Gear self-locking biasing device and rotary guide tool

Abstract

The present invention proposes a gear self-locking biasing device and a rotary steering tool, which belong to the field of drilling tools. It includes a circular ring-shaped stabilizing sleeve, and a cylindrical cavity is provided on the annular wall of the stabilizing sleeve; a power mechanism is arranged in the cavity, and the power mechanism provides rotational power; a rotation direction conversion mechanism connected to the power mechanism, and the power mechanism outputs rotation along the axial direction of the stabilizing sleeve to the rotation direction conversion mechanism, and the rotation direction conversion mechanism converts the direction and outputs rotation in the radial direction of the stabilizing sleeve; and a rotation and telescopic mechanism is arranged on the outer wall of the stabilizing sleeve, and the rotation and telescopic mechanism is connected to the output end of the rotation direction conversion mechanism and telescopes with the rotation of the rotation direction conversion mechanism.

Description

Technical Field

[0001] The invention relates to a gear self-locking biasing device and a rotary steering tool, belonging to the field of drilling tools. Background Art

[0002] During the drilling process of wells with complex structures, such as horizontal wells, extended reach wells, and branch wells, an offset device is required to push the drill bit onto the pre-designed drilling trajectory. Early offset deflection tools were mainly downhole screw drill bits with a bend. The offset direction of the bend was maintained unchanged through sliding drilling of the screw stator. However, sliding drilling generated a large amount of frictional resistance, resulting in severe support pressure after a certain length, making it impossible to drill normally. Later, people invented rotary steerable drilling tools. By rotating the outer casing or rotating most of the outer casing while keeping the very short part non-rotating, the support pressure phenomenon is reduced, enabling the construction of deeper and longer horizontal wells and directional wells. In recent years, rotary steerable drilling tools have gradually become a popular steerable drilling technology and one of the key technologies for efficient drilling.

[0003] The currently widely used rotary guide biasing mechanism mainly adopts the hydraulic principle, and produces the biasing effect through the high-pressure liquid of the hydraulic system. However, due to the existence of high pressure, the high-pressure seal fails, resulting in a short life of the entire system, a complex structure and high maintenance costs. Summary of the Invention

[0004] To address the aforementioned technical issues in the prior art, the present invention proposes a self-locking gear-biasing device and a rotary steerable tool. The self-locking gear-biasing device converts axial rotation into radial expansion and contraction, thereby achieving guidance. The rotary steerable tool can withstand high downhole pressures, is less susceptible to damage, has a long service life, and offers low maintenance costs.

[0005] One aspect of the present invention provides a gear self-locking biasing device, comprising:

[0006] A circular stabilizing sleeve, wherein a cylindrical cavity is provided on the annular wall of the stabilizing sleeve;

[0007] a power mechanism disposed in the cavity, the power mechanism providing rotational power;

[0008] a rotation direction conversion mechanism connected to the power mechanism, wherein the power mechanism outputs rotation in the axial direction of the stabilizing sleeve to the rotation direction conversion mechanism, and the rotation direction conversion mechanism converts the direction and outputs rotation in the radial direction of the stabilizing sleeve; and

[0009] A rotation and telescopic mechanism is provided on the outer wall of the stabilizing sleeve, and is connected to the output end of the rotation direction conversion mechanism and telescopes as the rotation direction conversion mechanism rotates.

[0010] A further improvement of the present invention is that the rotation direction conversion mechanism includes a driving gear connected to the power mechanism and a driven gear connected to the driving gear, the driving gear and the driven gear are in conical meshing, and the output end of the driven gear is connected to the rotation and telescopic mechanism.

[0011] A further improvement of the present invention is that both ends of the driving gear are provided with centering bearings.

[0012] A further improvement of the present invention is that the rotation and telescopic mechanism includes a thrust plate arranged on the outer wall of the stabilizing sleeve and capable of radially extending and contracting, a thrust nut is arranged on the inner side of the thrust plate for pushing the thrust plate to extend and contract, and the thrust nut is threadedly connected to a thrust screw; the thrust screw is connected to the rotation direction conversion mechanism;

[0013] The rotation direction conversion mechanism rotates to drive the thrust screw to rotate, and under the action of the thread, the nut moves radially and pushes the thrust plate to move radially.

