Downhole closed-loop Anti-tilting tool

Abstract

A downhole closed-loop anti-tilting tool, comprising: a housing; a rotating impeller (7) and a hydraulic pump (16) disposed in the housing; recessed parts circumferentially arranged at intervals on an outer circumference of the housing; a plunger (42) and a push plate (44); a plurality of hydraulic flow paths circumferentially arranged at intervals in the housing, the plurality of hydraulic flow paths respectively communicating the hydraulic pump (16) and each recessed part; and an eccentric flow dividing disc (26) disposed on the plurality of hydraulic flow paths, an outer circumference of the eccentric flow dividing disc being provided with a notch allowing one of the hydraulic flow paths to be communicated, the center of gravity and the notch of the eccentric flow dividing disc (26) being respectively located on two sides of a central axis (29), and the eccentric flow dividing disc (26) being capable of rotating around the central axis (29), wherein when the housing is inclined, the eccentric flow dividing disc (26) rotates to a state in which the notch is located at a higher position and the center of gravity is located at a lower position, so as to connect to one of the hydraulic flow paths and disconnect the other hydraulic flow paths, so that the plunger (42) and the push plate (44) corresponding to the connected hydraulic flow path move outward radially. The downhole closed-loop anti-tilting tool does not comprise an electronic device and can adapt to normal temperature, high temperature, and ultra-high temperature well environments.

Description

Downhole closed-loop anti-deflection tool

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application No. 202311198852.1 filed on September 15, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of directional drilling instruments in the oil drilling industry, and in particular to a downhole closed-loop anti-deflection tool. Background Art

[0004] Vertical wells account for 60% of all drilling worldwide. With the continuous expansion of exploration and development, the workload in high-steep structures and steeply inclined formations is increasing, and the challenge of preventing and straightening wells is becoming increasingly prominent. Preventing and straightening wells has always been a complex and pressing issue in drilling. Currently, two main approaches are used for preventing and straightening wells: active and passive.

[0005] Passive deflection prevention and fast drilling techniques include tower drill assemblies, pendulum drill assemblies, rigid drill assemblies, eccentric drill assemblies, and single-bend screw composite drilling assemblies. When formation deflection forces are low, utilizing tower and pendulum drill assemblies, along with inclination measurement while drilling and timely parameter adjustments, allows for efficient drilling and effective wellbore inclination control. However, when formation deflection forces are high, any deflection prevention assembly can only stabilize wellbore inclination to a certain extent, but will not effectively reduce inclination.

[0006] Active deflection prevention and straightening measures primarily involve the use of vertical drilling tools to achieve this drilling goal. Currently, the vast majority of vertical drilling tools, both domestically and internationally, utilize integrated electromechanical and hydraulic designs. These tools are characterized by significant deflection prevention and straightening effectiveness and high control precision. However, they are complex and expensive. Furthermore, with the advancement of deep and ultra-deep well drilling technology, downhole temperatures have risen, reaching 175°C or even above 200°C. Due to the temperature limitations of electronic components, the failure rate of vertical drilling tools has increased significantly, making them unable to meet the requirements for deflection prevention in drilling.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the problem in the prior art that drilling anti-deflection tools cannot withstand high-temperature environments underground.

[0009] In order to achieve the above-mentioned object, the present invention provides a downhole closed-loop anti-deflection tool, which comprises:

[0010] a housing, the two ends of which are respectively connectable to a drill rod and a drill bit;

[0011] A rotary impeller is disposed in the housing, the rotary impeller being capable of being driven to rotate by drilling fluid;

[0012] a hydraulic pump disposed in the housing and drivingly connected to the rotating impeller;

[0013] recessed portions provided at circumferential intervals on the outer periphery of the housing;

[0014] a plunger movably disposed in the recess and a push plate disposed on an outer surface of the plunger;

[0015] a plurality of hydraulic flow paths disposed in the housing at circumferential intervals, the plurality of hydraulic flow paths respectively communicating with the hydraulic pump and each of the recessed portions;

[0016] An eccentric diverter plate is provided on the plurality of hydraulic flow paths, wherein a notch is provided on the outer periphery of the eccentric diverter plate for allowing communication with one of the hydraulic flow paths, the center of gravity of the eccentric diverter plate and the notch are respectively located on either side of the central axis thereof, and the eccentric diverter plate is capable of rotating about the central axis;

[0017] When the shell is tilted, the eccentric diverter plate rotates to a state where the notch is at a higher position and the center of gravity is at a lower position, so as to connect one of the hydraulic flow paths and disconnect the other hydraulic flow paths, thereby driving the plunger and push plate corresponding to the connected hydraulic flow path to move radially outward.

[0018] In some embodiments, it further includes a non-magnetic outer cylinder, a drive shaft rotatably disposed in the non-magnetic outer cylinder and transmission-connected to the hydraulic pump, the rotating impeller is rotatably sleeved on the non-magnetic outer cylinder, and the drive shaft is magnetically coupled to the rotating impeller.

[0019] In some embodiments, a cone-shaped rod is connected to the upper end of the non-magnetic outer cylinder.

[0020] In some embodiments, the upper part of the non-magnetic outer cylinder is provided with an upper alloy inner ring and the lower part is provided with a lower alloy inner ring, the upper end of the rotating impeller is provided with an upper alloy outer ring that is rotatably mounted on the upper alloy inner ring and the lower end is provided with a lower alloy outer ring that is rotatably mounted on the lower alloy inner ring.

[0021] In some embodiments, the upper end of the drive shaft is mounted on the non-magnetic outer cylinder via a sliding bearing, and the lower end of the drive shaft is mounted on the non-magnetic outer cylinder via a lower bearing.

[0022] In some embodiments, the shell includes an upper outer cylinder, in which an oil storage cylinder and a rubber sleeve are provided on the oil storage cylinder. An annular hydraulic oil chamber is formed between the rubber sleeve and the oil storage cylinder, and the hydraulic oil chamber is connected to each of the hydraulic flow paths.

[0023] In some embodiments, an annular step is formed in the lower portion of the upper outer cylinder, and inlets corresponding to the plurality of hydraulic flow paths are provided on the annular step. The eccentric diverter plate is provided between the lower end of the oil storage cylinder and the annular step.

