A multi-directional oscillating impact screw drilling tool

Abstract

The present invention relates to the field of oil and gas drilling equipment, and in particular to a multi-directional oscillating impact screw drill, comprising a bypass valve assembly, a torsional oscillation assembly, a motor assembly, a transmission shaft assembly and an axial oscillation assembly which are sequentially connected from top to bottom, wherein the bypass valve assembly is used to open or block the drilling fluid from entering the torsional oscillation assembly; the torsional oscillation assembly is used to periodically change the flow of the drilling fluid entering the motor assembly; the motor assembly is used to convert the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around its central axis; the transmission shaft assembly is used to drive the axial oscillation assembly to rotate axially, and the bottom end of the axial oscillation assembly is connected to a drill bit to convert the fluid energy of the drilling fluid into an axial impact force on the drill bit. The beneficial effects of the present invention are: it can simultaneously generate a large rotary cutting torque, axial oscillation impact and torsional oscillation load, assist in rock breaking, and alleviate the "support pressure" phenomenon of the drill string.

Description

Technical Field

[0001] The invention relates to the field of oil and natural gas drilling equipment, and in particular to a multi-directional oscillating impact screw drilling tool. Background Art

[0002] With the development of exploration and development towards deep and unconventional areas, the widespread distribution of hard formations and the increase in the length of horizontal sections have caused a significant reduction in the mechanical drilling speed of conventional drilling, which has seriously restricted the development progress of oil and gas resources. The slow mechanical drilling speed is a comprehensive problem, which includes many factors. In the final analysis, the rock breaking energy transmitted to the drill bit is insufficient. In the process of horizontal well drilling, rock breaking is mainly carried out through the rotation of the drill bit. The drilling pressure is the pressure acting on the drill bit. It is an important parameter to ensure the depth of the drill bit into the rock. In order to ensure the drilling efficiency, sufficient drilling pressure needs to be transmitted to the drill bit. The drilling pressure is transmitted through the drill string. During the horizontal section drilling process, part of the drill string directly contacts the well wall under the action of gravity. In the process of applying the ground drilling pressure downward, a large part is absorbed by the friction resistance between the drill string and the well wall, thereby greatly reducing the axial pressure transmitted to the drill bit, which is the so-called "support pressure" phenomenon. An important reason for the "support and pressure" phenomenon of the drill string is that the downward movement speed of the drill string is relatively low, which makes the relative movement speed between the drill string and the well wall low. In some positions, it can be considered quasi-static. In order to solve the "support and pressure" problem, it is necessary to break the quasi-static state between the drill string and the well wall. At the same time, in the process of horizontal well drilling, due to the need for wellbore trajectory control, downhole power drilling tools are an essential tool. When drilling into hard formations, the efficiency of conventional rotary rock breaking is limited. Impact rock breaking is a speed-up method for hard formations, but directly using impact rock breaking in conjunction with downhole power drilling tools will affect the service life of downhole power drilling tools.

[0003] The rock breaking efficiency and mechanical drilling speed in hard formations are low, which often causes stick-slip vibration of PDC drill bits, causing the cutting teeth of PDC drill bits to break and fail prematurely, affecting the drilling speed. The lengthening of the horizontal section will make the wellbore cleaning worse, and the friction resistance between the drill tool and the well wall is large, so that the drilling pressure cannot be transmitted to the drill bit, which is the so-called "support pressure" phenomenon, resulting in frequent tripping and drilling, which seriously affects the drilling time.

[0004] At present, "downhole power drilling tools + PDC drill bits" have become the standard configuration for speeding up drilling sites, and have achieved good application results to a certain extent. The commonly used downhole power drilling tools on site mainly include screw drilling tools, turbine drilling tools, hydraulic oscillators and impact drilling speed-up tools. However, in the case of more complex drilling conditions brought about by hard formations and long horizontal sections, the shortcomings of existing power drilling tools are gradually emerging. For example, the mechanical drilling speed of screw drilling tools in hard formations is low, and the friction resistance near the drill bit cannot be reduced; the speed of the turbine drilling tool is too high, the output torque is small, and it can only use the "grinding" rock breaking method with the impregnated drill bit, which is relatively inefficient; the hydraulic oscillator can only vibrate the drill string at the upper end of the tool; it cannot achieve vibration near the drill bit, thereby failing to reduce the friction resistance near the drill bit; the torsional impact drilling tool cannot be used in conjunction with other speed-up tools, and the cutting depth is insufficient when drilling in hard formations with the PDC drill bit, etc. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a multi-directional oscillating impact screw drill, which can provide a constant cutting torque and rotation speed for direct rock breaking in the well, reduce the friction near the drill bit, and provide high-frequency and low-amplitude oscillating impact.