[0014] A further improvement of the present invention is that an annular fixing seat is radially provided on the outer wall of the stabilizing sleeve, the edge of the thrust plate is provided on the inner side of the fixing seat, and the edge of the thrust plate and the fixing seat are connected via a return spring;

[0015] When the return spring is in an extended state, the middle portion of the thrust plate is flush with the outer side of the fixing seat; when the thrust nut pushes the thrust plate to extend radially, the return spring is in a compressed state.

[0016] A further improvement of the present invention is that an annular pressure plate is provided on the stabilizing sleeve and located outside the thrust nut; a limiting edge is provided on one end of the thrust nut away from the thrust plate;

[0017] The pressure plate limits the rotation of the thrust nut, and when the thrust nut extends radially, the pressure plate blocks the limiting edge to limit the radial extension length of the thrust nut.

[0018] A further improvement of the present invention is that a thrust bearing is provided on the outer side of the thrust screw.

[0019] A further improvement of the present invention is that the power mechanism includes a motor, and the rotating shaft of the motor is connected to the driving gear of the rotation direction conversion mechanism through a reducer and a coupling.

[0020] According to another aspect of the present invention, a rotary steerable tool is provided, comprising:

[0021] A core shaft, wherein an annular groove is provided on the outer side wall of the core shaft, and the gear self-locking biasing device is provided in the annular groove;

[0022] A measurement and control circuit is arranged in the cavity of the stabilizing sleeve, and is connected to the power device through a wire to detect and control the rotation speed and direction of the power device.

[0023] A further improvement of the present invention is that the upper and lower ends of the stabilizing sleeve are connected to mud outer bearings, and the upper and lower ends of the annular groove of the core shaft are provided with mud inner bearings that match the mud outer bearings.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] The present invention provides a self-locking gear biasing device and a rotary steering tool that converts axial rotation into radial expansion and contraction to achieve guidance. The device can withstand high downhole pressure, is not prone to damage, has a long service life, and has low maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0027] Figure 1 Shown is a schematic structural diagram of a rotary steering tool according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A partial enlarged view shows the structural schematic diagram of the gear self-locking biasing device.

[0029] In the drawings, like components are denoted by like reference numerals, but the drawings are not necessarily drawn to scale.

[0030] The meanings of the reference numerals in the accompanying drawings are as follows: 1. gear self-locking biasing device, 2. core shaft, 3. mud inner bearing, 4. mud outer bearing, 5. measurement and control circuit, 11. stabilizing sleeve, 12. rotation direction conversion mechanism, 13. rotation and telescopic mechanism, 14. power mechanism, 15. cavity, 21. driving gear, 22. driven gear, 23. centering bearing, 24. thrust bearing, 31. thrust plate, 32. thrust nut, 33. thrust screw, 34. fixing seat, 35. pressure plate, 36. limit edge, 37. return spring, 41. motor, 42. reducer, 43. coupling. DETAILED DESCRIPTION

[0031] To make the technical solutions and advantages of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, and are not exhaustive. Furthermore, the embodiments and features of the embodiments of the present invention may be combined with each other unless there is a conflict.

[0032] Figure 1 A schematic diagram shows a gear self-locking biasing device according to one embodiment of the present invention. The device includes a stabilizing sleeve 11, which is annularly mounted on the outer side of the core shaft 2. The annular wall of the stabilizing sleeve 11 includes a cylindrical cavity 15. A power mechanism 14 is disposed within the cavity 15 of the stabilizing sleeve 11, providing rotational power. The power mechanism 14 is preferably an electric device, such as a motor 41. A rotation direction conversion mechanism 12 is also disposed within the cavity 15 of the stabilizing sleeve 11. The rotation direction conversion mechanism 12 is connected to the power mechanism 14 and outputs rotation along the axial direction of the stabilizing sleeve 11 to the rotation direction conversion mechanism 12. The rotation direction conversion mechanism 12 then converts the direction and outputs rotation in the radial direction of the stabilizing sleeve 11. A rotation and telescopic mechanism 13 is disposed on the outer wall of the stabilizing sleeve 11. The rotation and telescopic mechanism 13 is connected to the rotation direction conversion mechanism 12 and can extend or contract during rotation, thereby pushing the thrust plate 31 to extend or contract.

