An anchor device for a downhole cutting tool

Abstract

The application discloses a downhole cutting tool anchoring device, which solves the technical problem of poor anchoring effect. The device comprises an anchoring shell, an upper joint, a lower bearing and an inner core pipe, and further comprises: anchoring arms, which are multiple in number and are respectively hinged to the anchoring shell, the multiple anchoring arms are arranged at equal intervals along the circumference of the anchoring shell, the length direction of the anchoring arms is parallel to the axial direction of the anchoring shell, the axial direction of the hinge shafts on the anchoring arms is parallel to the axial direction of the anchoring shell, and the upper and lower ends of each anchoring arm on the side away from the hinge shaft are respectively provided with anchoring blocks for abutting against the inner wall of the pipe column; a control member is arranged between the anchoring shell and the multiple anchoring arms and is used for controlling the synchronous rotation of the multiple anchoring arms. The application can improve the anchoring effect, ensure the smooth cutting operation, and meanwhile, the anchoring arms can be automatically retracted, effectively reducing the risk of sticking during the lifting of the tool.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, and specifically relates to a downhole cutting tool anchoring device. Background Technology

[0002] As oilfield development and exploitation continue to deepen, the phenomena of deformation and misalignment of downhole casing and tubing are increasing year by year. When the tubing string gets stuck or cannot be pulled out normally during operation, it is necessary to cut the tubing string first. In the Chinese sea area alone, there are hundreds of well cutting operations required every year.

[0003] In the context of current cost reduction, efficiency improvement, and green development, downhole casing cutting tools have become a more environmentally friendly and efficient cutting tool. This instrument uses cable delivery and is a domestically produced instrument that can perform oil and casing cutting in deep wells, enabling quantitative and multiple cuts to be completed in one trip down the well.

[0004] Compared to traditional cutting methods, downhole casing cutting tools do not require the use of explosives or other pyrotechnics or hazardous chemicals. They are unaffected by well inclination, the liquid medium inside the well, or the flow of the liquid inside the well. The cutting process can be monitored from the ground, and the cutting precision is high, resulting in a smooth cut surface. They can be flexibly applied to various tubing cutting operations and have extremely high flexibility and convenience when dealing with 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 in the same plane circumferential direction to ensure the stability of the instrument. This anchoring method is only suitable for the working condition where the well is completely vertical. In wells with high deviance or horizontal wells, 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 the failure of the operation.

[0007] (2) The anchor arm lacks an automatic retraction function. When the cutting operation is completed or the instrument malfunctions and the anchor motor and pump stop working, the anchor arm is not retracted or is not retracted completely. During the lifting process, it is easy to get stuck, causing significant losses. Summary of the Invention

[0008] In order to solve all or some of the above problems, the purpose of this invention is to provide an anchoring device for downhole cutting tools, which can improve the anchoring effect, ensure the smooth progress of cutting operations, and the anchoring arm of the anchoring device can automatically retract, effectively reducing the risk of getting stuck during the tool lifting process.

[0009] This invention provides an anchoring device for downhole cutting tools, comprising:

[0010] The anchoring shell is cylindrical in shape.

[0011] The upper connector is located at the top of the anchoring shell and is used to connect to external instruments;

[0012] The lower bearing is located at the bottom of the anchor housing and is used for connection with external instruments;

[0013] The inner core tube is coaxially disposed inside the anchoring shell, and the top of the inner core tube is connected to the upper connector and the bottom is connected to the lower bearing;

[0014] Anchor arms, in multiple quantities, are hinged to the anchor shell. The multiple anchor arms are arranged at equal intervals along the circumference of the anchor shell, and the length direction of the anchor arms is parallel to the axial direction of the anchor shell. The axial direction of the hinge shaft on the anchor arm is parallel to the axial direction of the anchor shell. Each anchor arm has an anchor block at its upper and lower ends on the side away from its hinge shaft for abutting against the inner wall of the column.

[0015] A control element is disposed between the anchoring shell and the plurality of anchoring arms, and is used to control the synchronous rotation of the plurality of anchoring arms.

[0016] Optionally, the control element includes:

[0017] The control piston is slidably sleeved on the inner core tube, and a hydraulic annular cavity is formed between the control piston, the upper connector, the anchor shell, and the inner core tube.

[0018] A hydraulic channel is provided on the upper connector, one end of which is used to communicate with the hydraulic device of an external instrument, and the other end is used to communicate with the hydraulic annular cavity;

[0019] Multiple strip-shaped holes are provided on the anchoring shell, with the length direction of the strip-shaped holes parallel to the axial direction of the anchoring shell, and each of the multiple strip-shaped holes is provided in a one-to-one correspondence with a multiple of the anchoring arms;

[0020] Multiple guide blocks are fixed to the control piston, and each guide block is slidably connected to a corresponding strip hole.