[0006] The technical solution of the present invention for solving the above technical problems is as follows: a multi-directional oscillating impact screw drilling tool, comprising a bypass valve assembly, a torsional oscillation assembly, a motor assembly, a transmission shaft assembly and an axial oscillation assembly, wherein the bottom end of the bypass valve assembly is connected to the top end of the torsional oscillation assembly for opening or blocking the drilling fluid from entering the torsional oscillation assembly; the bottom end of the torsional oscillation assembly is connected to the top end of the motor assembly for periodically changing the flow rate of the drilling fluid entering the motor assembly, thereby periodically changing the rotation speed of the motor assembly so that the motor assembly generates torsional oscillations; the bottom end of the motor assembly is connected to the top end of the transmission shaft assembly for converting the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around its central axis; the bottom end of the transmission shaft assembly is connected to the top end of the axial oscillation assembly for driving the axial oscillation assembly to rotate axially, and the bottom end of the axial oscillation assembly is connected to the drill bit for converting the fluid energy of the drilling fluid into an axial impact force on the drill bit.

[0007] The beneficial effects of the present invention are: combined with multi-directional oscillation, it can simultaneously generate large rotary cutting torque, axial oscillation impact and torsional oscillation load, assist in rock breaking, and reduce friction resistance in the horizontal well drilling process while ensuring rock breaking efficiency, effectively suppress stick-slip vibration of PDC drill bits, and alleviate the "support pressure" phenomenon of the drill string. The tool can effectively deal with the drilling technical problems brought by hard formations and long horizontal sections, improve drilling efficiency, increase single-trip footage, and shorten drilling cycles.

[0008] Based on the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, the bypass valve assembly includes a bypass valve body, a valve core, a sieve plate and a valve sleeve. The bottom end of the bypass valve body is sealed and fixedly connected to the top end of the torsional oscillation assembly. The valve sleeve is fixedly arranged at the bottom of the bypass valve body. The valve core is seal-slidably arranged in the bypass valve body and is located vertically above the valve sleeve. The valve core is provided with a valve core center hole that passes through the top and bottom ends of the valve core. The side wall of the bypass valve body is provided with a side through hole connected to the inner cavity of the bypass valve body. The valve core opens or closes the side through hole during the sliding process of the valve core in the bypass valve body, and the sieve plate is provided in the side through hole.

[0010] The beneficial effect of adopting the above further scheme is: when the flow and pressure of the drilling fluid exceed the starting pressure of the tool, the valve core is driven to close the side through hole, the bypass valve assembly is in a closed state, and the drilling fluid enters the torsional oscillation assembly and the motor assembly in sequence through the center hole of the valve core, starting the motor assembly.

[0011] Furthermore, the motor assembly includes a stator with conductive top and bottom ends and a rotor arranged in the stator, the top end of the stator is fixedly connected and communicated with the bottom end of the torsional oscillation assembly, and the bottom end of the stator is fixedly connected and communicated with the top end of the transmission shaft assembly; a hollow hole is provided inside the rotor, and the two ends of the hollow hole are respectively communicated with the bottom end of the torsional oscillation assembly and the top end of the transmission shaft assembly.

[0012] The beneficial effect of adopting the above further scheme is: a hollow hole is set inside the rotor, and while the drilling fluid passes through, the rotor drives the transmission shaft assembly to rotate axially, thereby converting the hydraulic power of the drilling fluid into mechanical energy that drives the transmission shaft assembly to rotate around its central axis.

[0013] Furthermore, the torsional oscillation assembly includes an anti-drop joint, an eccentric valve disc and an anti-drop connecting rod. The anti-drop joint is a structure with top and bottom ends connected, the top of the anti-drop joint is fixedly connected to the bottom end of the bypass valve assembly, the bottom end of the anti-drop joint is fixedly connected and connected to the top of the stator, the eccentric valve disc is fixedly arranged at the upper end of the anti-drop joint, the anti-drop connecting rod is a hollow structure with top and bottom ends connected, the bottom end of the anti-drop connecting rod is fixedly connected and connected to the top of the rotor, and the top of the anti-drop connecting rod is connected to the eccentric hole of the eccentric valve disc.

