Electromagnetic coupling downhole cutting tool

Abstract

The present invention provides an electromagnetically coupled downhole cutting tool, relating to the field of deep drilling and well repair equipment. The cutting tool comprises a casing, a cutter assembly, a rotating main shaft located within the casing, and a magnetic coupling assembly. The magnetic coupling assembly comprises an upper magnetic coupling and a lower magnetic coupling that are capable of relative rotation. The upper magnetic coupling is fixedly disposed, a radial transmission portion is rotatably connected to the rotating main shaft, and the lower magnetic coupling is fixedly connected to the radial transmission portion. The casing comprises a rotating shell, and the rotating main shaft is fixedly connected to the rotating shell. When the magnetic coupling assembly is energized, the rotating main shaft drives the cutter assembly and the rotating shell to rotate about the axis of the casing. The radial transmission portion, under the influence of resistance exerted by the lower magnetic coupling, drives the cutter assembly radially out of or into the rotating shell. The present invention effectively solves the problem of damage to the cutter head caused by stress concentration during the deflection feed of a mechanical cutter, reduces cutting resistance during the cutting process, and improves the quality of the cut section of the tubular string.

Description

Technical Field

[0001] The present invention relates to the technical field of deep earth drilling and well repairing equipment, and in particular to an electromagnetic coupling downhole cutting tool. Background Art

[0002] Currently, surface exploration and collection are largely complete. Existing oil and mineral resources are largely derived from underground mineral resource development. As underground oilfields continue to be mined, the equipment and tools required for exploration and production are becoming increasingly demanding, and the frequency of downhole equipment failures is increasing year by year. Offshore oil facilities are typically designed for a service life of around 20 years. In recent years, a large number of wells have been abandoned. Some wells are no longer viable and require sealing and abandonment. Before abandoning oil and water wells, all casing below 4 meters below the seabed mudline must be removed. Furthermore, many oilfields have completed oil and gas production or are no longer viable, requiring the removal of downhole tubing for reuse. During the retrieval process, the tubing must be cut and removed to ensure its integrity. Downhole repairs often require retrieving damaged equipment to the surface for repair or replacement. Traditional methods of lifting the entire tubing string with large equipment are time-consuming and labor-intensive, and the lifting process can deform intact tubing, damage the wellbore, and delay construction progress. Therefore, downhole equipment maintenance usually requires cutting the downhole part into sections and then extracting it to the ground for maintenance. Existing downhole cutting methods such as chemical cutting, explosive cutting, RCT torch cutting, etc. have shortcomings such as many controlled conditions, poor cutting section quality, and uncontrollable cutting process.

[0003] There are also some mechanical cutting tools in the prior art. Existing mechanical cutting tools usually adopt deflection feeding, that is, the cutting knife of the cutting tool is set obliquely relative to the axis of the pipe to be cut, and the cutting knife continuously rotates circumferentially to cut the pipe.

[0004] The applicant has discovered that the prior art has at least the following technical problems: in existing mechanical cutting tools, the blades rotate circumferentially from contact with the inner wall of the pipe string to cutting into the circumferential wall of the pipe string. During this cutting process, the resistance encountered by the cutter increases continuously, resulting in a large amount of stress concentration, causing great damage to the cutter, seriously affecting the cutting quality and cutting efficiency; and after the cutting is completed, the cross-section of the pipe string is not flat, which affects the cutting quality. Summary of the Invention

[0005] The present invention aims to provide an electromagnetically coupled downhole cutting tool to address the existing technical issues of mechanical cutters, where stress concentration during deflection feeding can easily lead to damage to the cutter head and poor tubular cutting quality. The various technical advantages achieved by the preferred solution among the various technical solutions provided by the present invention are detailed below.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The electromagnetic coupling downhole cutting tool provided by the present invention comprises a casing, a cutter assembly, a rotating main shaft located in the casing, and a magnetic coupling assembly, wherein:

[0008] The magnetic coupling assembly includes an upper magnetic coupling and a lower magnetic coupling that can rotate relative to each other, the upper magnetic coupling is fixedly arranged, a radial transmission part is rotatably connected to the rotating main shaft, and the lower magnetic coupling is fixedly connected to the radial transmission part;

[0009] The tubular shell includes a rotating shell, and the rotating main shaft is fixedly connected to the rotating shell. When the magnetic coupling assembly is energized, the rotating main shaft drives the cutter assembly and the rotating shell to rotate around the axis of the tubular shell, and the radial transmission part drives the cutter assembly to extend radially out of the rotating shell or retract into the rotating shell under the action of the resistance exerted on the lower end magnetic coupling.

[0010] Preferably, the radial transmission portion includes a transmission sleeve, the transmission sleeve is rotatably connected to the rotating main shaft, and the lower end magnetic coupling is fixedly connected to the transmission sleeve; a gear is provided on the outer periphery of the transmission sleeve, and the cutting knife assembly includes a knife holder and a knife head, wherein:

[0011] The tool holder is arranged horizontally, and a rack is provided on the tool holder, the rack is meshed with the gear for transmission, and the tool head is fixed to the protruding end of the tool holder;

[0012] The tool holder includes one or more than two. When the tool holder includes more than two, all the tool holders are arranged at intervals around the axis of the tube shell.

