CN116480282A - Axial displacement type hydraulic oscillator - Google Patents

Abstract

The invention provides an axial displacement type hydraulic oscillator which comprises a first component, a second component, an oscillating mechanism and a mandrel. Wherein the first component is provided with at least one first through hole extending in radial direction. The second assembly includes a drive shaft disposed within the first assembly; a valve disc mechanism disposed on the drive shaft and including a fixed valve disc and a movable valve disc, the movable valve disc being configured to be driven to rotate by the drive shaft such that an area of flow passing through the valve disc mechanism varies periodically, and a drilling fluid diverting unit formed between the first assembly and the drive shaft. The mandrel is provided with at least one radially extending second through hole. The invention can reduce the minimum pressure consumption value required by pressure fluctuation, reduce the load of ground equipment, increase the fluctuation value range, further improve the impactor value and be more beneficial to reducing the friction between the drilling tool and the well wall in the drilling process.

Description

Axial displacement type hydraulic oscillator

Technical Field

The invention relates to the technical field of drilling equipment, in particular to an axial displacement type hydraulic oscillator.

Background

At present, the demands for petroleum and natural gas are increasing at home and abroad, and a plurality of stored oil gas with larger exploitation difficulty gradually enter a development stage so as to improve the yield of petroleum and natural gas, thereby meeting the increasing energy demands of people. Meanwhile, petroleum drilling technology is continuously developed, and a large number of novel downhole tools are continuously developed and used, so that drilling of unconventional structure wells is possible. Particularly, the occurrence of complex structure wells such as large displacement wells, multi-branch horizontal wells, high-inclination wells and the like, so that oil gas which does not have production conditions before is gradually developed, and the number of the complex structure wells is gradually increased.

In this case, how to achieve fast drilling and to increase the horizontal segment length is a focus of attention. However, because the well inclination angle is large, friction between the drill string and the well wall is large, the transmission efficiency of the bit pressure is low, the drilling speed is severely limited, and the underground faults such as differential pressure sticking and the like are easily caused. Especially in sliding drilling, a true and effective weight on bit cannot be applied, which reduces drilling efficiency and prolongs drilling period.

In order to solve the above problems, many companies at home and abroad have successively developed a hydraulic oscillator for improving drilling efficiency. The hydraulic oscillator is mainly applied to petroleum and natural gas drilling engineering, is used for enabling a drilling tool to vibrate in the axial direction, converting static friction force into dynamic friction force, reducing friction between the drilling tool and a well wall in the drilling process, and realizing efficient rock breaking of a drill bit.

However, the current hydraulic oscillators have some problems that vibration cannot be effectively generated, and static friction force is converted into dynamic friction force.

Disclosure of Invention

The invention aims to provide an axial displacement type hydraulic oscillator aiming at the technical problems.

According to the present invention, there is provided an axially displaced hydraulic oscillator comprising a first assembly for connection with an upper drilling tool, the first assembly being configured as a hollow cylinder and being provided with at least one radially extending first through hole; a second assembly disposed within the first assembly, the second assembly comprising a hollow drive shaft concentrically disposed within the first assembly, a valve disc mechanism disposed on the drive shaft, and a drilling fluid flow splitting unit formed between the first assembly and the drive shaft, wherein the drilling fluid flow splitting unit is configured to allow a portion of drilling fluid to flow directly into a central passage within the drive shaft while another portion of drilling fluid flows into the central passage through a turbine section disposed on the drive shaft; an oscillating mechanism disposed downstream of the second assembly; and a mandrel for connection to a lower drill, the mandrel having one end fixedly connected to the oscillating mechanism and the other end extending beyond the first assembly, the mandrel being configured as a hollow cylinder and being provided with at least one radially extending second through hole, wherein the second assembly is configured to enable a varying pressure to be generated within the central passage and to act on the oscillating mechanism to urge the mandrel to reciprocate axially relative to the first assembly, causing the first through hole to be periodically aligned with the second through hole to allow the interior of the hydraulic oscillator to periodically communicate with the exterior.

In one embodiment, the first assembly includes a cylinder barrel, a center joint, and an outer barrel that are disposed and fixed together in order from an upstream end to a downstream end in an axial direction, wherein the first through hole is disposed on an outer periphery of the outer barrel.