[0024] In some embodiments, a pump end joint, a flow conversion joint and a bypass joint are provided between the hydraulic pump and the oil storage cylinder, and the hydraulic pump and the oil storage cylinder are connected through the main flow path provided in the pump end joint, the flow conversion joint and the bypass joint.

[0025] In some embodiments, the invention further comprises a central shaft connected to the lower end of the upper outer cylinder, and a lower outer cylinder rotatably sleeved on the central shaft, wherein the recessed portion is provided on the lower outer cylinder.

[0026] In some embodiments, it also includes an inner sleeve fixedly mounted on the central shaft and an upper oil seal shell rotatably mounted on the inner sleeve via a sleeve bearing, the upper end of the lower outer cylinder is fixedly mounted on the upper oil seal shell, and the hydraulic flow path is respectively provided in the central shaft, the inner sleeve, and the lower outer cylinder.

[0027] In some embodiments, an upper lubricating oil chamber located on an upper side of the sleeve bearing is formed between the upper oil seal housing and the inner sleeve.

[0028] In some embodiments, a diverter ring is provided between the upper oil seal housing and the lower outer cylinder, and a plurality of radial flow paths arranged axially at intervals are provided in the diverter ring, and the plurality of radial flow paths are connected to each hydraulic flow path in a one-to-one aligned manner.

[0029] In some embodiments, a limit block is provided at the upper and lower ends of the recessed portion, respectively, and a radially retractable limit spring is provided between the limit block and the pushing plate; and / or a composite spring is provided between the pushing plate and the plunger.

[0030] In some embodiments, the lower end of the central shaft is connected to a lower joint, the upper portion of the lower joint is sleeved with a lower oil seal housing, and a lower lubricating oil chamber is formed between the lower oil seal housing and the lower joint.

[0031] In some embodiments, wear-resistant bosses are provided on both side end surfaces of the eccentric diverter disc; and / or, the eccentric diverter disc is provided with an eccentric hole.

[0032] Through the above technical solution, the automatic rotation of the eccentric diverter disk due to downhole gravity is relied upon to distribute the downhole high-pressure fluid, control the plunger movement, and realize closed-loop automatic operation; the entire tool set contains no electronic components, and unlike existing mechatronic anti-skew tools, there is no temperature limit and it can fully adapt to normal temperature, high temperature, and ultra-high temperature well environments; at the same time, due to the reduction of electronic components, the tool manufacturing cost will also be greatly reduced; the downhole closed-loop anti-skew tool can meet the downhole closed-loop anti-skew work needs during drilling while being low-cost and easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 1 to 4 are cross-sectional views of the downhole closed-loop anti-deflection tool at various positions through the central axis according to an embodiment of the present invention;

[0034] Figures 5 to 10 are cross-sectional views perpendicular to the central axis at various positions in Figures 1 to 4;

[0035] FIG11 is a schematic structural diagram of an eccentric diverter disk according to an embodiment of this solution;

[0036] FIG12 is a cross-sectional view of the eccentric diverter disc according to an embodiment of the present invention.

[0037] Explanation of reference numerals 1-upper outer cylinder; 2-cone rod 2; 3-sliding bearing; 4-upper alloy inner ring; 5-upper alloy outer ring; 6-driving shaft; 7-rotating impeller; 8-lower alloy outer ring; 9-lower alloy inner ring; 10-non-magnetic outer cylinder; 11-lower bearing; 12-disc spring; 13-compression rubber spring; 14-screw; 15-conversion joint; 16-hydraulic pump; 17-pump end joint; 18-commutation joint; 19-bypass joint; 20-upper fixing sleeve; 21-oil storage cylinder; 22-anti-collision sleeve; 23-screw; 24-rubber sleeve; 2 5-Lower fixing sleeve; 26-Eccentric diverter plate; 27-Sealing plug; 28-Rectangular ring; 29-Center shaft; 30-Inner sleeve; 31-Upper oil seal ring; 32-Upper oil seal housing; 33-Cone plug; 34-Sleeve bearing; 35-Oil-isolating rubber ring; 36-Lower outer cylinder; 37-Diverter ring; 38-Limiting block; 39-Orifice plate; 40-Bolt; 41-Limiting spring; 42-Plunger; 43-Compound spring; 44-Push plate; 45-Anti-drop ring; 46-Sealing rubber ring; 47-Lower oil seal housing; 48-Oil sealing ring; 49-Lower joint. DETAILED DESCRIPTION

[0038] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The detailed description of the following examples and the accompanying drawings are intended to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0039] The present disclosure provides these embodiments in order to make this disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0040] It should be noted that, in the description of this disclosure, unless otherwise specified, "plurality" means greater than or equal to two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are intended solely to facilitate and simplify the description of this disclosure, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0041] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different parts. "Perpendicular" does not mean perpendicular in the strict sense, but rather means within the tolerance range. "Parallel" does not mean parallel in the strict sense, but rather means within the tolerance range. "Include" or "comprising" and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0042] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this disclosure depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0043] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0044] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0045] Example 1

[0046] Referring to Figures 1 to 12 , this solution provides a downhole closed-loop anti-deflection tool, which includes:

[0047] a housing, the two ends of which are respectively connectable to a drill rod and a drill bit;

[0048] A rotary impeller 7 is provided in the housing, and the rotary impeller 7 can be driven to rotate by drilling fluid;

[0049] A hydraulic pump 16 disposed in the housing and drivingly connected to the rotating impeller 7;

[0050] recessed portions provided at circumferential intervals on the outer periphery of the housing;

[0051] a plunger 42 movably disposed in the recess and a biasing plate 44 disposed on an outer surface of the plunger 42 ;

[0052] a plurality of hydraulic flow paths provided in the housing at circumferential intervals, the plurality of hydraulic flow paths respectively connecting the hydraulic pump 16 and each of the recessed portions;

[0053] An eccentric diverter plate 26 is provided on the plurality of hydraulic flow paths, with a notch provided on the outer periphery of the eccentric diverter plate to allow communication with one of the hydraulic flow paths. The center of gravity of the eccentric diverter plate 26 and the notch are respectively located on either side of a central axis 29 thereof, and the eccentric diverter plate 26 is capable of rotating about the central axis 29;

[0054] When the shell is tilted, the eccentric diverter disc 26 rotates to a state where the notch is at a higher position and the center of gravity is at a lower position, so as to connect one of the hydraulic flow paths and disconnect the other hydraulic flow paths, thereby driving the plunger 42 and the push plate 44 corresponding to the connected hydraulic flow path to move radially outward.

