Magnetic-levitation drilling steering and Anti-deviation tool, and vertical drilling system

Abstract

The present solution relates to the field of vertical drilling. Provided are a magnetic-levitation drilling steering and anti-deviation tool, and a vertical drilling system. The magnetic-levitation drilling steering and anti-deviation tool comprises a mandrel capable of connecting to a drill bit; and a non-rotating outer sleeve coaxially arranged on the mandrel and capable of pushing against the inner wall of a wellbore, wherein the inner periphery and two axial ends of the non-rotating outer sleeve are spaced apart from the mandrel; and an electromagnetic bearing is provided between the non-rotating outer sleeve and the mandrel, such that the mandrel is in a magnetic-levitation state relative to the non-rotating outer sleeve. By means of the above technical solution, the electromagnetic bearing provided between the non-rotating outer sleeve and the mandrel can prevent or reduce direct contact between the non-rotating outer sleeve and the mandrel, thereby preventing or reducing wear between the two. Moreover, the electromagnetic bearing itself can prevent or reduce physical wear, such that the service life is prolonged, and the deviation of the electromagnetic bearing itself and the mandrel can also be prevented or reduced, thereby reducing or preventing the deviation of the wellbore and improving drilling operation quality.

Description

A magnetic levitation drilling guide and anti-deviation tool and a vertical drilling system

[0001] Cross-references to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411762503.2, filed on December 3, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the technical field of vertical drilling, and more particularly to a magnetic levitation drilling guide and anti-deviation tool, and to a vertical drilling system. Background Technology

[0004] In oil or geological exploration drilling, under complex geological conditions such as steep formations and thrust-overburden formations, there is a general requirement for anti-deviation drilling and rapid drilling to improve wellbore quality and reduce drilling costs. However, conventional drilling techniques, when encountering steep formations and steep dip angles, can cause the drill bit to deviate from the normal vertical axis of the wellbore trajectory due to the combined effects of formation dip angle, geostress, and drilling pressure. Conventional anti-deviation methods mostly come at the cost of sacrificing drilling pressure and reducing mechanical drilling rate, and cannot economically and efficiently solve the well deviation problem in steep and steep formations.

[0005] The automatic vertical drilling system is a downhole closed-loop control system that can actively correct and prevent deviation in the well. It can maintain vertical drilling even when the drilling pressure is completely released. It can be used to solve the technical problems of preventing deviation and speeding up drilling in steep piedmont structures and other easily deviated formations. It is a cutting-edge drilling technology in the field of drilling that can actively prevent deviation, effectively release drilling pressure, and achieve speed and efficiency improvement.

[0006] Automatic vertical drilling systems can be classified into push-type and stationary types according to the correction method of the actuator. Push-type vertical drilling tools have the advantages of large lateral force of the drill bit and high deviation reduction rate. In these systems, the non-rotating outer cylinder and the center rod are connected by a TC (carbide) bearing. The wear and lifespan of the TC bearing directly determine the stability of the deviation measurement environment, the accuracy of the deviation measurement data, and the ability of the vertical drilling tool to effectively and efficiently correct and stabilize the deviation. Wear on the TC bearing of the outer cylinder prevents it from remaining centered, leading to increased deviation measurement errors. Wear on the TC bearing also increases the gap between the outer cylinder and the center rod, making it impossible to maintain parallelism within 0.05, which in turn increases the measurement error of the deviation sensor. Summary of the Invention

[0007] One of the technical problems this disclosure aims to solve is: how to avoid well deviation caused by bearing wear in vertical drilling tools.

[0008] To solve the above-mentioned technical problems, this disclosure provides a magnetic levitation drilling guidance and anti-deviation tool, which includes a central rod that can be connected to the drill bit and a non-rotating outer cylinder that is coaxially sleeved on the central rod and can be pushed against the inner wall of the wellbore. The inner circumference and axial ends of the non-rotating outer cylinder are spaced apart from the central rod. An electromagnetic bearing is provided between the non-rotating outer cylinder and the central rod so that the central rod is in a magnetic levitation state relative to the non-rotating outer cylinder.