[0014] The beneficial effect of adopting the above further scheme is that the continuous rotation of the rotor will drive the anti-drop connecting rod to rotate continuously. Since the rotation of the rotor is a planetary rotation, that is, it rotates around its own rotation center and revolves around the center of the stator at the same time, the rotation characteristics of the rotor will drive the anti-drop connecting rod to rotate planetarily, so that the overlapping area of ​​the eccentric hole and the center hole of the anti-drop connecting rod changes periodically. The change of this part causes the flow of drilling fluid from the center hole of the anti-drop connecting rod and the center hole of the rotor to fluctuate periodically, and the speed of the rotor will fluctuate periodically, thereby generating certain torsional oscillations and transmitting them to the drill bit.

[0015] Furthermore, the torsional oscillation assembly also includes an anti-drop lock nut, which is coaxially arranged with the eccentric valve disc, and an internal thread is provided on the inner side of the anti-drop lock nut. The anti-drop connecting rod is arranged on the inner side of the anti-drop lock nut and is threadedly connected to the anti-drop lock nut.

[0016] The beneficial effect of adopting the above further solution is that the provision of the anti-drop lock nut can prevent the anti-drop connecting rod from being inserted into the space around the eccentric hole of the eccentric valve disc during rotation.

[0017] Furthermore, the transmission shaft assembly includes a universal joint housing, a ball universal joint and a first transmission shaft, the top end of the universal joint housing is fixedly connected and communicated with the bottom end of the motor assembly, and the bottom end of the universal joint housing is fixedly connected and communicated with the top end of the axial oscillation assembly; the first transmission shaft is arranged in the universal joint housing, and the top end of the first transmission shaft is transmission-connected to the bottom end of the rotor through the ball universal joint.

[0018] The beneficial effect of adopting the above further scheme is: the motor assembly and the first transmission shaft are connected through a ball-type universal joint, and the axial rotation of the first transmission shaft is driven by the motor assembly.

[0019] Furthermore, the transmission shaft assembly also includes a bearing housing and a thrust ball bearing group, the thrust ball bearing group is fixedly sleeved on the first transmission shaft, the bearing housing is sleeved on the thrust ball bearing group, the bearing housing is arranged between the universal joint housing and the axial oscillation assembly, the top end of the bearing housing is fixedly connected and communicated with the bottom end of the universal joint housing, and the bottom end of the bearing housing is fixedly connected and communicated with the top end of the axial oscillation assembly.

[0020] The beneficial effect of adopting the above further solution is that the arrangement of the bearing housing and the thrust ball bearing group can improve the stability of the first transmission shaft during rotation.

[0021] Furthermore, the transmission shaft assembly also includes a first centralizing bearing inner ring and a first centralizing bearing outer ring that are arranged in cooperation with each other, the first centralizing bearing inner ring is fixedly sleeved on the upper part of the first transmission shaft, the first centralizing bearing outer ring is sleeved outside the first centralizing bearing inner ring, and the lower end of the first centralizing bearing outer ring sleeve is fixedly connected to the inner wall of the upper end of the bearing outer shell sleeve.

[0022] The beneficial effect of adopting the above further solution is that the arrangement of the first straightening bearing inner ring and the first straightening bearing outer ring can further improve the stability of the rotation of the first rotating shaft.

[0023] Further, the axial oscillation assembly includes an axial oscillation pup joint outer shell, an isolation sleeve, a nozzle, a piston and an axial oscillation shaft, the top end of the axial oscillation pup joint outer shell is fixedly connected and communicated with the bottom end of the bearing shell, the top end of the axial oscillation shaft is circumferentially fixed to the bottom end of the first transmission shaft by a cylindrical spline, the axial oscillation shaft is provided with an axially through center hole, the axial oscillation shaft outer shell is provided with the isolation sleeve and the piston, the piston is arranged below the isolation sleeve, the outer wall of the isolation sleeve is fixedly connected to the inner wall of the axial oscillation pup joint outer shell, the lower part of the isolation sleeve is provided with circumferentially uniform isolation channels, a plurality of first high-pressure channels are provided on the middle side wall of the axial oscillation shaft, the first high-pressure channels correspond to the axial position of the isolation channels, and the part of the axial oscillation pup joint outer shell located at the isolation sleeve and the piston is provided with a through hole connected to the outside; a nozzle is fixedly provided in the axial oscillation shaft, and the nozzle is located below the first high-pressure channel.