[0013] Preferably, the rotating shell is provided with a through opening for the tool head to extend out; the tool holder is provided with a limiting groove, the rotating shell is provided with a limiting block, the limiting block is provided on the moving path of the tool holder, the limiting block extends into the limiting groove, and the tool holder is slidably connected to the rotating shell.

[0014] Preferably, an adjustment hole is provided on the transmission sleeve, and the adjustment hole is a long strip hole and is arranged vertically. The lower end magnetic coupling can be fixed at different positions of the adjustment hole, thereby adjusting the axial distance between the lower end magnetic coupling and the upper end magnetic coupling.

[0015] Preferably, the cutting tool further includes a driving device, which is fixed in the tube shell and connected to the rotating main shaft via a coupling, and is used to drive the rotating main shaft to rotate around the axis of the tube shell.

[0016] Preferably, the tube shell includes a suspension shell and a bottom shell, wherein:

[0017] The suspension shell is fixedly arranged, the rotating shell is located between the suspension shell and the bottom shell, the rotating shell is rotatably connected to the suspension shell, the rotating shell is fixedly connected to the bottom shell, and a conical portion is provided at the lower part of the bottom shell, and the tip of the conical portion is arranged away from the rotating shell.

[0018] Preferably, the cutting tool further comprises an anchoring assembly, which comprises a pushing device, a rotating hinge and an anchor body, wherein:

[0019] The rotating hinges are arranged at intervals around the axis of the tube shell, and include a first hinge and a second hinge. The extended end of the pushing device is drivingly connected to the upper end of the first hinge, the lower end of the second hinge is fixedly arranged, the upper end of the second hinge is rotatably connected to the lower end of the first hinge, and the anchor body is fixed to the second hinge.

[0020] The tube shell is provided with a side opening, and the pushing device can push the first hinge downward and make the second hinge rotate around the lower end of the second hinge as the axis, thereby making the rotating hinge radially expand, so that all the anchor bodies extend out of the side opening and press against the inner wall of the pipe column.

[0021] Preferably, the anchor body includes a sphere, and the sphere is an elastic sphere; the number of the spheres includes one or more than two. When more than two spheres are provided on the anchor body, the spheres are arranged around the axis of the tube shell.

[0022] Preferably, the pushing device includes an electric push rod, and the anchoring assembly further includes a guide sleeve and an anchoring connection plate, wherein:

[0023] The guide sleeve is arranged along the axis of the tube shell and is fixedly arranged in the tube shell. At least a portion of the anchor connection plate is sleeved outside the guide sleeve and is slidably connected to the guide sleeve.

[0024] The extension rod of the electric push rod is connected to the anchor connection plate, and the anchor connection plate is rotatably connected to the upper end of the first hinge.

[0025] Preferably, a guide groove is provided at the upper end of the peripheral wall of the guide sleeve;

[0026] The anchoring connection plate includes an inner ring portion, an outer ring portion and a connecting groove. The inner ring portion and the outer ring portion are connected by a partition. The inner ring portion is located inside the guide sleeve and is connected to the extension rod. The outer ring portion is sleeved outside the guide sleeve, and the partition passes through the guide groove. When the extension rod drives the anchoring connection plate to move vertically, the partition slides in the guide groove; the connecting groove is rotatably connected to the first hinge.

[0027] The magnetic coupling downhole cutting tool provided by the present invention has the following beneficial effects compared with the prior art: when the magnetic coupling assembly is energized, the lower end magnetic coupling is subjected to the resistance of the upper end magnetic coupling, and the radial transmission part drives the cutter assembly to extend radially out of the rotating shell under the resistance of the lower end magnetic coupling, and at the same time, the rotating main shaft drives the cutter assembly and the rotating shell to rotate around the axis of the pipe shell, so that the cutter assembly can rotate and cut the pipe string at the same time during the radial feeding process; compared with general mechanical cutting tools, the tool adopts a radial feeding method perpendicular to the pipe string to be cut, which effectively solves the problem of stress concentration of the deflection feeding of the general mechanical cutter causing damage to the cutter head, reduces the cutting resistance during the cutting process, and improves the quality of the cut section of the pipe string.

[0028] The electromagnetic coupling downhole cutting tool adopts the electromagnetic coupling anti-resistance torque feed transmission mode. It can control the transmission torque by adjusting the current of the magnetic coupling component, accurately control the cutting parameters, and ensure the stable and reliable cutting process. The electromagnetic coupling transmission mode has an overload self-slip function, which can effectively protect the cutter assembly when encountering unexpected cutting obstacles and can adapt to the complex working environment underground. The cutting is stable and reliable, and the quality of the cutting section is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is an overall view of the electromagnetic coupling downhole cutting tool;

[0031] Figure 2 yes Figure 1 Partial cross-sectional view at AA in the middle;

[0032] Figure 3 This is a structural view of the anchor assembly of an electromagnetically coupled downhole cutting tool;

[0033] Figure 4 This is a structural view of the coupling transmission part of the magnetic coupling assembly;

[0034] Figure 5 This is the radial structural view of the transmission sleeve and the cutter head;

[0035] Figure 6 It is the structural diagram of the anchor body;

[0036] Figure 7It is a structural diagram of the anchor connection plate;

[0037] Figure 8 It is a schematic diagram of the matching structure of the anchor connection plate and the guide sleeve;

[0038] Figure 9 It is a structural diagram of the transmission sleeve;

[0039] Figure 10 It is a structural diagram of the tool holder;

[0040] Figure 11 It is a structural diagram of the rotating shell and the bottom shell.