[0009] In some embodiments, a radial electromagnetic bearing is provided between the inner circumference of the non-rotating outer cylinder and the outer circumference of the central rod, so that the non-rotating outer cylinder and the central rod maintain a radial distance.

[0010] In some embodiments, the radial electromagnetic bearing includes a first stator portion disposed on the inner circumference of the non-rotating outer cylinder and a first rotor portion disposed on the outer circumference of the central rod. The first stator portion includes a plurality of first electromagnets spaced circumferentially, the magnetic poles of the first electromagnets being arranged to extend radially, and the first rotor portion including a first permanent magnet.

[0011] In some embodiments, a plurality of the first electromagnets are uniformly distributed circumferentially.

[0012] In some embodiments, the plurality of first electromagnets include a plurality of pairs of first electromagnets arranged symmetrically about a central axis.

[0013] In some embodiments, the magnetic force of each of the first electromagnets can be adjusted independently.

[0014] In some embodiments, the magnetic levitation drilling guide anti-deviation tool can be configured to: when a well deviation is detected, adjust the magnetic force of the first electromagnet set corresponding to the well deviation direction to drive the central rod to move relative to the non-rotating outer cylinder in a direction opposite to the well deviation direction.

[0015] In some embodiments, a well inclination sensor is provided on the non-rotating outer cylinder.

[0016] In some embodiments, the magnetic levitation drilling guide anti-deviation tool can be configured to: when a deviation of the central rod relative to the non-rotating outer cylinder is detected, adjust the magnetic force of the first electromagnet set corresponding to the deviation direction to drive the central rod to move relative to the non-rotating outer cylinder in a direction opposite to the deviation direction.

[0017] In some embodiments, the magnetic levitation drilling guide anti-deviation tool can be configured such that: when a well deviation is detected and the center rod deviates relative to the non-rotating outer cylinder, if the deviation direction is opposite to the well deviation direction, the deviation of the center rod is corrected after the well deviation is corrected; if the deviation direction is not opposite to the well deviation direction, the magnetic force of the first electromagnet is adjusted so that the center rod deviates in a direction opposite to the well deviation direction, and the deviation of the center rod is corrected after the well deviation is corrected.

[0018] In some embodiments, the central rod is provided with a displacement sensor for detecting the displacement of the central rod relative to the non-rotating outer cylinder in a direction perpendicular to the central axis.

[0019] In some embodiments, two radial electromagnetic bearings are included, located at the upper and lower portions of the non-rotating outer cylinder, respectively.

[0020] In some embodiments, axial electromagnetic bearings are respectively provided between the two axial ends of the non-rotating outer cylinder and the central rod.

[0021] In some embodiments, the axial electromagnetic bearing includes a second rotor portion disposed on the central rod and a second stator portion disposed at the end of the non-rotating outer cylinder. The second rotor portion includes a plurality of circumferentially spaced second electromagnets, the magnetic poles of the second electromagnets being arranged along the axial direction. The second stator portion includes a plurality of circumferentially spaced second permanent magnets.

[0022] In some embodiments, the non-rotating outer cylinder is provided with a hydraulic module and a pusher rib connected to the hydraulic module. The hydraulic module can drive the pusher rib to move radially to press against the inner wall of the well cylinder.

[0023] In some embodiments, a first electronic compartment is provided in the central rod, and a second electronic compartment is provided in the non-rotating outer cylinder, wherein the first electronic compartment and the second electronic compartment are electrically connected to the electromagnetic bearing.

[0024] In some embodiments, a rotary transformer is further included, disposed on the inner periphery of the non-rotating outer cylinder and the outer periphery of the central rod, the rotary transformer electrically connecting the first electronic compartment and the second electronic compartment to each other.

[0025] In some embodiments, the upper end of the central rod is provided with a conductive slip ring electrically connected to the first electronic compartment.

[0026] On the other hand, this solution provides a vertical drilling system, characterized in that it includes the magnetic levitation drilling guidance and anti-deviation tool described in the above solution.

