Underground adjustable percussion drilling tool

Abstract

The invention relates to an underground adjustable percussion drilling tool which comprises a supporting barrel, a drilling rod and a drilling rod, the rotary power structure comprises a first drilling fluid channel and a screw rod, and the screw rod can be driven by drilling fluid impact to rotate; the motion conversion structure is used for converting the rotating motion of the screw rod into axial impact motion and comprises an upper reverser, a lower reverser and a moving block, and the rotating motion of the screw rod is converted into the axial impact motion of the moving block through cooperation of the upper reverser and the lower reverser; a control block is arranged in the moving block, the control block is used for adjusting the extending number of the lower commutators so as to change the axial impact frequency of the moving block, and the axial impact conduction structure comprises an impact shaft for downwards transferring the axial impact of the moving block; a drill bit structure; and a controller. The frequency of the impact tool can be adjusted according to lithologic characteristics of different stratum rocks, so that the drill bit achieves the optimal rock breaking effect, the rock breaking efficiency of the drill bit is improved, and the service life of the drill bit is prolonged.

Description

Technical Field

[0001] This invention relates to the field of oil drilling engineering technology, and in particular to an adjustable downhole percussion drilling tool. Background Technology

[0002] As oil and gas resources gradually expand into deeper formations, the number of deep wells is increasing. During deep drilling, the challenges become more numerous and complex. Increased well depth leads to increased rock hardness, gradually reducing drillability, and resulting in unsatisfactory mechanical drilling speed and service life of the drill bit. Therefore, there is an urgent need for a technology that can improve the mechanical drilling speed in deep formations and reduce drill bit damage.

[0003] Domestic and international theoretical and experimental studies have shown that applying a certain impact force to the drill bit can effectively increase its rock-breaking energy while reducing stick-slip vibration, thus significantly improving its rock-breaking efficiency and lifespan. Currently, the impact frequency and other parameters of existing impact tools are essentially fixed after entering the well and cannot be adjusted in real time. For complex formations, different formation lithologies require different optimal impact frequencies. Therefore, if the impact frequency of the tool could be adjusted in real time downhole based on formation lithology and drilling parameters, the drill bit could achieve optimal rock-breaking performance, significantly improving its rock-breaking efficiency, increasing its working life, and enhancing the applicability of the impact tool.

[0004] Therefore, based on years of experience and practice in related industries, the inventor proposes an adjustable downhole percussion drilling tool to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable downhole percussion drilling tool that can adjust the frequency of the percussion tool according to the characteristics of different formation rocks, so as to achieve the best rock breaking effect, improve the rock breaking efficiency of the drill bit, and increase the working life of the drill bit.

[0006] The objective of this invention is achieved by providing a downhole adjustable percussion drilling tool, comprising:

[0007] A support cylinder that is open at the top and closed at the bottom;

[0008] A rotary power structure is disposed inside the support cylinder, including a first drilling fluid channel and a screw disposed at the center of the support cylinder, the screw being able to rotate under the impact drive of drilling fluid;

[0009] A motion conversion structure, disposed within the support cylinder, converts the rotational motion of the screw into axial impact motion. It includes an upper commutator, a lower commutator, and a moving block arranged from top to bottom. The upper commutator is eccentrically positioned relative to the support cylinder and rotates with the screw. The moving block has multiple lower commutators that can extend upwards or retract downwards, also eccentrically positioned relative to the support cylinder. The upper and lower commutators work together to convert the rotational motion of the screw into the axial impact motion of the moving block. A control block is disposed within the moving block to adjust the number of lower commutators extending to change the axial impact frequency of the moving block. A second drilling fluid channel, connected to the first drilling fluid channel, is provided within the motion conversion structure.

[0010] An axial impact transmission structure includes an impact shaft that transmits the axial impact of the moving block downwards, and a third drilling fluid channel that communicates with the second drilling fluid channel is provided within the axial impact transmission structure.

[0011] The drill bit structure is connected below the axial impact transmission structure and is used for axial impact crushing of rocks;

[0012] The controller is electrically connected to the control block.