[0021] The control balls are in multiple sets and are respectively fixed on the corresponding guide blocks;

[0022] Each set of control grooves is arc-shaped, and each set of control balls slides in cooperation with the corresponding control groove. When the control piston drives the control ball to slide along the inner core tube, the anchoring arm can rotate under the action of the corresponding control ball and control groove.

[0023] Optionally, the control element further includes:

[0024] A guide tube is sleeved on the inner core tube and its 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 disposed between the control piston and the guide tube and is used to push the control piston toward the upper connector so that the plurality of anchor arms can be retracted smoothly.

[0027] Optionally, the control spring is sleeved on the inner core tube, and a stepped 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 stepped groove, and is connected to the bottom of the stepped groove.

[0028] Optionally, the control piston is sealed to the anchoring shell and the inner core tube by sealing rings.

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

[0030] Optionally, the clearance ring groove is provided with multiple pairs of hinge blocks, each pair of hinge blocks is provided in a one-to-one correspondence with multiple anchoring arms, and each pair of hinge blocks is located at both ends of the corresponding anchoring arm. Each anchoring arm is provided with two hinge shafts, and the hinge shafts are distributed at both ends of the anchoring arm and are rotatably connected to the corresponding hinge blocks through rotating bushings.

[0031] Optionally, the clearance ring groove is provided with multiple pairs of support blocks, and the multiple pairs of support blocks are provided one-to-one with multiple anchoring arms. Each anchoring arm is provided with two support notches. Each pair of support blocks is located in the corresponding support notch. The end of the hinge shaft 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 relief groove is formed between two adjacent hinge blocks on the same side of the relief ring groove. When the anchoring arm is retracted, the multiple anchoring blocks can enter the corresponding relief grooves respectively, and the outer surface of the anchoring block is flush with the outer surface of the anchoring shell.

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

[0034] This device employs multi-point anchoring to effectively improve the anchoring effect, ensuring a stable connection between the instrument and the wellbore, thereby guaranteeing smooth cutting operations. Furthermore, after the cutting operation is completed, the anchoring arm can be smoothly retracted, reducing the risk of jamming during tool lifting and thus improving operational stability.

[0035] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0036] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

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

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

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

[0040] Figure 4 This is a bottom view of the anchoring arm when it is extended in an embodiment of the present invention;

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

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Anchor housing; 2. Upper connector; 3. Lower bearing; 4. Inner core tube; 5. Anchor arm; 6. Hinge shaft; 7. Anchor block; 8. Control component; 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. Relief ring groove; 11. Hinge block; 12. Rotating bushing; 13. Support block; 14. Relief groove; 15. Support notch. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5The illustration shows an embodiment of the present invention, which discloses a downhole cutting tool anchoring device, including a cylindrical anchoring shell 1. An upper connector 2 is fixedly connected to the top of the anchoring shell 1, and a lower bearing 3 is fixedly connected to the bottom. The upper connector 2 has a wiring terminal inside, enabling it to be electrically connected to external instruments. The lower bearing 3 is used to connect to external instruments that require rotation. An inner core tube 4 is coaxially arranged inside the anchoring shell 1. The top of the inner core tube 4 is connected to the upper connector 2, and the bottom is connected to the lower bearing 3. The inner core tube 4 mainly serves to pass wires or oil.

[0046] In one embodiment, such as Figure 1 , Figure 3 , Figure 4 As shown, multiple anchoring arms 5 are hinged to the outer side of the anchoring shell 1. These anchoring arms 5 are arranged at equal intervals along the circumference of the anchoring shell 1, and their length direction is parallel to the axial direction of the anchoring shell 1. The axial direction of the hinge shaft 6 on each anchoring arm 5 is parallel to the axial direction of the anchoring shell 1. An anchoring block 7 for abutting against the inner wall of the column is integrally formed at the upper and lower ends of each anchoring arm 5 on the side away from its hinge shaft 6. A control element 8 is provided between the anchoring shell 1 and the multiple anchoring arms 5, and the control element 8 is used to control the synchronous rotation of the multiple anchoring arms 5, so that the multiple anchoring arms 5 can be opened or retracted synchronously.

[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, ensure a stable connection between the instrument and the wellbore, and thus ensure 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 120° intervals. Therefore, the anchoring device has a total of six anchor points, which effectively improves the anchoring effect.