[0041] In the figure, 11 is armored cable; 12 is electrical control housing; 21 is anchor housing; 22 is base; 23 is extension rod; 24 is anchor connection plate; 241 is inner ring; 242 is outer ring; 243 is partition; 244 is connection groove; 25 is guide sleeve; 251 is guide groove; 26 is first hinge; 27 is anchor body; 271 is sphere; 28 is second hinge; 29 is hinge mounting seat; 31 is motor housing; 32 is servo motor; 33 is motor mounting seat; 34 is suspension housing; 35 is , magnetic coupling mounting seat; 36, customized coupling; 37, upper magnetic coupling; 38, lower magnetic coupling; 41, transmission sleeve; 410, adjustment hole; 42, linear sliding bearing; 43, first thrust bearing; 44, suspension mounting sleeve; 45, rotating spindle; 46, rotating shell; 461, limit block; 462, through port; 47, bearing sealing cover; 48, second thrust bearing; 49, bottom shell; 491, tapered portion; 411, tool holder; 412, tool head; 413, limit groove. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center," "length," "width," "height," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and "side" and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0044] The embodiment of the present invention provides an electromagnetically coupled downhole cutting tool, which can effectively solve the problem of damage to the cutter head caused by stress concentration during the deflection and feeding of a general mechanical cutter, reduce cutting resistance during the cutting process, and improve the quality of the cut section of the pipe string.

[0045] The following combination Figures 1-11 The technical solution provided by the present invention is described in more detail.

[0046] Example 1

[0047] like Figures 1-11 As shown, this embodiment provides an electromagnetic coupling downhole cutting tool, including a tubular housing, a cutter assembly, a rotating main shaft 45 located in the tubular housing, and a magnetic coupling assembly, wherein: the magnetic coupling assembly includes an upper magnetic coupling 37 and a lower magnetic coupling 38 that can rotate relative to each other, the upper magnetic coupling 37 is fixedly arranged, a radial transmission part is rotatably connected to the rotating main shaft 45, and the lower magnetic coupling 38 is fixedly connected to the radial transmission part; the tubular housing includes a rotating shell 46, and the rotating main shaft 45 is fixedly connected to the rotating shell 46. When the magnetic coupling assembly is energized, the lower magnetic coupling 38 is subjected to the resistance of the upper magnetic coupling 37, and the rotating main shaft 45 drives the cutter assembly and the rotating shell 46 to rotate around the axis of the tubular housing, and the radial transmission part drives the cutter assembly to extend radially out of the rotating shell 46 or retract into the rotating shell 46 under the resistance of the lower magnetic coupling 38.

[0048] When the magnetic coupling is powered off, the rotating main shaft 45 drives the lower end magnetic coupling 38, the radial transmission part, the rotating shell 46 and the cutter assembly to rotate synchronously around the axis of the tube shell.

[0049] For details, see Figure 1 As shown, the rotating main shaft 45 and the radial transmission part are connected by a linear sliding bearing 42, which allows the radial transmission part to rotate relative to each other when there is an angular difference between the two (when the magnetic coupling assembly is energized). The end of the rotating main shaft 45 is connected to the rotating shell 46 via a spline.

[0050] The cutting tool includes an electronic control unit, the upper end of which is connected to an armored cable 11. This cable 11 suspends the cutting tool and transmits data and information via wired transmission, controlling the servo motor 32 and magnetic coupling assembly. The electronic control unit includes a depth positioning sensor, a driver, an information data center processor, a base 22, and an electronic control unit housing 12. This unit processes cutting process data and transmits information to a ground control center, providing real-time control of the cutting progress. The depth positioning sensor and information data center processor are removably mounted on the wall of the electronic control unit. The base 22 and the housing 12 are positioned relative to the bosses, cooperating to achieve radial positioning and axial positioning at one end.

[0051] In the electromagnetic coupling downhole cutting tool of this embodiment, when the magnetic coupling assembly is energized, the lower end magnetic coupling 38 is subjected to the resistance of the upper end magnetic coupling 37. Under the resistance of the lower end magnetic coupling 38, the radial transmission part drives the cutter assembly to extend radially out of the rotating shell 46, and at the same time, the rotating main shaft 45 drives the cutter assembly and the rotating shell 46 to rotate around the axis of the shell, so that the cutter assembly can rotate and cut the pipe string simultaneously during the radial feeding process. Compared with general mechanical cutting tools, this tool adopts a radial feeding method perpendicular to the pipe string to be cut, which effectively solves the problem of stress concentration caused by the deflection feeding of general mechanical cutters, resulting in damage to the cutter head 412, reduces the cutting resistance during the cutting process, and improves the quality of the cut section of the pipe string.