[0013] In a preferred embodiment of the present invention, a commutator receiving groove is provided on the movable block, and each of the lower commutators is disposed in the commutator receiving groove; a control block receiving groove is provided on the radially outer side wall of the commutator receiving groove, and the control block is disposed in the control block receiving groove; a plurality of telescopic heads are connected to the control block, and a limiting groove is provided on the side wall of each of the lower commutators, and each telescopic head is respectively disposed corresponding to each limiting groove; when the control block controls the telescopic head to extend and lock into the limiting groove, the corresponding lower commutator extends out and is exposed outside the movable block and is fixed; when the control block controls the telescopic head to retract, the corresponding lower commutator can move up and down along the commutator receiving groove.

[0014] In a preferred embodiment of the present invention, a power supply and a controller are disposed at the lower part of the moving block, and the power supply is electrically connected to the controller and the control block to provide electrical energy.

[0015] In a preferred embodiment of the present invention, a first spring is provided below each of the lower commutators, and the two ends of the first spring respectively abut against the bottom surface of the lower commutator and the top surface of the power supply; the first spring is used to control the rebound and retraction of the lower commutator.

[0016] In a preferred embodiment of the present invention, a fixed sleeve is fixedly disposed inside the support cylinder, and the movable block is disposed inside the fixed sleeve; a spline is provided on the outer wall of the movable block, and a spline groove is provided on the inner wall of the fixed sleeve, and the spline is slidably sleeved in the spline groove so that the movable block can move axially along the fixed sleeve.

[0017] In a preferred embodiment of the present invention, an outer sleeve is fixedly fitted inside the support cylinder, the inner wall surface of the outer sleeve is wavy, and the screw is helical; an axially penetrating annular channel is provided between the inner wall of the outer sleeve and the screw, the annular channel forming the first drilling fluid channel; the inner wall of the outer sleeve and the screw are helically engaged so that when the drilling fluid passes through the annular channel, it generates a force that drives the screw to rotate, thereby driving the screw to rotate.

[0018] In a preferred embodiment of the present invention, a reversing shaft is connected to the bottom end of the screw, and the reversing shaft is used to convert the non-concentric motion of the bottom end of the screw into concentric motion.

[0019] In a preferred embodiment of the present invention, the reversing shaft is connected to the rotary head via a connecting plate at its lower end, and the upper reversing device is connected to the bottom end of the rotary head; the connecting plate is provided with a connecting plate through hole that communicates with the first drilling fluid channel; the rotary head is used to transmit the rotational motion of the reversing shaft to the upper reversing device, and the rotary head is provided with a rotary head through hole that communicates with the connecting plate through hole, and the connecting plate through hole and the rotary head through hole are used for drilling fluid flow.

[0020] In a preferred embodiment of the present invention, a first bearing and a second bearing are sleeved on the outer wall of the rotating head. The outer ring of the first bearing is fixedly connected to the support cylinder, and the inner ring of the first bearing is fixedly connected to the rotating head. The first bearing is used to straighten the rotating head. The outer ring of the second bearing is fixedly connected to the support cylinder, and the inner ring of the second bearing is fixedly connected to the rotating head. The second bearing is used to straighten the rotating head and bear axial force.

[0021] In a preferred embodiment of the present invention, the upper commutator includes an upper cam fixedly connected to the bottom end of the rotary head, the upper cam being eccentrically disposed relative to the support cylinder, and the upper cam extending from top to bottom; the lower commutator includes a lower cam telescopically disposed within the moving block, the lower cam being eccentrically disposed relative to the support cylinder, and the lower cam extending from bottom to top.

[0022] In a preferred embodiment of the present invention, the axial impact transmission structure further includes a drive shaft disposed below the moving block, a universal joint disposed below the drive shaft, and an impact shaft disposed below the universal joint; the universal joint is used to prevent uneven wear between the drive shaft and the impact shaft; the diameter of the universal joint is smaller than the diameter of the drive shaft and the impact shaft; a second spring is disposed between the end faces of the drive shaft and the impact shaft, the second spring providing an upward rebound force to the moving block and serving to buffer the impact.

[0023] In a preferred embodiment of the present invention, the support cylinder is provided with a first stepped portion with a decreasing diameter, and the outer wall of the top end of the impact shaft is provided with a convex ring portion with an increasing diameter, the bottom surface of the convex ring portion abutting against the first stepped portion.

[0024] In a preferred embodiment of the present invention, a second step portion with a decreasing diameter is provided inside the support cylinder below the first step portion, and a third spring is provided between the convex ring portion and the second step portion. The third spring is used to provide a rebound force for the impact shaft and to buffer the impact.