[0033] When using the self-locking gear biasing device described in this embodiment, the power mechanism 14 rotates the rotation direction conversion mechanism 12, which in turn changes the direction of rotation to extend or retract the rotation and telescopic mechanism 13. Axial rotation is converted into radial telescopic movement, thus achieving guidance. The device can withstand high underground pressures and is not susceptible to damage.

[0034] In one embodiment, Figure 2 As shown, the rotation direction conversion mechanism 12 includes a driving gear 21 connected to the power mechanism 14 and a driven gear 22 connected to the driving gear 21. The driving gear 21 and the driven gear 22 are in bevel meshing, and the output end of the driven gear 22 is connected to the rotating telescopic mechanism 13. The driving gear 21 rotates as the power mechanism 14 rotates. The driving gear 21 drives the driven gear 22 to rotate, and the rotation of the driven gear drives the rotating telescopic mechanism 13 to rotate. The driving gear 21 and the driven gear 22 are in bevel meshing, and both the driving gear 21 and the driven gear 22 are bevel gears. After meshing, the output axis of the driven gear 22 forms a 90° angle with the output axis of the driving gear 21. The driving gear 21 rotates along the axial direction of the stabilizing sleeve 11, driving the driven gear 22 to rotate along the radial direction of the stabilizing sleeve 11.

[0035] In this embodiment, the driving gears 21 of the rotation direction conversion mechanism 12 are conical in structure, with two sets arranged opposite each other. The upper set in the figure is connected to the power mechanism 14, and the lower set in the figure is coaxially arranged opposite the upper set. The upper driving gear 21 primarily rotates, while the lower driving gear 21 stabilizes the rotation of the upper driving gear 21. Drive teeth are provided on the conical surfaces of the driving gears 21. There are two driven gears 22, one on either side of the axis of the driving gear 21. The driven gears 22 are also conical in shape, and have drive teeth on their conical surfaces. The drive teeth of the driven gears 22 mate with the drive teeth of the driving gear 21.

[0036] In a preferred embodiment, a centering bearing 23 is provided at each end of the driving gear 21. The centering bearing 23 is located in the center. The centering bearing 23 can keep the driving gear 21 in the center, avoiding deviation or tilt during rotation.

[0037] In one embodiment, Figure 2 As shown, the rotation and telescopic mechanism 13 includes a thrust plate 31, which is arranged on the outer wall of the stabilizing sleeve 11 and can be extended and retracted in the radial direction of the stabilizing sleeve 11. A thrust nut 32 is provided on the inner side of the thrust plate 31, that is, on the side radially close to the central axis of the stabilizing sleeve 11. The thrust nut 32 is extended and retracted to push the thrust plate 31 to extend and retract. The inner side of the thrust nut 32 is connected to a thrust screw 33, which is arranged in the radial direction of the stabilizing sleeve 11. In this embodiment, the thrust screw 33 is provided with a thread that matches the thread of the thrust nut 32. When the thrust screw 33 rotates, the thrust nut 32 will move radially due to the action of the thread. The inner side of the thrust screw 33 is connected to the rotation direction conversion mechanism 12.

[0038] In the gear-locking biasing device of this embodiment, the rotation of the power mechanism 14 drives the rotation direction conversion mechanism 12, which converts axial rotation into radial rotation. The driven gear 22 of the rotation direction conversion mechanism 12 drives the thrust screw 33 to rotate. As the thrust screw 33 rotates, the threads of the screw 33 cause the thrust nut 32 to move radially. As the nut moves radially outward, it pushes the thrust plate 31 to extend radially.

