Pressure generating device for drilling

Abstract

A drilling pressure generating device includes multiple upper swirl vanes arranged around a main shaft below a flow channel, and multiple lower swirl vanes arranged around the main shaft below the upper swirl vanes. An upper flow plate is laterally fixed to a lower connector and includes an upper main flow hole, an upper auxiliary flow hole, and two needle valve holes. An axial bevel gear is threaded to the bottom end of the main shaft, and radial bevel gears are respectively engaged with the axial bevel gear at 90°. Two cams are respectively keyway-fixed to the radial bevel gears. A lower flow plate is laterally connected to the lower connector and located below the upper flow plate. The lower flow plate includes a lower main flow hole and a lower auxiliary flow hole. Needle valves are respectively inserted into the needle valve holes and located below the cams. The circumferential rotation of the cams is converted into the axial reciprocating motion of the needle valves. The axial reciprocating motion of the needle valves causes the lower auxiliary flow hole to open and close, resulting in periodic hydraulic pressure changes as the drilling fluid pressure switches between low and high points. This device alleviates pressure build-up and improves drilling efficiency.

Description

Technical Field

[0001] This invention relates to the field of oil drilling technology, and more particularly to a pressure generating device for drilling. Background Technology

[0002] As oilfield exploration and development deepens, drilling is gradually shifting from shallow and easily developed wells to deep and complex-structured wells. The number of extended reach wells, horizontal wells, and highly deviated wells is increasing, leading to more complex geological conditions and more downhole instabilities. In particular, extended reach wells and horizontal wells commonly face technical challenges such as high directional friction, easy pressure build-up, and incomplete cuttings bed cleaning, significantly hindering drilling speed and efficiency. Currently, the mainstream technology for solving the problem of slow directional drilling speed due to pressure build-up is hydraulic oscillator technology. The hydraulic oscillator converts hydraulic energy into high-frequency vibrations of key components, generating vibrations along the drill string assembly or drill pipe axis. This vibration effectively changes the friction between the drill string and the wellbore, reducing frictional resistance and alleviating pressure build-up problems.

[0003] Existing hydraulic oscillators primarily use a screw rotor to drive a rotating moving valve, achieving periodic switching between the moving and stationary valves. This results in periodic pressure changes in the upper flow channel of the tool, which in turn drives the vibration unit to vibrate at high frequencies. However, the presence of rubber components in the screw limits the tool's usability and lifespan in high-temperature wells. Furthermore, the high-speed rotation of the moving and stationary valves during operation easily leads to severe wear and failure of the valve bodies, and even valve body detachment causing pump blockage. Additionally, the eccentric structure of the screw rotor and stator increases the lateral vibration of the oscillator, exacerbating the overall vibration of the drill string and reducing drilling efficiency. Therefore, how to change the current situation of poor drilling efficiency of hydraulic oscillators and how to improve their lifespan and performance have become urgent problems for those skilled in the art.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a drilling pressure generating device that adopts an all-mechanical metal structure design, which can significantly improve the service life and operating temperature of the hydraulic oscillator, enabling the hydraulic oscillator to efficiently alleviate pressure build-up during directional drilling in large displacement / long horizontal sections and high-angle wells, and playing an excellent role in improving drilling pressure transmission efficiency.

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

[0007] A drilling pressure generating device according to the present invention includes:

[0008] The upper connector has a hollow channel for introducing drilling fluid;

[0009] A connecting cylinder, which connects to the bottom end of the upper connector;

[0010] The lower connector has a hollow channel for discharging drilling fluid, and the upper connector, connecting cylinder and lower connector form a flow channel for drilling fluid;

[0011] A hydrocyclone, disposed within the connecting cylinder, the hydrocyclone comprising,

[0012] A fixed disc, threadedly connected to the connecting cylinder, is provided with a central hole and multiple flow channels.

[0013] A main shaft, which is rotatably inserted through the central hole and extends downward.