[0024] The beneficial effect of adopting the above further scheme is that after the drilling fluid flows into the center hole of the axial oscillation shaft, it periodically drives the axial oscillation shaft to move up and down in the axial direction, and at the same time rotates axially under the drive of the motor assembly, thereby improving the rock breaking efficiency.

[0025] Furthermore, the lower end of the first transmission shaft extends into the upper part of the outer shell of the axial oscillation short section, and a second straightening bearing inner ring is sleeved on the lower end of the first transmission shaft, and a second straightening bearing outer ring is sleeved on the outer side of the second straightening bearing inner ring, and the second straightening bearing outer ring is fixedly connected to the upper inner wall of the outer shell of the axial oscillation short section.

[0026] The beneficial effect of adopting the above further solution is that the second inner ring of the centering bearing and the second outer ring of the centering bearing can further improve the stability of the rotation of the first transmission shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the multi-directional oscillating impact screw drilling tool of the present invention;

[0028] Figure 2It is a schematic diagram of the structure of the axial oscillation assembly of the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of the eccentric valve disc of the present invention;

[0030] Figure 4 It is a schematic diagram of the isolation sleeve structure of the present invention.

[0031] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0032] 1. Bypass valve assembly;

[0033] 11. Bypass valve body; 12. Valve core; 13. Screen plate; 14. Valve sleeve;

[0034] 2. Torsion oscillation assembly;

[0035] 21. Anti-drop joint; 22. Eccentric valve disc; 23. Anti-drop lock nut; 24. Anti-drop connecting rod;

[0036] 221, eccentric hole; 222, fixing rib; 223 fan-shaped channel;

[0037] 3. Motor assembly;

[0038] 31. stator; 32. rotor;

[0039] 4. Transmission shaft assembly;

[0040] 41. Cardan shaft housing; 42. Ball cardan shaft; 43. First transmission shaft; 44. First centering bearing inner ring; 45. First centering bearing outer ring; 46. Bearing housing; 47. Thrust ball bearing group; 48. Second centering bearing outer ring; 49. Second centering bearing inner ring;

[0041] 5. Axial oscillation assembly;

[0042] 51. axial oscillation short section outer shell; 52. spline; 53. isolation sleeve; 54. nozzle; 55. piston; 56. axial oscillation shaft; 57. lower joint;

[0043] 561, first high-pressure channel; 511, first low-pressure outlet; 512, piston cavity; 531, isolation channel. DETAILED DESCRIPTION

[0044] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0045] like Figure 1As shown, an embodiment of the present invention includes a bypass valve assembly 1, a torsional oscillation assembly 2, a motor assembly 3, a transmission shaft assembly 4 and an axial oscillation assembly 5, wherein the bottom end of the bypass valve assembly 1 is connected to the top end of the torsional oscillation assembly 2 for opening or blocking the drilling fluid from entering the torsional oscillation assembly 2; the bottom end of the torsional oscillation assembly 2 is connected to the top end of the motor assembly 3 for periodically changing the flow rate of the drilling fluid entering the motor assembly 3, thereby periodically changing the rotation speed of the motor assembly 3 so that the motor assembly 3 generates torsional oscillations; the bottom end of the motor assembly 3 is connected to the top end of the transmission shaft assembly 4 for converting the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly 4 to rotate around its central axis; the bottom end of the transmission shaft assembly 4 is connected to the top end of the axial oscillation assembly 5 for driving the axial oscillation assembly 5 to rotate axially, and the bottom end of the axial oscillation assembly 5 is connected to the drill bit for converting the fluid energy of the drilling fluid into an axial impact force on the drill bit.

[0046] In an embodiment of the present invention, the bypass valve assembly 1 includes a bypass valve body 11, a valve core 12, a sieve plate 13 and a valve sleeve 14. The bottom end of the bypass valve body 11 is sealed and fixedly connected to the top end of the torsional oscillation assembly 2. The valve sleeve 14 is fixedly arranged at the bottom of the bypass valve body 11. The valve core 12 is sealingly slidably arranged in the bypass valve body 11 and is located vertically above the valve sleeve 14. The valve core 12 is provided with a valve core 12 center hole that passes through the top and bottom ends of the valve core 12. The side wall of the bypass valve body 11 is provided with a side through hole that is connected to the inner cavity of the bypass valve body 11. The valve core 12 opens or closes the side through hole during the sliding process in the bypass valve body 11, and the sieve plate 13 is provided in the side through hole. When the flow and pressure of the drilling fluid exceed the starting pressure of the tool, the valve core 12 is driven to close the side through hole, the bypass valve assembly 1 is in a closed state, and the drilling fluid enters the torsional oscillation assembly 2 and the motor assembly 3 in sequence through the center hole of the valve core 12, and the motor assembly 3 is started.

