Magnetic guiding tool and guiding method thereof

Abstract

The invention discloses a magnetic guiding tool and a guiding method thereof, and relates to the technical field of petroleum equipment. The magnetic guiding tool comprises a center shaft and a shell; the shell is sleeved on the central shaft; a center hole is formed in the center shaft; the inner side of the shell and the center shaft are provided with a deflection assembly and a magnetic assembly which correspond in position. And the deflection assembly and the magnetic assembly form a non-contact magnetic suspension bearing for supporting the central shaft, so that the shell and the central shaft are guided through non-contact deflection. According to the magnetic guiding tool and the guiding method thereof disclosed by the invention, the magnetic guiding tool generates magnetic force through the deflection assembly and the corresponding magnetic assembly and controls guiding to realize a non-contact supported magnetic suspension bearing, so that a guiding function is realized; and the abrasion problem of a traditional contact bearing is avoided through the non-contact supported magnetic suspension bearing, so that the service life of the equipment is greatly prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum equipment, and in particular to a magnetic guidance tool and a guidance method thereof. Background Art

[0002] Drilling refers to the work of drilling a hole from the ground using mechanical equipment or manpower. In the prior art, when drilling, the location of the borehole is different from the location of the underground oil layer, so the drill pipe needs to be able to bend and change in the formation to drill towards the target position, so the directional drilling technology was born, that is, a drilling process method that allows the wellbore to drill to the target layer along a pre-designed direction and trajectory, generally referring to oblique drilling and horizontal drilling. In directional wells, the early method was to connect a bend joint, which is a drill pipe with a bending angle. When drilling, the drill pipe will bend at this fixed angle. The disadvantage is that the bending angle is fixed, and the angle of the drilling trajectory is difficult to change. At the same time, due to the use of a bend joint, the drill pipe cannot rotate with the drill bit, so the drilling speed and efficiency will be reduced. Later, a rotary steering tool was developed. The so-called rotary steering is a rotary steering tool connected between the drill pipe and the drill bit. The practice of the rotary steering tool is generally to have a support arm on the rotary steering tool to push the drill bit at the front end to change the angle. So that the entire drill pipe can be drilled together along the changed angle. Although the rotary steerable tool avoids the disadvantage of using a fixed bent joint drill pipe that cannot rotate, the rotary steerable tool uses a more complex structure with a support arm. The support arm requires a matching mechanical structure to help it push out and retract, and is also equipped with bearings, which also brings many disadvantages. The downhole environment is full of mud, crude oil, and other formation fluids. These fluids contain a large amount of impurities such as silt. Since the rotary steerable tool is equipped with bearings inside, these silt impurities cause great damage to the bearings. In addition, the bearings, as the main supporting components, continue to receive huge impact forces. Therefore, the rotary steerable tool has a lifespan of only one hundred to two hundred hours. At present, there is an urgent need for a tool with a long service life that can improve drilling speed and efficiency. Summary of the invention

[0003] The present invention provides a magnetic guidance tool and a guidance method thereof, which solve the above-mentioned technical problems.

[0004] The present invention provides a magnetic guidance tool, comprising: a central shaft and a housing;

[0005] The outer shell is sleeved on the central axis;

[0006] The central shaft is provided with a central hole;

[0007] A deflection assembly and a magnetic assembly are arranged at corresponding positions on the inner side of the shell and the central axis;

[0008] The deflection assembly and the magnetic assembly form a magnetic suspension bearing for non-contact support of the central axis, so that the housing and the central axis are guided by non-contact deflection.

[0009] Optionally, an axial deflection assembly and an axial magnetic assembly are respectively arranged on the inner side of the shell and the central axis; the axial deflection assembly and the axial magnetic assembly are sleeved and relatively connected to form an axial magnetic suspension bearing;

[0010] and / or

[0011] A radial deflection assembly and a radial magnetic assembly are respectively arranged on the inner side of the shell and the central axis; the radial deflection assembly and the radial magnetic assembly are adjacent to each other to form a radial magnetic suspension bearing.