[0025] In a preferred embodiment of the present invention, a sealing cylinder is sleeved at the bottom end of the support cylinder, a sealing cylinder center hole is provided at the center of the sealing cylinder, the impact shaft passes through the sealing cylinder center hole, and a sealing structure is provided between the side wall of the sealing cylinder center hole and the outer wall of the impact shaft.

[0026] In a preferred embodiment of the present invention, the sealing structure includes a packing structure, an O-ring, and a combined sealing structure arranged at intervals from top to bottom.

[0027] In a preferred embodiment of the present invention, the drill bit structure includes a drill bit body connected below the impact shaft, the drill bit body is provided with cutting teeth, and a fourth drilling fluid channel communicating with the third drilling fluid channel is provided inside the drill bit body.

[0028] In a preferred embodiment of the present invention, a filter structure is connected to the top of the support cylinder. The filter structure includes a filter screen cylinder connected to the top of the support cylinder. A filter screen is disposed inside the filter screen cylinder, and the filter screen is used to filter particulate matter in the drilling fluid.

[0029] As described above, the downhole adjustable percussion drilling tool of the present invention has the following beneficial effects:

[0030] In this invention, the drilling fluid drives the screw rotation in the rotary power structure, providing a stable power source for the tool. The motion conversion structure converts the screw's rotational motion into axial impact motion, achieving stable power conversion. The controller adjusts the number of extensions of the lower commutator constituting the passive commutation structure in the motion conversion structure in real time according to the formation lithology and construction parameters, thereby achieving multi-level real-time adjustment of the tool's impact frequency. This enables the drill bit to achieve optimal rock-breaking effect, significantly improving the drill bit's rock-breaking efficiency, enhancing the applicability of the impact tool, reducing drilling costs, ensuring the effective and safe operation of the impact tool, and realizing safe and efficient rock breaking by the downhole drill bit. Attached Figure Description

[0031] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0032] in:

[0033] Figure 1 This is a cross-sectional view of the adjustable downhole percussion drilling tool of the present invention.

[0034] Figure 2 This is an enlarged schematic diagram of the moving block and the lower commutator of the present invention.

[0035] In the picture:

[0036] 1. Filter screen cylinder; 2. Limit nut; 3. Filter screen; 4. Support cylinder; 5. Outer sleeve; 6. Screw; 7. Reversing shaft; 8. Connecting disc; 9. Connecting disc through hole; 10. Rotating head; 11. First bearing; 12. Second bearing; 13. Rotating head through hole; 14. Upper commutator; 15. Fixed sleeve; 16. Moving block; 17. Lower commutator; 18. Spline; 19. Control block; 20. Telescopic head; 21. Limit groove; 22. Signal line; 23. First spring; 24. Controller; 25. Power supply; 26. Drive shaft; 27. Universal joint; 28. Second spring; 29. ​​Impact shaft; 30. Third spring; 31. Sealing cylinder; 32. Packing structure; 33. O-ring; 34. Combined sealing structure; 35. Drill bit body; 36. Cutting teeth. Detailed Implementation

[0037] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0038] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] like Figure 1 , Figure 2 As shown, the present invention provides a downhole adjustable percussion drilling tool, comprising:

[0041] A support cylinder 4 that is open at the top and closed at the bottom; the support cylinder 4 is used to support the internal parts.

[0042] The rotary power structure is located inside the support cylinder 4 and includes a first drilling fluid channel and a screw 6 located at the center of the support cylinder 4. The screw 6 can rotate under the impact drive of the drilling fluid.

[0043] The motion conversion structure, located within the support cylinder 4, converts the rotational motion of the screw 6 into axial impact motion. It includes an upper commutator 14, a lower commutator 17, and a moving block 16 arranged from top to bottom. The upper commutator 14 is eccentrically positioned relative to the support cylinder 4 and rotates with the screw 6. The moving block 16 has multiple lower commutators 17 that can extend upwards or retract downwards, also eccentrically positioned relative to the support cylinder 4. The upper and lower commutators 14 work together to convert the rotational motion of the screw 6 into the axial impact motion of the moving block 16. A control block 19 is located within the moving block 16, used to adjust the number of lower commutators 17 extending to change the axial impact frequency of the moving block 16. A second drilling fluid channel, connected to the first drilling fluid channel, is located within the motion conversion structure. The upper commutator 14 and lower commutator 17 are key components in converting rotational motion into axial impact motion. The upper commutator 14 is the active component, and the lower commutator 17 constitutes a passive motion commutation structure. The two work together to convert rotary motion into axial impact motion.