In one embodiment, the outer cylinder is configured as a hollow sleeve, at least one axially extending key slot is arranged on the inner wall of the hollow sleeve, at least one axially extending key tooth is arranged on the outer wall of the mandrel, and the key slot is matched with the key tooth and used for transmitting torque transmission and simultaneously enabling the mandrel to axially slide in the outer cylinder.

In one embodiment, the first through hole is partially disposed on the keyway within the outer barrel and the second through hole is partially disposed on the key tooth outside the mandrel.

In one embodiment, the valve disc mechanism includes a fixed valve disc and a movable valve disc, wherein the movable valve disc is configured to be driven in rotation by the drive shaft such that an area of flow between the fixed valve disc and the movable valve disc varies periodically.

In one embodiment, the oscillating mechanism comprises an inner sleeve fixedly connected with the fixed valve disc and an elastic piece arranged between the inner sleeve and the first component, and two ends of the elastic piece are respectively abutted with the fixed valve disc and the first component.

In one embodiment, the drilling fluid splitting unit comprises a connector disposed within the first assembly, a splitting member disposed within the connector, and a force transfer sleeve disposed within the first assembly, the turbine section being disposed within the force transfer sleeve, wherein the splitting member is configured to allow a portion of the drilling fluid to flow directly into a central passage within the drive shaft and another portion of the drilling fluid to flow through the turbine section into the central passage.

In one embodiment, the diverter is configured as a sleeve member having a plurality of slots in a circumferential wall thereof to allow a portion of the drilling fluid to flow into the turbine section, the diverter being secured to an upstream end of the drive shaft and a nozzle being mounted within the drive shaft adjacent the diverter.

In one embodiment, an adjustment ring is provided downstream of the turbine section, and a through slot is provided in the drive shaft in the region corresponding to the adjustment ring for guiding drilling fluid flowing through the turbine section to the central passage.

In one embodiment, two ends of the force transmission sleeve are fixedly connected with the connector and the fixed valve disc respectively, wherein the turbine section is configured to drive the transmission shaft to rotate under the action of drilling fluid.

The hydraulic oscillator comprises an oscillating mechanism, and the oscillating mechanism can enable a drilling tool to vibrate in the axial direction, so that static friction force is converted into dynamic friction force, friction between the drilling tool and a well wall in the horizontal drilling process is reduced, and efficient rock breaking of a drill bit is achieved. In addition, when the overflow area between the movable valve disc and the static valve disc is maximum and the pressure consumption is minimum, the first through hole and the second through hole are aligned through the axial displacement of the mandrel, so that the pressure consumption at the moment is further reduced. The highest pressure consumption value of the hydraulic oscillator is unchanged, and the lowest pressure consumption value is reduced, so that the integral pressure fluctuation of the hydraulic oscillator is maximum, the amplitude of the generated axial impact force is larger, and the reduction of the pressure is facilitated.

Drawings

The present invention will be described below with reference to the accompanying drawings.

Fig. 1 schematically shows the structure of an axially displaced hydraulic oscillator according to the present invention at an upstream portion.

Fig. 2 schematically shows the structure of the axially displaced hydraulic oscillator according to the present invention at the downstream portion.

Fig. 3 schematically shows the structure of an axially displaced hydraulic oscillator according to the present invention at an upstream portion.

Fig. 4 schematically shows the structure of the axially displaced hydraulic oscillator according to the present invention at the downstream portion.

Fig. 5 schematically shows the internal structure of the outer tub in the axial displacement type hydraulic oscillator according to the present invention;

fig. 6 schematically shows the internal structure of a spindle in an axial displacement type hydraulic oscillator according to the present invention.

In this application, all of the figures are schematic drawings which are intended to illustrate the principles of the invention and are not to scale.

In addition, throughout the drawings, the same reference numerals are used to designate the same components or structures.

Detailed Description

The invention is described below with reference to the accompanying drawings. For ease of understanding, in this application, the end near the wellhead is defined as the upper end, upstream end, or similar term, and the end far from the wellhead is defined as the lower end, downstream end, or similar term; meanwhile, a longitudinal direction along the length of the hydraulic oscillator is referred to as a longitudinal direction, an axial direction, or the like, and a direction perpendicular thereto is referred to as a lateral direction, a radial direction, or the like.