[0012] Optionally, radial magnetic components are respectively arranged at both ends of the inner side of the shell; an axial deflection component is arranged between the two groups of radial magnetic components on the inner side of the shell;

[0013] Two groups of radial deflection components are arranged on the central axis, adjacent to and opposite to the two groups of radial magnetic components respectively; the radial magnetic components and the radial deflection components constitute a radial magnetic suspension bearing;

[0014] An axial magnetic component is also arranged on the central axis; the axial deflection component and the axial magnetic component are sleeved and relatively connected to form an axial magnetic suspension bearing.

[0015] Optionally, the magnetic component includes one or more of a natural magnet, an artificial magnet, or an electromagnet; the deflection component includes one or more of a natural magnet, an artificial magnet, or an electromagnet.

[0016] Optionally, the axial magnetic force assembly is a magnet arranged around the central axis; the axial deflection assembly is a magnet arranged around the inner side of the housing;

[0017] The radial magnetic assembly is a magnet arranged in the radial direction; the radial deflection assembly is a magnet arranged in the radial direction.

[0018] The present invention also provides a guiding method for a magnetic guiding tool, comprising: guiding by an axial magnetic suspension bearing.

[0019] The present invention further provides a guiding method for a magnetic guiding tool, including guiding by a radial magnetic suspension bearing.

[0020] The present invention further provides a guidance method for a magnetic guidance tool, including guidance by radial magnetic suspension bearings and mixed guidance by radial magnetic suspension bearings.

[0021] Beneficial effects of the present invention: The present invention provides a magnetic guidance tool and a guidance method thereof. The magnetic guidance tool generates magnetic force through a deflection assembly and a corresponding magnetic assembly and controls the guidance to realize a non-contact supported magnetic levitation bearing. Not only does it realize the guidance function, but it also avoids the wear problem of traditional contact bearings through the non-contact supported magnetic levitation bearing, thereby greatly improving the life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A cross-sectional structural diagram of a magnetic guidance tool provided in Example 2 of the present invention;

[0023] Figure 2 A cross-sectional structural diagram of a magnetic guidance tool provided in Example 2 of the present invention;

[0024] Figure 3 A cross-sectional structural diagram of a magnetic guidance tool provided in Example 2 of the present invention;

[0025] Figure 4 A schematic structural diagram of a drilling tool assembly including a magnetic guidance tool provided in Example 2 of the present invention;

[0026] Figure 5 A schematic structural diagram of a magnetic guide tool provided in Example 3 of the present invention when magnetic deflection is not activated;

[0027] Figure 6 A schematic diagram of a deflection trajectory of a magnetic guidance tool guided by an axial magnetic suspension bearing provided in Example 3 of the present invention;

[0028] Figure 7 A schematic diagram of a deflection trajectory of a magnetic guidance tool guided by a radial magnetic bearing provided in Example 3 of the present invention;

[0029] Figure 8 A schematic diagram of the deflection trajectory of a magnetic guidance tool provided in Example 3 of the present invention using a mixed guidance of radial magnetic suspension bearings and axial magnetic suspension bearings. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides a magnetic guidance tool, including:

[0033] Center shaft and housing;

[0034] The outer shell is sleeved on the central shaft;

[0035] A central hole is provided in the central axis;

[0036] A deflection assembly and a magnetic assembly are arranged on the inner side of the shell and the central axis in corresponding positions;

[0037] The deflection assembly and the magnetic assembly form a magnetic suspension bearing for non-contact support of the central axis, so that the outer shell and the central axis are guided by non-contact deflection.

[0038] Preferably, an axial deflection assembly and an axial magnetic assembly are respectively arranged on the inner side of the housing and the central axis; the axial deflection assembly and the axial magnetic assembly are sleeved and relatively connected to form an axial magnetic suspension bearing;

[0039] and / or

[0040] A radial deflection component and a radial magnetic component are respectively arranged on the inner side of the shell and the central axis; the radial deflection component and the radial magnetic component are adjacent to each other to form a radial magnetic suspension bearing.

[0041] Preferably, radial magnetic components are respectively arranged at both ends of the inner side of the shell; an axial deflection component is arranged between the two groups of radial magnetic components on the inner side of the shell;

[0042] Two groups of radial deflection components are arranged on the central axis, adjacent to and opposite to the two groups of radial magnetic components respectively; the radial magnetic components and the radial deflection components constitute a radial magnetic suspension bearing;

[0043] An axial magnetic component is also arranged on the central axis; the axial deflection component and the axial magnetic component are sleeved and relatively connected to form an axial magnetic suspension bearing.