[0044] The axial impact transmission structure includes an impact shaft 29 that transmits the axial impact of the moving block 16 downwards, and a third drilling fluid channel that communicates with the second drilling fluid channel is provided within the axial impact transmission structure.

[0045] The drill bit structure is connected below the axial impact transmission structure and is used for axial impact to break rocks;

[0046] Controller 24 is electrically connected to control block 19.

[0047] In this invention, the drilling fluid drives the screw rotation in the rotary power structure, providing a stable power source for the tool. The motion conversion structure converts the screw's rotational motion into axial impact motion, achieving stable power conversion. The controller adjusts the number of extensions of the lower commutator constituting the passive commutation structure in the motion conversion structure in real time according to the formation lithology and construction parameters, thereby achieving multi-level real-time adjustment of the tool's impact frequency. This enables the drill bit to achieve optimal rock-breaking effect, significantly improving the drill bit's rock-breaking efficiency, enhancing the applicability of the impact tool, reducing drilling costs, ensuring the effective and safe operation of the impact tool, and realizing safe and efficient rock breaking by the downhole drill bit.

[0048] Furthermore, such as Figure 1 , Figure 2 As shown, a commutator receiving slot is provided on the moving block 16, and each lower commutator 17 is disposed in the commutator receiving slot; multiple lower commutators 17 can be arranged around the moving block 16. After the number of lower commutators 17 is increased, the impact frequency of the tool can be increased. By controlling the number of lower commutators 17 extending, the impact frequency of the tool can be controlled.

[0049] A control block receiving groove is provided on the radial outer side wall of the commutator receiving groove, and a control block 19 is disposed in the control block receiving groove; multiple telescopic heads 20 are connected to the control block 19, and a limiting groove 21 is provided on the side wall of each lower commutator 17, with each telescopic head 20 corresponding to a limiting groove; when the control block 19 controls the telescopic head 20 to extend and lock into the limiting groove 21, the corresponding lower commutator 17 extends out and is fixed to the moving block, cooperating with the upper commutator 14 to complete the motion conversion; when the control block 19 controls the telescopic head 20 to retract, the corresponding lower commutator 17 can move, and the lower commutator 17 can move up and down along the commutator receiving groove.

[0050] Furthermore, such as Figure 1 , Figure 2 As shown, a power supply 25 and a controller 24 are provided at the lower part of the moving block 16. The power supply 25 is electrically connected to the controller 24 and the control block 19, and the power supply 25 provides power to the controller 24 and the control block 19.

[0051] Control block 19 is connected to controller 24 via signal line 22. When controller 24 receives a signal, it processes the signal and transmits the processed signal command to control block 19 via signal line 22 to control the extension and retraction of telescopic head 20.

[0052] Furthermore, such as Figure 1 , Figure 2 As shown, a first spring 23 is provided below each lower commutator 17. The two ends of the first spring 23 abut against the bottom surface of the lower commutator 17 and the top surface of the power supply 25, respectively. The first spring 23 is used to control the rebound and retraction of the lower commutator 17.

[0053] When it is necessary to adjust the impact frequency of the tool, a corresponding signal is loaded into the drilling fluid at the wellhead. The signal is transmitted to the controller 24 through the drilling fluid. The controller 24 receives and processes the signal and transmits the command to the control block 19 through the signal line 22. The control block 19 causes the telescopic head 20 to extend. After the telescopic head 20 extends, under the action of the first spring 23, the telescopic head 20 aligns with the limit groove 21 and enters the limit groove 21, locking and fixing the lower commutator 17. This realizes the adjustment of the working quantity of the lower commutator 17, thereby adjusting the impact frequency of the tool.

[0054] Furthermore, such as Figure 1 As shown, a fixed sleeve 15 is fixedly installed inside the support cylinder 4 to fix its internal parts. A movable block 16 is installed inside the fixed sleeve 15. The movable block 16 is used to transmit impact motion and is equipped with an internal control device (control block 19).

[0055] A spline 18 is provided on the outer wall of the movable block 16, and a spline groove is provided on the inner wall of the fixed sleeve 15. The spline 18 is slidably sleeved in the spline groove so that the movable block 16 can move axially along the fixed sleeve 15, ensuring that the movable block 16 can move freely up and down in impact motion.