[0055] The main function of the downhole closed-loop anti-deflection tool is to prevent the drill bit from lateral deflection during drilling.

[0056] The housing is generally tubular and is formed by connecting multiple tubular structures. During use, the housing is arranged to extend in a vertical direction, and when tilted, its central axis forms an angle with respect to the vertical direction.

[0057] The rotary impeller 7 is coaxially arranged in the housing and can rotate under the action of the drilling fluid passing through the housing, thereby transmitting torque to the hydraulic pump 16 to drive the hydraulic pump 16 to operate. The hydraulic pump 16 can deliver hydraulic oil to the hydraulic flow path to act on the plunger 42 through the hydraulic oil.

[0058] The plunger 42 and the push plate 44 are disposed in a recessed portion on the outer periphery of the housing and can move radially outward under the action of hydraulic oil, so that the push plate 44 protrudes to support the wellbore wall.

[0059] When the drill rod or drill bit is deflected, the shell is also deflected, for example, deflected toward the first direction. Due to the deflection of the shell, the central axis of the eccentric diverter disc 26 also forms a deflection angle with the vertical axis. In addition, the eccentric center of gravity of the eccentric diverter disc 26 is eccentrically set, so that the eccentric diverter disc 26 rotates under the action of gravity, and its center of gravity is at a lower position, while the position of the notch (relatively far away from the center of gravity) is at a higher position. The notch is also located in the first direction. The notch connects to the corresponding hydraulic flow path, so that the plunger 42 located in the first direction moves radially outward under the pressure of the hydraulic oil, thereby pushing the push plate 44 to extend and support on the drilling wall. The other push plates 44 are not extended. Therefore, the extended push plates 44 cause the shell to return to the non-deflected position where the center axis extends vertically.

[0060] For example, when the drill rod or drill bit deviates to the east, the center of gravity of the eccentric diverter plate 26 rotates to the west side of the central axis, and the notch rotates to the east side of the central axis to connect the hydraulic flow path on the east side, so that the plunger 42 and the push plate 44 extend outward and are supported on the drilling wall, thereby causing the shell and the drill rod or drill bit to move westward through the reaction force of the drilling wall, correcting the deflection.

[0061] In this solution, the automatic rotation of the eccentric diverter disk due to downhole gravity distributes the downhole high-pressure fluid, controls the plunger movement, and realizes closed-loop automatic operation. The entire tool set contains no electronic components, and unlike existing mechatronic anti-skew tools, it has no temperature restrictions and can fully adapt to normal temperature, high temperature, and ultra-high temperature well environments. At the same time, due to the reduction of electronic components, the tool manufacturing cost will also be greatly reduced. The downhole closed-loop anti-skew tool can meet the downhole closed-loop anti-skew work requirements during drilling while being low-cost and easy to maintain.

[0062] The downhole closed-loop anti-deflection tool further includes a non-magnetic outer cylinder 10, a drive shaft 6 rotatably disposed within the non-magnetic outer cylinder 10 and transmission-connected to the hydraulic pump 16, and a rotating impeller 7 rotatably sleeved on the non-magnetic outer cylinder 10. The drive shaft 6 and the rotating impeller 7 are magnetically coupled. The non-magnetic outer cylinder 10 is used to isolate the hydraulic pump 16, the drive shaft 6, and the rotating impeller 7 to better protect the hydraulic pump 16 and the drive shaft 6 from or reduce the impact of drilling fluid. The drive shaft 6 can be made of a magnetic material or embedded with magnets, and the rotating impeller 7 can similarly be made of a magnetic material or embedded with magnets. The drive shaft 6 and the rotating impeller 7 are magnetically coupled to each other, and when the rotating impeller 7 rotates, it also magnetically acts on the drive shaft 6, driving the drive shaft 6 to rotate. The drive shaft 6 is coaxially connected to the hydraulic pump 16 to transmit torque to the hydraulic pump 16.

[0063] The upper end of the non-magnetic outer cylinder 10 is connected to a conical rod 2. The upper end of the conical rod 2 is tapered to guide the drilling fluid around it, thereby impacting the rotating impeller 7. The conical rod 2 is a stepped shaft-like component with four rubber ribs vulcanized at the step to engage the inner circumference of the housing (e.g., the upper outer cylinder 1). The lower end of the conical rod 2 is threaded to connect with the non-magnetic outer cylinder 10.

[0064] The non-magnetic outer cylinder 10 is sleeved with an upper alloy inner ring 4 on its upper portion and a lower alloy inner ring 9 on its lower portion. The rotating impeller 7 is provided with an upper alloy outer ring 5 rotatably sleeved on the upper alloy inner ring 4 at its upper end and a lower alloy outer ring 8 rotatably sleeved on the lower alloy inner ring 9 at its lower end. The upper alloy inner ring 4 and 5, and the lower alloy inner ring 9 and 8 form a bearing-like structure, allowing the rotating impeller 7 to be rotatably mounted on the outer circumference of the non-magnetic outer cylinder 10.

[0065] The upper end of the drive shaft 6 is mounted on the non-magnetic outer cylinder 10 via a sliding bearing 3 , and the lower end of the drive shaft 6 is mounted on the non-magnetic outer cylinder 10 via a lower bearing 11 .

[0066] The non-magnetic outer cylinder 10 is a threaded component with both ends. The lower end is threaded onto a conversion joint 15. The outer cylindrical step fits over the rotating impeller 7, and the inner bore houses the sliding bearing 3, drive shaft 6, and lower bearing 11. The inner ring of the sliding bearing 3 fits over the drive shaft 6, while the outer ring fits over the non-magnetic outer cylinder 10. The outer ring of the lower bearing 11 fits over the non-magnetic outer cylinder 10, while the inner ring fits over the drive shaft 6. The drive shaft 6 is a magnetic component electrochemically coated with magnetic powder. One end is machined with a square hole for inserting a hydraulic pump 16. A disc spring 12 and a compression rubber spring 13 are mounted on the outer cylindrical portion. One end of the disc spring 12 engages the boss end of the drive shaft 6, while the other end engages the compression rubber spring 13. This creates compression when the non-magnetic outer cylinder 10 is threadedly connected to the conversion joint 15. The conversion joint 15 partially fits over the upper end of the hydraulic pump 16 and is screwed to the hydraulic pump 16 via screws 14. In addition, the lower end of the hydraulic pump 16 is provided with a commutation joint 18 connected to the conversion joint 15. The conversion joint 15 and the commutation joint 18 form a seal at the lower end of the non-magnetic outer cylinder 10, thereby forming a sealed space inside the non-magnetic outer cylinder 10.