[0014] Multiple upper swirl blades are located below the flow channel and arranged around the main shaft, and the flow from the upper swirl blades is clockwise when viewed from above.

[0015] Multiple lower swirling blades are located below multiple upper swirling blades and arranged around the main axis. The multiple lower swirling blades rotate counterclockwise when viewed from above.

[0016] The upper flow plate is horizontally fixed in the lower connector and includes an upper main flow hole, an upper auxiliary flow hole and two needle valve holes.

[0017] A gear mechanism, disposed within the connecting cylinder, comprises,

[0018] An axial bevel gear, threadedly connected to the bottom end of the spindle.

[0019] Two symmetrically distributed radial bevel gears, each engaging with an axial bevel gear at a 90° angle.

[0020] Two cams, each with a keyway, are fixedly connected to the radial bevel gear;

[0021] The lower flow plate is laterally connected to the lower connector and located below the upper flow plate. The lower flow plate includes a lower main flow hole and a lower secondary flow hole.

[0022] Two needle valves are respectively inserted into the needle valve hole and located below the cam. The circumferential rotation of the cam is converted into the axial reciprocating motion of the needle valve. The axial reciprocating motion of the needle valve causes the lower auxiliary flow hole to open and close, so that the drilling fluid pressure switches between low and high points to generate periodic hydraulic pressure changes.

[0023] In the drilling pressure generating device described above, the central axes of the upper connector, connecting cylinder, lower connector and the main shaft are collinear.

[0024] In the drilling pressure generating device, the central axis of the connecting cylinder is a vertical axis, and the upper and lower flow plates are both horizontally fixed in the lower connector.

[0025] In the drilling pressure generating device, the upper connector, connecting cylinder and lower connector are detachably connected in sequence.

[0026] In the drilling pressure generating device, eight flow channels of the same size are symmetrically distributed around the central hole, six upper swirling blades are at a 30° angle to the main shaft, and six lower swirling blades are at a 15° angle to the main shaft.

[0027] In the drilling pressure generating device described above, the hydrocyclone further includes,

[0028] A radial bearing comprising an inner ring that interferes with the spindle and an outer ring that interferes with the center bore.

[0029] The pressure cap is threaded onto the fixed plate.

[0030] In the aforementioned drilling pressure generating device, the gear mechanism further includes,

[0031] A support frame is supported on the upper flow plate, and radial bevel gears are rotatably connected to the support frame.

[0032] The supporting rib is a herringbone structure supported at the top of the support frame. A protective cap is provided at the top of the herringbone structure, and the upper end of the axial bevel gear passes through the protective cap.

[0033] A thrust bearing is disposed on the protective cap, the thrust bearing comprising an upper thrust ring at the upper end of the axial bevel gear that is interference-fitted and a lower thrust ring at the protective cap that is interference-fitted.

[0034] In the drilling pressure generating device described above, the lower main flow orifice and the upper main flow orifice are the same size, and the lower auxiliary flow orifice and the upper auxiliary flow orifice are the same size.

[0035] In the drilling pressure generating device, two lower auxiliary flow holes are symmetrically arranged relative to the lower main flow hole, and two upper auxiliary flow holes are symmetrically arranged relative to the upper main flow hole. When viewed from top to bottom, the line connecting the lower auxiliary flow holes and the lower main flow holes is perpendicular to the line connecting the upper auxiliary flow holes and the upper main flow holes.

[0036] In the drilling pressure generating device described above, the needle valve includes,

[0037] The valve body is threadedly connected to the needle valve hole.

[0038] A spring, which is disposed within the valve body,

[0039] A pressure cap, which is sealed to the top of the valve body to compress the spring, is threadedly connected to the needle valve hole.

[0040] The valve core, which passes through a spring to be installed in the valve body, extends out of the valve body at both ends. The upper end of the valve core contacts the cam line and the lower end contacts the lower auxiliary flow hole surface. The circumferential rotation of the cam is converted into the axial reciprocating motion of the valve core. The axial reciprocating motion of the valve core causes the lower auxiliary flow hole to open and close.