[0049] In one embodiment, such as Figure 1 , Figure 2 , Figure 3 As shown, the control component 8 includes a control piston 81 slidably sleeved on the inner core tube 4. The inner wall of the control piston 81 is in close contact with the inner core tube 4, and the outer wall is in close contact with the anchoring shell 1. A hydraulic annular cavity 82 is formed between the top of the control piston 81, the inner wall of the anchoring shell 1, and the outer wall of the inner core tube 4. A hydraulic channel 83 is provided on the upper connector 2. One end of the hydraulic channel 83 is used to communicate with the hydraulic device of an external instrument, and the other end is used to communicate with the hydraulic annular cavity 82. When the hydraulic medium enters the hydraulic annular 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, such as Figure 1 , Figure 2 , Figure 3As shown, multiple slotted holes 84 are provided through the anchoring shell 1, and each slotted hole 84 corresponds to one of the anchoring arms 5. The length direction of the slotted holes 84 is parallel to the axial direction of the anchoring shell 1. Multiple guide blocks 90 are fixedly connected to the control piston 81. The guide blocks 90 are vertically slidingly engaged with the corresponding slotted holes 84, and a set of control balls 85 are fixedly connected to each guide block 90.

[0051] In one embodiment, such as Figure 2 , Figure 3 , Figure 5 As shown, each anchoring arm 5 is provided with a set of arc-shaped control grooves 86 on the side near its hinge axis 6. Each set of control balls 85 slides in cooperation with the corresponding control grooves 86. When the control piston 81 drives the control ball 85 to slide along the inner core tube 4, the anchoring arm 5 can rotate under the action of the corresponding control ball 85 and control groove 86.

[0052] In one embodiment, such as Figure 2 As shown, the control component 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, such as Figure 2 As shown, the control component 8 also includes a control spring 88 sleeved on the inner core tube 4. A stepped 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 stepped groove 89 and connected to the bottom of the stepped groove 89. When the control piston 81 moves downward, the control spring 88 undergoes compression deformation. 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 into 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, multiple anchoring arms 5 rotate under the action of the corresponding control ball 85 and the inner wall of the control groove 86, that is, multiple anchoring arms 5 are opened synchronously until the anchoring blocks 7 at both ends of each anchoring arm 5 are tightly abutted against the inner wall of the well barrel, thereby realizing the anchoring of the instrument.

[0055] When the cutting operation is completed, or when the instrument malfunctions and the anchoring motor or pump stops 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. Multiple anchoring arms 5 rotate under the action of the corresponding control ball 85 and the inner wall of the control groove 86, that is, multiple anchoring arms 5 retract synchronously to avoid jamming when the tool is lifted.

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

[0057] In one embodiment, such as Figure 2 As shown, the control piston 81 is sealed to both the anchor shell 1 and the inner core tube 4 by sealing rings 9. Specifically, sealing rings 9 are fixedly fitted at both ends of the outer wall of the control piston 81, and these sealing rings 9 are in close contact with the inner wall of the anchor shell 1 to ensure an effective seal between the control piston 81 and the anchor shell 1. Simultaneously, a sealing ring 9 is also fixedly embedded in the inner wall of the control piston 81, and this sealing ring 9 is in close contact with the outer wall of the inner core tube 4 to ensure an effective seal between the control piston 81 and the inner core tube 4.

[0058] In one embodiment, such as Figure 1 , Figure 3 As shown, the outer surface of the anchoring shell 1 is provided with a relief annular groove 10 along its circumference, and the cross-section of each anchoring arm 5 is arc-shaped. When the anchoring arm 5 is extended, the end of the anchoring arm 5 near the anchoring block 7 can protrude from the relief annular groove 10, causing the anchoring block 7 to abut against the inner wall of the wellbore. When the anchoring arm 5 is retracted, the inner surface of the anchoring arm 5 is in close contact with the bottom of the relief annular groove 10, and the outer surface of the anchoring arm 5 is flush with the outer surface of the anchoring shell 1. This design can minimize the outer diameter of the anchoring device, allowing the anchoring device to enter wellbores with smaller inner diameters, thereby improving its adaptability.

[0059] In one embodiment, such as Figure 1 , Figure 3 As shown, multiple pairs of hinge blocks 11 are provided in the clearance annular groove 10. Each pair of hinge blocks 11 corresponds to one of the multiple anchoring arms 5, and each pair of hinge blocks 11 is symmetrically distributed at both ends of the corresponding anchoring arm 5. At the same time, each anchoring arm 5 has two hinge shafts 6, which are symmetrically distributed at both ends of the anchoring arm 5 and are rotatably connected to the corresponding hinge blocks 11 through rotating bushings 12.