[0067] The housing includes an upper outer cylinder 1, which is provided with an oil reservoir 21 and a rubber sleeve 24 that is sleeved on the oil reservoir 21. An annular hydraulic oil chamber is formed between the rubber sleeve 24 and the oil reservoir 21, and the hydraulic oil chamber is connected to each of the hydraulic flow paths. As shown in FIG2 , the outer diameters of the oil reservoir 21 are larger at both ends, and an annular groove is formed on the outer periphery of the middle portion. A hydraulic oil chamber is formed between the middle portion and the rubber sleeve 24. The hydraulic oil chamber can store a certain volume of hydraulic oil so that the hydraulic pump 16 can deliver it to the corresponding recessed portion and act on the plunger 42. Oil circuits are formed in the two end portions of the oil reservoir 21 to connect the oil circuits to other structures on the upper and lower sides of the oil reservoir 21.

[0068] An anti-collision sleeve 22 is embedded in the inner hole of the left end of the oil reservoir 21. This sleeve 22 is a cylindrical component with a tapered inner hole. Annular grooves are provided on the outer circumference of both ends of the oil reservoir 21. Annular protrusions are provided on the inner circumference of both ends of the rubber sleeve 24, each of which is accommodated in the two annular grooves. An upper fixing sleeve 20 and a lower fixing sleeve 25 are respectively mounted on the ends of the rubber sleeve 24 to press the rubber sleeve 24 against the oil reservoir 21.

[0069] The lower portion of the upper outer cylinder 1 is formed with an annular step, which is provided with inlets corresponding to the multiple hydraulic flow paths. The eccentric diverter plate 26 is disposed between the lower end of the oil reservoir 21 and the annular step. A certain gap exists between the eccentric diverter plate 26, the oil reservoir 21, and the annular step, allowing a small amount of hydraulic oil to pass through the gap and reach the center hole of the upper outer cylinder 1. When the housing returns from a deflected state to a vertical position, the previously extended push plate 44 and plunger 42 move radially inward under the action of the wellbore wall, causing the hydraulic oil to return along the hydraulic flow path. At this time, due to the non-deflected state, the eccentric diverter plate 26 may not rotate as much as before, allowing the hydraulic oil to return to the hydraulic oil chamber through the gap. If the gap is offset, the hydraulic oil can enter the center hole of the upper outer cylinder 1 through the gap between the eccentric diverter plate 26 and the annular step of the upper outer cylinder 1.

[0070] In addition, a pump end connector 17, a flow converter connector 18, and a bypass connector 19 are provided between the hydraulic pump 16 and the oil reservoir 21. The hydraulic pump 16 and the oil reservoir 21 are connected via a main flow path provided in the pump end connector 17, the flow converter connector 18, and the bypass connector 19. Each of the pump end connector 17, the flow converter connector 18, and the bypass connector 19 can include a main flow path to connect the hydraulic pump 16 to the oil path in the oil reservoir 21. As shown in FIG2 , the bypass connector 19 has a center hole, which bypasses the surrounding annulus through radial holes, allowing drilling fluid in the annulus to enter the bypass connector 19 and flow downward. The bypass connector 19 has elongated channels machined into it: one channel is a high-pressure oil output channel, and the other is a low-pressure oil return channel. The high-pressure oil output channel and the low-pressure oil return channel are connected to the flow converter connector 18 and the oil reservoir 21 at their respective ends.

[0071] In addition, part of the hydraulic flow path is provided in the upper outer cylinder 1 , and a radial blind hole communicating with the hydraulic flow path is provided, and the radial blind hole is sealed by a sealing plug 27 .

[0072] The downhole closed-loop anti-deflection tool also includes a central shaft 29 connected to the lower end of the upper outer tube 1, and a lower outer tube 36 rotatably mounted on the central shaft 29. The lower outer tube 36 is provided with the recessed portion. A portion of the hydraulic flow path is provided within the central shaft 29, and a rectangular ring 28 is provided between the central shaft 29 and the upper outer tube 1, surrounding the hydraulic flow path to enhance sealing. The lower outer tube 36 can rotate relative to the central shaft 29, allowing the push plate 44 to rotate relative to the upper outer tube 1 and the central shaft 29, thereby preventing the downhole closed-loop anti-deflection tool from becoming stuck as it rotates with the drill pipe.

[0073] The downhole closed-loop anti-deflection tool also includes an inner sleeve 30 fixedly mounted on the central shaft 29 and an upper oil seal housing 32 rotatably mounted on the inner sleeve 30 via a sleeve bearing 34. The upper end of the lower outer cylinder 36 is fixedly mounted on the upper oil seal housing 32. The central shaft 29, the inner sleeve 30, and the lower outer cylinder 36 are each provided with a hydraulic flow path. The inner sleeve 30 is connected to the lower outer cylinder 26, and the upper oil seal housing 32 is connected to the central shaft 29. A sleeve bearing 34 is provided between the inner sleeve 30 and the upper oil seal housing 32 to enable rotation therebetween.

[0074] An upper lubricating oil chamber, located above the sleeve bearing 34, is formed between the upper oil seal housing 32 and the inner sleeve 30. A sealing ring groove is machined into the inner inclined surface of the inner sleeve 30, housing a sealing ring. An upper oil seal ring 31 and the upper oil seal housing 32 are mounted on the outer circumference of the inner sleeve 30. The upper oil seal ring 31, upper oil seal housing 32, inner sleeve 30, and oil-isolating rubber ring 35 form the upper lubricating oil chamber. This chamber is filled with lubricating oil through a tapered hole in the upper oil seal housing 32 (sealed by a tapered plug 33), providing lubrication for the sleeve bearing 34.