[0027] Through the above technical solution, the electromagnetic bearing installed between the non-rotating outer cylinder and the center rod can avoid or reduce direct contact between the non-rotating outer cylinder and the center rod, thereby avoiding or reducing wear between them. Furthermore, the electromagnetic bearing itself can avoid or reduce physical wear, which on the one hand extends its service life, and on the other hand, can avoid or reduce the deviation of the electromagnetic bearing itself and the center rod, thereby reducing or preventing wellbore deviation and improving drilling operation quality. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 is a cross-sectional view of the magnetic levitation drilling guidance and anti-deviation tool disclosed in an embodiment of this disclosure;

[0030] Figure 2 is a schematic diagram of the structure of the radial electromagnetic bearing disclosed in this embodiment;

[0031] Figure 3 is a schematic diagram of the structure of the central rod, non-rotating outer cylinder and axial electromagnetic bearing disclosed in the embodiment of this disclosure;

[0032] Figure 4 is a schematic diagram of the structure of the second rotor section disclosed in an embodiment of this disclosure;

[0033] Figure 5 is a schematic diagram of the structure of the second stator section disclosed in an embodiment of this disclosure.

[0034] Explanation of reference numerals in the attached drawings: 1. Non-rotating outer cylinder; 2. Hydraulic module; 3. Pushing rib plate; 4. First electronic compartment; 5. Second electronic compartment; 6. Rotary transformer; 7. Center rod; 8. Axial electromagnetic bearing; 9. Radial electromagnetic bearing; 10. First electromagnet; 11. First permanent magnet; 12. Second electromagnet; 13. Second permanent magnet; 14. Conductive slip ring. Detailed Implementation

[0035] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0036] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0037] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0038] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0039] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0040] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0041] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0042] Referring to Figures 1-5, this solution provides a magnetic levitation drilling guidance and anti-deviation tool, which includes a central rod 7 that can be connected to the drill bit and a non-rotating outer cylinder 1 that is coaxially sleeved on the central rod 7 and can be pushed against the inner wall of the wellbore. The inner circumference and axial ends of the non-rotating outer cylinder 1 are spaced apart from the central rod 7. An electromagnetic bearing is provided between the non-rotating outer cylinder 1 and the central rod 7 so that the central rod 7 is in a magnetic levitation state relative to the non-rotating outer cylinder 1.

[0043] The lower end of the center rod 7 can be connected to the drill bit and rotate synchronously with the drill bit.

[0044] The non-rotating outer cylinder 1 is sleeved on the outside of the central rod 7 and is spaced apart from the central rod 7 without contacting it. The non-rotating outer cylinder 1 can be pushed against the inner wall of the well shaft to provide support for the central rod 7, so that the central rod 7 is in a proper position and to avoid or reduce the occurrence of deflection.

[0045] Furthermore, to ensure that the non-rotating outer cylinder 1 supports the central rod 7 in a non-contact manner, an electromagnetic bearing is installed between the non-rotating outer cylinder 1 and the central rod 7. The electromagnetic bearing consists of two relatively rotatable parts, namely a stator and a rotor. These two parts are supported by magnetic force without direct contact. Therefore, the non-rotating outer cylinder 1 can support the central rod 7 through the magnetic force of the electromagnetic bearing, making the central rod 7 magnetically levitated relative to the non-rotating outer cylinder 1. In this way, during the rotation of the central rod 7, there is no direct contact between the moving and stationary parts, that is, there is no direct contact between the non-rotating outer cylinder 1 and the central rod 7, and there is also no direct contact between the two relatively rotating parts of the electromagnetic bearing. Therefore, there is no physical friction, which can avoid wear between the non-rotating outer cylinder 1 and the central rod 7, as well as between the stator and rotor of the electromagnetic bearing. This can extend the service life of the tool and avoid or reduce the occurrence of misalignment problems after bearing wear, thus ensuring the quality of drilling operations.

[0046] In this design, the electromagnetic bearing installed between the non-rotating outer cylinder and the center rod can avoid or reduce direct contact between the two, thereby avoiding or reducing wear between them. Furthermore, the electromagnetic bearing itself can avoid or reduce physical wear, thus extending its service life. On the other hand, it can avoid or reduce the deviation of the electromagnetic bearing itself and the center rod, thereby reducing or preventing wellbore deviation and improving drilling operation quality.

