Negative pressure type all-metal hydraulic oscillator

Abstract

The invention belongs to the technical field of roller bits, and particularly relates to a negative pressure type all-metal hydraulic oscillator. Comprising a lower connector, a locking nut, a stator adjusting sleeve, a first alignment bearing outer ring, a first alignment bearing inner ring, a stator adjusting pad, a turbine stator, a turbine rotor, a turbine shell, a second alignment bearing outer ring, a second alignment bearing inner ring, a rotor mandrel, a first adjusting sleeve, a valve shaft, a TC bearing moving ring, a TC bearing static ring, a string bearing, a second adjusting sleeve, a shell, an alloy nozzle and a middle sleeve. The device comprises a pressing cap, a piston shaft, a balance piston, a disc spring, an adjusting pad, a transmission shell, an upper connector and a transmission mandrel. Due to the fact that the negative pressure difference acting mode is adopted, effective pressure fluctuation can still be generated under the high pumping pressure working condition of a deep well and an ultra-deep well, and the problem that the pulse amplitude of traditional positive pressure difference driving is attenuated in the high-pressure environment is solved.

Description

Technical Field

[0001] This invention belongs to the field of oscillator technology, specifically relating to a negative pressure all-metal hydraulic oscillator. Background Technology

[0002] In drilling engineering for oil, natural gas, and geothermal resources, as exploration and development extend to deeper and more complex formations, directional and horizontal well technologies have become important means to improve oil and gas recovery. However, during directional drilling, the friction between the drill string and the wellbore is particularly prominent, often leading to the phenomenon of "pressure backing." Pressure backing not only reduces the efficiency of drill pressure transmission but also seriously affects the rate of drilling, prolongs the drilling cycle, and increases operating costs.

[0003] To alleviate pressure drag issues, the industry has developed various anti-pressure drag tools, mainly including screw-type, pulse-type, and all-metal turbine-type hydraulic oscillators. These tools improve the contact between the drill string and the wellbore by generating axial vibrations or pressure pulses, reducing friction and increasing drilling pressure transmission efficiency. Among them, the all-metal turbine-type hydraulic oscillator has achieved good application results in some well conditions due to its simple structure, high temperature resistance, and strong adaptability.

[0004] However, with increasing drilling depths, especially in deep and ultra-deep well operations, the high downhole temperatures and drilling fluid pump pressures pose challenges to the operational stability of existing hydraulic oscillators under high-pressure environments. Traditional tools often rely on positive pressure differentials for internal pressure pulses, which are prone to insufficient pulse amplitude, seal failure, and weakened vibration under high-pressure conditions, making them unsuitable for high-temperature, high-pressure well operations. Therefore, there is an urgent need to develop a new type of hydraulic oscillator capable of stable operation under high pump pressure and high-temperature environments to improve drilling efficiency and safety in deep and ultra-deep wells. Summary of the Invention