Fig. 1 to 4 collectively show the structure of an axial displacement type hydraulic oscillator 100 according to the present invention. It will be readily appreciated that the axially displaced hydraulic oscillator 100 is divided into two parts, shown in figures 1 to 2 and figures 3 to 4, respectively, merely for reasons of the size of the figures. The division of the hydro oscillator 100 according to the invention between fig. 1 to 2 and fig. 3 to 4 is merely exemplary and does not limit the scope of the invention in any way.

As shown in fig. 1 to 4, the hydraulic oscillator 100 includes a first member 2 configured in a cylindrical shape, which is radially outside the hydraulic oscillator 100. The first component 2 is configured as a hollow cylinder and is provided with at least one first through-hole 601 extending in radial direction. The first assembly 2 remains stationary during operation of the hydro-oscillator 100 and does not undergo axial movement or rotation.

The first assembly 2 includes a cylinder tube 10, a center joint 50, and an outer tube 60 disposed in this order from an upstream end to a downstream end in the axial direction of the hydraulic oscillator 100. The upstream end of the cylinder 10 is provided with a conical connector for connection with an upper drill (not shown). The cylinder 10 and the center joint 50 and the outer cylinder 60 can be fixedly connected to each other by a taper joint. Fig. 5 schematically shows the internal structure of the outer cylinder 60 in the axial displacement type hydraulic oscillator 100 according to the present invention. As shown in fig. 5, a first through hole 601 is provided on the outer circumference of the outer cylinder 60. The outer barrel 60 is configured as a hollow sleeve with at least one circumferentially extending keyway 602 provided in an inner wall thereof.

As shown in fig. 1 and 3, a transmission shaft 12 is provided in the inner cavity of the cylinder tube 10, and the transmission shaft 12 is arranged concentrically with the cylinder tube 10. A central passage 11 for the over-flow drilling fluid is provided in the drive shaft 12, and the central passage 11 extends all the way downstream in the axial direction, constituting a central passage for the over-flow drilling fluid of the entire hydraulic oscillator 100. A drilling fluid diverting unit 20 is provided between the cylinder 10 and the drive shaft 12. The drilling fluid diverting unit 20 comprises a joint 15 sealingly mounted on the inner wall of the cylinder 10 by means of a first sealing ring 19. The connection head 15 is configured as a hollow cylinder, and an upstream end thereof is butted against a step formed on the inner surface of the cylinder tube 10. A shunt 13 is mounted in the joint 15. A gap is formed between the upstream end of the flow divider 13 and a step formed on the inner surface of the joint 15 to avoid affecting the rotation of a turbine section 28 (described in detail below) mounted downstream, while the downstream end is butted against the upstream end of the drive shaft 12. A first gap 5 is formed between the radially outer surface of the shunt 13 and the radially inner surface of the connector 15. The first gap 5 is part of the annular space between the drive shaft 12 and the cylinder 10.

According to the illustrated embodiment of the invention, the flow divider 13 is configured as a sleeve member, on the circumferential wall of which a number of slits 6 are provided, which are evenly distributed at intervals along the circumference of the sleeve member. A nozzle 14 is also mounted at the upstream end of the drive shaft 12 adjacent the splitter 13. Thus, when drilling fluid from the upper drilling tool passes through the flow divider 13, a portion of the drilling fluid (hereinafter referred to as first drilling fluid) flows directly through the nozzle 14 into the central passage 11 of the drive shaft 12, and another portion of the drilling fluid (hereinafter referred to as second drilling fluid) enters the first gap 5 through the gap 6 in the sidewall of the flow divider 13, thereby effecting flow division of the drilling fluid. The flow of the second drilling fluid will be described in detail below.

To ensure tightness between the nozzle 14 and the drive shaft 12, in one embodiment, a sealing groove is provided on the inner surface of the drive shaft 12 in contact with the nozzle 14, in which groove an O-ring is mounted, thereby achieving a seal between the nozzle 14 and the drive shaft 12. The nozzle 14 may be made of erosion resistant material. In a preferred embodiment, the nozzle 14 is made of cemented carbide. Thus, not only can the sealing performance between the nozzle 14 and the transmission shaft 12 be effectively ensured, but also the nozzle 14 can be ensured to have certain hardness, so that the nozzle 14 is ensured not to be eroded but the inner diameter size of the nozzle is ensured to be unchanged, and the diversion proportion of drilling fluid is ensured to be unchanged. In addition, nozzles having different inside diameter sizes may be installed according to the requirements of use in the field. In this way, the ratio of the diversion of drilling fluid can be more easily and effectively adjusted, thereby changing the frequency of the change in the area of the flow passing between the movable valve disc 35 and the fixed valve disc 35, and thus changing the vibration frequency of the hydraulic oscillator 100.