[0047] In one embodiment of the present invention, the torsional oscillation assembly 2 includes an eccentric valve disc 22, an anti-drop lock nut 23, an anti-drop joint 21 and an anti-drop connecting rod 24. The eccentric valve disc 22 is fixedly installed inside the anti-drop joint 24 through external threads. An anti-drop lock nut 23 is coaxially arranged at the lower end of the eccentric valve disc 22; the anti-drop lock nut 23 is a stepped shaft with a hollow structure, a pentagonal prism is arranged on the outer side of the upper end, and threads are arranged inside; the anti-drop connecting rod 24 is a stepped shaft with a hollow structure, a through hole is arranged inside; the upper and lower sections of the anti-drop connecting rod 24 are respectively arranged with threads; the lower end of the anti-drop lock nut 23 is fixedly connected to the anti-drop connecting rod 24 through threads, and the lower end of the anti-drop connecting rod 24 is installed on the top of the screw rotor 32 through threads.

[0048] Preferably, Figure 3As shown, the eccentric valve disc 22 includes an outer ring and an inner disc arranged on the inner side of the outer ring. The outer ring is provided with threads on the outside, and the inside is fixedly connected to the inner disc by four circumferentially evenly distributed fixing ribs 222. A hollow eccentric hole 221 is provided at an eccentric position inside the inner disc. The four circumferentially evenly distributed fixing ribs 222 form four fan-shaped channels 223 between the outer ring and the inner disc.

[0049] like Figure 1 As shown, in the embodiment of the present invention, the motor assembly 3 includes a stator 31 with both ends connected, and a rotor 32 arranged in the stator 31. The top of the stator 31 is fixedly connected and communicated with the bottom of the anti-drop joint 21, and the bottom of the stator 31 is fixedly connected and communicated with the top of the universal shaft housing 41. A hollow hole is provided inside the rotor 32, and the two ends of the hollow hole are respectively communicated with the bottom end of the anti-drop connecting rod 24 and the top end of the first transmission shaft 43. The hollow hole is provided inside the rotor 32. When the drilling fluid passes through, the rotor 32 drives the transmission shaft assembly 4 to rotate axially, so as to realize the conversion of the hydraulic power of the drilling fluid into mechanical energy that drives the first transmission shaft 43 to rotate around its central axis.

[0050] like Figure 1 As shown, in a preferred embodiment of the present invention, the transmission shaft assembly 4 includes a universal joint housing 41, and a ball universal joint 42 which is arranged in the universal joint housing 41 and the upper end of which is fixedly connected to the rotor 32, and the top of the universal joint housing 41 is fixedly connected and communicated with the bottom end of the stator 31; a first transmission shaft 43 is arranged at the lower end of the ball universal joint 42, and the first transmission shaft 43 is a stepped shaft with a hollow structure; the outside of the first transmission shaft 43 is provided with a first centering bearing inner ring 44 and a first centering bearing outer ring 45 in sequence from the inside to the outside; the first centering bearing inner ring 44 is arranged on the outside of the upper end of the first transmission shaft 43 by interference fit; the first centering bearing outer ring 44 is fixedly mounted inside the bearing housing 46 by interference fit; the first transmission shaft 43 is coaxially mounted inside the bearing housing 46, the bottom end of the bearing housing 46 is fixedly connected and communicated with the top end of the axial oscillation short section outer shell 51, and the top end of the bearing housing 46 is fixedly connected and communicated with the bottom end of the universal joint housing 41; a thrust ball bearing group 47 is arranged inside the bearing housing 46; a second stabilizing bearing group is arranged at the lower end of the thrust ball bearing group 47, including a second stabilizing bearing inner ring 48 interference-fitted on the outside of the lower end of the first transmission shaft 43 and a second stabilizing bearing outer ring 49 assembled inside the axial oscillation short section outer shell 51 by interference fit.