[0005] The purpose of this invention is to provide a negative pressure all-metal hydraulic oscillator to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a negative pressure all-metal hydraulic oscillator, comprising: a lower connector, a locking nut, a stator adjusting sleeve, a first straightening bearing outer ring, a first straightening bearing inner ring, a stator adjusting pad, a turbine stator, a turbine rotor, a turbine housing, a second straightening bearing outer ring, a second straightening bearing inner ring, a rotor spindle, a first adjusting sleeve, a valve shaft, a TC bearing moving ring, a TC bearing stationary ring, a tandem bearing, a second adjusting sleeve, a housing, an alloy nozzle, a middle sleeve, a pressure cap, a piston shaft, a balance piston, a disc spring, an adjusting pad, a transmission housing, an upper connector, and a transmission spindle; The upper connector is equipped with a sealing ring inside, and the lower end of the upper connector is threaded to the upper end of the transmission housing; the lower end of the transmission housing is threaded to the upper end of the middle sleeve, and the lower end of the middle sleeve is threaded to the upper end of the housing; the lower end of the housing is connected to the upper end of the turbine housing, and the lower end of the turbine housing is connected to the lower connector. The transmission spindle passes through the inside of the transmission housing, and its upper end communicates with the inner hole of the upper connector. The transmission spindle and the transmission housing are connected by a spline. The disc spring is sleeved on the transmission spindle in a back-to-back combination, and the adjusting shim is set at the lower end of the disc spring. The lower end of the piston shaft is threaded to the upper end of the transmission spindle, and the upper end of the piston shaft is threaded to the pressure cap. The balance piston is sleeved on the piston shaft. The valve shaft is located inside the housing. The upper end of the valve shaft is limited by the second adjusting sleeve, and the lower end of the valve shaft is connected to the upper end of the rotor core shaft by the first adjusting sleeve. The stationary ring and the moving ring of the TC bearing are sleeved on the upper part of the valve shaft, and the tandem bearing is sleeved on the valve shaft and located below the TC bearing. The rotor spindle is fitted with, from top to bottom, a second centralizing bearing inner ring, a second centralizing bearing outer ring, a turbine rotor, a turbine stator, a stator adjusting shim, a first centralizing bearing inner ring, a first centralizing bearing outer ring, a stator adjusting sleeve, and a locking nut; the turbine rotor and turbine stator are alternately arranged. The alloy nozzles are multiple and are respectively installed on the middle sleeve and the valve shaft.

[0007] Preferably, four alloy nozzles are evenly distributed circumferentially on the middle sleeve, and four alloy nozzles are evenly distributed circumferentially on the valve shaft. The alloy nozzles on the valve shaft and the alloy nozzles on the middle sleeve form a periodic overlapping and closing cooperation structure when the valve shaft rotates.

[0008] Preferably, the disc spring is a multi-piece back-to-back combination, sleeved on the outside of the transmission spindle, with the upper and lower ends of the disc spring respectively limited by adjusting pads.

[0009] Preferably, the spline connection between the transmission mandrel and the transmission housing is an axial sliding fit structure.

[0010] Preferably, the turbine stator and turbine rotor are arranged in multiple alternating sets to form a turbine powertrain.

[0011] Preferably, the inner ring of the first centralizing bearing and the outer ring of the first centralizing bearing are correspondingly fitted and disposed at the upper end of the turbine stator and the turbine rotor; the inner ring of the second centralizing bearing and the outer ring of the second centralizing bearing are correspondingly fitted and disposed at the lower end of the turbine stator and the turbine rotor.

[0012] Preferably, the upper end of the valve shaft is supported on the inner wall of the housing by a tandem bearing and a TC bearing.

[0013] Preferably, the lower connector has a female thread at its lower end and the upper connector has a male thread at its upper end, for connecting the drill rod.

[0014] The beneficial effects of this invention are as follows: This invention uses a turbine to drive the valve shaft to rotate, causing the alloy nozzle on the valve shaft to periodically overlap and close with the alloy nozzle on the middle sleeve, forming periodic pressure pulses inside the tool. These pressure pulses directly act on the inside of the housing and drive the oscillating joint to generate axial vibration. Due to the use of a negative pressure differential action, effective pressure fluctuations can still be generated under high pump pressure conditions in deep and ultra-deep wells, avoiding the problem of pulse amplitude attenuation in high-pressure environments caused by traditional positive pressure differential drives. Simultaneously, the all-metal structure design gives it excellent high-temperature resistance, allowing stable operation in well sections above 200℃. The preload of the disc spring assembly can be adjusted via adjusting shims, adapting to the vibration requirements of different well conditions. The multi-point support structure of the centering bearing ensures the smoothness and reliability of the rotating components. The overall structure is compact, easy to assemble and maintain, effectively alleviating the pressure drag problem in directional and horizontal well drilling, shortening the drilling cycle, and reducing operating costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a negative pressure all-metal hydraulic oscillator according to the present invention; Figure 2 for Figure 1 A magnified view of the upper middle section; Figure 3 for Figure 1 A magnified view of the lower middle section.