[0041] In the above technical solution, the drilling pressure generating device provided by the present invention has the following beneficial effects: An axial bevel gear is driven to rotate by a cyclone separator with a reduction gear structure. The axial bevel gear is connected to two radial bevel gears, each of which is designed with a cam. The upper end of a needle valve is connected to the cam. The rotation of the cam drives the needle valve to perform axial reciprocating motion. The lower end of the needle valve cooperates with the flow channel of the lower flow plate, completing the periodic opening and closing of the flow channel of the lower flow plate, thereby forming a high-low pressure switching of the fluid above the lower flow plate, resulting in axial vibration of the entire friction-reducing tool. This device adopts a fully mechanical metal structure design, has low manufacturing cost, long service life, and high temperature resistance, and can meet the requirements of efficient and low-cost sliding directional drilling. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0043] Figure 1 This is a schematic diagram of a drilling pressure generating device provided in an embodiment of the present invention.

[0044] Figure 2 This is a schematic diagram of the structure of a hydrocyclone for a drilling pressure generating device provided in an embodiment of the present invention.

[0045] Figure 3 This is a schematic diagram of the connection of a hydrocyclone in a drilling pressure generating device provided in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of the gear mechanism of a drilling pressure generating device provided in an embodiment of the present invention.

[0047] Figure 5 This is a schematic diagram of the gear mechanism of a drilling pressure generating device provided in an embodiment of the present invention.

[0048] Figure 6This is a schematic diagram of the structure of a needle valve for a drilling pressure generating device provided in an embodiment of the present invention.

[0049] Figure 7 for Figure 6 A cross-sectional schematic diagram of the needle valve of a drilling pressure generating device provided in this embodiment of the invention.

[0050] Figure 8 This is a schematic diagram of the lower flow plate of a drilling pressure generating device provided in an embodiment of the present invention.

[0051] Figure 9 for Figure 8 A cross-sectional schematic diagram of the lower flow plate BB of a drilling pressure generating device provided in an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0054] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0059] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0060] See Figure 1-9 As shown, in one embodiment, a drilling pressure generating device of the present invention includes,

[0061] Upper connector 1 has a hollow channel for introducing drilling fluid;

[0062] Connecting cylinder 2, which is connected to the bottom end of the upper connector 1;

[0063] The lower connector 7 has a hollow channel for discharging drilling fluid, and the upper connector 1, connecting cylinder 2 and lower connector 7 form a flow channel for drilling fluid;

[0064] Hydrocyclone 3, which is disposed in the connecting cylinder 2, includes,

[0065] The fixed disk 9 is threadedly connected to the connecting cylinder 2. The fixed disk 9 has a central hole and multiple flow channels.

[0066] A main shaft, which is rotatably inserted through the central hole and extends downward.

[0067] Multiple upper swirl blades 11 are located below the flow channel and arranged around the main shaft. The multiple upper swirl blades 11 rotate clockwise when viewed from above.

[0068] Multiple lower swirling blades 12 are located below multiple upper swirling blades 11 and arranged around the main axis. The multiple lower swirling blades 12 rotate counterclockwise when viewed from above.

[0069] The upper flow plate 5 is horizontally fixed in the lower connector 7, and includes an upper main flow hole 20, an upper auxiliary flow hole 21 and two needle valve holes 22.

[0070] Gear mechanism 4, which is disposed in the connecting cylinder 2, includes,

[0071] Axial bevel gear 16, which is threadedly connected to the bottom end of the main shaft.

[0072] Two symmetrically distributed radial bevel gears 17, each of which engages with an axial bevel gear 16 at a 90° angle.

[0073] Two cams 18 are respectively keyway fixedly connected to the radial bevel gear 17;

[0074] The lower flow plate 6 is laterally connected to the lower connector 7 and located below the upper flow plate 5. The lower flow plate 6 includes a lower main flow hole 29 and a lower secondary flow hole 30.