[0052] The electromagnetic coupling downhole cutting tool adopts the electromagnetic coupling anti-resistance torque feed transmission mode. It can control the transmission torque by adjusting the current of the magnetic coupling component, accurately control the cutting parameters, and ensure the stable and reliable cutting process. The electromagnetic coupling transmission mode has an overload self-slip function, which can effectively protect the cutter assembly when encountering unexpected cutting obstacles and can adapt to the complex working environment underground. The cutting is stable and reliable, and the quality of the cutting section is guaranteed.

[0053] As an optional implementation, the cutting tool of this embodiment further includes a driving device, which is fixed in the tube shell and connected to the rotating main shaft 45 through a coupling, and is used to drive the rotating main shaft 45 to rotate around the axis of the tube shell.

[0054] The driving device includes a servo motor 32. The output end of the servo motor 32 is connected to the upper end of the rotating main shaft 45 through a customized coupling 36. When the servo motor 32 rotates, it can drive the rotating main shaft 45 to rotate around the axis of the tube shell. Figure 2 The servo motor 32 is fixed by a motor mounting base 33 .

[0055] See also Figure 2 and Figure 11As shown, the housing of this embodiment includes, from top to bottom, an electrical control housing 12, an anchor housing 21, a motor housing 31, a suspension housing 34, a rotating housing 46, and a bottom housing 49. The suspension housing 34 is fixedly disposed, and the rotating housing 46 is located between the suspension housing 34 and the bottom housing 49. The rotating housing 46 is rotatably connected to the suspension housing 34, and the rotating housing 46 is fixedly connected to the bottom housing 49. A tapered portion 491 is provided at the bottom of the bottom housing 49, with the tip of the tapered portion 491 facing away from the rotating housing 46. The tapered portion 491 on the bottom housing 49 facilitates the smooth insertion of the cutting tool housing into the pipe string for cutting, allowing the tool to more smoothly enter the wellbore for operation in complex downhole environments and maintaining the tool upright.

[0056] like Figure 2 As shown, the suspension device primarily comprises a suspension mounting sleeve 44, a first thrust bearing 43, and a suspension housing 34. The suspension housing 34 features a boss that engages with the lower contact surface of the first thrust bearing 43 while separating from the upper contact surface. The upper contact surface of the first thrust bearing 43 engages with the suspension mounting sleeve 44. The suspension device provides a rotational connection between the suspension housing 34 and the rotating housing 46. The suspension housing 34, through the first thrust bearing 43, also withstands axial forces from the lower end. Rotational connections between the suspension housing 34 and the rotating housing 46, as well as between the rotating housing 46 and the bottom housing 49, ensure smooth rotation of the rotating housing 46. The remaining adjacent housings are fixed together with bolts for easy assembly and disassembly.

[0057] The cutting tool of this embodiment can achieve vertical cutting compared to the axis of the pipe string to be cut. As an optional embodiment, see Figure 2 and Figure 5 As shown, the radial transmission portion includes a transmission sleeve 41, which is rotatably connected to the rotating main shaft 45, and the lower end magnetic coupling 38 is fixedly connected to the transmission sleeve 41; a gear is provided on the outer periphery of the transmission sleeve 41, and the cutting knife assembly includes a knife holder 411 and a cutter head 412, wherein: the knife holder 411 is arranged horizontally, and a rack is provided on the knife holder 411, and the rack is engaged with the gear for transmission, and the cutter head 412 is fixed to the protruding end of the knife holder 411; the knife holder 411 includes one or more than two knife holders 411. When the knife holder 411 includes more than two, all the knife holders 411 are arranged at intervals around the axis of the tube shell.

[0058] Specifically, the cutter head 412 is welded to the tool holder 411 and is a carbide steel cutter. The teeth on the rack are directly machined by the transmission sleeve 41. The machining parameters are: a gear module of 1, 36 teeth, and a tooth profile angle of 20° (not limited to these parameters). The tooth surfaces undergo heat treatment after machining, with a hardness of 220-250 HB. The transmission sleeve 41 is deburred and finished after machining to ensure an overall roughness below Ra6.3.

[0059] Specifically, the magnetic coupling mounting base 35 is bolted to the motor housing 31 and secures the upper magnetic coupling 37. The upper magnetic coupling 37 can be secured by either clamping or jacking, while the lower magnetic coupling 38 can be secured by either clamping or jacking. They are secured to the transmission sleeve 41 by bolts or the like. A certain gap exists between the upper and lower magnetic couplings 37, 38 to ensure relative rotation and to minimize the collinearity of their central axes. The mounting position is adjusted to maintain an axial distance of 2-5 mm between the upper and lower magnetic couplings 37, 38.