[0075] A diverter ring 37 is disposed between the upper oil seal housing 32 and the lower outer cylinder 36. Multiple radial flow paths are arranged in an axially spaced relationship within the diverter ring 37, and these radial flow paths are aligned and connected to each hydraulic flow path. The radial flow paths within the diverter ring 37 are connected to each hydraulic flow path within the inner sleeve 30 and to each hydraulic flow path within the lower outer cylinder 36.

[0076] Among them, the upper and lower ends of the recessed portion are respectively provided with limit blocks 38, and a radially retractable limit spring 41 is provided between the limit block 38 and the push plate 44; and / or, a composite spring 43 is provided between the push plate 44 and the plunger 42. The limit block 38 is a square part, which is connected to the orifice plate 39 by a bolt 40. The orifice plate 39 is inserted into the stepped inner groove of the lower outer cylinder 36. A limit spring 41 is installed between the limit block 38 and the push plate 44. There are two groups of limit blocks 38, limit springs 41, orifice plates 39, and bolts 40, which are respectively installed at both ends of the push plate 44. The push plate 44 is a long strip-shaped part with a superhard material such as PDC or cemented carbide inlaid on the surface and a square groove inside. The two ends extend out and are limited by the limit spring 41, the limit block 38, etc.

[0077] The plunger 42 is a rectangular boss mounted in a recessed portion within the lower outer cylinder 36. Its top surface abuts against the support plate 44, while its bottom surface communicates with the hydraulic flow path of the lower outer cylinder 36. Composite springs 43 are mounted between the top and sides of the plunger 42 and the support plate 44. Composite springs 43 are an elastic combination of cylindrical rubber and compression springs, used to stabilize the movement of the support plate 44.

[0078] In addition, the lower end of the central shaft 29 is connected to a lower joint 49, and a lower oil seal housing 47 is sleeved on the upper portion of the lower joint 49, forming a lower lubricating oil chamber between the lower oil seal housing 47 and the lower joint 49. The lower oil seal housing 47 is a T-shaped cylindrical component with a tapered threaded hole machined radially on the outer circumference, and a tapered hole installed within the hole. The sealing rubber ring 46, the lower oil seal housing 47, and the oil sealing ring 48 are sleeved onto the outer circumference of the lower joint 49 to form a sealed cavity, which is filled with lubricating oil through the tapered hole in the lower oil seal housing 47. The oil sealing ring 48 is a component with a sealing ring groove machined on the inner bevel and a sealing ring installed. The inner bevel is adjacent to the bevel of the lower joint 49. The lower joint 49 is a joint with threads at both ends. The left end is threadedly connected to the central shaft 29, and the end face is adjacent to the anti-drop ring 45, limiting the anti-drop ring 45.

[0079] As shown in Figures 11 and 12 , the eccentric diverter disc 26 is provided with wear-resistant bosses on both end surfaces; and / or, the eccentric diverter disc 26 is provided with an eccentric hole. Columnar carbide is inlaid on both sides of the eccentric diverter disc 26 to form wear-resistant bosses. One end of the carbide contacts the end surface of the oil reservoir 21, and the other end contacts the columnar carbide on the inner step surface of the upper outer cylinder 1.

[0080] Example 2

[0081] Referring to Figures 1 to 12 , this solution provides a downhole closed-loop anti-deflection tool, which includes:

[0082] a housing, the two ends of which are respectively connectable to a drill rod and a drill bit;

[0083] A rotary impeller 7 is provided in the housing, and the rotary impeller 7 can be driven to rotate by drilling fluid;

[0084] A hydraulic pump 16 disposed in the housing and drivingly connected to the rotating impeller 7;

[0085] recessed portions provided at circumferential intervals on the outer periphery of the housing;

[0086] a plunger 42 movably disposed in the recess and a biasing plate 44 disposed on an outer surface of the plunger 42 ;

[0087] a plurality of hydraulic flow paths provided in the housing at circumferential intervals, the plurality of hydraulic flow paths respectively connecting the hydraulic pump 16 and each of the recessed portions;

[0088] An eccentric diverter plate 26 is provided on the plurality of hydraulic flow paths, with a notch provided on the outer periphery of the eccentric diverter plate to allow communication with one of the hydraulic flow paths. The center of gravity of the eccentric diverter plate 26 and the notch are respectively located on either side of a central axis 29 thereof, and the eccentric diverter plate 26 is capable of rotating about the central axis 29;

[0089] When the shell is tilted, the eccentric diverter disc 26 rotates to a state where the notch is at a higher position and the center of gravity is at a lower position, so as to connect one of the hydraulic flow paths and disconnect the other hydraulic flow paths, thereby driving the plunger 42 and the push plate 44 corresponding to the connected hydraulic flow path to move radially outward.

[0090] The main function of the downhole closed-loop anti-deflection tool is to prevent the drill bit from lateral deflection during drilling.

[0091] The housing is generally tubular and is formed by connecting multiple tubular structures. During use, the housing is arranged to extend in a vertical direction, and when tilted, its central axis forms an angle with respect to the vertical direction.

[0092] The rotary impeller 7 is coaxially arranged in the housing and can rotate under the action of the drilling fluid passing through the housing, thereby transmitting torque to the hydraulic pump 16 to drive the hydraulic pump 16 to operate. The hydraulic pump 16 can deliver hydraulic oil to the hydraulic flow path to act on the plunger 42 through the hydraulic oil.

[0093] The plunger 42 and the push plate 44 are disposed in a recessed portion on the outer periphery of the housing and can move radially outward under the action of hydraulic oil, so that the push plate 44 protrudes to support the wellbore wall.

[0094] When the drill rod or drill bit is deflected, the shell is also deflected, for example, deflected toward the first direction. Due to the deflection of the shell, the central axis of the eccentric diverter disc 26 also forms a deflection angle with the vertical axis. In addition, the eccentric center of gravity of the eccentric diverter disc 26 is eccentrically set, so that the eccentric diverter disc 26 rotates under the action of gravity, and its center of gravity is at a lower position, while the position of the notch (relatively far away from the center of gravity) is at a higher position. The notch is also located in the first direction. The notch connects to the corresponding hydraulic flow path, so that the plunger 42 located in the first direction moves radially outward under the pressure of the hydraulic oil, thereby pushing the push plate 44 to extend and support on the drilling wall. The other push plates 44 are not extended. Therefore, the extended push plates 44 cause the shell to return to the non-deflected position where the center axis extends vertically.