According to the invention, the drilling fluid distribution unit 20 further comprises a force transfer sleeve 25 mounted on the inner wall of the cylinder 10. As shown in fig. 1 and 3, the force transmission sleeve 25 is configured in a cylindrical shape. The upstream end of the force transmission sleeve 25 is fixedly connected with the connector 15. In one embodiment, threads are provided on the inside surface of both ends of the force transfer sleeve 25, and the upstream end of the force transfer sleeve 25 is screwed to the connection head 15 and further secured by the first set screw 21. In this way, stability between the force transmission sleeve 25 and the connection head 15 can be effectively ensured. The downstream end of the force transfer sleeve 25 is connected to a valve disc mechanism 30, which will be described in more detail below.

As shown in fig. 1 and 3, a plurality of turbine sections 28 are provided at the lower end of the connection head 15. According to the invention, all turbine sections 28 are mounted on the drive shaft 12 and are inside the force transmission sleeve 25. Each turbine section 28 comprises a stator and a rotor, wherein the stator is in close contact with the inner wall of the force transfer sleeve 25 and the rotor is mounted to the drive shaft 12. The rotor is configured to rotate under the influence of a drilling fluid (i.e., a second drilling fluid) to rotate the drive shaft 12 by friction between the rotor and the drive shaft 12. Rolling bearings 22 may be mounted at both the upper and lower ends of the plurality of turbine sections 28 for radial support and righting. The upper end surfaces of the rolling bearings mounted on the upper ends of the turbine sections 28 can abut against the lower end surfaces of the connectors 15 to achieve positioning in the axial direction. The turbine sections 28 are pressed tightly by the rolling bearings 22 at both ends, and the axial position of the turbine sections 28 is adjusted by the adjusting ring 27. In this embodiment, the length of the adjustment ring 27 can be adjusted by the actual fit size to avoid machining errors. Thus, when the second drilling fluid flowing into the annular space between the transmission shaft 12 and the cylinder tube 10 from the splitter 13 flows through the turbine joint 28, the rotor is rotated, and the transmission shaft 12 is rotated by the friction between the turbine joint 28 and the transmission shaft 12, thereby achieving the rotation of the transmission shaft 12.

According to the invention, a through-channel 29 is provided in the region of the drive shaft 12 corresponding to the adjusting ring 27 for guiding the second drilling fluid flowing through the turbine section 28 into the central channel 11 of the drive shaft 12. In this way, during operation, the diverted second drilling fluid can continually flow through the turbine section 28, thereby ensuring continued rotation of the turbine section 28. The length and width of the through slots 29 may be calculated based on the displacement of drilling fluid, tool parameters, etc. The angle of the through slots 29 is generally 30-60 degrees, preferably 45 degrees, according to the present invention.

According to the present invention, the drilling fluid distribution unit further comprises a valve disc mechanism 30. As shown in fig. 2, valve disc mechanism 30 includes a fixed valve disc 32 mounted within cylinder 10. The valve plate 32 is located downstream of the force transmission sleeve 25, fixedly connected to the force transmission sleeve 25, and remains stationary during operation of the hydraulic oscillator 100. In one embodiment, the valve plate 32 is connected to the force transfer sleeve 25 by threads and a second set screw 37 is provided between the valve plate 32 and the force transfer sleeve 25 for further fixation. In order to ensure tightness between the valve disc 32 and the force transmission sleeve 25, in one embodiment a sealing groove is provided on the outer surface of the valve disc 32, in which groove a glair 38 is mounted for sealing. An anti-wear sleeve 36 may also be mounted on the inside of the fixed valve disc 32, wherein the inner surface of the fixed valve disc 32 is mounted with an interference fit to the anti-wear sleeve 36.

In the present embodiment, a movable valve disc 35 is mounted on the upstream end of the fixed valve disc 32, for example, via a bearing 33. The movable valve disc 35 is fixedly connected with the turbine seat 31, and the turbine seat 31 is fixedly connected with the transmission shaft 12, so that the movable valve disc 35 forms a fixed connection with the transmission shaft 12. In one embodiment, the movable valve disc 35 is fixedly coupled to the turbine housing 31 by threads.