[0016] In the diagram: 1-Lower connector, 2-Locking nut, 3-Stator adjusting sleeve, 4-Outer ring of the first centralizing bearing, 5-Inner ring of the first centralizing bearing, 6-Stator adjusting pad, 7-Turbine stator, 8-Turbine rotor, 9-Turbine housing, 10-Outer ring of the second centralizing bearing, 11-Inner ring of the second centralizing bearing, 12-Rotor spindle, 13-First adjusting sleeve, 14-Valve shaft, 15-TC bearing moving ring, 16-TC bearing stationary ring, 17-String bearing, 18-Second adjusting sleeve, 19-Housing, 20-Alloy nozzle, 21-Middle sleeve, 22-Pressure cap, 23-Piston shaft, 24-Balance piston, 25-Disc spring, 26-Adjusting pad, 27-Transmission housing, 28-Upper connector, 29-Transmission spindle. Detailed Implementation

[0017] In the description of this disclosure, it should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0018] 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 disclosure, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a communication connection; 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 disclosure according to the specific circumstances.

[0020] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0021] like Figure 1-3 As shown, the present invention provides a negative pressure all-metal hydraulic oscillator, which mainly includes: a lower connector 1, a locking nut 2, a stator adjusting sleeve 3, a first straightening bearing outer ring 4, a first straightening bearing inner ring 5, a stator adjusting pad 6, a turbine stator 7, a turbine rotor 8, a turbine housing 9, a second straightening bearing outer ring 10, a second straightening bearing inner ring 11, a rotor spindle 12, a first adjusting sleeve 13, a valve shaft 14, a TC bearing moving ring 15, a TC bearing stationary ring 16, a tandem bearing 17, a second adjusting sleeve 18, a housing 19, an alloy nozzle 20, a middle sleeve 21, a pressure cap 22, a piston shaft 23, a balance piston 24, a disc spring 25, an adjusting pad 26, a transmission housing 27, an upper connector 28, and a transmission spindle 29.

[0022] The upper connector 28 is the upper connecting part of this tool, and it is equipped with a sealing ring to ensure sealing performance. The upper end of the upper connector 28 is provided with a male thread for connecting the upper drill rod; the lower end of the upper connector 28 is fixedly connected to the upper end of the transmission housing 27 by a thread.

[0023] The transmission housing 27 is a hollow cylindrical structure, with its lower end fixedly connected to the upper end of the middle sleeve 21 via threads; the lower end of the middle sleeve 21 is fixedly connected to the upper end of the housing 19 via threads. The lower end of the housing 19 is fixedly connected to the upper end of the turbine housing 9, and the lower end of the turbine housing 9 is fixedly connected to the lower connector 1. The lower connector 1 has a female thread at its lower end for connecting the lower drill rod. The whole structure forms a series structure from top to bottom: upper connector 28, transmission housing 27, middle sleeve 21, housing 19, turbine housing 9, and lower connector 1.

[0024] The drive spindle 29 passes through the inside of the drive housing 27 and can slide axially. The upper end of the drive spindle 29 communicates with the inner hole of the upper connector 28, forming a mud flow channel. The drive spindle 29 and the drive housing 27 are connected by a spline, which is an axial sliding fit structure, allowing the drive spindle 29 to move axially within the drive housing 27 while transmitting torque.

[0025] A disc spring 25 is fitted onto the transmission spindle 29. This disc spring 25 is a multi-plate back-to-back arrangement, meaning two disc springs are installed opposite each other in multiple consecutive groups. An adjusting shim 26 is located at the lower end of the disc spring 25 to adjust the preload of the disc spring assembly. By selecting the thickness of the adjusting shim 26, the initial compression of the disc spring assembly can be controlled, thereby adjusting the vibration characteristics of the oscillator.