[0047] In some embodiments, a radial electromagnetic bearing 9 is provided between the inner circumference of the non-rotating outer cylinder 1 and the outer circumference of the central rod 7, so that the non-rotating outer cylinder 1 and the central rod 7 maintain a radial distance. The radial electromagnetic bearing 9 includes two parts, namely a stator part and a rotor part, disposed on the non-rotating outer cylinder 1 and the central rod 7. There is a supporting force acting on each other in the radial direction between the two parts, so that there is a radial supporting force between the non-rotating outer cylinder 1 and the central rod 7. This supporting force makes the stator part and the rotor part form a gap without contact, and makes the non-rotating outer cylinder 1 and the central rod 7 form an annular gap without contact.

[0048] In some embodiments, the radial electromagnetic bearing 9 includes a first stator portion disposed on the inner circumference of the non-rotating outer cylinder 1 and a first rotor portion disposed on the outer circumference of the central rod 7. The first stator portion includes a plurality of first electromagnets 10 spaced apart circumferentially, with the magnetic poles of the first electromagnets 10 extending radially. The first rotor portion includes a first permanent magnet 11. The first stator portion is generally annular, and the first rotor portion can be annular or rod-shaped concentric with the central rod 7. The force exerted by the first stator portion on the first rotor portion is radially inward or radially outward and distributed circumferentially, thereby balancing the forces on the first rotor portion and keeping the central rod 7 at the central axis position of the non-rotating outer cylinder 1. In this structure, multiple first electromagnets 10 are arranged in a ring shape, with the magnetic poles of each electromagnet 10 pointing radially to apply a radial force to the first permanent magnet 11. This force can be radially inward or radially outward, i.e., it can apply an attractive or repulsive force to the first permanent magnet 11. The first permanent magnet 11 can be a rod-shaped structure coaxial with the central rod 7, or it can be a ring-shaped structure sleeved around the outer periphery of the central rod 7. For example, the first permanent magnet 11 can be a coating of magnetic material formed on the outer periphery of the central rod 7, with the outer surface of the coating being either an N pole or a S pole, and the inner surface being either an S pole or a N pole.

[0049] In some embodiments, multiple first electromagnets 10 are evenly distributed circumferentially. The multiple electromagnets 10 can have the same structure, and each electromagnet 10 can include an iron core and a coil disposed on the iron core. When the coil is energized, the force exerted by each electromagnet 10 on the first permanent magnet 11 is the same, meaning the force exerted by the first stator on the first permanent magnet 11 in the circumferential direction is more uniform, ensuring that the central rod 7 can be coaxial with the non-rotating outer cylinder 1, and an annular gap can be formed between them.

[0050] In some embodiments, the plurality of first electromagnets 10 include multiple pairs of first electromagnets 10 arranged symmetrically about the central axis. For example, the first stator may include 4 pairs, i.e., 8 electromagnets 10. Each pair of first electromagnets 10 is arranged symmetrically about the central axis of the non-rotating outer cylinder 1. Therefore, when the central rod 7 is coaxial with the non-rotating outer cylinder 1, the forces exerted by each pair of first electromagnets 10 on the first permanent magnet 11 are opposite in direction and equal in magnitude, and are in a state of mutual balance. If the central rod 7 is deflected toward one of the first electromagnets 10, the force exerted by that first electromagnet 10 on it will increase, while the force exerted by the other symmetrically arranged first electromagnet 10 on the first permanent magnet 11 will decrease. This allows the first permanent magnet 11 and the central rod 7 to move toward the other first electromagnet 10 and eventually return to the position coaxial with the non-rotating outer cylinder 1. Furthermore, multiple pairs of first electromagnets 10 can keep the central rod 7 coaxial with the non-rotating outer cylinder 1 in other directions. Ultimately, through the action of multiple pairs of first electromagnets 10 on the first permanent magnet 11, the central rod 7 is kept coaxial with the non-rotating outer cylinder 1. Referring to Figure 2, the first stator section includes four pairs of first electromagnets 10, which can limit the deflection of the central rod 7 in four different directions, keeping the central rod 7 coaxial with the non-rotating outer cylinder 1. Of course, in other embodiments, more pairs of first electromagnets 10 can be provided.