According to the present invention, since the fixed valve disc 32 is fixed against rotation and the movable valve disc 35 is rotated by the drive shaft 12, and the hole in the fixed valve disc 32 and the hole in the movable valve disc 35 are in eccentric relation, the flow area of the valve disc mechanism 30 periodically changes as the movable valve disc 35 rotates. This results in a pressure above the dynamic valve disc 35 that acts to create a periodically varying pressure at the connection head 15. The force is variable at a high frequency, the frequency of which depends on the frequency of rotation of the turbine section 28, and the magnitude of which depends on the magnitude of the change in the area of the flow between the dynamic valve disc 35 and the static valve disc 32. The effect of this force will be described below.

The structure and function of the turbine section 28 and the valve disk mechanism 30 are well known in the art, and a detailed description of the structure thereof is omitted herein.

The hydraulic oscillator 100 according to the present invention further includes an oscillating mechanism 40. As shown in fig. 2, the oscillating mechanism 40 is disposed between the valve disc mechanism 30 and the center joint 50 in the axial direction. The oscillating mechanism 40 includes a tubular inner sleeve 44 having an upstream end fixedly attached to the inner surface of the stationary valve disc 32 and a downstream end fixedly attached to an inner sleeve outer ring 47 (see fig. 2 or 4, which will be described later). A second gap 46 is defined axially between the downstream end face of the fixed valve disc 32 of the valve disc mechanism 30 and the upstream end face of the center joint 50 and radially between the inner sleeve 44 and the cylinder tube 10. The oscillating mechanism 40 further includes an elastic member disposed in the second gap 46 and having both ends connected to the downstream end face of the fixed valve disc 32 and the upstream end face of the center joint 50, respectively. Preferably, the elastic member is formed by a plurality of sets of disc springs 45 connected in series. In addition, gaskets 42 are respectively disposed at two ends of the disc spring 45 for adjusting the initial pre-tightening force of the disc spring 45.

Fig. 3 shows the structure of a portion of the axially displaced hydraulic oscillator 100 according to the present invention downstream. As shown in fig. 3, an inner sleeve outer ring 47 is provided in the inner cavity of the middle joint 50, wherein a sealing ring is provided between the inner surface of the middle joint 50 and the outer surface of the inner sleeve outer ring 47 to form a sealed connection. An upstream portion of the inner surface of the inner housing outer ring 47 is fixedly attached to a downstream portion of the outer surface of the inner housing 44, such as by a threaded connection. On the other hand, a mandrel 70 is also provided downstream of the inner sleeve 44.

Fig. 6 schematically shows the internal structure of the mandrel 70 in the axially displaced hydraulic oscillator 100 according to the present invention. As shown in fig. 6, the mandrel 70 is configured as a hollow cylinder and is provided with at least one radially extending second through hole 701. According to the present invention, during operation, the second through hole 701 can be periodically aligned with the first through hole 601, thereby periodically communicating the inside with the outside of the hydraulic oscillator 100. At least one key tooth 702 extending along the circumferential direction is arranged on the outer wall of the mandrel 70, and the key tooth 702 is matched with the key groove 602 on the outer barrel 60. In addition, the keyways 602 and the teeth 702 are capable of transmitting torque within the hydroscillator 100. Specifically, the torque of the upper drilling tool is transmitted to the outer barrel 60 through the outer shell 10 and the middle joint 50, and the key groove 602 on the outer barrel 60 and the key tooth 702 on the mandrel 70 can enable the torque to be transmitted from the outer barrel 60 to the mandrel 70, and further transmitted to the lower drilling tool of the tool, so that normal drilling is realized; while the keyway 602 and the key teeth 702 allow the mandrel 70 to slide axially within the outer barrel 60. In addition, the second through hole 701 is partially provided on the key tooth 702. The engagement between the key teeth 702 and the key grooves 602 effectively prevents the spindle 70 from rotating inside the outer tube 60.

It should be noted that the term "periodically aligned" or "periodically connected" does not mean that there is a fixed period, but alternate "aligned" and "not aligned" and alternate "connected" and "not connected", but the interval between the two states is not fixed.