[0026] The lower end of the piston shaft 23 is threaded to the upper end of the transmission spindle 29, and the upper end of the piston shaft 23 is threaded to the pressure cap 22. A balance piston 24 is fitted on the piston shaft 23. The balance piston 24 can slide axially on the piston shaft 23 to balance the mud pressure and reduce the impact of pressure fluctuations on the seal.

[0027] The turbine housing 9 houses the turbine power assembly. The rotor spindle 12 is the central shaft of the turbine section, on which, from top to bottom, are fitted the following components: the inner ring 11 of the second centralizing bearing, the outer ring 10 of the second centralizing bearing, the turbine rotor 8, the turbine stator 7, the stator adjusting shim 6, the inner ring 5 of the first centralizing bearing, the outer ring 4 of the first centralizing bearing, the stator adjusting sleeve 3, and the locking nut 2.

[0028] The turbine rotor 8 and turbine stator 7 are arranged in multiple alternating sets to form a multi-stage turbine structure. The specific number can be adjusted according to actual working conditions; in this embodiment, six sets of turbine stators and turbine rotors are used. The turbine rotor 8 is fixedly connected to the rotor spindle 12, and the turbine stator 7 is fixedly connected to the inner wall of the turbine housing 9. When the slurry flows through the turbine assembly, it drives the turbine rotor 8 to rotate, thereby driving the rotor spindle 12 to rotate.

[0029] The inner ring 5 of the first centralizing bearing and the outer ring 4 of the first centralizing bearing are correspondingly fitted and are located at the upper end of the turbine stator 7 and the turbine rotor 8, serving a centralizing and supporting function. The inner ring 11 of the second centralizing bearing and the outer ring 10 of the second centralizing bearing are correspondingly fitted and are located at the lower end of the turbine stator 7 and the turbine rotor 8, also serving a centralizing function. The stator adjusting shim 6 is used to adjust the axial clearance between the turbine stator 7 and the turbine rotor 8, and the stator adjusting sleeve 3 and the locking nut 2 are used to lock the entire turbine assembly.

[0030] The valve shaft 14 is disposed inside the housing 19. The upper end of the valve shaft 14 is limited by the second adjusting sleeve 18, and the lower end of the valve shaft 14 is fixedly connected to the upper end of the rotor spindle 12 by the first adjusting sleeve 13, thereby realizing the torque transmission between the turbine powertrain and the valve shaft. The valve shaft 14 rotates synchronously with the rotor spindle 12.

[0031] A TC bearing stationary ring 16 and a TC bearing moving ring 15 are fitted onto the upper part of the valve shaft 14. Together, they form a TC tungsten carbide bearing to bear axial loads. Below the TC bearing, a tandem bearing 17 is fitted onto the valve shaft 14 for radial support. The upper end of the valve shaft 14 is supported on the inner wall of the housing 19 by the tandem bearing 17 and the TC bearings 15 and 16, ensuring smooth rotation.

[0032] Four alloy nozzles 20 are evenly distributed circumferentially along the upper edge of the middle sleeve 21, and four alloy nozzles 20 are also evenly distributed circumferentially along the upper edge of the valve shaft 14. The alloy nozzles on the valve shaft 14 and the alloy nozzles on the middle sleeve 21 form a periodic overlapping and closing mechanism as the valve shaft rotates. When the nozzles overlap, the mud flow area increases and the pressure decreases; when the nozzles are offset, the flow area decreases and the pressure increases. This generates periodic pressure pulses.

[0033] During drilling operations, drilling mud enters from the upper connector 28, flows downward through the inner hole of the drive spindle 29, and enters the turbine power assembly inside the turbine housing 9. As the drilling mud flows through the turbine stator 7 and the turbine rotor 8, it drives the turbine rotor 8 to rotate. The turbine rotor 8 drives the valve shaft 14 to rotate synchronously through the rotor spindle 12.