[0060] When the magnetic coupling assembly is powered on and begins operation, if there is a relative rotation angle or relative rotation tendency between the upper magnetic coupling 37 and the lower magnetic coupling 38, they are subjected to a resistance torque. The magnitude of the transmission resistance torque is related to factors such as the magnetic coupling structure, the control current, and the center distance. Therefore, the transmission torque can be controlled by adjusting the control current of the magnetic coupling assembly during cutting. Electromagnetic coupling downhole cutting utilizes the principle of counter-resistance torque to control the relative rotation of the gear sleeve and the tool holder 411 to a certain angle, thereby extending or retracting the cutter head 412.

[0061] In order to facilitate the adjustment of the transmission torque, as an optional embodiment, see Figure 9 An adjustment hole 410 is provided on the transmission sleeve 41. The adjustment hole 410 is a long strip hole and is arranged vertically. The lower end magnetic coupling 38 can be fixed at different positions of the adjustment hole 410, thereby adjusting the axial distance between the lower end magnetic coupling 38 and the upper end magnetic coupling 37.

[0062] Specifically, the lower magnetic coupling 38 is fixed to the transmission sleeve 41 by bolts, which facilitates the disassembly of the lower magnetic coupling 38. Since the upper magnetic coupling 37 is fixed and located above the lower magnetic coupling 38, the lower magnetic coupling 38 can be fixed at different vertical positions of the adjustment hole 410 to adjust the axial distance between the lower magnetic coupling 38 and the upper magnetic coupling 37, thereby adjusting the resistance of the lower magnetic coupling 38, thereby creating a speed difference between the transmission sleeve 41 and the cutting knife assembly, which facilitates the radial feeding of the cutter head 412.

[0063] As an alternative embodiment, see Figure 10 and Figure 11 As shown, the rotating shell 46 is provided with a through opening 462 for the cutter head 412 to extend out; a limiting groove 413 is provided on the tool holder 411, and a limiting block 461 is provided on the rotating shell 46. The limiting block 461 is set on the moving path of the tool holder 411, and the limiting block 461 extends into the limiting groove 413, and the tool holder 411 is slidably connected to the rotating shell 46.

[0064] The matching structure of the limit block 461 and the limit groove 413, and the sliding connection between the tool holder 411 and the rotating shell 46, facilitate the smooth radial feeding of the cutting knife assembly, and can limit the movement stroke of the tool holder 411 to prevent the tool holder 411 from sliding out of the rotating shell 46 due to excessive movement; ensure that the feed of the cutter head 412 is stable and the force conditions are good, and at the same time limit the maximum extension and retraction.

[0065] In order to ensure the mechanical strength of the tool holder 411, the tool holder 411 should be manufactured using a forging process. After the tooth profile and slide groove are processed, heat treatment and further finishing are required to ensure that the strength after treatment reaches 210-250HRB and the tooth profile parallelism form and position tolerance reaches 0.02.

[0066] In this embodiment of the electromagnetically coupled downhole cutting tool, when the electromagnetic coupling assembly is de-energized, the rotating main shaft 45 drives the rotating housing 46 and the cutter head 411 to rotate around the central axis of the tubular housing. The transmission sleeve 41 rotates together via a gear and rack mechanism. The cutter head 411 and the transmission sleeve 41 remain relatively stationary, and the cutter head 411 does not experience radial feed displacement. This process serves as preparatory work before cutting. The synchronous rotation of the rotating main shaft 45, rotating housing 46, cutter head 411, and transmission sleeve 41 allows the cutter head 412 to rotate before radial feed. During this rotation, the cutter head 412 contacts the inner wall of the tubular string, reducing cutting resistance. This process facilitates pre-cutting adjustments of the cutter assembly's rotational speed and the extension length of the cutter head 412 to accommodate tubulars of varying diameters, enhancing the controllability of the cutting tool.

[0067] When the armored cable 11 transmits a signal to control the magnetic coupling to start working, the upper magnetic coupling 37 is fixedly mounted on the magnetic coupling mounting base 35 and is in a stationary state, while the lower magnetic coupling 38 rotates with the rotating shell 46 . Since there is a relative rotation speed between the upper magnetic coupling 37 and the lower magnetic coupling, the master and slave rotors of the magnetic coupling have a relative rotation angle or relative rotation trend, and the master and slave rotors will transmit the relative torque working principle. The lower magnetic coupling 38 is subjected to the resistance torque, so that there is a relative rotation angle between the transmission sleeve 41 and the tool holder 411. Since the transmission sleeve 41 is engaged with the tool holder 411, the tool holder 411 is pushed out radially, and the cutter head 412 presses the inner wall of the pipe column, the tool realizes radial feed, and starts cutting; after the cutting is completed, the transmission signal controls the servo motor 32 to reverse the rotation of the main shaft 45, and the upper magnetic coupling 37 and the lower magnetic coupling still have relative rotation. The transmission sleeve 41 is subjected to the resistance torque and has a relative rotation angle with the tool holder 411. The tool holder 411 is retracted to the limit position and the cutter head 412 is retracted.

[0068] During this process, the rotational speeds of the transmission sleeve 41 and the rotating main shaft 45 are different, and the linear sliding bearing 42 between the transmission sleeve 41 and the rotating main shaft 45 realizes a rotational connection between the two.