An upstream portion of the outer surface of the mandrel 70 is fixedly attached to a downstream portion of the inner surface of the inner sleeve outer ring 47, such as by a threaded connection. In addition, in the illustrated embodiment, a third set screw 52 is provided to secure the mandrel 70 and the inner and outer sleeve 47 together.

The mandrel 70 is disposed within the interior cavity of the outer barrel 60 and extends in a downstream direction from the outer barrel 60. The downstream end of the mandrel 70 is configured as an internally threaded button for connection to a lower drilling tool, such as a drill pipe, a weighted drill pipe, or a drill collar. A second seal 62 may be provided between the spindle 70 and the outer barrel 60 for forming a sealed connection.

The axially displaced hydraulic oscillator 100 according to the present invention is mounted on a drill string with both ends connected to an upper tool and a lower tool, respectively. During normal sliding drilling, the drilling fluid flows through the central passage 11 of the fluidic oscillator 100. The drilling fluid, when flowing through the flow divider 13, creates a flow divider in which a portion of the drilling fluid (i.e., the first drilling fluid) continues to flow along the central passage 11 of the hydraulic oscillator 100, downstream through the nozzle 14. Another portion of the drilling fluid, i.e. the second drilling fluid, passes through the gap 6 of the shunt member 13 into the first gap 5 and further through the rolling bearing 22 and the turbine section 28. When flowing through the turbine section 28, the second drilling fluid drives the turbine rotor to rotate, thereby driving the transmission shaft 12 to rotate, and further driving the turbine seat 31 and the movable valve disc 35 of the valve disc mechanism 30 to rotate. Since the fixed valve disk 32 of the valve disk mechanism 30 remains non-rotating and the aperture in the fixed valve disk 32 is in eccentric relation to the aperture in the moving valve disk 35, the flow area of the valve disk mechanism 30 varies periodically as the moving valve disk 35 rotates. This results in a pressure above the dynamic valve disc 35 that acts to create a periodically varying pressure at the connection head 15. The force is variable at a high frequency, the frequency of which depends on the frequency of rotation of the turbine section 28, and the magnitude of which depends on the magnitude of the change in the area of the flow between the dynamic valve disc 35 and the static valve disc 32.

As described above, the joint head 15, the force-transmitting sleeve 25, the valve disc 32, the inner sleeve 44 and the inner sleeve outer ring 47 and the spindle 70 are fixedly connected to each other. In this case, therefore, the high frequency varying force is transmitted to the mandrel 70 via the connection head 15, the force transmission sleeve 25, the valve disc 32, the inner sleeve 44 and the inner sleeve outer ring 47, and further to the lower drill, so that normal drilling is achieved. This force causes the mandrel 70 to move axially relative to the first component 2, thereby radially aligning the first through bore 601 with the second through bore 701. In this way, the inside of the hydro-oscillator 100 is communicated with the outside, thereby reducing the pressure consumption of the hydro-oscillator 100.

According to the present invention, as shown in fig. 1 and 2, when the movable valve disc 35 rotates by a certain angle, the flow area between the movable valve disc 35 and the static valve disc 32 is maximum, the pressure loss generated by the hydraulic oscillator 100 is minimum, the axial impact force generated by the hydraulic oscillator 100 is minimum, and the first through hole 601 and the second through hole 701 are aligned in the radial direction. In addition, when the first through hole 601 and the second through hole 701 are aligned in the radial direction, since the drilling fluid flows from the inside to the outside of the hydro oscillator 100 through the first through hole 601 and the second through hole 701 in order, the minimum pressure loss of the hydro oscillator 100 as a whole is reduced.

According to the present invention, as shown in fig. 3 and 4, when the movable valve disc 35 rotates by a certain angle, the flow area between the movable valve disc 35 and the static valve disc 32 is minimum, the pressure loss generated by the hydraulic oscillator 100 is maximum, the axial impact force generated by the hydraulic oscillator 100 is maximum, the mandrel 70 moves downward under the action of the axial impact force, and at this time, the first through holes 601 and the second through holes 701 are distributed in a staggered manner in the radial direction.

By the above way, the highest pressure consumption value of the hydraulic oscillator 100 is unchanged, but the lowest pressure consumption value is reduced, so that the whole pressure of the hydraulic oscillator 100 has a larger fluctuation range, the amplitude of the axial impact force generated by the hydraulic oscillator 100 is larger, and the reduction of the backing pressure is more facilitated.