[0044] Preferably, the magnetic component includes one or more of natural magnets, artificial magnets or electromagnets; the deflection component includes one or more of natural magnets, artificial magnets or electromagnets.

[0045] Preferably, the axial magnetic force assembly is a magnet arranged around the central axis; the axial deflection assembly is a magnet arranged around the inner side of the housing;

[0046] The radial magnetic assembly is a magnet arranged in the radial direction; the radial deflection assembly is a magnet arranged in the radial direction.

[0047] This embodiment also provides a guidance method for a magnetic guidance tool, which is guided by an axial magnetic suspension bearing for drilling guidance or by a radial magnetic suspension bearing; or by a combination of an axial magnetic suspension bearing and a radial magnetic suspension bearing.

[0048] The present embodiment provides a magnetic guidance tool and a guidance method thereof. The magnetic guidance tool generates magnetic force and controls the guidance through a deflection assembly and a corresponding magnetic assembly to realize a magnetic levitation bearing that supports the central axis in a non-contact manner. Not only does it realize the guidance function, but it also avoids the wear problem of traditional contact bearings through the non-contact supported magnetic levitation bearings, thereby greatly improving the life of the equipment.

[0049] In this embodiment, the magnetic bearing refers to an axial community composed of an axial magnetic component and an axial deflection component, and / or a radial community composed of a radial magnetic component and a radial deflection component.

[0050] Example 2

[0051] This embodiment provides a magnetic guidance tool, such as Figure 1 As shown, it includes: a central axis 1, an axial magnetic assembly 2, an axial deflection assembly 3, an upper radial magnetic assembly 4-1, an upper radial deflection assembly 5-1, a lower radial magnetic assembly 4-2, a lower radial deflection assembly 5-2 and a housing 6;

[0052] The central axis 1 is the core of the entire structure, and all structures are based on the central axis. The central axis 1 is a long tubular structure with a central hole, which is specifically a through hole. One end of the through hole is connected to the water hole in the drill pipe, and the other end is connected to the water hole of the drill bit, which can be used as a flow channel for drilling fluid. The upper end of the central axis 1 has a threaded structure, which can be used to connect with the drill pipe. The central axis 1 has a protrusion near the upper end of the thread, which is used as a structure for installing the upper radial deflection component 5-1. The upper radial deflection component 5-1 is arranged in a ring shape around the central axis along the radial direction; the middle section of the central axis 1 has an installation position for installing the axial magnetic component 2, and the magnetic component 2 surrounds the middle section of the central axis 1 in a ring shape; the lower end of the central axis 1 has a protrusion, which is used as a structure for installing the lower radial deflection component 5-2. The lower radial deflection component 5-2 is arranged in a ring shape around the central axis along the radial direction. It should be noted that the protrusion on the central shaft for mounting the radial deflection assembly serves as a limiting structure of the radial magnetic assembly and can be arranged at the upper end position of the central shaft 1 and / or the lower end position of the central shaft 1 .

[0053] On the outside of the central axis 1, a housing 6 is sleeved and installed. The housing 6 is a tubular structure with a diameter larger than that of the central axis 1. Inside the upper tubular part of the housing 6, an upper radial magnetic component 4-1 is installed along the tubular shape; the upper radial magnetic component 4-1 is adjacent to and opposite to the upper radial deflection component 5-1. Inside the middle section of the housing 6, at a position corresponding to the axial magnetic component 2 of the central axis 1, an axial deflection component 3 is installed along the tubular shape, and the axial deflection component 3 is sleeved and opposite to the axial magnetic component 2. At the lower end of the housing 6, a radial magnetic component 4-2 is installed around a position corresponding to the lower radial deflection component 5-2; the lower radial deflection component 5-2 is adjacent to and opposite to the lower radial magnetic component 4-2; the lower end of the housing 6 has a thread for connecting a drill bit.

[0054] An axial magnetic component 2 is provided at the middle section of the central axis 1 to correspond to the axial deflection component 3 on the housing 6 to provide magnetic support.