[0039] In one embodiment, a fixing seat 34 is provided on the outer wall of the stabilizing sleeve 11, and the fixing seat 34 is an annular structure. Figure 2As shown, the outer wall of the fixed seat 34 has a conical structure, and the inner wall forms an annular baffle at the outer end. In this embodiment, the thrust plate 31 has a cross-section in the shape of a Chinese character "J," with a radially outwardly convex center and a radially inwardly concave edge forming an annular edge. The edge of the thrust plate 31 is positioned inside the fixed seat 34, and the edge of the thrust plate 31 is connected to the fixed seat 34 via a return spring 37.

[0040] When the return spring 37 is in an extended state, the middle of the thrust plate 31 is flush with the outer side of the fixing seat 34 ; when the thrust nut 32 pushes the thrust plate 31 to extend radially, the return spring 37 is in a compressed state.

[0041] When the gear self-locking biasing device described in this embodiment is working, the thrust nut 32 and the thrust plate 31 are separated, so that there is no rigid connection between the thrust nut 32 and the thrust plate 31, thereby avoiding the thrust nut 32 moving a little larger or a little smaller, causing a rigid pull or push on the thrust plate 31, causing the thrust plate 31 to squeeze or collide with the stabilizing sleeve 11.

[0042] In one embodiment, the stabilizing sleeve 11 is provided with an annular pressure plate 35, positioned within the fixing seat 34. Its main body is radially cylindrical, with an outer edge that is annular. The annular shape of the pressure plate 35 matches the shape of the thrust nut 32. For example, if the thrust nut 32 is a hexagonal nut, the center ring of the pressure plate 35 is also hexagonal. In this embodiment, a limiting edge 36 is provided on the inner side of the thrust nut 32, i.e., on the end away from the thrust plate 31.

[0043] The pressure plate 35 restricts the rotation of the thrust nut 32. When the thrust screw 33 rotates, the threads of the thrust nut 32 and the thrust screw 33 engage, causing the thrust nut 32 to extend radially outward. After extending a certain distance, the pressure plate 35 contacts and blocks the stop edge 36, stopping the outward movement of the thrust nut 32 and thus limiting the radial extension length of the thrust nut 32.

[0044] In one embodiment, a thrust bearing 24 is provided on the outer side of the thrust screw 33. The thrust bearing 24 is mounted on the shaft of the driven gear 22 to ensure that the axial force on the screw is borne on the thrust bearing 24 rather than the gear shaft.

[0045] In one embodiment, the power mechanism 14 includes a motor 41, the shaft of which is axially aligned with the stabilizing sleeve 11. In this embodiment, a reducer 42 is provided on the shaft of the motor 41 for converting a faster input rotational frequency into a slower rotational frequency. The reducer 42 is connected to the driving gear 21 of the rotation direction conversion mechanism 12 via a coupling 43.

[0046] In this embodiment, lateral extension and retraction are achieved by rotating the motor 41 in coordination with the rotation direction conversion mechanism 12 and the rotation retractable mechanism 13 to achieve a biasing effect. Compared with other power methods, such as hydraulics, this is safer and will not cause sealing failure and render the tool unusable in the high-pressure environment underground.

[0047] According to another aspect of the present invention, a rotary guide tool is also provided. Figure 1 As shown, it includes a core shaft 2. The core shaft 2 is a cylindrical structure with a flow channel in the center and a circular groove on the outer wall. The gear self-locking biasing device described in the above embodiment is arranged in the circular groove.

[0048] A measurement and control circuit 5 is housed within the cavity 15 of the stabilizer sleeve 11. This circuit is connected to the power unit via wires to detect and control the unit's rotational speed and direction. This circuit includes a control circuit that controls the forward and reverse rotation of the motor 41 to extend and retract the thrust plate 31 in the modular gear-locking biasing device. The extension and retraction distances of the thrust plate 31 are controlled by controlling the rotation time of the motor 41.

[0049] In one embodiment, the upper and lower ends of the stabilizing sleeve 11 are connected to mud external bearings 4 , and the upper and lower ends of the annular groove of the core shaft 2 are provided with mud internal bearings 3 that match the mud external bearings 4 .