[0051] Preferably, Figure 1 , Figure 2 , Figure 4As shown, an axial oscillation assembly 5 is provided at the lower end of the first transmission shaft 43; the axial oscillation short section 5 assembly includes an axial oscillation short section outer shell 51, and an axial oscillation shaft 56 which is arranged in the axial oscillation short section outer shell 51 and can move back and forth along the axial direction, the top end of the axial oscillation short section outer shell 51 is fixedly connected and communicated with the bottom end of the bearing shell 46; the upper end of the axial oscillation shaft 56 is circumferentially fixed to the first transmission shaft 43 by a cylindrical spline 52, and the axial oscillation shaft 56 can rotate coaxially with the first transmission shaft 43; the axial oscillation shaft 56 is provided with an axially through center hole; the axial oscillation short section outer shell 51 is provided outside the axial oscillation shaft 56; a fixedly connected isolation sleeve 53 is provided inside the axial oscillation short section outer shell 51, and the isolation sleeve 53 is a hollow stepped sleeve, the upper end of which is provided with an external thread, and the lower end of which is provided with circumferentially uniform isolation channels 531.

[0052] like Figure 1 , Figure 2 As shown, two circumferentially evenly distributed first high-pressure channels 561 are arranged on the middle side wall of the axial oscillation shaft 56; the first high-pressure channel 561 corresponds to the axial position of the isolation channel 531 of the isolation sleeve 53; a nozzle 54 is arranged at the lower end of the middle flow channel groove of the axial oscillation shaft 56; a piston 55 is fixedly arranged in the middle of the axial oscillation shaft 56 by interference fit, and the piston 55 can rotate coaxially with the above-mentioned axial oscillation shaft 56; a lower joint 57 is coaxially sleeved at the bottom of the axial oscillation short section outer shell 51, a piston cavity 512 is formed between the piston 55 and the isolation sleeve 53, and a first low-pressure outlet connected to the piston cavity 512 is arranged on the outer wall of the axial oscillation short section outer shell 51.

[0053] The working principle of the present invention is as follows: the drilling fluid flows to the torsional oscillation assembly 2 through the bypass valve assembly 1, at which time a portion of the drilling fluid continues to flow downward into the motor assembly 3 through the channel around the eccentric valve disc 22, driving the rotor 32 to rotate relative to the stator 31, and the rotation of the rotor 32 drives the ball universal joint 42 and the first transmission shaft 43 to rotate, and the first transmission shaft 43 drives the axial oscillation shaft 56 to rotate through the spline 52, and transmits the torque to the drill bit (prior art).

[0054] When the drilling fluid passes through the eccentric disc valve 22, most of the drilling fluid will flow downward from the fan-shaped channel 223 into the cavity between the stator 31 and the rotor 32, driving the rotor 32 to continuously rotate relative to the stator 31. When the drilling fluid passes through the eccentric disc valve 22, a portion of the drilling fluid will flow downward through the eccentric hole 221, through the center hole of the anti-drop lock nut 23, the center hole of the anti-drop connecting rod 24, the center hole of the rotor 32, and the side hole of the ball universal shaft 42, and merge with the drilling fluid passing between the rotor 32 and the stator 31. The continuous rotation of the rotor 32 will drive the anti-drop lock nut 23 and the anti-drop connecting rod 24 to continuously rotate, because the rotation of the rotor 32 is a planetary rotation, that is, it rotates around its own rotation center and can revolve around the center of the stator 31 at the same time. The rotation characteristics of the rotor 32 will drive the anti-drop lock nut 23 and the anti-drop connecting rod 24 to rotate in a planetary manner, so that the overlapping area of ​​the eccentric hole 221 and the center hole of the anti-drop lock nut 23 changes periodically. This partial change causes the flow of drilling fluid from the center hole of the anti-drop lock nut 23, the center hole of the anti-drop connecting rod 24, and the center hole of the rotor 32 to fluctuate periodically. Since the total inlet displacement of the tool is a certain value, that is, the sum of the flow through the eccentric hole 221 and the fan-shaped channel 223 is a constant value, when the flow through the eccentric hole 221 fluctuates, the flow through the fan-shaped channel 223, that is, the flow between the stator 31 and the rotor 32, fluctuates periodically. Since the rotation speed of the rotor 32 is proportional to the flow entering between the rotor 32 and the stator 31, that is, the greater the flow, the greater the rotation speed of the rotor 32. Therefore, the rotation speed of the rotor 32 will fluctuate periodically, thereby generating a certain torsional oscillation and transmitting it to the drill bit.