[0056] Furthermore, such as Figure 1 As shown, an outer sleeve 5 is fixedly fitted inside the support cylinder 4. The inner wall surface of the outer sleeve 5 is wavy and made of elastic or metallic material. The screw 6 is spirally arranged and made of metallic material. An axially penetrating annular channel is provided between the inner wall of the outer sleeve 5 and the screw 6, and the annular channel constitutes the first drilling fluid channel. The inner wall of the outer sleeve 5 and the screw 6 are spirally engaged so that when the drilling fluid passes through the annular channel, it generates a force that drives the screw 6 to rotate, thereby driving the screw 6 to rotate.

[0057] Furthermore, such as Figure 1 As shown, a reversing shaft 7 is connected to the bottom end of the screw 6. The reversing shaft 7 is used to convert the misaligned motion of the bottom end of the screw 6 into concentric motion. Specifically, the reversing shaft 7 is threadedly connected to the screw 6. When the screw 6 rotates, the lower part of the screw head moves in a misaligned manner. The reversing shaft 7 can convert the misaligned motion of the screw head into concentric motion.

[0058] Furthermore, such as Figure 1 As shown, the commutator 7 is connected to the rotary head 10 via a connecting plate 8. Specifically, the connecting plate 8 is threaded to the commutator 7, and the upper commutator 14 is connected to the bottom of the rotary head 10. The connecting plate 8 is provided with a connecting plate through hole 9 that communicates with the first drilling fluid channel. The connecting plate through holes 9 are evenly distributed around the commutator 7 for the flow of drilling fluid. The rotary head 10 is used to transmit the rotational motion of the commutator 7 to the upper commutator 14. The rotary head 10 is provided with a rotary head through hole 13 that communicates with the connecting plate through hole 9. The rotary head through hole 13 is located at the center of the rotary head 10. The connecting plate through hole 9 and the rotary head through hole 13 are used to receive drilling fluid and continue to transmit it downwards.

[0059] Furthermore, such as Figure 1 As shown, a first bearing 11 and a second bearing 12 are fitted onto the outer wall of the rotating head 10. The outer ring of the first bearing 11 is fixedly connected to the support cylinder 4, and the inner ring of the first bearing 11 is fixedly connected to the rotating head 10. The first bearing 11 is used to straighten the rotating head 10, allowing it to rotate freely. The outer ring of the second bearing 12 is fixedly connected to the support cylinder 4, and the inner ring of the second bearing 12 is fixedly connected to the rotating head 10. The second bearing 12 is used to straighten the rotating head 10 and bear axial force, allowing it to rotate freely. Under the action of the bearings (first bearing 11 and second bearing 12), the internal rotational motion of the rotating head 10 is more centralized.

[0060] Furthermore, such as Figure 1As shown, the upper commutator 14 includes an upper cam (which may be a cam-like structure with a downwardly protruding apex) fixedly connected to the bottom end of the rotary head 10. The upper cam is eccentrically positioned relative to the support cylinder 4 and extends from top to bottom. The upper cam is threadedly connected to the rotary head 10. The lower commutator 17 includes a lower cam that is telescopically positioned within the moving block 16. The lower cam is eccentrically positioned relative to the support cylinder 4 and extends from bottom to top.

[0061] The upper commutator 14 (upper cam) rotates under the drive of the rotating head 10. After the upper commutator 14 (upper cam) and the lower commutator 17 (lower cam) come into contact, as the upper commutator 14 (upper cam) rotates, the lower commutator 17 (lower cam) begins to move downward under the action of the upper commutator 14 (upper cam). After the cam apex of the upper commutator 14 (upper cam) abuts against the cam apex of the lower commutator 17 (lower cam), the lower commutator 17 (lower cam) and the moving block 16 move to the lowest point. The upper commutator 14 (upper cam) continues to rotate, and the lower commutator 17 (lower cam) and the moving block 16 move upward from the lowest point, forming a reciprocating movement cycle.

[0062] Furthermore, such as Figure 1 As shown, the axial impact transmission structure also includes a drive shaft 26, which is located below the moving block 16 (specifically below the power supply 25). A universal joint 27 is located below the drive shaft 26, and an impact shaft 29 is located below the universal joint 27. The drive shaft 26 transmits the impact motion of the moving block 16 to the universal joint 27. The universal joint 27 is used to prevent uneven wear between the drive shaft 26 and the impact shaft 29. The universal joint 27 is located between the drive shaft 26 and the impact shaft 29, and it can prevent uneven wear when the drive shaft 26 and the impact shaft 29 are not concentric, thus avoiding damage to the drive shaft 26 and the impact shaft 29.