[0051] In other embodiments, the first electromagnet 10 may be disposed on the central rod 7, and the permanent magnet may be disposed on the non-rotating outer cylinder 1, or electromagnets that cooperate with each other may be disposed on the non-rotating outer cylinder 1 and the central rod 7 respectively.

[0052] In some embodiments, the magnetic force of each first electromagnet 10 can be adjusted independently. Each first electromagnet 10 is relatively independent of the others, and its magnetic force can be adjusted independently, largely unaffected by the other first electromagnets 10. In some cases, there may be uneven magnetic forces at different locations along the circumferential direction. In such cases, the magnetic force of the corresponding first electromagnet 10 can be adjusted to ensure a uniformly distributed force. The magnetic force of the first electromagnet 10 can be adjusted by regulating the current flowing through its coil.

[0053] In some embodiments, the magnetic levitation drilling guidance and anti-deviation tool can be configured to: when a well deviation is detected, adjust the magnetic force of the first electromagnet 10 corresponding to the deviation direction to drive the central rod 7 to move relative to the non-rotating outer cylinder 1 in a direction opposite to the deviation direction. Well deviation refers to the angle between the central axis of the wellbore and the vertical line of the earth, resulting in wellbore skewness. Correspondingly, the magnetic levitation drilling guidance and anti-deviation tool located within it also skews, particularly the non-rotating outer cylinder 1, which skews at an angle to the vertical line of the earth. In this case, the magnetic force of the first electromagnet 10 in the corresponding direction can be adjusted according to the deviation direction, causing the central rod 7 to deflect in the opposite direction. The drill bit connected to the central rod 7 also deflects accordingly, thus correcting the deviation of the wellbore as it continues to descend. After the well deviation is corrected, the magnetic force of the first electromagnet corresponding to the deviation direction is readjusted, causing the central rod 7 to return to a position coaxial with the non-rotating outer cylinder 1.

[0054] In some embodiments, a well deviation sensor is provided on the non-rotating outer cylinder 1. The well deviation sensor can be used to detect whether there is well deviation in the magnetic levitation drilling guide anti-deviation tool, especially to detect whether there is well deviation in the non-rotating outer cylinder 1, because the non-rotating outer cylinder 1 is pushed against the inner wall of the well barrel and is basically coaxial with the well barrel, which can reflect whether there is a well deviation problem in the well barrel.

[0055] In some embodiments, the magnetic levitation drilling guide anti-deviation tool can be configured to: when a deviation of the central rod 7 relative to the non-rotating outer cylinder 1 is detected, adjust the magnetic force of the first electromagnet 10 corresponding to the deviation direction to drive the central rod 7 to move relative to the non-rotating outer cylinder 1 in a direction opposite to the deviation direction. In some cases, the central rod 7 may accidentally deviate relative to the non-rotating outer cylinder 1; therefore, it is necessary to correct this deviation by adjusting the magnetic force of the first electromagnet 10 corresponding to the deviation direction, so that the central rod 7 is subjected to a magnetic force opposite to the deviation direction, so as to return to a position coaxial with the non-rotating outer cylinder 1.

[0056] In some embodiments, the magnetic levitation drilling guide anti-deviation tool can be configured such that: when a well deviation is detected and the center rod 7 deviates relative to the non-rotating outer cylinder 1, if the deviation direction is opposite to the well deviation direction, the deviation of the center rod 7 is corrected after the well deviation is corrected; if the deviation direction is not opposite to the well deviation direction, the magnetic force of the first electromagnet 10 is adjusted to make the center rod 7 deviate in the opposite direction to the well deviation direction, and the deviation of the center rod 7 is corrected after the well deviation is corrected. That is, the deviation of the center rod 7 can exist in at least two situations: one is that it is intentionally set to a deviated state to correct the well deviation of the non-rotating outer cylinder 1, and the other is unintentional, possibly due to the action of external forces. When a well deviation occurs, the center rod 7 is adjusted to deviate relative to the non-rotating outer cylinder 1; after the well deviation is corrected, the center rod 7 is adjusted to a position coaxial with the non-rotating outer cylinder 1. Additionally, if the deflection direction of the center rod 7 is not opposite to the well inclination direction, the position of the center rod 7 needs to be adjusted first so that its deflection direction is opposite to the well inclination direction, in order to correct the well inclination. After the well inclination is corrected, the position of the center rod 7 is adjusted again to return to the position coaxial with the non-rotating outer cylinder 1. Specifically, if the deflection direction of the center rod 7 is not opposite to the well inclination direction, the center rod 7 can be temporarily adjusted to be coaxial with the non-rotating outer cylinder 1, and then adjusted to deflect in the opposite direction to the well inclination direction, or it can be directly adjusted to deflect in the opposite direction to the well inclination direction. This adjustment includes adjusting the magnetic force of at least two pairs of first electromagnets 10, one pair corresponding to the initial deflection direction of the center rod 7 and the other pair corresponding to the well inclination direction.