[0075] Two needle valves 23 are respectively inserted into the needle valve hole 22 and located below the cam 18. The circumferential rotation of the cam 18 is converted into the axial reciprocating motion of the needle valve 23. The axial reciprocating motion of the needle valve 23 causes the lower auxiliary flow hole 30 to open and close, so that the drilling fluid pressure switches between low and high points to generate periodic hydraulic pressure changes.

[0076] In a preferred embodiment of the drilling pressure generating device, the upper connector 1, the connecting cylinder 2, the lower connector 7, and the central axis of the main shaft are collinear.

[0077] In a preferred embodiment of the drilling pressure generating device, the central axis of the connecting cylinder 2 is a vertical axis, and the upper flow plate 5 and the lower flow plate 6 are both horizontally fixed in the lower connector 7.

[0078] In a preferred embodiment of the drilling pressure generating device, the upper connector 1, the connecting cylinder 2, and the lower connector 7 are sequentially and detachably connected.

[0079] In a preferred embodiment of the drilling pressure generating device, eight flow channels of the same size are symmetrically distributed around the central hole, six upper swirling blades 11 are all at a 30° angle to the main shaft, and six lower swirling blades 12 are all at a 15° angle to the main shaft.

[0080] In a preferred embodiment of the drilling pressure generating device, the hydrocyclone 3 further includes,

[0081] The radial bearing 10 includes an inner ring that interferes with the spindle and an outer ring that interferes with the center hole.

[0082] The pressure cap 8 is threaded onto the fixed plate 9.

[0083] In a preferred embodiment of the drilling pressure generating device, the gear mechanism 4 further includes,

[0084] Support frame 19, which is supported on the upper flow plate 5, and radial bevel gears 17 are rotatably connected to support frame 19.

[0085] The supporting rib 15 is a herringbone structure supported at the top of the support frame 19. A protective cap 14 is provided at the top of the herringbone structure, and the upper end of the axial bevel gear 16 passes through the protective cap 14.

[0086] A thrust bearing 13 is disposed on the protective cap 14. The thrust bearing 13 includes an upper thrust ring that is interference-fitted to the upper end of the axial bevel gear 16 and a lower thrust ring that is interference-fitted to the protective cap 14.

[0087] In a preferred embodiment of the drilling pressure generating device, the lower main flow hole 29 and the upper main flow hole 20 are the same size, and the lower auxiliary flow hole 30 and the upper auxiliary flow hole 21 are the same size.

[0088] In a preferred embodiment of the drilling pressure generating device, two lower auxiliary flow holes 30 are symmetrically arranged relative to the lower main flow hole 29, and two upper auxiliary flow holes 21 are symmetrically arranged relative to the upper main flow hole 20. When viewed from top to bottom, the line connecting the lower auxiliary flow holes 30 and the lower main flow hole 29 is perpendicular to the line connecting the upper auxiliary flow holes 21 and the upper main flow hole 20.

[0089] In a preferred embodiment of the drilling pressure generating device, the needle valve 23 includes,

[0090] Valve body 26, which is threadedly connected to the needle valve hole 22.

[0091] Spring 27 is disposed inside the valve body 26.

[0092] A pressure cap 25, which is sealed to the top of the valve body 26 to compress the spring 27, is threadedly connected to the needle valve hole 22.

[0093] The valve core 24 passes through the spring 27 to be installed in the valve body 26 and both ends of the valve core 24 extend out of the valve body 26. The upper end of the valve core 24 is in line contact with the cam 18 and the lower end is in surface contact with the lower auxiliary flow hole 30. The circumferential rotation of the cam 18 is converted into the axial reciprocating motion of the valve core 24. The axial reciprocating motion of the valve core 24 causes the lower auxiliary flow hole 30 to open and close.

[0094] In one embodiment, the periodic hydrodynamic pressure change is a sinusoidal periodic change.

[0095] In one embodiment, the drilling pressure generating device includes...