[0055] The drilling fluid passing through the motor assembly continues to flow downward, and passes through the central hole of the axial oscillation shaft 56 and the nozzle 54. There is a sudden decrease in cross-sectional area at the nozzle 54, where a certain pressure is generated, so that a part of the high-pressure drilling fluid flows into the piston cavity 512 through the first high-pressure channel 561 and the isolation channel 531, so that the pressure in the cavity 512 increases and drives the piston 55 to drive the axial oscillation shaft 56 to move downward. The axial oscillation shaft 56 continues to rotate under the drive of the rotor 32. When the isolation channel 531 is offset from the first high-pressure channel 561, the high-pressure fluid cannot enter the piston cavity 512. At this time, due to the effect of the drilling pressure, the axial oscillation shaft 56 will move upward. At this time, the fluid in the piston cavity 512 flows into the annulus through the first low-pressure outlet 511. When the axial oscillation shaft 56 moves to the uppermost position, it returns to the original position. The continuous rotation of the axial oscillation shaft 56 will continuously change the pressure in the piston cavity 512, generate a certain pressure fluctuation, and transmit it to the drill bit.

[0056] In the description of the present invention, it is necessary to understand that the terms "center", "length", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "inside", "outside", "peripheral", "circumferential" and the like 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, and do not indicate or imply that the referred system or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0057] In the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-directional oscillating impact screw drill, characterized in that: The invention comprises a bypass valve assembly (1), a torsional oscillation assembly (2), a motor assembly (3), a transmission shaft assembly (4) and an axial oscillation assembly (5), wherein the bottom end of the bypass valve assembly (1) is connected to the top end of the torsional oscillation assembly (2) for opening or blocking the drilling fluid from entering the torsional oscillation assembly (2); the bottom end of the torsional oscillation assembly (2) is connected to the top end of the motor assembly (3) for periodically changing the flow rate of the drilling fluid entering the motor assembly (3), thereby periodically changing the rotation speed of the motor assembly (3). The motor assembly (3) generates torsional oscillations at a high speed; the bottom end of the motor assembly (3) is connected to the top end of the transmission shaft assembly (4) for converting the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly (4) to rotate around its central axis; the bottom end of the transmission shaft assembly (4) is connected to the top end of the axial oscillation assembly (5) for driving the axial oscillation assembly (5) to rotate axially; the bottom end of the axial oscillation assembly (5) is connected to the drill bit for converting the fluid energy of the drilling fluid into an axial impact force on the drill bit; The motor assembly (3) comprises a stator (31) with conductive top and bottom ends, and a rotor (32) arranged in the stator (31); the top end of the stator (31) is fixedly connected to and communicated with the bottom end of the torsion oscillation assembly (2), and the bottom end of the stator (31) is fixedly connected to and communicated with the top end of the transmission shaft assembly (4); a hollow hole is provided inside the rotor (32), and the two ends of the hollow hole are respectively communicated with the bottom end of the torsion oscillation assembly (2) and the top end of the transmission shaft assembly (4); The torsional oscillation assembly (2) comprises an anti-drop joint (21), an eccentric valve disc (22) and an anti-drop connecting rod (24); the anti-drop joint (21) is a structure with both ends connected; the top end of the anti-drop joint (21) is fixedly connected to and communicated with the bottom end of the bypass valve assembly (1); the bottom end of the anti-drop joint (21) is fixedly connected to and communicated with the top end of the stator (31); the eccentric valve disc (22) is fixedly arranged at the upper end of the anti-drop joint (21); the anti-drop connecting rod (24) is a hollow structure with both ends connected; the bottom end of the anti-drop connecting rod (24) is fixedly connected to and communicated with the top end of the rotor (32); the top end of the anti-drop connecting rod (24) is connected to the eccentric hole (221) of the eccentric valve disc (22).

2. A multi-directional oscillating impact screw drill according to claim 1, characterized in that: The bypass valve assembly (1) comprises a bypass valve body (11), a valve core (12), a sieve plate (13) and a valve sleeve (14); the bottom end of the bypass valve body (11) is sealed and fixedly connected to the top end of the torsional oscillation assembly (2); the valve sleeve (14) is fixedly arranged at the bottom of the bypass valve body (11); the valve core (12) is sealingly slidably arranged in the bypass valve body (11) and is located vertically above the valve sleeve (14); the valve core (12) is provided with a valve core (12) center hole penetrating the top and bottom ends of the valve core (12); the side wall of the bypass valve body (11) is provided with a side through hole connected to the inner cavity of the bypass valve body (11); the valve core (12) opens or closes the side through hole during the sliding process in the bypass valve body (11); the sieve plate (13) is arranged in the side through hole.

