 87, and the top is located in the step groove 89 and connected to the bottom of the step groove 89. When the control piston 81 moves downward, the control spring 88 is compressed and deformed, and when the hydraulic medium is depressurized, the control spring 88 can push the control piston 81 to move upward.

[0054] When the hydraulic device of the external instrument delivers the hydraulic medium to the hydraulic ring cavity 82, the control piston 81 drives the control ball 85 to move downward under the action of the hydraulic medium. At this time, the multiple anchoring arms 5 rotate under the action of the corresponding control balls 85 and the inner wall of the control groove 86, that is, the multiple anchoring arms 5 are synchronously expanded until the anchoring blocks 7 at both ends of each anchoring arm 5 are tightly abutted against the inner wall of the wellbore, thereby realizing the anchoring of the instrument.

[0055] When the cutting operation is completed, or the instrument fails and the anchoring motor and pump stop working, the hydraulic medium no longer provides thrust. At this time, the control spring 88 pushes the control piston 81 to drive the control ball 85 to move upward, and the multiple anchoring arms 5 rotate under the action of the corresponding control balls 85 and the inner walls of the control groove 86, that is, the multiple anchoring arms 5 are retracted synchronously to avoid jamming when the tool is lifted.

[0056] In this embodiment, each group of control balls 85 is provided with two, that is, each group of control slots 86 is provided with two, so as to improve the fault tolerance and ensure that the anchor arm 5 can be smoothly opened and retracted. By converting the vertical force of the control ball 85 into the rotational force of the anchor arm 5, the design is ingenious. Compared with other control mechanisms, this design can effectively save costs and ensure that the anchor arm 5 rotates smoothly and reliably.

[0057] In one embodiment, Figure 2 As shown, the control piston 81 and the anchor shell 1 and the inner core tube 4 are sealed by sealing rings 9, that is, the two ends of the outer wall of the control piston 81 are respectively fixedly sleeved with sealing rings 9, and the sealing rings 9 are tightly abutted against the inner wall of the anchor shell 1 to ensure effective sealing between the control piston 81 and the anchor shell 1. At the same time, the inner wall of the control piston 81 is also fixedly embedded with a sealing ring 9, and the sealing ring 9 is tightly abutted against the outer wall of the inner core tube 4 to ensure effective sealing between the control piston 81 and the inner core tube 4.

[0058] In one embodiment, Figure 1 , Figure 3 As shown, the outer surface of the anchor shell 1 is provided with a clearance ring groove 10 along its circumference, and the cross section of each anchor arm 5 is arc-shaped. When the anchor arm 5 is spread out, the end of the anchor arm 5 close to the anchor block 7 can be exposed from the clearance ring groove 10, and the anchor block 7 is pressed against the inner wall of the wellbore. When the anchor arm 5 is retracted, the inner surface of the anchor arm 5 is in close contact with the bottom of the clearance ring groove 10, and the outer surface of the anchor arm 5 is flush with the outer surface of the anchor shell 1. This design can minimize the outer diameter of the anchor device, so that the anchor device can enter a wellbore with a smaller inner diameter to improve the adaptability of use.

[0059] In one embodiment, Figure 1 , Figure 3 As shown, multiple pairs of hinge blocks 11 are arranged in the clearance ring groove 10, and the multiple pairs of hinge blocks 11 are arranged one by one corresponding to the multiple anchor arms 5, and each pair of hinge blocks 11 is symmetrically distributed at the two ends of the corresponding anchor arm 5. At the same time, two hinge shafts 6 are respectively provided on each anchor arm 5, and the two hinge shafts 6 are symmetrically distributed at the two ends of the anchor arm 5, and are rotatably connected with the corresponding hinge block 11 through the rotating shaft sleeve 12.

[0060] In one embodiment, Figure 1 , Figure 3As shown, multiple pairs of support blocks 13 are arranged in the yielding ring groove 10, and the multiple pairs of support blocks 13 are arranged one by one with the multiple anchoring arms 5, and each pair of support blocks 13 are symmetrically distributed on both sides of the corresponding strip hole 84. Two support notches 15 are respectively arranged on each anchoring arm 5, and each pair of support blocks 13 are respectively located in the corresponding support notches 15. At the same time, one end of each hinge block 11 away from the rotating shaft sleeve 12 passes through the corresponding support block 13 and is rotatably connected with the support block 13 to improve the support effect on the anchoring arm 5, thereby improving stability.

[0061] In one embodiment, Figure 1 , Figure 3 As shown, a clearance groove 14 is formed between two adjacent hinge blocks 11 located on the same side of the clearance ring groove 10. When the anchor arm 5 is retracted, multiple anchor blocks 7 can enter the corresponding clearance grooves 14 respectively, and the outer surface of the anchor block 7 is flush with the outer surface of the anchor shell 1, so as to improve the compactness of the design and reduce the overall size of the anchoring device.

[0062] As can be seen from the above, the anchoring device can improve the anchoring effect, ensure the instrument is firmly connected to the wellbore, and thus ensure the smooth progress of the cutting operation. At the same time, the anchoring arm 5 can be smoothly retracted and urgently retracted, which can not only reduce the risk of getting stuck when lifting the tool, but also ensure that the anchoring arm 5 can be urgently retracted when the anchoring device fails, thereby improving the stability of use.