[0050] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made in accordance with the embodiments of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A gear self-locking biasing device, characterized in that: include: A circular stabilizing sleeve (11), wherein a cylindrical cavity (15) is provided on the annular wall of the stabilizing sleeve (11); a power mechanism (14) disposed in the cavity (15), wherein the power mechanism (14) provides rotational power; A rotation direction conversion mechanism (12) connected to the power mechanism (14), wherein the power mechanism (14) outputs rotation in the axial direction of the stabilizing sleeve (11) to the rotation direction conversion mechanism (12), and the rotation direction conversion mechanism (12) converts direction and outputs rotation in the radial direction of the stabilizing sleeve (11); and a rotating and telescopic mechanism (13) provided on the outer wall of the stabilizing sleeve (11), the rotating and telescopic mechanism (13) being connected to the output end of the rotating direction conversion mechanism (12) and telescoping as the rotating direction conversion mechanism (12) rotates; The rotation direction conversion mechanism (12) includes a driving gear (21) connected to the power mechanism (14) and a driven gear (22) connected to the driving gear (21), wherein the driving gear (21) and the driven gear (22) are in conical meshing. The driving gear (21) and the driven gear (22) are both bevel gears. After meshing, the output axis of the driven gear (22) forms an angle of 90° with the output axis of the driving gear (21), and the output end of the driven gear (22) is connected to the rotation and telescopic mechanism (13); Both ends of the driving gear (21) are provided with centering bearings (23); The invention is characterized in that the rotation and telescopic mechanism (13) comprises a thrust plate (31) arranged on the outer wall of the stabilizing sleeve (11) and capable of radially extending and contracting, a thrust nut (32) for pushing the thrust plate (31) to extend and contract is arranged on the inner side of the thrust plate (31), and the thrust nut (32) is connected to a thrust screw (33) through a thread; the thrust screw (33) is connected to the rotation direction conversion mechanism (12); The rotation direction conversion mechanism (12) rotates to drive the thrust screw (33) to rotate, and under the action of the thread, the thrust nut moves radially and pushes the thrust plate (31) to move radially.

2. The gear self-locking biasing device according to claim 1, characterized in that: An annular fixing seat (34) is radially provided on the outer wall of the stabilizing sleeve (11), an edge of the thrust plate (31) is provided on the inner side of the fixing seat (34), and the edge of the thrust plate (31) and the fixing seat (34) are connected via a return spring (37); When the return spring (37) is in an extended state, the middle portion of the thrust plate (31) is flush with the outer side of the fixing seat (34); when the thrust nut (32) pushes the thrust plate (31) to extend radially, the return spring (37) is in a compressed state.

3. The gear self-locking biasing device according to claim 2, characterized in that: An annular pressure plate (35) is provided on the stabilizing sleeve (11) and located outside the thrust nut (32); a limiting edge (36) is provided on one end of the thrust nut (32) away from the thrust plate (31); The pressure plate (35) limits the rotation of the thrust nut (32), and when the thrust nut (32) extends radially, the pressure plate (35) blocks the limiting edge (36) to limit the radial extension length of the thrust nut (32).

4. The gear self-locking biasing device according to claim 3, characterized in that: A thrust bearing (24) is provided on the outer side of the thrust screw (33).

5. The gear self-locking biasing device according to claim 4, characterized in that: The power mechanism (14) includes a motor (41), and the rotating shaft of the motor (41) is connected to the driving gear (21) of the rotation direction conversion mechanism (12) through a reducer (42) and a coupling (43).

6. A rotary guide tool, characterized in that: include: A core shaft (2), wherein an annular groove is provided on the outer side wall of the core shaft (2), and a gear self-locking biasing device according to any one of claims 1 to 5 is provided in the annular groove; A measurement and control circuit (5) is arranged in the cavity (15) of the stabilizing sleeve (11), and the measurement and control circuit (5) is connected to the power device via a wire to detect and control the rotation speed and direction of the power device.

7. The rotary guide tool according to claim 6, wherein: The upper and lower ends of the stabilizing sleeve (11) are connected to mud outer bearings (4), and the upper and lower ends of the annular groove of the core shaft (2) are provided with mud inner bearings (3) that match the mud outer bearings (4).

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