[0057] In some embodiments, the central rod 7 is equipped with a displacement sensor for detecting the displacement of the central rod 7 relative to the non-rotating outer cylinder 1 in a direction perpendicular to the central axis. The displacement sensor can be used to detect the displacement of the central rod 7 relative to the central axis of the non-rotating outer cylinder 1, that is, to detect the direction and amount of deviation of the central rod 7 relative to the central axis of the non-rotating outer cylinder 1, so as to determine whether the central rod 7 is coaxial with the non-rotating outer cylinder 1. When they are not on the same axis, the magnetic force of the first electromagnet 10 can be adjusted to bring the central rod 7 back to the coaxial position.

[0058] In some embodiments, the magnetic levitation drilling guide anti-deviation tool includes two radial electromagnetic bearings 9 located at the upper and lower parts of the non-rotating outer cylinder 1, respectively. The non-rotating outer cylinder 1 can support the central rod 7 through the two radial electromagnetic bearings 9, so that the central rod 7 is kept coaxial with the non-rotating outer cylinder 1 at two axial positions, thereby ensuring that the central rod 7 as a whole remains coaxial with the non-rotating outer cylinder 1.

[0059] In some embodiments, axial electromagnetic bearings 8 are respectively provided between the two axial ends of the non-rotating outer cylinder 1 and the central rod 7. The axial electromagnetic bearings 8 provide axial support force to the central rod 7, and the forces exerted by the two axial electromagnetic bearings 8 on the central rod 7 are in opposite directions, thereby holding the central rod 7 in a predetermined position and positioning it axially relative to the non-rotating outer cylinder 1. For example, the non-rotating outer cylinder 1 applies a downward (or upward) force to the central rod 7 through the upper axial electromagnetic bearing 8, and correspondingly, the non-rotating outer cylinder 1 applies an upward (or downward) force to the central rod 7 through the lower axial electromagnetic bearing 8. These two forces are balanced with other axial forces that the central rod 7 may experience (e.g., part of the weight of the central rod 7), thus holding the central rod 7 in the predetermined position.

[0060] In some embodiments, the axial electromagnetic bearing 8 includes a second rotor portion disposed on the central rod 7 and a second stator portion disposed at the end of the non-rotating outer cylinder 1. The second rotor portion includes a plurality of circumferentially spaced second electromagnets 12, the magnetic poles of the second electromagnets 12 being oriented along the axial direction. The second stator portion includes a plurality of circumferentially spaced second permanent magnets 13. The plurality of second electromagnets 12 can apply magnetic force to the second permanent magnets 13. The forces of the two axial electromagnetic bearings 8 cooperate with each other to keep the central rod 7 balanced relative to the non-rotating outer cylinder 1 in the axial direction, i.e., in a magnetically levitated state.

[0061] The center rod 7 may have protrusions on the upper and lower sides of the non-rotating outer cylinder 1 to facilitate the installation of the rotor portion of the axial electromagnetic bearing 8, and the protrusion on the lower side of the non-rotating outer cylinder 1 may be formed by a joint detachably connected to the lower end of the center rod 7.

[0062] Therefore, the combined action of the radial electromagnetic bearing 9 and the axial electromagnetic bearing 8 allows the central rod 7 to remain spaced apart from the non-rotating outer cylinder 1 in both the axial and radial directions without contacting it, thus achieving a magnetic levitation state.