[0069] Example 2

[0070] The cutting tool of this embodiment also includes an anchoring assembly, which is used to anchor the pipe string when cutting the pipe string to prevent the cutting tool from shaking during the cutting process, thereby facilitating the smooth progress of the cutting work.

[0071] See also Figure 2 and Figure 3 As shown, the anchoring assembly of this embodiment includes a pushing device, a rotating hinge and an anchor body 27, wherein: the rotating hinges are arranged at intervals around the axis of the tube shell, the rotating hinges include a first hinge 26 and a second hinge 28, the protruding end of the pushing device is drivingly connected to the upper end of the first hinge 26, the lower end of the second hinge 28 is fixedly arranged, the upper end of the second hinge 28 is rotatably connected to the lower end of the first hinge 26, and the anchor body 27 is fixed on the second hinge 28; a side opening is provided on the tube shell, and the pushing device can push the first hinge 26 to move downward and make the second hinge 28 rotate with the lower end of the second hinge 28 as the axis, thereby making the rotating hinge expand radially, so that all anchor bodies 27 extend out of the side opening and press against the inner wall of the pipe column.

[0072] See also Figure 3 As shown, when the protruding end of the pushing device is extended, it can push the first hinge 26 to move downward, and make the second hinge 28 rotate with the lower end of the second hinge 28 as the axis, thereby making the rotating hinge radially expand, and all the anchor bodies 27 move radially outward and extend from the side opening, thereby anchoring the inner wall of the pipe string; when the protruding end of the pushing device is retracted, it can pull the rotating hinge radially back, thereby pulling the anchor body 27 back into the pipe string, realizing the separation of the cutting tool and the pipe string.

[0073] As an alternative embodiment, see Figure 6 As shown, the anchor body 27 includes a sphere 271, which is an elastic sphere. The number of the spheres 271 includes one or more than two. When more than two spheres 271 are provided on the anchor body 27, the spheres 271 are arranged around the axis of the shell.

[0074] The arrangement of the sphere 271 increases the contact area between the anchor body 27 and the pipe string, enhancing the stability of the anchoring. The structure of the sphere 271 ensures optimal contact between the anchor body 27 and the pipe string. The elastic deformation of the sphere 271 provides a good anti-slip coefficient, ensuring close contact between the anchor body 27 and the inner wall of the pipe string, facilitating more stable anchoring of the pipe string and preventing movement. The anchor body 27 is detachably mounted on the second hinge 28, allowing for replacement of the appropriate anchor body 27 according to different working environments.

[0075] As an alternative embodiment, see Figure 2 、 Figure 6 and Figure 8As shown, the pushing device includes an electric push rod, and the anchoring assembly also includes a guide sleeve 25 and an anchoring connection plate 24, wherein: the guide sleeve 25 is arranged along the axis of the tube shell and is fixedly arranged in the tube shell, and at least part of the anchoring connection plate 24 is sleeved outside the guide sleeve 25 and is slidingly connected to the guide sleeve 25; the protruding rod 23 of the electric push rod is connected to the anchoring connection plate 24 as the protruding end of the pushing device, and the anchoring connection plate 24 is rotatably connected to the upper end of the first hinge 26.

[0076] The guide sleeve 25 can limit the vertical movement of the anchoring connection plate 24 and prevent radial displacement of the anchoring connection plate 24. The electric push rod is connected to the rotary hinge through the anchoring connection plate 24 to facilitate radial expansion and retraction of the rotary hinge.

[0077] As an alternative embodiment, see Figure 7 、 Figure 8 As shown, a guide groove 251 is provided at the upper end of the peripheral wall of the guide sleeve 25; the anchoring connecting plate 24 includes an inner ring portion 241, an outer ring portion 242 and a connecting groove 244, the inner ring portion 241 and the outer ring portion 242 are connected by a partition 243, the inner ring portion 241 is located inside the guide sleeve 25 and is connected to the extension rod 23, the outer ring portion 242 is sleeved on the outside of the guide sleeve 25, and the partition 243 passes through the guide groove 251, when the extension rod 23 drives the anchoring connecting plate 24 to move vertically, the partition 243 slides in the guide groove 251; the connecting groove 244 is rotatably connected to the first hinge 26.

[0078] The matching structure of the first hinge 26 and the connecting groove 244 can limit the rotation and radial displacement of the first hinge 26 around the central axis, ensuring a smooth anchoring process.

[0079] For details, see Figure 3 The hinge mounting base 29 is fixedly mounted to the motor housing 31 via bolts. The first hinge 26 and the second hinge 28 are rotatably connected via bolts. The connecting groove 244 is rotatably connected to the first hinge 26, and the second hinge 28 is rotatably connected to the hinge mounting base 29 via bolts. To ensure that the electric push rod moves downward and radially expands the anchor body 27 by rotating the hinge, the anchor connection plate 24 is embedded in the guide groove 251 of the guide sleeve 25. The assembly end of the second hinge 28 should be farther from the central axis than the assembly end of the first hinge 26.