[0063] The diameter of the universal joint 27 is smaller than the diameter of the drive shaft 26 and the impact shaft 29. A second spring 28 is provided between the end faces of the drive shaft 26 and the impact shaft 29. The second spring 28 can provide an upward rebound force to the moving block 16 and is used to buffer the impact. It can provide a certain buffer for the drive shaft 26 and reduce the impact on the drive shaft 26 and the above parts.

[0064] Furthermore, such as Figure 1 As shown, the support cylinder 4 has a first step with a decreasing diameter inside, and the top outer wall of the impact shaft 29 has a convex ring (ear structure) with an increasing diameter. The bottom surface of the convex ring abuts against the first step to prevent the impact shaft 29 from falling off.

[0065] Furthermore, such as Figure 1As shown, a second step with a decreasing diameter is provided below the first step inside the support cylinder 4. A third spring 30 is provided between the convex ring and the second step. The third spring 30 is used to provide a rebound force for the impact shaft 29 and to buffer the impact. It can protect the impact shaft and prevent the upper parts from getting stuck.

[0066] The second spring 28 and the third spring 30 together form a buffer structure, which can effectively prevent the adjustable downhole impact drilling tool of the present invention from getting stuck.

[0067] Furthermore, such as Figure 1 As shown, a sealing cylinder 31 is fitted onto the bottom end of the support cylinder 4. A central hole is provided at the center of the sealing cylinder 31. The impact shaft 29 passes through the central hole of the sealing cylinder, and a sealing structure is provided between the side wall of the central hole of the sealing cylinder and the outer wall of the impact shaft 29. The sealing cylinder 31 is used to install the internal sealing structure and also supports the upper structure. The sealing cylinder 31 and its internal sealing structure form a proprietary sealing support structure, preventing the impact shaft 29 from falling off and achieving sealing of the tool against the high-pressure drilling fluid.

[0068] Specifically, the sealing structure includes a packing structure 32, an O-ring 33, and a combined sealing structure 34 arranged at intervals from top to bottom.

[0069] The packing structure 32 is disposed between the sealing cylinder 31 and the impact shaft 29 to seal the drilling fluid inside and outside the tool, serving as the first seal for the high-pressure drilling fluid; the O-ring 33 is disposed between the impact shaft 29 and the sealing cylinder 31 to seal the drilling fluid inside and outside the tool, serving as the second seal for the high-pressure drilling fluid; and the combined sealing structure 34 is disposed between the impact shaft 29 and the sealing cylinder 31 to seal the drilling fluid inside and outside the tool, serving as the third seal for the high-pressure drilling fluid.

[0070] Furthermore, such as Figure 1 As shown, the drill bit structure includes a drill bit body 35 connected to the lower part of the impact shaft, cutting teeth 36 are provided on the drill bit body 35, and a fourth drilling fluid channel communicating with the third drilling fluid channel is provided inside the drill bit body 35.

[0071] The impact shaft 29 is connected to the drill bit body 35 by a thread. The impact shaft 29 directly transmits the impact motion of the tool to the drill bit body 35. The drill bit body 35 transmits the impact force of the impact shaft 29 to the cutting teeth 36. The cutting teeth 36 apply the impact force of the tool to the rock and break the rock.

[0072] Furthermore, such as Figure 1 As shown, a filter structure is connected to the top of the support cylinder 4. The filter structure includes a filter screen cylinder 1 connected to the top of the support cylinder 4, and a filter screen 3 is installed inside the filter screen cylinder 1. The filter screen 3 is used to filter particulate matter in the drilling fluid. Specifically, the filter screen 3 is connected to the filter screen cylinder 1 by a limiting nut 2.

[0073] The filter screen cylinder 1 is located at the top of the tool to support the internal parts. The limit nut 2 is an internal hexagonal nut that can be threaded onto the filter screen cylinder 1 to fix the filter screen 3 at the bottom. The filter screen 3 is installed on the internal step of the filter screen cylinder 1 and is limited by the limit nut 2. The filter screen 3 is used to filter large particles in the drilling fluid to prevent large particles from clogging the tool flow channel or causing significant erosion.