[0063] In some embodiments, the non-rotating outer cylinder 1 is provided with a hydraulic module 2 and a pusher rib 3 connected to the hydraulic module 2. The hydraulic module 2 can drive the pusher rib 3 to move radially to press against the inner wall of the wellbore. A recess can be provided on the outer periphery of the non-rotating outer cylinder 1 to accommodate the hydraulic module 2 and the pusher rib 3. The hydraulic module 2 can drive the pusher rib 3 to move radially outward to extend radially from the outer periphery of the non-rotating outer cylinder 1, and the pusher rib 3 can push against the inner wall of the wellbore. Of course, the hydraulic module 2 can also drive the pusher rib 3 to move radially inward to disengage from the inner wall of the wellbore. Multiple sets of hydraulic modules 2 and pusher ribs 3 can be provided on the non-rotating outer cylinder 1 at circumferential intervals, for example, three sets evenly distributed circumferentially, or four or more sets.

[0064] In some embodiments, a first electronic compartment 4 is provided in the central rod 7, and a second electronic compartment 5 is provided in the non-rotating outer cylinder 1. The first electronic compartment 4 and the second electronic compartment 5 are electrically connected to the electromagnetic bearing. The electronic compartment may include a circuit module, such as a control module, a power transmission module, etc. The first electronic compartment 4 can provide power to the second electromagnet 12 of the axial electromagnetic bearing 8, the second electronic compartment 5 can provide power to the first electromagnet 10 of the radial electromagnetic bearing 9, and can also provide power to the hydraulic module 2.

[0065] In some embodiments, the magnetic levitation drilling guidance and anti-deviation tool also includes a rotary transformer 6 disposed on the inner circumference of the non-rotating outer cylinder 1 and the outer circumference of the central rod 7. The rotary transformer 6 electrically connects the first electronic chamber 4 and the second electronic chamber 5 to each other. The rotary transformer 6 can be used to transmit electrical energy and signals, and includes a stator part and a rotor part. The stator part and the rotor part can be kept apart from each other without contact to avoid friction and wear between them, and to avoid affecting the non-contact engagement between the non-rotating outer cylinder 1 and the central rod 7.

[0066] In some embodiments, the upper end of the central rod 7 is provided with a conductive slip ring 14 electrically connected to the first electronic compartment 4. The conductive slip ring 14 may be made of a conductive material and is disposed at the upper end of the central rod 7 for electrical connection with other devices, particularly in cases where it can rotate relative to the connected device, to facilitate the transmission of electrical energy and signals. The upper end of the central rod 7 may have an annular groove to accommodate the conductive slip ring 14, and an insulating material is disposed between the central rod 7 and the conductive slip ring 14 to ensure that electrical energy and signals can be transmitted to the first electronic compartment 4. The conductive slip ring 14 can be connected to the first electronic compartment 4 via a wire disposed in the central rod 7.

[0067] On the other hand, this solution provides a vertical drilling system, which includes the magnetic levitation drilling guidance and anti-deviation tool described in the above solution. The lower end of the central rod 7 can be connected to the drill bit, and the upper end can be connected to other drilling equipment.

[0068] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0069] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A magnetic levitation drilling direction deviation prevention tool, characterized in that, It includes a central rod (7) that can be connected to the drill bit, and a non-rotating outer cylinder (1) that is coaxially sleeved on the central rod (7) and can be pushed against the inner wall of the well. The inner circumference and axial ends of the non-rotating outer cylinder (1) are spaced apart from the central rod (7). An electromagnetic bearing is provided between the non-rotating outer cylinder (1) and the central rod (7) so that the central rod (7) is in a magnetic levitation state relative to the non-rotating outer cylinder (1). A radial electromagnetic bearing (9) is provided between the inner circumference of the non-rotating outer cylinder (1) and the outer circumference of the central rod (7) so that the non-rotating outer cylinder (1) and the central rod (7) maintain a radial distance. The radial electromagnetic bearing (9) includes a first stator part provided on the inner circumference of the non-rotating outer cylinder (1) and a first rotor part provided on the outer circumference of the central rod (7). The first stator part includes a plurality of first electromagnets (10) arranged circumferentially, and the magnetic pole direction of the first electromagnets (10) is set to extend radially. The first rotor part includes a first permanent magnet (11). The magnetic force of each of the first electromagnets (10) can be adjusted independently; The magnetic levitation drilling guide anti-deviation tool can be configured to: when a well deviation is detected, adjust the magnetic force of the first electromagnet (10) set in the direction of well deviation to drive the central rod (7) to move relative to the non-rotating outer cylinder (1) in a direction opposite to the direction of well deviation; The magnetic levitation drilling guide anti-deviation tool can be configured such that when the deviation of the center rod (7) relative to the non-rotating outer cylinder (1) is detected, the magnetic force of the first electromagnet (10) set in the direction of deviation is adjusted to drive the center rod (7) to move relative to the non-rotating outer cylinder (1) in a direction opposite to the direction of deviation.