[0096] Upper connector 1 has a hollow channel for introducing drilling fluid;

[0097] Connecting cylinder 2, which is connected to the bottom end of the upper connector 1;

[0098] The lower connector 7 has a hollow channel for discharging drilling fluid. The upper connector 1, connecting cylinder 2 and lower connector 7 form a flow channel for drilling fluid. The central axes of the upper connector 1, connecting cylinder 2 and lower connector 7 are collinear. The upper connector 1, connecting cylinder 2 and lower connector 7 are detachably connected in pairs. Furthermore, they are threadedly connected in pairs.

[0099] Hydrocyclone 3, which is disposed in the connecting cylinder 2, includes,

[0100] The fixed disk 9 is threadedly connected to the connecting cylinder 2. The fixed disk 9 has a central hole and multiple flow channels, with eight identical flow channels surrounding the central hole.

[0101] A main shaft, rotatably passing through the central hole and extending downward, further wherein the central axis of the main shaft is collinear with the central axis of the connecting cylinder 2, and the central axis of the connecting cylinder 2 is a vertical axis.

[0102] The radial bearing 10 includes an inner ring that interferes with the spindle and an outer ring that interferes with the center hole.

[0103] The pressure cap 8 is threadedly connected to the fixing disc 9.

[0104] Multiple upper swirl blades 11 are located below the flow channel and arranged around the main shaft. The multiple upper swirl blades 11 rotate clockwise when viewed from above. Furthermore, each of the multiple upper swirl blades 1111 forms a 30° angle with the main shaft.

[0105] Multiple lower swirling blades 12 are located below multiple upper swirling blades 11 and arranged around the main axis. The multiple lower swirling blades 12 rotate counterclockwise when viewed from above. Furthermore, the multiple lower swirling blades 1212 are all at a 15° angle to the main axis.

[0106] The upper flow plate 5 is horizontally fixed in the lower connector 7, and includes an upper main flow hole 20, an upper auxiliary flow hole 21, and two needle valve holes 22; the upper flow plate 5 is horizontally fixed in the lower connector 7.

[0107] Gear mechanism 4, which is disposed in the connecting cylinder 2, includes,

[0108] Support frame 19, which is supported on the upper flow plate 5,

[0109] The supporting rib 15 is a herringbone structure supported at the top of the support frame 19, and a protective cap 14 is provided at the top of the herringbone structure.

[0110] An axial bevel gear 16, the upper end of which passes through a protective cap 14 and is threadedly connected to the bottom end of the main shaft.

[0111] A thrust bearing 13 is disposed on the protective cap 14. The thrust bearing 13 includes an upper thrust ring that is interference-fitted to the upper end of the axial bevel gear 16 and a lower thrust ring that is interference-fitted to the protective cap 14.

[0112] Two symmetrically distributed radial bevel gears 17 are rotatably connected to the support frame 19 and are engaged with the axial bevel gear 16 at 90°.

[0113] Two cams 18 are respectively keyway fixedly connected to the radial bevel gear 17;

[0114] The lower flow plate 6 is laterally connected to the lower connector 7 and located below the upper flow plate 5. Further, it is threadedly connected to the lower connector 7 and remains horizontal. The lower flow plate 6 includes a lower main flow hole 2929 and a lower auxiliary flow hole 3030. Viewed from top to bottom, the lower auxiliary flow hole 30 and the upper auxiliary flow hole 21 are arranged at 90°. The two lower auxiliary flow holes 30 are symmetrically arranged relative to the lower main flow hole 29. The lower main flow hole 29 and the upper main flow hole 20 are the same size, and the lower auxiliary flow hole 30 and the upper auxiliary flow hole 21 are the same size.

[0115] Two needle valves 23 are respectively disposed in the needle valve holes 22 and located below the cam 18. Each needle valve 23 includes...

[0116] Valve body 26, which is threadedly connected to the needle valve hole 22.

[0117] Spring 27 is disposed inside the valve body 26.