[0074] As described above, the downhole adjustable percussion drilling tool of the present invention has the following beneficial effects:

[0075] In this invention, the drilling fluid drives the screw rotation in the rotary power structure, providing a stable power source for the tool. The motion conversion structure converts the screw's rotational motion into axial impact motion, achieving stable power conversion. The controller adjusts the number of extensions of the lower commutator constituting the passive commutation structure in the motion conversion structure in real time according to the formation lithology and construction parameters, thereby achieving multi-level real-time adjustment of the tool's impact frequency. This enables the drill bit to achieve optimal rock-breaking effect, significantly improving the drill bit's rock-breaking efficiency, enhancing the applicability of the impact tool, reducing drilling costs, ensuring the effective and safe operation of the impact tool, and realizing safe and efficient rock breaking by the downhole drill bit.

[0076] In this invention, the second spring and the third spring together constitute a buffer structure, which can effectively prevent the adjustable downhole impact drilling tool of this invention from getting stuck.

[0077] In this invention, the sealing cylinder and its internal sealing structure form a proprietary sealing support structure to prevent the impact shaft from falling off and to achieve sealing of the tool against the high-pressure drilling fluid.

[0078] In this invention, a filter screen located at the top of the tool filters out large particles in the drilling fluid, preventing large particles from clogging the tool's flow channel or causing significant erosion.

[0079] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A downhole adjustable percussion drilling tool, characterized in that, include: A support cylinder that is open at the top and closed at the bottom; A rotary power structure is disposed inside the support cylinder, including a first drilling fluid channel and a screw disposed at the center of the support cylinder, the screw being able to rotate under the impact drive of drilling fluid; A motion conversion structure, disposed within the support cylinder, converts the rotational motion of the screw into axial impact motion. It includes an upper commutator, a lower commutator, and a moving block arranged from top to bottom. The upper commutator is eccentrically positioned relative to the support cylinder and rotates with the screw. The moving block has multiple lower commutators that can extend upwards or retract downwards, also eccentrically positioned relative to the support cylinder. The upper and lower commutators work together to convert the rotational motion of the screw into the axial impact motion of the moving block. A control block is disposed within the moving block to adjust the number of lower commutators extending to change the axial impact frequency of the moving block. A second drilling fluid channel, connected to the first drilling fluid channel, is provided within the motion conversion structure. An axial impact transmission structure includes an impact shaft that transmits the axial impact of the moving block downwards, and a third drilling fluid channel that communicates with the second drilling fluid channel is provided within the axial impact transmission structure. The drill bit structure is connected below the axial impact transmission structure and is used for axial impact crushing of rocks; The controller is electrically connected to the control block.

2. The downhole adjustable percussion drilling tool as described in claim 1, characterized in that, The movable block is provided with a commutator receiving slot, and each of the lower commutators is disposed in the commutator receiving slot; a control block receiving slot is provided on the radial outer wall of the commutator receiving slot, and the control block is disposed in the control block receiving slot; multiple telescopic heads are connected to the control block, and a limiting slot is provided on the side wall of each of the lower commutators, and each telescopic head is respectively disposed in relation to each limiting slot; when the control block controls the telescopic head to extend and lock into the limiting slot, the corresponding lower commutator extends out of the movable block and is fixed; when the control block controls the telescopic head to retract, the corresponding lower commutator can move up and down along the commutator receiving slot.

3. The downhole adjustable percussion drilling tool as described in claim 2, characterized in that, The lower part of the moving block is provided with a power supply and the controller, and the power supply is electrically connected to the controller and the control block to provide electrical energy.

4. The downhole adjustable percussion drilling tool as described in claim 3, characterized in that, A first spring is provided below each of the lower commutators, with its two ends respectively abutting against the bottom surface of the lower commutator and the top surface of the power supply; the first spring is used to control the rebound and retraction of the lower commutator.

5. The downhole adjustable percussion drilling tool as described in claim 2, characterized in that, A fixed sleeve is fixedly installed inside the support cylinder, and the movable block is disposed inside the fixed sleeve; a spline is provided on the outer wall of the movable block, and a spline groove is provided on the inner wall of the fixed sleeve, and the spline is slidably sleeved in the spline groove so that the movable block can move axially along the fixed sleeve.