[0055] The axial magnetic assembly 2 is a magnet arranged around the central axis, and the number of the magnets can be one or more; the magnetic source can be a natural magnet, an artificial magnet, an electromagnet, or a combination of the above. Preferably, the axial magnetic assembly 2 includes a plurality of magnets tightly mounted on the central axis along the axial direction.

[0056] The axial deflection assembly 3 is a magnet arranged and mounted on the inner side of the housing; the number of the magnets can be one or more; the source of the magnetic force can be a natural magnet, an artificial magnet, an electromagnet, or a combination of the above. Preferably, the axial deflection assembly 3 includes: a plurality of magnets tightly mounted on the inner side of the housing, and sleeved and opposed to the axial magnetic assembly 2.

[0057] like Figure 2 As shown, the installation position of the axial deflection assembly 3 is opposite to the axial magnetic assembly 2 on the central shaft 1. The axial deflection assembly 3 and the axial magnetic assembly 2 form a set of axial magnetic suspension bearings. By controlling the size and direction of the magnetic field, the central shaft 1 is separated from the housing 6, and the axial magnetic assembly and the axial deflection assembly maintain a certain distance and do not contact each other.

[0058] It should be noted that the positions of the axial deflection assembly 3 and the axial magnetic assembly 2 can be interchanged.

[0059] The radial magnetic assembly is a magnet arranged in a ring along the radial direction; the number of the radial magnetic assembly can be one or more; the source of the magnetic force can be a natural magnet, an artificial magnet, an electromagnet, or a combination of the above.

[0060] The radial deflection assembly can be a magnet arranged in a ring along the radial direction, and these magnets correspond to the magnets of the radial magnetic assembly in the radial direction. The number of the magnets can be one or more. The source of the magnetic force can be a natural magnet, an artificial magnet, an electromagnet, or a combination of the above.

[0061] For example, the radial magnetic component and the radial deflection component are both in annular shape, and are respectively sleeved on the central axis and the outer shell; the disk surfaces of the radial magnetic component and the radial deflection component are opposite to each other.

[0062] like Figure 1 and Figure 3 As shown, the radial deflection assembly is adjacent to and opposite to the radial magnetic assembly. The upper radial deflection assembly 5-1 near the upper end of the central axis 1 is used to correspond to the upper radial magnetic assembly 4-1 on the housing 6 to provide magnetic support. The lower radial deflection assembly 5-2 near the lower end of the central axis 1 is used to correspond to the lower radial magnetic assembly 4-2 on the housing 6 to provide magnetic support.

[0063] The radial magnetic assembly and the radial deflection assembly separate the magnetic assembly and the deflection assembly by controlling the magnitude and direction of the magnetic field, and the two maintain a certain distance and do not contact each other. The radial magnetic assembly and the radial deflection assembly constitute a set of radial magnetic suspension bearings.

[0064] It should be noted that the positions of the upper radial magnetic assembly 4 - 1 and the upper radial deflection assembly 5 - 1 can be interchanged; the positions of the lower radial magnetic assembly 4 - 2 and the lower radial deflection assembly 5 - 2 can be interchanged.

[0065] The magnetic bearing in this example refers to a part that relies on a magnetic field to support a load. Magnetic levitation refers to the fact that two relative magnetic components are kept at a certain distance from each other through the action of a magnetic field, without contacting each other. The magnetic field in the magnetic bearing is generated by, but not limited to, the magnetic field generated by natural magnets, the magnetic field generated by electromagnets, the magnetic field generated by artificial permanent magnets, or a combination of the above. The supported loads include, but are not limited to, axial loads, radial loads, and loads caused by external impacts.

[0066] like Figure 4As shown, the installation order of the magnetic guidance tool provided in the present embodiment in the drilling tool assembly can be, but is not limited to, such as: the upper end of the magnetic guidance tool is connected to the drill rod through the thread on the central axis 1, the uppermost end of the drill rod is connected to the drilling rig on the ground, and the outer shell 6 is not connected to the drill rod. Then the lower end of the magnetic guidance tool is connected to the screw rod through the thread on the outer shell 6, and the central axis 1 is not connected to the screw rod. The lower end of the screw rod 8 is connected to the drill bit. This connection method can prevent the drill rod from swinging after bending due to guidance during the guidance process, resulting in increased torque, thereby damaging the drill rod drilling. For energy issues, a high-power downhole generator can be used, and even a dedicated power transmission cable can be made. For example, the motor can be connected to the central axis through a thread, and then the power line is connected together on the central axis by laying a pipeline.