[0034] During the rotation of valve shaft 14, the four alloy nozzles 20 on it periodically overlap and close with the four alloy nozzles 20 on the middle sleeve 21, causing periodic changes in the mud flow area, thereby generating periodic pressure pulses inside the tool. These pressure pulses act on piston shaft 23 and balance piston 24, pushing piston shaft 23 axially and compressing disc spring 25. When the pressure decreases, disc spring 25 releases energy, pushing piston shaft 23 back to its original position. This cycle repeats, creating axial vibration.

[0035] The key feature of this tool is that the pressure pulse acts directly inside the casing 19, creating a negative pressure differential. Unlike traditional positive pressure differential driving methods, the negative pressure differential can still generate effective pressure fluctuations under high pressure environments, avoiding the problem of pulse amplitude attenuation under high pressure conditions. In deep and ultra-deep wells with high pump pressure conditions, this tool can operate stably and effectively alleviate drill string pressure problems.

[0036] In this preferred embodiment, the turbine stator 7 and turbine rotor 8 are made entirely of metal to withstand the high-temperature downhole environment. All bearings are made of wear-resistant materials, such as tungsten carbide and cemented carbide. The seals are made of high-temperature resistant fluororubber.

[0037] The disc spring 25 is made of 60Si2MnA spring steel and its hardness reaches HRC45-50 after heat treatment. The adjusting shim 26 is available in various thicknesses, such as 1mm, 2mm, and 3mm, which can be adjusted on-site according to actual vibration requirements.

[0038] The alloy nozzle 20 is made of hard alloy, which has good wear resistance. The number of nozzles on the middle sleeve 21 and valve shaft 14 is not limited to four, and can be adjusted according to flow and pressure requirements, such as six or eight.

[0039] The spline between the transmission spindle 29 and the transmission housing 27 is an involute spline with 24 teeth, a module of 2, and a pressure angle of 30°, ensuring smooth transmission and allowing axial sliding.

[0040] During assembly, follow these steps: First, assemble the turbine power assembly: place the rotor spindle 12 vertically, and install the second centralizing bearing inner ring 11 and the second centralizing bearing outer ring 10 in sequence from the bottom. Then, alternately install the turbine rotor 8 and the turbine stator 7. Adjust the clearance after each set is installed. Finally, install the first centralizing bearing inner ring 5, the first centralizing bearing outer ring 4, the stator adjusting sleeve 3, and the locking nut 2, and lock them in place.

[0041] Next, assemble the valve shaft: install the valve shaft 14 into the housing 19, install the tandem bearing 17, the TC bearing stationary ring 16, and the TC bearing moving ring 15 in sequence, install the alloy nozzle 20 on the valve shaft 14, and then install the second adjusting sleeve 18 for limiting.

[0042] Then, connect the turbine part and the valve shaft part: connect the upper end of the assembled turbine powertrain to the lower end of the valve shaft 14 through the first adjusting sleeve 13, and connect the turbine housing 9 to the housing 19.

[0043] Next, assemble the oscillating joint: install the transmission spindle 29 into the transmission housing 27, fit the adjusting shim 26 and disc spring 25, connect the lower end of the piston shaft 23 to the transmission spindle 29, fit the balance piston 24, and connect the pressure cap 22 to the upper end of the piston shaft 23.

[0044] Finally, connect the oscillator to the valve body: connect the transmission housing 27 to the middle sleeve 21, connect the middle sleeve 21 to the housing 19, install the alloy nozzle 20 on the middle sleeve 21, install the upper connector 28 on the upper end of the transmission housing 27, and install the lower connector 1 on the lower end of the turbine housing 9.