[0095] For example, when the drill rod or drill bit deviates to the east, the center of gravity of the eccentric diverter plate 26 rotates to the west side of the central axis, and the notch rotates to the east side of the central axis to connect the hydraulic flow path on the east side, so that the plunger 42 and the push plate 44 extend outward and are supported on the drilling wall, thereby causing the shell and the drill rod or drill bit to move westward through the reaction force of the drilling wall, correcting the deflection.

[0096] In this solution, the automatic rotation of the eccentric diverter disk due to downhole gravity distributes the downhole high-pressure fluid, controls the plunger movement, and realizes closed-loop automatic operation. The entire tool set contains no electronic components, and unlike existing mechatronic anti-skew tools, it has no temperature restrictions and can fully adapt to normal temperature, high temperature, and ultra-high temperature well environments. At the same time, due to the reduction of electronic components, the tool manufacturing cost will also be greatly reduced. The downhole closed-loop anti-skew tool can meet the downhole closed-loop anti-skew work requirements during drilling while being low-cost and easy to maintain.

[0097] The downhole closed-loop anti-deflection tool further includes a non-magnetic outer cylinder 10, a drive shaft 6 rotatably disposed within the non-magnetic outer cylinder 10 and transmission-connected to the hydraulic pump 16, and a rotating impeller 7 rotatably sleeved on the non-magnetic outer cylinder 10. The drive shaft 6 and the rotating impeller 7 are magnetically coupled. The non-magnetic outer cylinder 10 is used to isolate the hydraulic pump 16, the drive shaft 6, and the rotating impeller 7 to better protect the hydraulic pump 16 and the drive shaft 6 from or reduce the impact of drilling fluid. The drive shaft 6 can be made of a magnetic material or embedded with magnets, and the rotating impeller 7 can similarly be made of a magnetic material or embedded with magnets. The drive shaft 6 and the rotating impeller 7 are magnetically coupled to each other, and when the rotating impeller 7 rotates, it also magnetically acts on the drive shaft 6, driving the drive shaft 6 to rotate. The drive shaft 6 is coaxially connected to the hydraulic pump 16 to transmit torque to the hydraulic pump 16.

[0098] The upper end of the non-magnetic outer cylinder 10 is connected to a conical rod 2. The upper end of the conical rod 2 is tapered to guide the drilling fluid around it, thereby impacting the rotating impeller 7. The conical rod 2 is a stepped shaft-like component with four rubber ribs vulcanized at the step to engage the inner circumference of the housing (e.g., the upper outer cylinder 1). The lower end of the conical rod 2 is threaded to connect to the non-magnetic outer cylinder 10.

[0099] The non-magnetic outer cylinder 10 is sleeved with an upper alloy inner ring 4 on its upper portion and a lower alloy inner ring 9 on its lower portion. The rotating impeller 7 is provided with an upper alloy outer ring 5 rotatably sleeved on the upper alloy inner ring 4 at its upper end and a lower alloy outer ring 8 rotatably sleeved on the lower alloy inner ring 9 at its lower end. The upper alloy inner ring 4 and 5, and the lower alloy inner ring 9 and 8 form a bearing-like structure, allowing the rotating impeller 7 to be rotatably mounted on the outer circumference of the non-magnetic outer cylinder 10.

[0100] The upper end of the drive shaft 6 is mounted on the non-magnetic outer cylinder 10 via a sliding bearing 3 , and the lower end of the drive shaft 6 is mounted on the non-magnetic outer cylinder 10 via a lower bearing 11 .

[0101] The non-magnetic outer cylinder 10 is a threaded component with both ends. The lower end is threaded onto a conversion joint 15. The outer cylindrical step fits over the rotating impeller 7, and the inner bore houses the sliding bearing 3, drive shaft 6, and lower bearing 11. The inner ring of the sliding bearing 3 fits over the drive shaft 6, while the outer ring fits over the non-magnetic outer cylinder 10. The outer ring of the lower bearing 11 fits over the non-magnetic outer cylinder 10, while the inner ring fits over the drive shaft 6. The drive shaft 6 is a magnetic component electrochemically coated with magnetic powder. One end is machined with a square hole for inserting a hydraulic pump 16. A disc spring 12 and a compression rubber spring 13 are mounted on the outer cylindrical portion. One end of the disc spring 12 engages the boss end of the drive shaft 6, while the other end engages the compression rubber spring 13. This creates compression when the non-magnetic outer cylinder 10 is threadedly connected to the conversion joint 15. The conversion joint 15 partially fits over the upper end of the hydraulic pump 16 and is screwed to the hydraulic pump 16 via screws 14. In addition, the lower end of the hydraulic pump 16 is provided with a commutation joint 18 connected to the conversion joint 15. The conversion joint 15 and the commutation joint 18 form a seal at the lower end of the non-magnetic outer cylinder 10, thereby forming a sealed space inside the non-magnetic outer cylinder 10.

[0102] The housing includes an upper outer tube 1, which is provided with a tubular oil reservoir. An annular hydraulic oil chamber is formed within the reservoir, which is connected to each of the hydraulic flow paths. The reservoir can be composed of an inner tube, an outer tube, and annular end plates at both ends.

[0103] The lower portion of the upper outer cylinder 1 is formed with an annular step, which is provided with inlets corresponding to the multiple hydraulic flow paths. The eccentric diverter plate 26 is disposed between the lower end of the oil reservoir 21 and the annular step. A certain gap exists between the eccentric diverter plate 26, the oil reservoir 21, and the annular step, allowing a small amount of hydraulic oil to pass through the gap and reach the center hole of the upper outer cylinder 1. When the housing returns from a deflected state to a vertical position, the previously extended push plate 44 and plunger 42 move radially inward under the action of the wellbore wall, causing the hydraulic oil to return along the hydraulic flow path. At this time, due to the non-deflected state, the eccentric diverter plate 26 may not rotate as much as before, allowing the hydraulic oil to return to the hydraulic oil chamber through the gap. If the gap is offset, the hydraulic oil can enter the center hole of the upper outer cylinder 1 through the gap between the eccentric diverter plate 26 and the annular step of the upper outer cylinder 1.