6. The downhole adjustable percussion drilling tool as described in claim 1 or 2, characterized in that, An outer sleeve is fixedly fitted inside the support cylinder. The inner wall surface of the outer sleeve is wavy, and the screw is spirally arranged. An axially penetrating annular channel is provided between the inner wall of the outer sleeve and the screw, and the annular channel constitutes the first drilling fluid channel. The inner wall of the outer sleeve and the screw are spirally engaged so that when the drilling fluid passes through the annular channel, it generates a force that drives the screw to rotate.

7. The downhole adjustable percussion drilling tool as described in claim 6, characterized in that, The bottom end of the screw is connected to a reversing shaft, which is used to convert the non-concentric motion of the bottom end of the screw into concentric motion.

8. The downhole adjustable percussion drilling tool as described in claim 7, characterized in that, The commutator shaft is connected to the rotary head via a connecting plate at its lower end, and the upper commutator is connected to the bottom end of the rotary head. The connecting plate is provided with a connecting plate through hole that communicates with the first drilling fluid channel. The rotary head is used to transmit the rotational motion of the commutator shaft to the upper commutator. The rotary head is provided with a rotary head through hole that communicates with the connecting plate through hole. The connecting plate through hole and the rotary head through hole are used for drilling fluid flow.

9. The downhole adjustable percussion drilling tool as described in claim 8, characterized in that, The outer wall of the rotating head is fitted with a first bearing and a second bearing. The outer ring of the first bearing is fixedly connected to the support cylinder, and the inner ring of the first bearing is fixedly connected to the rotating head. The first bearing is used to straighten the rotating head. The outer ring of the second bearing is fixedly connected to the support cylinder, and the inner ring of the second bearing is fixedly connected to the rotating head. The second bearing is used to straighten the rotating head and bear axial force.

10. The downhole adjustable percussion drilling tool as described in claim 8, characterized in that, The upper commutator includes an upper cam fixedly connected to the bottom end of the rotary head, the upper cam being eccentrically positioned relative to the support cylinder, and the upper cam extending from top to bottom; the lower commutator includes a lower cam telescopically positioned within the moving block, the lower cam being eccentrically positioned relative to the support cylinder, and the lower cam extending from bottom to top.

11. The downhole adjustable percussion drilling tool as described in claim 2, characterized in that, The axial impact transmission structure further includes a drive shaft, which is disposed below the moving block. A universal joint is disposed below the drive shaft, and the impact shaft is disposed below the universal joint. The universal joint is used to prevent uneven wear between the drive shaft and the impact shaft. The diameter of the universal joint is smaller than the diameter of the drive shaft and the impact shaft. A second spring is disposed between the end faces of the drive shaft and the impact shaft. The second spring can provide an upward rebound force to the moving block and is used to buffer the impact.

12. The downhole adjustable percussion drilling tool as described in claim 11, characterized in that, The support cylinder has a first stepped portion with a decreasing diameter inside, and the outer wall of the top end of the impact shaft has a convex ring portion with an increasing diameter. The bottom surface of the convex ring portion abuts against and overlaps the first stepped portion.

13. The downhole adjustable percussion drilling tool as described in claim 12, characterized in that, A second step with a decreasing diameter is provided below the first step inside the support cylinder. A third spring is abutted between the convex ring and the second step. The third spring is used to provide a rebound force for the impact shaft and to buffer the impact.

14. The downhole adjustable percussion drilling tool as described in claim 1 or 2, characterized in that, A sealing cylinder is fitted at the bottom end of the support cylinder, and a central hole is provided at the center of the sealing cylinder. The impact shaft passes through the central hole of the sealing cylinder, and a sealing structure is provided between the side wall of the central hole of the sealing cylinder and the outer wall of the impact shaft.

15. The downhole adjustable percussion drilling tool as described in claim 14, characterized in that, The sealing structure includes packing structures, O-rings, and combined sealing structures arranged at intervals from top to bottom.

16. The downhole adjustable percussion drilling tool as described in claim 1 or 2, characterized in that, The drill bit structure includes a drill bit body connected below the impact shaft, the drill bit body is provided with cutting teeth, and a fourth drilling fluid channel connected to the third drilling fluid channel is provided inside the drill bit body.

17. The downhole adjustable percussion drilling tool as described in claim 1 or 2, characterized in that, The top of the support cylinder is connected to a filter structure, which includes a filter screen cylinder connected to the top of the support cylinder. A filter screen is installed inside the filter screen cylinder, and the filter screen is used to filter particulate matter in the drilling fluid.

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