[0045] It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A negative pressure all-metal hydraulic oscillator, characterized in that, include: The components are: lower connector (1), locking nut (2), stator adjusting sleeve (3), outer ring of first straightening bearing (4), inner ring of first straightening bearing (5), stator adjusting pad (6), turbine stator (7), turbine rotor (8), turbine housing (9), outer ring of second straightening bearing (10), inner ring of second straightening bearing (11), rotor spindle (12), first adjusting sleeve (13), valve shaft (14), moving ring of TC bearing (15), stationary ring of TC bearing (16), tandem bearing (17), second adjusting sleeve (18), housing (19), alloy nozzle (20), middle sleeve (21), pressure cap (22), piston shaft (23), balance piston (24), disc spring (25), adjusting pad (26), transmission housing (27), upper connector (28), and transmission spindle (29). The upper connector (28) is equipped with a sealing ring inside. The lower end of the upper connector (28) is connected to the upper end of the transmission housing (27) by a thread. The lower end of the transmission housing (27) is connected to the upper end of the middle sleeve (21) by a thread. The lower end of the middle sleeve (21) is connected to the upper end of the housing (19) by a thread. The lower end of the housing (19) is connected to the upper end of the turbine housing (9). The lower end of the turbine housing (9) is connected to the lower connector (1). The transmission spindle (29) passes through the inside of the transmission housing (27), and the upper end of the transmission spindle (29) is connected to the inner hole of the upper connector (28). The transmission spindle (29) and the transmission housing (27) are connected by a spline. The disc spring (25) is sleeved on the transmission spindle (29) in a back-to-back combination, and the adjusting shim (26) is set at the lower end of the disc spring (25). The lower end of the piston shaft (23) is threaded to the upper end of the transmission spindle (29), and the upper end of the piston shaft (23) is threaded to the pressure cap (22). The balance piston (24) is sleeved on the piston shaft (23). The valve shaft (14) is located inside the housing (19). The upper end of the valve shaft (14) is limited by the second adjusting sleeve (18), and the lower end of the valve shaft (14) is connected to the upper end of the rotor spindle (12) by the first adjusting sleeve (13). The stationary ring (16) and the moving ring (15) of the TC bearing are sleeved on the upper part of the valve shaft (14), and the tandem bearing (17) is sleeved on the valve shaft (14) and located below the TC bearing. The rotor spindle (12) is fitted with, from top to bottom, a second centralizing bearing inner ring (11), a second centralizing bearing outer ring (10), a turbine rotor (8), a turbine stator (7), a stator adjusting shim (6), a first centralizing bearing inner ring (5), a first centralizing bearing outer ring (4), a stator adjusting sleeve (3), and a locking nut (2); the turbine rotor (8) and the turbine stator (7) are arranged alternately. The alloy nozzles (20) are multiple and are respectively installed on the middle sleeve (21) and the valve shaft (14).

2. The negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The middle sleeve (21) has four alloy nozzles (20) evenly distributed along the circumference, and the valve shaft (14) has four alloy nozzles (20) evenly distributed along the circumference. The alloy nozzles on the valve shaft (14) and the alloy nozzles on the middle sleeve (21) form a periodic overlapping and closing cooperation structure when the valve shaft rotates.

3. The negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The disc spring (25) is a multi-piece back-to-back combination, sleeved on the outside of the transmission spindle (29), and the upper and lower ends of the disc spring (25) are respectively limited by the adjusting pad (26).

4. A negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The spline connection between the transmission spindle (29) and the transmission housing (27) is an axial sliding fit structure.

5. A negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The turbine stator (7) and turbine rotor (8) are arranged in multiple alternating sets to form a turbine power assembly.

6. A negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The first centralizing bearing inner ring (5) and the first centralizing bearing outer ring (4) are correspondingly matched and are located at the upper end of the turbine stator (7) and the turbine rotor (8); the second centralizing bearing inner ring (11) and the second centralizing bearing outer ring (10) are correspondingly matched and are located at the lower end of the turbine stator (7) and the turbine rotor (8).

7. A negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The upper end of the valve shaft (14) is supported on the inner wall of the housing (19) by a tandem bearing (17) and a TC bearing.

8. A negative pressure all-metal hydraulic oscillator according to claim 1, characterized in that, The lower connector (1) has a female thread at its lower end and the upper connector (28) has a male thread at its upper end, which are used to connect the drill rod.

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