[0104] In addition, a pump end connector 17, a flow converter connector 18, and a bypass connector 19 are provided between the hydraulic pump 16 and the oil reservoir 21. The hydraulic pump 16 and the oil reservoir 21 are connected via a main flow path provided in the pump end connector 17, the flow converter connector 18, and the bypass connector 19. Each of the pump end connector 17, the flow converter connector 18, and the bypass connector 19 can include a main flow path to connect the hydraulic pump 16 to the oil path in the oil reservoir 21. As shown in FIG2 , the bypass connector 19 has a center hole, which bypasses the surrounding annulus through radial holes, allowing drilling fluid in the annulus to enter the bypass connector 19 and flow downward. The bypass connector 19 has elongated channels machined into it: one channel is a high-pressure oil output channel, and the other is a low-pressure oil return channel. The high-pressure oil output channel and the low-pressure oil return channel are connected to the flow converter connector 18 and the oil reservoir 21 at their respective ends.

[0105] In addition, part of the hydraulic flow path is provided in the upper outer cylinder 1 , and a radial blind hole communicating with the hydraulic flow path is provided, and the radial blind hole is sealed by a sealing plug 27 .

[0106] The downhole closed-loop anti-deflection tool also includes a central shaft 29 connected to the lower end of the upper outer tube 1, and a lower outer tube 36 rotatably mounted on the central shaft 29. The lower outer tube 36 is provided with the recessed portion. A portion of the hydraulic flow path is provided within the central shaft 29, and a rectangular ring 28 is provided between the central shaft 29 and the upper outer tube 1, surrounding the hydraulic flow path to enhance sealing. The lower outer tube 36 can rotate relative to the central shaft 29, allowing the push plate 44 to rotate relative to the upper outer tube 1 and the central shaft 29, thereby preventing the downhole closed-loop anti-deflection tool from becoming stuck as it rotates with the drill pipe.

[0107] The downhole closed-loop anti-deflection tool also includes an inner sleeve 30 fixedly mounted on the central shaft 29 and an upper oil seal housing 32 rotatably mounted on the inner sleeve 30 via a sleeve bearing 34. The upper end of the lower outer cylinder 36 is fixedly mounted on the upper oil seal housing 32. The central shaft 29, the inner sleeve 30, and the lower outer cylinder 36 are each provided with a hydraulic flow path. The inner sleeve 30 is connected to the lower outer cylinder 26, and the upper oil seal housing 32 is connected to the central shaft 29. A sleeve bearing 34 is provided between the inner sleeve 30 and the upper oil seal housing 32 to enable rotation therebetween.

[0108] An upper lubricating oil chamber, located above the sleeve bearing 34, is formed between the upper oil seal housing 32 and the inner sleeve 30. A sealing ring groove is machined into the inner inclined surface of the inner sleeve 30, housing a sealing ring. An upper oil seal ring 31 and the upper oil seal housing 32 are mounted on the outer circumference of the inner sleeve 30. The upper oil seal ring 31, upper oil seal housing 32, inner sleeve 30, and oil-isolating rubber ring 35 form the upper lubricating oil chamber. This chamber is filled with lubricating oil through a tapered hole in the upper oil seal housing 32 (sealed by a tapered plug 33), providing lubrication for the sleeve bearing 34.

[0109] A diverter ring 37 is disposed between the upper oil seal housing 32 and the lower outer cylinder 36. Multiple radial flow paths are arranged in an axially spaced relationship within the diverter ring 37, and these radial flow paths are aligned and connected to each hydraulic flow path. The radial flow paths within the diverter ring 37 are connected to each hydraulic flow path within the inner sleeve 30 and to each hydraulic flow path within the lower outer cylinder 36.

[0110] Among them, a limit block 38 is provided at the upper and lower ends of the recessed portion, and a radially retractable limit spring 41 is provided between the limit block 38 and the push plate 44; and / or, a composite spring 43 is provided between the push plate 44 and the plunger 42. The limit block 38 is a square part, which is connected to the orifice plate 39 by a bolt 40, and the orifice plate 39 is inserted into the stepped inner groove of the lower outer cylinder 36. A limit spring 41 is installed between the limit block 38 and the push plate 44. There are two groups of limit blocks 38, limit springs 41, orifice plates 39, and bolts 40, which are respectively installed at both ends of the push plate 44. The push plate 44 is a long strip-shaped part with a surface inlaid with superhard materials such as PDC or cemented carbide and a square groove inside. Both ends extend out, and the limiting is achieved by the limit spring 41, the limit block 38, etc.

[0111] The plunger 42 is a rectangular boss mounted in a recessed portion within the lower outer cylinder 36. Its top surface abuts against the support plate 44, while its bottom surface communicates with the hydraulic flow path of the lower outer cylinder 36. Composite springs 43 are mounted between the top and sides of the plunger 42 and the support plate 44. Composite springs 43 are an elastic combination of cylindrical rubber and compression springs, used to stabilize the movement of the support plate 44.

[0112] In addition, the lower end of the central shaft 29 is connected to a lower joint 49, and a lower oil seal housing 47 is sleeved on the upper portion of the lower joint 49, forming a lower lubricating oil chamber between the lower oil seal housing 47 and the lower joint 49. The lower oil seal housing 47 is a T-shaped cylindrical component with a tapered threaded hole machined radially on the outer circumference, and a tapered hole installed within the hole. The sealing rubber ring 46, the lower oil seal housing 47, and the oil sealing ring 48 are sleeved onto the outer circumference of the lower joint 49 to form a sealed cavity, which is filled with lubricating oil through the tapered hole in the lower oil seal housing 47. The oil sealing ring 48 is a component with a sealing ring groove machined on the inner bevel and a sealing ring installed. The inner bevel is adjacent to the bevel of the lower joint 49. The lower joint 49 is a joint with threads at both ends. The left end is threadedly connected to the central shaft 29, and the end face is adjacent to the anti-drop ring 45, limiting the anti-drop ring 45.

[0113] As shown in Figures 11 and 12 , the eccentric diverter disc 26 is provided with wear-resistant bosses on both end surfaces; and / or, the eccentric diverter disc 26 is provided with an eccentric hole. Columnar carbide is inlaid on both sides of the eccentric diverter disc 26 to form wear-resistant bosses. One end of the carbide contacts the end surface of the oil reservoir 21, and the other end contacts the columnar carbide on the inner step surface of the upper outer cylinder 1.