[0080] The above-mentioned matching structure of the anchor connection plate 24 and the guide sleeve 25 allows the guide sleeve 25 to limit the vertical movement of the anchor connection plate 24 and simultaneously drive the rotary hinge to radially expand or retract, thereby preventing the anchor connection plate 24 from moving in the radial direction.

[0081] The cutting tool of this embodiment, such as Figure 3As shown, when the cutting tool is anchored and straightened, the electric push rod pushes out the extension rod 23. Since the anchor connection plate 24 is slidably connected with the guide sleeve 25, the horizontal displacement and rotation around the central axis of the anchor connection plate 24 are restricted. The upper end of the first hinge 26 is driven by the electric push rod extension rod 23 to move axially downward. The first hinge 26 and the second hinge 28 form a rotating hinge. The second hinge 28 rotates around the lower end of the second hinge 28 toward the outside of the tool as the anchoring progresses. The anchor body 27 rotates with the second hinge 28 to expand radially until it is pressed against the inner wall of the pipe string, completing the anchoring and providing the straightening force required for cutting.

[0082] In the above-mentioned anchoring assembly, the electric push rod receives the electrical signal, axially pushes out the extension rod 23, drives the first hinge 26 to move downward, and rotates the hinge to make the anchor body 27 installed on the second hinge 28 extend radially until the anchor body 27 of the elastic material is tightly attached to the inner wall of the pipe string and deformed to a certain extent, completing the tool anchoring.

[0083] The cutting tool of this embodiment features wiring holes and slots in the electrical control housing 12, anchor guide sleeve 25, motor housing 31, and motor mounting base 33. Due to the vibrations and significant cutting resistance experienced during downhole cutting, the electromagnetically coupled downhole cutting tool utilizes bolted connections throughout to ensure structural strength and facilitate subsequent replacement and repair of tool components.

[0084] like Figure 2 As shown, a second thrust bearing 48 is installed between the transmission sleeve 41 and the rotating shell 46. Since the transmission sleeve 41 and the rotating shell 46 rotate relative to each other when the tool holder 411 moves radially, the second thrust bearing 48 can ensure smooth relative rotation and axially position the transmission sleeve 41.

[0085] like Figure 2 As shown, a bearing sealing cover 47 is mounted on the second thrust bearing 48. The bearing sealing cover 47 is mounted on the rotating housing 46 by means of hexagon socket bolts. The bearing sealing cover 47 can prevent chips from accidentally entering the tool and affecting the normal rotation of the second thrust bearing 48.

[0086] See also Figure 1 Specifically, the control center of the electromagnetic coupling downhole cutting tool, the driver of the servo motor 32, the base 22 and the control regulator of the magnetic coupling assembly are installed inside the electronic control part housing 12; the guide sleeve 25 and the motor mounting seat 33 are installed in the anchor part housing 21; the servo motor 32 is installed in the motor mounting seat 33; the motor mounting seat 33, the suspension housing 34 and the magnetic coupling mounting seat 35 are fixed by bolts.

[0087] Example 3

[0088] This embodiment also provides a method for performing downhole cutting using an electromagnetically coupled downhole cutting tool, comprising the following steps:

[0089] Step a: lowering the electromagnetic coupling downhole cutting tool into the vertical well by manipulating the armored cable 11 until it reaches the set working depth;

[0090] Step b: The armored cable 11 transmits a control signal to control the electric push rod, the extension rod 23 of the electric push rod extends, and the anchoring device pushes the anchor body 27 close to the inner wall of the pipe string, completing the tool anchoring.

[0091] Step c, the armored cable 11 transmits a control signal to start the servo motor 32, which outputs the set speed and torque counterclockwise (looking down). The customized coupling 36 is spline-connected to the rotating main shaft 45, driving the rotating main shaft 45 to rotate. The spline at the lower end of the rotating main shaft 45 cooperates with the rotating shell 46 to drive the rotating part to rotate as a whole. The lower end magnetic coupling 38, the tool holder 411 and the tool head 412 begin to rotate around the center axis of the tool, completing the preparation before cutting.

[0092] Step d: The armored cable 11 transmits a control signal to start the magnetic coupling. There is a speed difference between the upper magnetic coupling 37 and the lower magnetic coupling. The lower magnetic coupling 38 is subjected to a clockwise resistance torque, driving the transmission sleeve 41 to rotate clockwise. The transmission sleeve 41 rotates clockwise relative to the tool holder 411. The gear on the transmission sleeve 41 and the rack on the tool holder 411 cooperate with each other to push out the tool holder 411. The cutter head 412 feeds radially to cut a certain thickness of the pipe wall.

[0093] After the pipe string is cut, the armored cable 11 transmits a signal to control the servo motor 32 to rotate clockwise. The upper and lower magnetic couplings 37 and 38 rotate relative to each other, causing the transmission sleeve 41 to rotate counterclockwise relative to the tool holder 411. The rack and pinion structure then retracts the tool holder 411. After the tool holder 411 retracts, a control signal controls the electric push rod to retract the extension rod 23, separating the anchor body 27 from the inner wall of the pipe string and releasing the tool from the anchor.