[0063] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present invention should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0064] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A downhole cutting tool anchoring device, characterized in that: include: An anchor shell (1) is arranged in a cylindrical shape; An upper connector (2) is arranged on the top of the anchor shell (1) and is used to connect with external instruments; A lower bearing (3), arranged at the bottom of the anchor shell (1) and used for connecting with external instruments; An inner core tube (4) is coaxially arranged in the anchor shell (1), and the top of the inner core tube (4) is connected to the upper joint (2), and the bottom is connected to the lower bearing (3); A plurality of anchoring arms (5) are respectively hinged to the anchoring shell (1); the plurality of anchoring arms (5) are arranged at equal intervals along the circumference of the anchoring shell (1); the length direction of the anchoring arms (5) is parallel to the axial direction of the anchoring shell (1); the axial direction of the hinge shaft (6) on the anchoring arm (5) is parallel to the axial direction of the anchoring shell (1); and an anchoring block (7) for pressing against the inner wall of the pipe column is respectively arranged at the upper and lower ends of each anchoring arm (5) away from the hinge shaft (6); A control component (8) is arranged between the anchoring shell (1) and the plurality of anchoring arms (5), and is used to control the synchronous rotation of the plurality of anchoring arms (5).

2. The downhole cutting tool anchoring device according to claim 1, characterized in that: The control member (8) comprises: A control piston (81) is slidably sleeved on the inner core tube (4), and a hydraulic ring chamber (82) is formed between the control piston (81), the upper joint (2), the anchor shell (1) and the inner core tube (4); A hydraulic channel (83) is provided on the upper joint (2), one end of the hydraulic channel (83) is used to communicate with a hydraulic device of an external instrument, and the other end of the hydraulic channel (83) is communicated with the hydraulic ring chamber (82); A plurality of strip holes (84) are respectively arranged on the anchor shell (1); the length direction of the strip holes (84) is parallel to the axial direction of the anchor shell (1); and the plurality of strip holes (84) are arranged in one-to-one correspondence with the plurality of anchor arms (5); A plurality of guide blocks (90) are respectively fixed on the control piston (81), and the plurality of guide blocks (90) are respectively slidably connected to the corresponding strip-shaped holes (84); Control balls (85), which are in multiple groups and are respectively fixed on the corresponding guide blocks; Control grooves (86), which are in multiple groups and are respectively arranged on the corresponding anchoring arms (5); Each group of the control grooves (86) is arc-shaped, and each group of the control balls (85) is slidably matched with the corresponding control grooves (86). When the control piston (81) drives the control balls (85) to slide along the inner core tube (4), the anchoring arm (5) can rotate under the action of the corresponding control balls (85) and the control grooves (86).

3. The downhole cutting tool anchoring device according to claim 2, characterized in that: The control element (8) further comprises: The guide tube (87) is sleeved on the inner core tube (4) and the bottom is connected to the lower bearing (3). The bottom of the control piston (81) is slidably sleeved on the guide tube (87).

4. The downhole cutting tool anchoring device according to claim 3, characterized in that: The control element (8) further comprises: A control spring (88) is disposed between the control piston (81) and the guide tube (87) and is used to push the control piston (81) to move toward the upper joint (2) so that the plurality of anchor arms (5) can be smoothly retracted.

5. The downhole cutting tool anchoring device according to claim 4, characterized in that: The control spring (88) is sleeved on the inner core tube (4), and a step groove (89) is provided at the lower end of the inner wall side of the control piston (81). The bottom of the control spring (88) is connected to the guide tube (87), and the top is located in the step groove (89) and connected to the bottom of the step groove (89).

6. The downhole cutting tool anchoring device according to claim 2, characterized in that: The control piston (81) and the anchor shell (1) and the inner core tube (4) are sealed respectively by sealing rings (9).

7. The downhole cutting tool anchoring device according to claim 1, characterized in that: The outer surface of the anchor shell (1) is provided with a clearance ring groove (10) along its circumference, and the cross section of each anchor arm (5) is arc-shaped. When the anchor arm (5) is retracted, the inner surface of the anchor arm (5) is tightly attached to the bottom of the clearance ring groove (10), and the outer surface is flush with the outer surface of the anchor shell (1).

8. The downhole cutting tool anchoring device according to claim 7, characterized in that: A plurality of pairs of hinge blocks (11) are arranged in the clearance ring groove (10), and the plurality of pairs of hinge blocks (11) are arranged in one-to-one correspondence with the plurality of anchor arms (5), and each pair of hinge blocks (11) is respectively located at the two end positions of the corresponding anchor arms (5), and two hinge shafts (6) are respectively arranged on each anchor arm (5), and the hinge shafts (6) are distributed at the two ends of the anchor arm (5), and are rotatably connected with the corresponding hinge block (11) through a rotating shaft sleeve (12).

9. The downhole cutting tool anchoring device according to claim 8, characterized in that: A plurality of pairs of support blocks (13) are arranged in the clearance ring groove (10), and the plurality of pairs of support blocks (13) are arranged in one-to-one correspondence with the plurality of anchor arms (5), and each anchor arm (5) is respectively provided with two support notches (15), and each pair of support blocks (13) is respectively located in the corresponding support notches (15), and an end of the hinge shaft (6) on each hinge block (11) away from the corresponding hinge block (11) passes through the corresponding support block (13) and is rotatably connected to the support block (13).

10. The downhole cutting tool anchoring device according to claim 8, characterized in that: A clearance groove (14) is formed between two adjacent hinge blocks (11) located on the same side of the clearance ring groove (10). When the anchor arm (5) is retracted, a plurality of anchor blocks (7) can enter the corresponding clearance groove (14) respectively, and the outer surface of the anchor block (7) is flush with the outer surface of the anchor shell (1).

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