[0060] In one embodiment, such as Figure 1 , Figure 3As shown, multiple pairs of support blocks 13 are provided in the clearance annular groove 10. Each pair of support blocks 13 corresponds to one of the multiple anchoring arms 5, and each pair of support blocks 13 is symmetrically distributed on both sides of the corresponding strip hole 84. Each anchoring arm 5 is provided with two support notches 15, and each pair of support blocks 13 is located in the corresponding support notch 15. At the same time, the end of each hinge block 11 away from the rotating bushing 12 passes through the corresponding support block 13 and is rotatably connected to the support block 13 to improve the support effect on the anchoring arm 5, thereby improving stability.

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

[0062] As can be seen from the above, the use of this anchoring device can improve the anchoring effect, ensure a stable connection between the instrument and the wellbore, and thus ensure the smooth progress of the cutting operation. At the same time, the anchoring arm 5 can be smoothly and urgently retracted, which can reduce the risk of jamming when lifting the tool and ensure that the anchoring arm 5 can be urgently retracted in case of malfunction of the anchoring device, thereby improving the stability of use.

[0063] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0064] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0065] 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 therein. 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, and they should all be covered within 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 the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A downhole cutting tool anchoring device, characterized by, The utility model relates to an anchor casing (1) is provided with the upper joint (2) and the lower bearing (3) and the inner core pipe (4) and the anchor arm (5) and the control member (8), the anchor casing (1) is provided with the let -one -ring groove (10) on the outside surface along the circumference, and the anchor arm (5) is provided with the anchor block (7) on the upper end position and the lower end position of the side away from the hinged axle (6) respectively, and the anchor casing (1) is provided with the control piston (81) and the hydraulic passage (83) and the strip -shaped hole (84) and the guide block (90) and the control ball (85) and the control groove (86) on the inside surface. The utility model relates to an anchor casing (1) is provided with the upper joint (2) and the lower bearing (3) and the inner core pipe (4) and the anchor arm (5) and the control member (8), the anchor casing (1) is provided with the let -one -ring groove (10) on the outside surface along the circumference, and the anchor arm (5) is provided with the anchor block (7) on the upper end position and the lower end position of the side away from the hinged axle (6) respectively, and the anchor casing (1) is provided with the control piston (81) and the hydraulic passage (83) and the strip -shaped hole (84) and the guide block (90) and the control ball (85) and the control groove (86) on the inside surface. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A plurality of pairs of hinged blocks (11) are arranged in the yielding ring groove (10), and the plurality of pairs of hinged blocks (11) are arranged in one-to-one correspondence with the plurality of anchor arms (5), and each pair of hinged blocks (11) is located at the two end positions of the corresponding anchor arm (5), and two hinged shafts (6) are arranged on each anchor arm (5), and the hinged shafts (6) are distributed at the two ends of the anchor arm (5) and are rotatably connected to the corresponding hinged blocks (11) through rotating shaft sleeves (12).

2. The downhole cutting tool anchoring device of claim 1, wherein, The control member (8) further comprises: A guide pipe (87) is sleeved on the inner core pipe (4) and connected to the lower bearing (3) at the bottom, and the bottom of the control piston (81) is sleeved on the guide pipe (87).

3. The downhole cutting tool anchoring apparatus of claim 2, wherein, The control member (8) further comprises: A control spring (88) is arranged between the control piston (81) and the guide pipe (87) and is used to push the control piston (81) towards the upper joint (2) to smoothly retract the plurality of anchor arms (5).

4. The downhole cutting tool anchoring apparatus of claim 3, wherein, The control spring (88) is sleeved on the inner core pipe (4), a stepped groove (89) is arranged at the lower end position of the inner wall side of the control piston (81), the bottom of the control spring (88) is connected to the guide pipe (87), and the top is located in the stepped groove (89) and connected to the groove bottom of the stepped groove (89).

5. The downhole cutting tool anchoring apparatus of claim 1, wherein, The control piston (81), the anchor shell (1) and the inner core pipe (4) are respectively sealed by a sealing ring (9).

6. The downhole cutting tool anchoring apparatus of claim 1, wherein, A plurality of pairs of support blocks (13) are arranged in the yielding 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), two support notches (15) are arranged on each anchor arm (5), each pair of support blocks (13) is located in the corresponding support notch (15), and the end of the hinged shaft (6) away from the corresponding hinged block (11) penetrates through the corresponding support block (13) and is rotatably connected to the support block (13).

7. The downhole cutting tool anchoring apparatus of claim 1, wherein, Adjacent two hinged blocks (11) located on the same side of the yielding ring groove (10) form a yielding groove (14), when the anchor arm (5) is retracted, a plurality of anchor blocks (7) can enter the corresponding yielding groove (14), and the outer side surface of the anchor block (7) is flush with the outer side surface of the anchor shell (1).

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