[0067] The magnetic guidance tool provided in this embodiment relies on the principle that like magnets repel each other and opposite magnets attract each other. By controlling the size and direction of the magnetic field strength, it can achieve contactless load bearing while controlling the position between the axial magnetic component and the axial deflection component. By controlling the size and direction of the magnetic field, the angle between the central axis and the outer shell is changed, thereby achieving the guidance function.

[0068] Example 3

[0069] The present embodiment provides a guidance method for a magnetic guidance tool. The magnetic guidance tool in the present embodiment can achieve normal drilling state and guided drilling during guidance. The normal drilling state refers to the method in which the magnetic guidance tool drills in a straight line according to the existing trajectory during drilling. In the normal drilling state, the magnetic guidance tool is started in order to maintain straight drilling along the existing trajectory. The axial magnetic suspension bearing and the radial magnetic suspension bearing of the magnetic guidance tool both keep the center line of the central axis coincident with the center line of the outer shell. At this time, the magnetic guidance tool guides the drill rod to drill in a straight line.

[0070] There are three guidance methods in the guided drilling state.

[0071] The first guidance method: axial magnetic bearing-dominated guidance;

[0072] The second guidance method: guidance dominated by radial magnetic bearings;

[0073] The third guidance method: mixed guidance.

[0074] It should be noted that the dominant control refers to the main output of one direction, which is deflection, while the other direction is used to follow and maintain. For example, when the axial magnetic bearing is dominant, the main output of the axial magnetic bearing is used for "deflection", while the radial magnetic bearing is mainly used for "following and maintaining".

[0075] The following describes each of them separately.

[0076] Axial magnetic bearing-dominated guidance methods: Figure 5 As shown, when the magnetic deflection is not activated, the center line of the housing 6-1 coincides with the center line of the central axis 1-1; after the magnetic force guide tool is activated, the axial magnetic assembly 2-1 and the axial deflection assembly 3-1 are activated, and when the magnetic field is turned on, the central axis 1-1 will serve as a "base" to push the housing 6-1 to deflect. By controlling the size and direction of the magnetic field, a deflection force is applied between the axial deflection assembly 3-1 and the axial magnetic assembly 2-1, and the center line of the housing 6-1 does not coincide with the center line of the central axis 1-1, as shown in FIG. Figure 6 As shown. At the same time, the radial magnetic bearing starts, only bearing the load without controlling the deflection. At this time, the centerline of the central axis no longer coincides with the centerline of the shell, but presents an angle. The shell and the central axis are deflected. At this time, the magnetic guide tool is bent. The drilling trajectory immediately changes along this bending angle, thus achieving guidance.

[0077] In this embodiment, only bearing the load means that the magnetic bearing is responsible for maintaining the distance between the central axis and the housing at a constant value. In this paragraph, the axial magnetic bearing is used as the main bearing to control the deflection. The radial magnetic bearing is only responsible for following. In other words, the radial magnetic bearing follows the deflection angle of the axial magnetic bearing.

[0078] In addition, radial magnetic bearings and axial magnetic bearings can be used as working bearings alone to actively provide large forces to promote deflection; they can also be used together to distribute forces to control deflection. When one of the bearings is not used as the main control bearing, its main working purpose is to help the other bearing "maintain the current state", that is, "only bear the load".

[0079] Guidance method dominated by radial magnetic bearings:

[0080] The axial magnetic bearing only bears the load and does not control the deflection. Instead, the radial magnetic component and the radial deflection component control the central axis and the housing to deflect the angle, completing the guiding work. Figure 7 As shown; under the action of the radial deflection component 5-3 and the radial magnetic component 4-3, the shell 6-2 and the central axis 1-2 are deflected, and the center line of the shell 6-2 does not coincide with the center line of the central axis 1-2.