As described above, the force is periodically variable. Thus, when it is at the peak, the force is transmitted downstream against the inherent elastic force of the disc spring 45 of the oscillating mechanism 40, while causing the disc spring 45 to store energy. When the force is in the trough, the energy stored in the disc spring 45 is released, resulting in an axially upward displacement of the spindle 70 relative to the outer barrel 60. This achieves a reciprocating movement of the mandrel 70 in the axial direction. Since the mandrel 70 is fixedly connected to the lower tool (e.g., a weighted drill rod), it is achieved that the entire tool vibrates reciprocally in the axial direction (i.e., the drilling direction). Therefore, the static friction force of the whole drilling tool in the axial direction during sliding drilling is converted into dynamic friction force, so that friction between the drilling tool and a well wall in the sliding drilling process is reduced, and efficient rock breaking of the drilling bit is realized.

In addition, when the drill bit is axially impacted during the breaking process, the resulting axial impact force is transferred to the mandrel 70 via the lower drill (e.g., the weighted drill pipe). Thus, as described above, the axial impact force is transmitted to the coupling head 15 via the inner sleeve outer ring 47, the inner sleeve 44, the valve disc 32 and the force transmitting sleeve 25, thereby providing an additional amount of variation in the high frequency varying force developed at the coupling head 15, which is advantageous in enhancing the dynamic friction conditions developed. At the same time, the upward transmission of the axial impact force does not pass through the disc spring 45 of the oscillating mechanism 40, and thus the disc spring 45 does not absorb the axial impact force. Therefore, the efficiency of the axial impact force is maximally utilized. At the same time, the normal operation and working life of the disc spring 45 are not affected.

As shown in fig. 2 and 4, according to a preferred embodiment of the present invention, a balance hole 43 is provided in an inner sleeve 44, which communicates with the central passage 11 of the hydraulic oscillator 100 and the second gap 46 for mounting the disc spring 45. In this way, drilling fluid is free to pass in and out between the central passage 11 and the second gap 46. In addition, the volume of the second gap 46 is periodically changed during the compression and release of the disc spring 45, and the drilling fluid flows in and out through the balance hole 43 to adapt to the above-mentioned periodic change, so that the operation of the disc spring 45 is not affected.

In addition, according to the present invention, the number of turbine sections 28, the inner diameter of the nozzle 14, the size of the slit 6 on the flow divider 13, the sizes of the movable valve disc 35 and the fixed valve disc 32, the number and combination of the disc springs 45, etc. in the hydraulic oscillator 100 can be adjusted according to actual requirements, thereby realizing parameterized customization. Thus, design effort is greatly simplified.

According to the present invention, a first through hole 601 and a second through hole 701 are provided on the outer cylinder 60 and the mandrel 70, respectively. During operation, the first through hole 601 and the second through hole 701 can be periodically aligned in the radial direction according to the reciprocation of the mandrel 70 and the outer cylinder 60, thereby reducing the pressure consumption of the hydraulic oscillator 100 and the load of the ground equipment. The highest pressure consumption value of the hydraulic oscillator 100 is unchanged, and the lowest pressure consumption value is reduced, so that the integral pressure fluctuation of the hydraulic oscillator 100 is maximum, the amplitude of the axial impact force generated by the hydraulic oscillator 100 is larger, and the reduction of the backing pressure is facilitated.

In the embodiment shown in fig. 5 and 6, the first through hole 601 is partially disposed on the keyway 602 of the outer cylinder 60, and the second through hole 701 is partially disposed on the keyway 702 of the mandrel 70.

Although the individual components of the axially displaced hydraulic oscillator according to the present invention are described in detail above, it should be understood that not all components are necessary. Conversely, some of the components may be omitted as long as the corresponding functional implementation of the hydraulic oscillator according to the present invention is not affected.