[0114] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0115] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts.

Claims

1. A downhole closed-loop anti-deflection tool, characterized in that: include: A housing, two ends of which can be connected to a drill rod and a drill bit respectively; A rotating impeller (7) disposed in the housing, wherein the rotating impeller (7) can be driven to rotate by drilling fluid; a hydraulic pump (16) disposed in the housing and drivingly connected to the rotating impeller (7); recessed portions disposed circumferentially spaced apart on the outer periphery of the housing; a plunger (42) movably disposed in the recessed portion and a push plate (44) disposed on an outer surface of the plunger (42); a plurality of hydraulic flow paths spaced circumferentially apart and arranged in the housing, the plurality of hydraulic flow paths respectively connecting the hydraulic pump (16) and each of the recessed portions; An eccentric flow divider plate (26) is arranged on the plurality of hydraulic flow paths, a notch is arranged on the outer periphery of the eccentric flow divider plate to allow one of the hydraulic flow paths to communicate, the center of gravity of the eccentric flow divider plate (26) and the notch are respectively located on both sides of the central axis (29) line thereof, and the eccentric flow divider plate (26) can rotate around the central axis (29) line; When the housing is tilted, the eccentric diverter disc (26) rotates to a state where the notch is at a higher position and the center of gravity is at a lower position, so as to connect one of the hydraulic flow paths and disconnect the other hydraulic flow paths, thereby driving the plunger (42) and the push plate (44) corresponding to the connected hydraulic flow path to move radially outward.

2. The downhole closed-loop anti-deflection tool according to claim 1, characterized in that: It also comprises a non-magnetic outer cylinder (10) and a drive shaft (6) rotatably arranged in the non-magnetic outer cylinder (10) and drivingly connected to the hydraulic pump (16); the rotating impeller (7) is rotatably sleeved on the non-magnetic outer cylinder (10); and the drive shaft (6) is magnetically coupled to the rotating impeller (7).

3. The downhole closed-loop anti-deflection tool according to claim 2, characterized in that: The upper end of the non-magnetic outer cylinder (10) is connected to a cone head rod (2).

4. The downhole closed-loop anti-deflection tool according to claim 2, characterized in that: The non-magnetic outer cylinder (10) has an upper alloy inner ring (4) sleeved on its upper part and a lower alloy inner ring (9) sleeved on its lower part; the rotating impeller (7) has an upper alloy outer ring (5) rotatably sleeved on the upper alloy inner ring (4) at its upper end and a lower alloy outer ring (8) rotatably sleeved on the lower alloy inner ring (9) at its lower end.

5. The downhole closed-loop anti-deflection tool according to claim 2, characterized in that: The upper end of the drive shaft (6) is mounted on the non-magnetic outer cylinder (10) via a sliding bearing (3), and the lower end of the drive shaft (6) is mounted on the non-magnetic outer cylinder (10) via a lower bearing (11).

6. The downhole closed-loop anti-deflection tool according to claim 1, characterized in that: The housing comprises an upper outer cylinder (1), an oil storage cylinder (21) and a rubber sleeve (24) sleeved on the oil storage cylinder (21) are arranged in the upper outer cylinder (1), an annular hydraulic oil chamber is formed between the rubber sleeve (24) and the oil storage cylinder (21), and the hydraulic oil chamber is connected to each of the hydraulic flow paths.

7. The downhole closed-loop anti-deflection tool according to claim 6, characterized in that: An annular step is formed in the lower portion of the upper outer cylinder (1), and inlets corresponding to the plurality of hydraulic paths are arranged on the annular step. The eccentric flow distribution plate (26) is arranged between the lower end of the oil storage cylinder (21) and the annular step.

8. The downhole closed-loop anti-deflection tool according to claim 6, characterized in that: A pump end joint (17), a flow conversion joint (18) and a bypass joint (19) are provided between the hydraulic pump (16) and the oil storage cylinder (21); the hydraulic pump (16) and the oil storage cylinder (21) are connected via a main flow path provided in the pump end joint (17), the flow conversion joint (18) and the bypass joint (19).

9. The downhole closed-loop anti-deflection tool according to claim 6, characterized in that: It also comprises a central axis (29) connected to the lower end of the upper outer cylinder (1), and a lower outer cylinder (36) rotatably sleeved on the central axis (29), wherein the lower outer cylinder (36) is provided with the recessed portion.

10. The downhole closed-loop anti-deflection tool according to claim 9, characterized in that: It also includes an inner sleeve (30) fixedly sleeved on the central shaft (29) and an upper oil seal shell (32) rotatably sleeved on the inner sleeve (30) via a sleeve bearing (34); the upper end of the lower outer cylinder (36) is fixedly sleeved on the upper oil seal shell (32); and the central shaft (29), the inner sleeve (30), and the lower outer cylinder (36) are respectively provided with the hydraulic flow path.

11. The downhole closed-loop anti-deflection tool according to claim 10, characterized in that: An upper lubricating oil chamber located on the upper side of the sleeve bearing (34) is formed between the upper oil seal housing (32) and the inner sleeve (30).

12. The downhole closed-loop anti-deflection tool according to claim 10, characterized in that: A flow divider ring (37) is provided between the upper oil seal housing (32) and the lower outer cylinder (36), and a plurality of radial flow paths arranged axially at intervals are provided in the flow divider ring (37), and the plurality of radial flow paths are connected to each hydraulic flow path in a one-to-one aligned manner.

13. The downhole closed-loop anti-deflection tool according to claim 10, characterized in that: A limit block (38) is provided at the upper end and the lower end of the recessed portion, respectively; a radially retractable limit spring (41) is provided between the limit block (38) and the push plate (44); and / or a composite spring (43) is provided between the push plate (44) and the plunger (42).

14. The downhole closed-loop anti-deflection tool according to claim 9, characterized in that: The lower end of the central shaft (29) is connected to a lower joint (49), the upper part of the lower joint (49) is sleeved with a lower oil seal housing (47), and a lower lubricating oil chamber is formed between the lower oil seal housing (47) and the lower joint (49).

15. The downhole closed-loop anti-deflection tool according to claim 1, characterized in that: Wear-resistant bosses are provided on both side end surfaces of the eccentric diverter disc (26); and / or, the eccentric diverter disc (26) is provided with an eccentric hole.

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