3. The multi-directional oscillating impact screw drill according to claim 1, characterized in that: The torsional oscillation assembly (2) also includes an anti-drop lock nut (23), which is coaxially arranged with the eccentric valve disc (22), and an internal thread is provided on the inner side of the anti-drop lock nut (23). The anti-drop connecting rod (24) is arranged on the inner side of the anti-drop lock nut (23) and is threadedly connected to the anti-drop lock nut (23).

4. A multi-directional oscillating impact screw drill according to any one of claims 1 to 3, characterized in that: The transmission shaft assembly (4) comprises a universal joint housing (41), a ball universal joint (42) and a first transmission shaft (43); the top end of the universal joint housing (41) is fixedly connected to and communicated with the bottom end of the motor assembly (3); the bottom end of the universal joint housing (41) is fixedly connected to and communicated with the top end of the axial oscillation assembly (5); the upper part of the first transmission shaft (43) is arranged in the universal joint housing (41); the top end of the first transmission shaft (43) is transmission-connected to the bottom end of the rotor (32) through the ball universal joint (42).

5. A multi-directional oscillating impact screw drill according to claim 4, characterized in that: The transmission shaft assembly (4) further comprises a bearing housing (46) and a thrust ball bearing group (47); the thrust ball bearing group (47) is fixedly sleeved on the first transmission shaft (43); the bearing housing (46) is sleeved on the thrust ball bearing group (47); the bearing housing (46) is arranged between the universal shaft housing (41) and the axial oscillation assembly (5); the top end of the bearing housing (46) is fixedly connected and communicated with the bottom end of the universal shaft housing (41); and the bottom end of the bearing housing (46) is fixedly connected and communicated with the top end of the axial oscillation assembly (5).

6. A multi-directional oscillating impact screw drill according to claim 5, characterized in that: The transmission shaft assembly (4) further comprises a first centering bearing inner ring (44) and a first centering bearing outer ring (45) which are arranged in cooperation with each other, wherein the first centering bearing inner ring (44) is fixedly sleeved on the upper part of the first transmission shaft (43), and the first centering bearing outer ring (45) is sleeved outside the first centering bearing inner ring (44), and the lower end of the first centering bearing outer ring (45) sleeve is fixedly connected to the inner wall of the upper end of the bearing housing (46) sleeve.

7. The multi-directional oscillating impact screw drill according to claim 5, characterized in that: The axial oscillation assembly (5) comprises an axial oscillation short section outer shell (51), an isolating sleeve (53), a nozzle (54), a piston (55) and an axial oscillation shaft (56). The top end of the axial oscillation short section outer shell (51) is fixedly connected and communicated with the bottom end of the bearing housing (46). The top end of the axial oscillation shaft (56) is circumferentially fixed to the bottom end of the first transmission shaft (43) via a cylindrical spline (52). The axial oscillation shaft (56) is provided with an axially through-hole. The axial oscillation shaft (56) is provided with the isolating sleeve (53) and the piston (55) on its outer shell. The piston (55) is arranged below the isolating sleeve (53). The outer wall of the isolation sleeve (53) is fixedly connected to the inner wall of the axial oscillation short section outer shell (51); the lower part of the isolation sleeve (53) is provided with circumferentially uniformly distributed isolation channels (531); the middle side wall of the axial oscillation shaft (56) is provided with a plurality of first high-pressure channels (561); the first high-pressure channels (561) correspond to the axial positions of the isolation channels (531); the part of the axial oscillation short section outer shell (51) located between the isolation sleeve (53) and the piston (55) is provided with a through hole connected to the outside; a nozzle (54) is fixedly provided inside the axial oscillation shaft (56); the nozzle (54) is located below the first high-pressure channel (561).

8. The multi-directional oscillating impact screw drill according to claim 7, characterized in that: The lower end of the first transmission shaft (43) extends into the upper part of the outer shell (51) of the axial oscillation short section, and a second centering bearing inner ring (49) is sleeved on the lower end of the first transmission shaft (43). A second centering bearing outer ring (48) is sleeved outside the second centering bearing inner ring (49), and the second centering bearing outer ring (48) is fixedly connected to the upper inner wall of the outer shell (51) of the axial oscillation short section.

Images