[0118] A pressure cap 25, which is sealed to the top of the valve body 26 to compress the spring 27, is threadedly connected to the needle valve hole 22.

[0119] The valve core 24 passes through the spring 27 and is installed in the valve body 26, with both ends of the valve core 24 extending out of the valve body 26. The upper end of the valve core 24 is in line contact with the cam 18, and the lower end is in surface contact with the lower auxiliary flow orifice 30. The circumferential rotation of the cam 18 is converted into the axial reciprocating motion of the valve core 24. The axial reciprocating motion of the valve core 24 causes the lower auxiliary flow orifice 30 to open and close, causing the drilling fluid pressure to switch between low and high points to generate periodic hydraulic pressure changes. When the lower auxiliary flow orifice 30 is open, the drilling fluid pressure is at a low point, and when the lower auxiliary flow orifice 30 is closed, the drilling fluid pressure is at a high point.

[0120] In one embodiment, the drilling pressure generating device comprises an upper connector 1, a connecting cylinder 2, a hydrocyclone 3, a gear mechanism 4, a needle valve 23, an upper flow plate 5, a lower flow plate 6, and a lower connector 7. The hydrocyclone 3 includes a pressure cap 8, a fixed plate 9, a radial bearing 10, an upper swirling blade 11, and a lower swirling blade 12. The fixed plate 9 is connected to the connecting cylinder 2 by threads. The fixed plate 9 is provided with eight flow channels of the same size. The outer ring of the radial bearing 10 is interference-fitted with the fixed plate 9, and the inner ring of the radial bearing 10 is interference-fitted with the main shaft of the hydrocyclone 3. The pressure cap 8 is threadedly connected to the fixed plate 9 and prevents the radial bearing 10 from eroding and failing. All six upper swirling blades 11 are at a 30° angle to the main shaft, resulting in clockwise swirling when viewed from above. All six lower swirling blades 12 are at a 15° angle to the main shaft, resulting in counter-clockwise swirling when viewed from above. Because the counter-clockwise force generated by the lower swirling blades 12 can partially counteract the clockwise force generated by the upper swirling blades 11, the hydrocyclone 3 will not experience a significant increase in rotational speed with increasing drilling fluid discharge. The lower swirling blades 12 play a role in stabilizing the rotational speed of the hydrocyclone 3. The gear mechanism mainly consists of an axial bevel gear 16, a radial bevel gear 17, a cam 18, a protective cap 14, an axial thrust bearing 13, a support rib 15, and a support frame 19. The upper end of the axial bevel gear 16 is connected to the lower end of the hydrocyclone 3 via a thread. The thrust bearing 13 is an axial thrust bearing. The upper thrust ring of the thrust bearing 13 is interference-fitted with the main shaft of the axial bevel gear 16, and the lower thrust ring is interference-fitted with the protective cap. The protective cap 14 is fixed on the support rib 15, and the support rib 15 is fixed on the support frame 19. The protective cap 14 not only supports the axial bevel gear 16, but also protects the axial bevel gear 16 and the radial bevel gear 17 from erosion by high-pressure, high-speed fluid. Two radial bevel gears 17 are provided, symmetrically distributed, and are respectively connected to the axial bevel gear 16. The bevel gears 16 are engaged at 90°. Each radial bevel gear 17 is provided with a cam 18. The cam 18 is fixedly connected to the radial bevel gear 17 through a keyway. The gear end of the radial bevel gear 17 is engaged with the axial bevel gear. The main shaft end is fixed on the support frame 19. The support frame 19 is fixed on the upper flow plate 5. The upper flow plate 5 is fixed on the lower connector 7 through a threaded connection. The upper flow plate 5 is provided with an upper main flow hole 20 and two upper auxiliary flow holes 21. At the same time, the upper flow plate 5 is provided with two needle valve holes 22, which are used to fix the needle valve 23. The needle valve 23 is mainly composed of a valve core 24, a gland 25, a valve body 26, a spring 27, and an O-ring 28. The spring 27 is installed in the valve body 26, and the valve core 24 passes through the spring 27 and is installed in the valve body 26. The valve body 26 is connected to the needle valve hole 22 in the upper flow plate 5 by threads. The gland 25 is connected to the needle valve hole 22 in the upper flow plate 5 by threads. The gland 25 not only compresses the spring 27, but also seals the needle valve cavity. The upper end of the valve core 24 is in line contact with the cam 18 on the radial bevel gear 17, and the lower end is in surface contact with the lower auxiliary flow hole 30 on the lower flow plate 6.The lower flow plate 6 is provided with one lower main flow hole 29 and two lower auxiliary flow holes 30, and is connected to the lower connector 7 by threads. The two lower auxiliary flow holes 30 are symmetrically arranged. The lower main flow hole 29 in the lower flow plate 6 is the same size as the upper main flow hole 20 in the upper flow plate 5. The lower auxiliary flow hole 30 in the lower flow plate 6 is the same size as the upper auxiliary flow hole 21 in the upper flow plate 5. After the lower flow plate 6 is fixed, when viewed from top to bottom, the two lower auxiliary flow holes 30 and the two upper auxiliary flow holes 21 in the upper flow plate 5 are arranged at 90°.