2. The magnetic levitation drilling and deviation control tool of claim 1, wherein, Multiple first electromagnets (10) are evenly distributed circumferentially.

3. The magnetic levitation drilling and deviation control tool of claim 1, wherein, The plurality of first electromagnets (10) include multiple pairs of first electromagnets (10) arranged symmetrically about the central axis.

4. The magnetic levitation drilling and deviation control tool of claim 1, wherein, A well inclination sensor is installed on the non-rotating outer cylinder (1).

5. The magnetic levitation drilling and deviation control tool of claim 1, wherein, The magnetic levitation drilling guide anti-deviation tool can be configured such that when a well deviation is detected and the center rod (7) deviates relative to the non-rotating outer cylinder (1), if the deviation direction is opposite to the well deviation direction, the deviation of the center rod (7) is corrected after the well deviation is corrected; if the deviation direction is not opposite to the well deviation direction, the magnetic force of the first electromagnet (10) is adjusted so that the center rod (7) deviates in the opposite direction to the well deviation direction, and the deviation of the center rod (7) is corrected after the well deviation is corrected.

6. The magnetic levitation drilling and deviation control tool of claim 1, wherein, The center rod (7) is provided with a displacement sensor for detecting the displacement of the center rod (7) relative to the non-rotating outer cylinder (1) in a direction perpendicular to the central axis.

7. The magnetic levitation drilling and deviation control tool of claim 1, wherein, It includes two radial electromagnetic bearings (9) located at the upper and lower parts of the non-rotating outer cylinder (1), respectively.

8. The magnetic levitation drilling and deviation control tool of claim 1, wherein, Axial electromagnetic bearings (8) are respectively provided between the two axial ends of the non-rotating outer cylinder (1) and the central rod (7).

9. The magnetic buoyancy drilling and deviation control tool of claim 8, wherein, The axial electromagnetic bearing (8) includes a second rotor portion disposed on the central rod (7) and a second stator portion disposed at the end of the non-rotating outer cylinder (1). The second rotor portion includes a plurality of second electromagnets (12) spaced circumferentially, and the magnetic pole direction of the second electromagnets (12) is set along the axial direction. The second stator portion includes a plurality of second permanent magnets (13) spaced circumferentially.

10. The magnetic levitation drilling and deviation control tool of claim 1, wherein, The non-rotating outer cylinder (1) is provided with a hydraulic module (2) and a push rib (3) connected to the hydraulic module (2). The hydraulic module (2) can drive the push rib (3) to move radially to press against the inner wall of the well.

11. The magnetic levitation drilling guidance and anti-deviation tool according to claim 1, characterized in that, The central rod (7) is provided with a first electronic compartment (4), and the non-rotating outer cylinder (1) is provided with a second electronic compartment (5). The first electronic compartment (4) and the second electronic compartment (5) are respectively electrically connected to the electromagnetic bearing.

12. The magnetic buoyancy drilling and deviation control tool of claim 11, wherein, It also includes a rotary transformer (6) disposed on the inner circumference of the non-rotating outer cylinder (1) and the outer circumference of the central rod (7), the rotary transformer (6) electrically connecting the first electronic compartment (4) and the second electronic compartment (5) to each other.

13. The magnetic buoyancy drilling and deviation control tool of claim 12, wherein, The upper end of the central rod (7) is provided with a conductive slip ring (14) that is electrically connected to the first electronic compartment (4).

14. A vertical drilling system, characterized by Includes the magnetic levitation drilling guidance and anti-deviation tool as described in any one of claims 1-13.

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