[0081] Hybrid guidance method with axial and radial magnetic bearings:

[0082] Hybrid guidance method: The axial magnetic bearing controls the deflection of the central axis and the housing. At the same time, the radial magnetic bearing also deflects. Under the joint action of the two, the magnetic guidance tool is finally controlled to deflect, thereby guiding the subsequent drilling trajectory to change and achieve guidance. Figure 8 As shown, under the action of the upper radial deflection assembly 5-4 and the upper radial magnetic assembly 4-4, the lower radial deflection assembly 5-5 and the lower radial magnetic assembly 4-5, the axial magnetic assembly 2-2 and the axial deflection assembly 3-2, the outer shell 6-3 and the central axis 1-3 are deflected, and the center line of the outer shell 6-3 does not coincide with the center line of the central axis 1-3.

[0083] Magnetic bearings achieve the purpose of controlling the distance between the inner circle and the outer circle by applying magnetic force through multiple magnets on the circumference. Therefore, the change in the position of the inner circle and the outer circle can also be achieved by changing the magnetic force. Based on this method, we designed this magnetic guidance tool that relies on magnetic bearings. There are many ways to control the size of the magnetic force and affect the position of the inner and outer circles, such as using software control, using feedback sensors, or manually setting a fixed value. The above methods can achieve the deflection of the magnetic bearing, and this patent is not limited to the above methods.

[0084] The magnetic guide tool provided in this embodiment, the axial magnetic component and the axial deflection component rely on magnetic force to keep the central axis and the outer shell in a relatively centered position without friction between the central axis and the outer shell in the axial direction; the radial magnetic component and the radial deflection component are also relative to each other, ensuring that the outer shell does not rub against the central axis, and the service life can be increased to thousands of hours.

[0085] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A magnetic guidance tool, characterized in that: include: Center shaft and housing; The outer shell is sleeved on the central axis; The central shaft is provided with a central hole; A deflection assembly and a magnetic assembly are arranged at corresponding positions on the inner side of the shell and the central axis; The deflection assembly and the magnetic assembly form a magnetic suspension bearing for non-contact support of the central axis, so that the housing and the central axis are guided by non-contact deflection.

2. The magnetic guidance tool according to claim 1, characterized in that: An axial deflection assembly and an axial magnetic assembly are respectively arranged on the inner side of the shell and the central axis; the axial deflection assembly and the axial magnetic assembly are sleeved and relatively connected to form an axial magnetic suspension bearing; and / or A radial deflection assembly and a radial magnetic assembly are respectively arranged on the inner side of the shell and the central axis; the radial deflection assembly and the radial magnetic assembly are adjacent to each other to form a radial magnetic suspension bearing.

3. The magnetic guidance tool according to claim 2, characterized in that: The two ends of the inner side of the shell are respectively provided with radial magnetic components; an axial deflection component is provided between the two groups of radial magnetic components on the inner side of the shell; Two groups of radial deflection components are arranged on the central axis, adjacent to and opposite to the two groups of radial magnetic components respectively; the radial magnetic components and the radial deflection components constitute a radial magnetic suspension bearing; An axial magnetic component is also arranged on the central axis; the axial deflection component and the axial magnetic component are sleeved and relatively connected to form an axial magnetic suspension bearing.

4. The magnetic guidance tool according to claim 1, characterized in that: The magnetic component includes one or more of a natural magnet, an artificial magnet or an electromagnet; the deflection component includes one or more of a natural magnet, an artificial magnet or an electromagnet.

5. The magnetic guidance tool according to claim 2, characterized in that: The axial magnetic force assembly is a magnet arranged around the central axis; the axial deflection assembly is a magnet arranged around the inner side of the housing; The radial magnetic assembly is a magnet arranged in the radial direction; the radial deflection assembly is a magnet arranged in the radial direction.

6. A guidance method for a magnetic guidance tool, applicable to the magnetic guidance tool as claimed in claims 1 to 5, characterized in that: Guided by axial magnetic bearings.

7. A guidance method for a magnetic guidance tool, applicable to the magnetic guidance tool as claimed in claims 1 to 5, characterized in that: Guided by radial magnetic bearings.

8. A guidance method for a magnetic guidance tool, applicable to the magnetic guidance tool as claimed in claims 1 to 5, characterized in that: It is guided by a combination of axial magnetic bearings and radial magnetic bearings.

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