[0094] Step f: If multiple consecutive cuts are required, steps a to e can be repeated until all cutting tasks are completed, and the tool is pulled out of the well by the armored cable 11.

[0095] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0096] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0097] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An electromagnetically coupled downhole cutting tool, characterized in that: The invention comprises a tube shell, a cutting knife assembly, a rotating main shaft located in the tube shell, and a magnetic coupling assembly, wherein: The magnetic coupling assembly includes an upper magnetic coupling and a lower magnetic coupling that can rotate relative to each other, the upper magnetic coupling is fixedly arranged, a radial transmission part is rotatably connected to the rotating main shaft, and the lower magnetic coupling is fixedly connected to the radial transmission part; The tubular shell includes a rotating shell, the rotating main shaft is fixedly connected to the rotating shell, and when the magnetic coupling assembly is energized, the rotating main shaft drives the cutter assembly and the rotating shell to rotate around the axis of the tubular shell, and the radial transmission part drives the cutter assembly to extend radially out of the rotating shell or retract into the rotating shell under the action of the resistance exerted on the lower end magnetic coupling; The radial transmission part includes a transmission sleeve, the transmission sleeve is rotatably connected to the rotating main shaft, and the lower end magnetic coupling is fixedly connected to the transmission sleeve; a gear is provided on the outer periphery of the transmission sleeve, and the cutting knife assembly includes a knife holder and a knife head, wherein: The tool holder is arranged horizontally, and a rack is provided on the tool holder, the rack is meshed with the gear for transmission, and the tool head is fixed to the protruding end of the tool holder; The tool holder includes one or more than two. When the tool holder includes more than two, all the tool holders are arranged at intervals around the axis of the tube shell; The rotating shell is provided with a through opening for the tool head to extend out; the tool holder is provided with a limiting groove, and the rotating shell is provided with a limiting block, the limiting block is provided on the moving path of the tool holder, the limiting block extends into the limiting groove, and the tool holder is slidably connected to the rotating shell; The cutting tool further includes a driving device, which is fixed in the tube shell and connected to the rotating main shaft via a coupling, and is used to drive the rotating main shaft to rotate around the axis of the tube shell.

2. The electromagnetic coupling downhole cutting tool according to claim 1, characterized in that: The transmission sleeve is provided with an adjustment hole, which is a long strip hole and arranged vertically. The lower end magnetic coupling can be fixed at different positions of the adjustment hole, thereby adjusting the axial distance between the lower end magnetic coupling and the upper end magnetic coupling.

3. The electromagnetic coupling downhole cutting tool according to claim 1, characterized in that: The tube shell includes a suspension shell and a bottom shell, wherein: The suspension shell is fixedly arranged, the rotating shell is located between the suspension shell and the bottom shell, the rotating shell is rotatably connected to the suspension shell, the rotating shell is fixedly connected to the bottom shell, and a conical portion is provided at the lower part of the bottom shell, and the tip of the conical portion is arranged away from the rotating shell.

4. The electromagnetic coupling downhole cutting tool according to claim 1, characterized in that: The cutting tool further comprises an anchoring assembly, which comprises a pushing device, a rotating hinge and an anchor body, wherein: The rotating hinges are arranged at intervals around the axis of the tube shell, and include a first hinge and a second hinge. The extended end of the pushing device is drivingly connected to the upper end of the first hinge, the lower end of the second hinge is fixedly arranged, the upper end of the second hinge is rotatably connected to the lower end of the first hinge, and the anchor body is fixed to the second hinge. The tube shell is provided with a side opening, and the pushing device can push the first hinge downward and make the second hinge rotate around the lower end of the second hinge as the axis, thereby making the rotating hinge radially expand, so that all the anchor bodies extend out of the side opening and press against the inner wall of the pipe column.

5. The electromagnetic coupling downhole cutting tool according to claim 4, characterized in that: The anchor body includes a sphere, which is an elastic sphere. The number of the spheres includes one or more than two. When more than two spheres are provided on the anchor body, the spheres are arranged around the axis of the tube shell.

6. The electromagnetic coupling downhole cutting tool according to claim 4, characterized in that: The pushing device includes an electric push rod, and the anchoring assembly also includes a guide sleeve and an anchoring connection plate, wherein: The guide sleeve is arranged along the axis of the tube shell and is fixedly arranged in the tube shell. At least a portion of the anchor connection plate is sleeved outside the guide sleeve and is slidably connected to the guide sleeve. The extension rod of the electric push rod is connected to the anchor connection plate, and the anchor connection plate is rotatably connected to the upper end of the first hinge.

7. The electromagnetic coupling downhole cutting tool according to claim 6, characterized in that: The upper end of the peripheral wall of the guide sleeve is provided with a guide groove; The anchoring connection plate includes an inner ring portion, an outer ring portion and a connecting groove. The inner ring portion and the outer ring portion are connected by a partition. The inner ring portion is located inside the guide sleeve and is connected to the extension rod. The outer ring portion is sleeved outside the guide sleeve, and the partition passes through the guide groove. When the extension rod drives the anchoring connection plate to move vertically, the partition slides in the guide groove; the connecting groove is rotatably connected to the first hinge.

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