Finally, it should be noted that the above description is only of a preferred embodiment of the invention and is not to be construed as limiting the invention in any way. Although the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the techniques described in the foregoing examples, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An axially displaced hydraulic oscillator (100), comprising:

a first assembly (2) for connection with an upper drilling tool, the first assembly (2) being configured as a hollow cylinder and being provided with at least one first through hole (601) extending in a radial direction;

a second assembly (1) disposed within the first assembly (2), the second assembly (1) comprising a hollow drive shaft (12) concentrically disposed within the first assembly (2), a valve disc mechanism (30) disposed on the drive shaft (12), and a drilling fluid flow splitting unit (20) formed between the first assembly (2) and the drive shaft (12), wherein the drilling fluid flow splitting unit (20) is configured to allow a portion of drilling fluid to flow directly into a central passage (11) within the drive shaft (12) while another portion of drilling fluid flows into the central passage (11) via a turbine section (28) disposed on the drive shaft (12);

an oscillating mechanism (40) arranged downstream of the second assembly (1); and

a mandrel (70) for connection to a lower drilling tool, one end of the mandrel (70) being fixedly connected to the oscillating mechanism (40) and the other end extending beyond the first component (2), the mandrel (70) being configured as a hollow cylinder and being provided with at least one radially extending second through-going hole (701),

wherein the second assembly (1) is configured to enable a varying pressure within the central passage (11) and to act on the oscillating mechanism (40) to urge the spindle (70) to reciprocate axially relative to the first assembly (2), causing the first through hole (601) to be periodically aligned with the second through hole (701) to thereby periodically communicate the interior with the exterior of the hydraulic oscillator (100).

2. The axially displaced hydraulic oscillator according to claim 1, wherein the first assembly (2) includes a cylinder tube (10), a center joint (50) and an outer tube (60) which are disposed and fixed together in this order from an upstream end to a downstream end in an axial direction, wherein the first through hole (601) is provided on an outer periphery of the outer tube (60).

3. The axially displaced hydraulic oscillator according to claim 2, wherein the outer cylinder (60) is configured as a hollow sleeve, at least one axially extending key groove (602) is provided on an inner wall thereof, at least one axially extending key tooth (702) is provided on an outer wall of the spindle (70), and the key groove (602) is adapted to the key tooth (702) for transmitting torque transmission while the spindle (70) slides axially within the outer cylinder (60).

4. An axially displaced hydraulic oscillator as claimed in claim 3, characterized in that the first through hole (601) is provided partly on the keyway (602) inside the outer cylinder (60), and the second through hole (701) is provided partly on the key teeth (702) outside the spindle (70).

5. The axially displaced hydraulic oscillator of claim 4, wherein the valve disc mechanism (30) comprises a fixed valve disc (32) and a movable valve disc (35), wherein the movable valve disc (35) is configured to be driven in rotation by the drive shaft (12) such that an area of flow passing between the fixed valve disc (32) and the movable valve disc (35) varies periodically.

6. The axially displaced hydraulic oscillator according to claim 5, wherein the oscillating mechanism (40) comprises an inner sleeve (44) fixedly connected with the valve-fixing disc (32), and an elastic member arranged between the inner sleeve (44) and the first component (2), and both ends of the elastic member are respectively abutted against the valve-fixing disc (32) and the first component (2).

7. The axially displaced hydraulic oscillator according to claim 6, characterized in that the drilling fluid distribution unit (20) comprises a connection head (15) arranged in the first component (2), a distribution piece (13) arranged inside the connection head (15), and a force transmission sleeve (25) sleeved in the first component (2), the turbine section (28) being arranged in the force transmission sleeve (25),

wherein the diverter (13) is configured to allow a portion of drilling fluid to flow directly into a central passage (11) within the drive shaft (12) and another portion of drilling fluid to flow into the central passage (11) via the turbine section (28).

8. An axially displaced hydraulic oscillator as claimed in claim 7, characterized in that said flow divider (13) is configured as a sleeve member, on the circumferential wall of which slits (6) are provided, allowing a portion of the drilling fluid to flow into said turbine section (28),

the splitter (13) is fixed to an upstream end of the drive shaft (12) and a nozzle (14) is mounted within the drive shaft (12) adjacent the splitter (13).

9. The axially displaced hydraulic oscillator according to claim 8, characterized in that an adjusting ring (27) is provided downstream of the turbine section (28), and that a through-slot (29) is provided in the region of the drive shaft (12) corresponding to the adjusting ring (27) for guiding drilling fluid flowing through the turbine section (28) to the central channel (11).

10. The axially displaced hydraulic oscillator according to claim 9, characterized in that both ends of the force transmission sleeve (25) are fixedly connected with the connector (15) and the valve fixing disc (32) respectively,

wherein the turbine section (28) is configured to rotate the drive shaft (12) under the influence of drilling fluid.