[0121] When the drilling pressure generating device is working: Viewed from above, when the high-pressure drilling fluid flows through the upper connector, it first flows through the upper swirling blade 11 of the hydrocyclone 3. Since the upper swirling blade 11 forms a 30° clockwise angle with the main shaft, the hydrocyclone 3 generates a clockwise force. The drilling fluid flows through the lower swirling blade 12. Since the lower swirling blade 12 forms a 15° counterclockwise angle with the main shaft, the hydrocyclone 3 generates a counterclockwise force. Because the counterclockwise force generated by the lower swirling blade 12 is less than the clockwise force generated by the upper swirling blade 11, the hydrocyclone 3 rotates at high speed under the action of the clockwise force, driving the axial bevel gear 16 to rotate at high speed. The radial bevel gear 17 and the axial bevel gear 16 are engaged at 90°, so the high-speed rotation of the axial bevel gear 16 becomes the high-speed rotation of the radial bevel gear 17. The cam 18 is fixed on the radial bevel gear 17. As the radial bevel gear 17 rotates at high speed, the valve core 24 of the needle valve 23 is in line contact with the cam 18. Therefore, the circumferential rotation of the cam 18 is converted into the axial reciprocating motion of the valve core 24 of the needle valve 23. The lower end of the valve core 24 is in surface contact with the lower auxiliary flow hole 30 of the lower flow plate 6. The axial reciprocating motion of the valve core 24 causes the lower auxiliary flow hole 30 of the lower flow plate 6 to open and close. When the lower auxiliary flow hole 30 of the lower flow plate 6 is open, the drilling fluid pressure is at a low point. When the lower auxiliary flow hole 30 of the lower flow plate 6 is closed, the drilling fluid pressure is at a high point. As the lower auxiliary flow hole 30 of the lower flow plate 6 opens and closes, the drilling fluid pressure also switches between low and high points, generating periodic hydraulic pressure changes. The periodic pressure fluctuations are converted into periodic vibration force and tool amplitude through the vibration of the hydraulic oscillator, which drives the drill string that is close to the well wall to move, thus relieving drag pressure.

[0122] Finally, it should be noted that the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0123] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A pressure generating device for drilling, characterized in that, It includes, The upper connector has a hollow channel for introducing drilling fluid; A connecting cylinder, which connects to the bottom end of the upper connector; The lower connector has a hollow channel for discharging drilling fluid, and the upper connector, connecting cylinder and lower connector form a flow channel for drilling fluid; A hydrocyclone, disposed within the connecting cylinder, the hydrocyclone comprising, A fixed disc, threadedly connected to the connecting cylinder, is provided with a central hole and multiple flow channels. A main shaft, which is rotatably inserted through the central hole and extends downward. Multiple upper swirl blades are located below the flow channel and arranged around the main shaft, and the flow from the upper swirl blades is clockwise when viewed from above. Multiple lower swirling blades are located below multiple upper swirling blades and arranged around the main axis. The multiple lower swirling blades rotate counterclockwise when viewed from above. The upper flow plate is horizontally fixed in the lower connector and includes an upper main flow hole, an upper auxiliary flow hole and two needle valve holes. A gear mechanism, disposed within the connecting cylinder, comprises, An axial bevel gear, threadedly connected to the bottom end of the spindle. Two symmetrically distributed radial bevel gears, each engaging with an axial bevel gear at a 90° angle. Two cams, each with a keyway, are fixedly connected to the radial bevel gear; The lower flow plate is laterally connected to the lower connector and located below the upper flow plate. The lower flow plate includes a lower main flow hole and a lower secondary flow hole. Two needle valves are respectively inserted into the needle valve hole and located below the cam. The circumferential rotation of the cam is converted into the axial reciprocating motion of the needle valve. The axial reciprocating motion of the needle valve causes the lower auxiliary flow hole to open and close, so that the drilling fluid pressure switches between low and high points to generate periodic hydraulic pressure changes.

2. The drilling pressure generating device according to claim 1, characterized in that, The upper connector, connecting cylinder, lower connector, and the central axis of the main shaft are collinear.

3. A drilling pressure generating device according to claim 2, characterized in that, The central axis of the connecting cylinder is a vertical axis, and both the upper and lower flow plates are horizontally fixed in the lower connector.

4. A drilling pressure generating device according to claim 1, characterized in that, The upper connector, connecting cylinder, and lower connector are detachably connected in sequence.

5. A drilling pressure generating device according to claim 1, characterized in that, Eight identical flow channels are symmetrically distributed around the central hole. Six upper swirling blades are at a 30° angle to the main axis, and six lower swirling blades are at a 15° angle to the main axis.

6. A drilling pressure generating device according to claim 1, characterized in that, The hydrocyclone also includes, A radial bearing comprising an inner ring that interferes with the spindle and an outer ring that interferes with the center bore. The pressure cap is threaded onto the fixed plate.

7. A drilling pressure generating device according to claim 1, characterized in that, The gear mechanism also includes, A support frame is supported on the upper flow plate, and radial bevel gears are rotatably connected to the support frame. The supporting rib is a herringbone structure supported at the top of the support frame. A protective cap is provided at the top of the herringbone structure, and the upper end of the axial bevel gear passes through the protective cap. A thrust bearing is disposed on the protective cap, the thrust bearing comprising an upper thrust ring at the upper end of the axial bevel gear that is interference-fitted and a lower thrust ring at the protective cap that is interference-fitted.

8. A drilling pressure generating device according to claim 1, characterized in that, The lower main flow orifice and the upper main flow orifice are the same size, and the lower auxiliary flow orifice and the upper auxiliary flow orifice are the same size.

9. A drilling pressure generating device according to claim 1, characterized in that, The two lower auxiliary flow holes are symmetrically arranged with respect to the lower main flow hole, and the two upper auxiliary flow holes are symmetrically arranged with respect to the upper main flow hole. When viewed from top to bottom, the line connecting the lower auxiliary flow hole and the lower main flow hole is perpendicular to the line connecting the upper auxiliary flow hole and the upper main flow hole.

10. A drilling pressure generating device according to claim 1, characterized in that, The needle valve includes, The valve body is threadedly connected to the needle valve hole. A spring, which is disposed within the valve body, A pressure cap, which is sealed to the top of the valve body to compress the spring, is threadedly connected to the needle valve hole. The valve core, which passes through a spring to be installed in the valve body, extends out of the valve body at both ends. The upper end of the valve core contacts the cam line and the lower end contacts the lower auxiliary flow hole surface. The circumferential rotation of the cam is converted into the axial reciprocating motion of the valve core. The axial reciprocating motion of the valve core causes the lower auxiliary flow hole to open and close.

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