CN111577120B

CN111577120B - Torsional impact screw drill

Info

Publication number: CN111577120B
Application number: CN202010353332.3A
Authority: CN
Inventors: 查春青; 柳贡慧; 李军
Original assignee: China University of Petroleum Beijing; Beijing University of Technology
Current assignee: China University of Petroleum Beijing; Beijing University of Technology
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2021-08-20
Anticipated expiration: 2040-04-29
Also published as: CN111577120A

Abstract

The invention relates to a torsional impact screw drill which comprises a screw drill body, wherein the screw drill body comprises a bypass valve assembly for controlling the flow direction of drilling fluid, a motor assembly is arranged below the bypass valve assembly and is connected with a transmission shaft assembly through a universal shaft assembly, the motor assembly is used for converting the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around a central shaft, and the bottom of the transmission shaft assembly is used for connecting a drill bit; the lower part of the transmission shaft assembly is sleeved with an axially fixed torsional impact assembly, and the torsional impact assembly is used for converting fluid energy of drilling fluid into torsional impact force on the transmission shaft assembly. The tool solves the problems of drill bit stick-slip, low rock breaking efficiency or poor deflecting capability and the like in the prior art, the torsional impact screw drill combines the screw drill and the torsional impactor together, the compatibility is good, and the mechanical drilling speed and the drilling capability of the drill are effectively improved.

Description

Torsional impact screw drill

Technical Field

The invention relates to an underground drilling tool in the field of petroleum development, in particular to a torsional impact screw drill.

Background

With the rapid development of the drilling engineering, the screw drill has been developed greatly, and the screw drill is the most widely applied downhole power tool in the drilling engineering. In order to improve the drilling capacity and the mechanical rotating speed of the screw drill, some scholars at home and abroad improve motors to increase the torque of the screw drill, such as a series motor, a lengthened motor and the like. While the rate of penetration is increased, the drill bit wears more quickly. In addition, when a hard formation is drilled, the rotating speed and the torque applied to the drill bit have large fluctuation, and the stick-slip phenomenon still occurs. The stick-slip effect greatly reduces the rock breaking efficiency of the drill bit, increases the irregular impact damage of the drill bit and accelerates the failure of the drill bit.

In order to solve the stick-slip condition which is easy to occur when a PDC drill bit is adopted for drilling in a deep well hard stratum, some scholars at home and abroad develop a torsion impactor. The PDC drill bit is adjusted by providing high-frequency low-amplitude torsional impact for the PDC drill bit, so that the stability of the PDC drill bit is improved, and the torsional vibration of the PDC drill bit is restrained. At present, the tool is widely applied to a drilling site, and a good speed-up effect is achieved. However, such tools also present certain problems, such as: if the tool is matched with a screw drill for use, particularly a bent screw, the deflecting capacity of the bent screw can be influenced.

Therefore, the inventor provides the torsional impact screw drill by virtue of experience and practice of related industries for many years so as to overcome the defects in the prior art.

Disclosure of Invention

The invention aims to provide a torsional impact screw drill tool, which solves the problems of stick-slip of a drill bit, low rock breaking efficiency or poor deflecting capability and the like in the prior art.

The invention aims to realize the purpose, and the torsional impact screw drill comprises a screw drill body, wherein the screw drill body comprises a bypass valve assembly for controlling the flow direction of drilling fluid, a motor assembly is arranged below the bypass valve assembly and is connected with a transmission shaft assembly through a universal shaft assembly, the motor assembly is used for converting the hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around a central shaft, and the bottom of the transmission shaft assembly is used for connecting a drill bit; the lower part of the transmission shaft assembly is sleeved with an axially fixed torsional impact assembly, and the torsional impact assembly is used for converting fluid energy of drilling fluid into torsional impact force on the transmission shaft assembly.

In a preferred embodiment of the present invention, the transmission shaft assembly includes a transmission shaft, the transmission shaft is provided with a transmission shaft center hole which is axially through, a first radial through hole is radially through-arranged at a position on the side wall of the transmission shaft above the torsional impact assembly, a second radial through hole is radially through-arranged at a position on the side wall of the transmission shaft below the torsional impact assembly, a plurality of through slots are circumferentially arranged at intervals at a position on the side wall of the transmission shaft opposite to the torsional impact assembly, a sixth step portion with a reduced diameter is arranged below the through slot in the transmission shaft center hole, and a shrinkage cavity at the sixth step portion forms a nozzle structure; the drilling fluid in the central hole of the transmission shaft can flow to the torsional impact assembly from top to bottom through the first radial through hole, the drilling fluid in the central hole of the transmission shaft can flow to the torsional impact assembly from inside to outside through the long through groove, and the drilling fluid flowing through the torsional impact assembly flows back into the central hole of the transmission shaft through the second radial through hole.

In a preferred embodiment of the present invention, the torsional impact assembly includes a reversing structure, a pendulum and an impact cylinder, which are sequentially sleeved on the transmission shaft from inside to outside and are axially fixed, the lower portion of the impact cylinder is hermetically sleeved on the transmission shaft, and the pendulum can circumferentially reciprocate to impact the impact cylinder under the action of the drilling fluid; the inner wall of the reversing structure is abutted to and sleeved on the transmission shaft, the inner wall of the pendulum bob is rotated and abutted to the outer wall of the reversing structure, and the outer wall of the pendulum bob is rotated and abutted to the inner wall of the impact barrel.

In a preferred embodiment of the present invention, a transmission shaft housing is sleeved on an outer side of an upper portion of the transmission shaft, a torsional impact housing is connected below the transmission shaft housing, a bottom end of the transmission shaft penetrates through a bottom end of the torsional impact housing for connecting a drill, and an outer wall of the impact cylinder and an inner wall of the torsional impact housing are rotatably abutted; the impact barrel comprises a barrel body, and 2 impact barrel fan-shaped through grooves with openings at the tops and arranged radially and symmetrically are formed in the side wall of the barrel body; the inner wall of the cylinder body is provided with 2 impact cylinder inner channels which are radially symmetrical, the 2 impact cylinder inner channels and the 2 impact cylinder fan-shaped through grooves are arranged in a cross manner, the top of each impact cylinder inner channel is opened, and the bottom of each impact cylinder inner channel is flush with the bottom of each impact cylinder fan-shaped through groove; the outer wall of the cylinder body is provided with impact cylinder outer channels at two circumferential sides of each impact cylinder inner channel, the top of each impact cylinder outer channel is opened, the bottom of each impact cylinder outer channel is higher than the bottom of the impact cylinder fan-shaped through groove, and a radially through outer channel through groove is arranged in each impact cylinder outer channel; the end cover is arranged below the first radial through hole in a sealing sleeved mode on the transmission shaft, the bottom face of the end cover is axially abutted to the top face of the barrel body, the outer wall of the end cover and the inner wall of the torsional impact shell are rotatably abutted to the end cover, and the end cover which can be communicated with the outer channel of the impact barrel is arranged on the end cover and flows through the through groove.

In a preferred embodiment of the present invention, the reversing structure includes a cylindrical reversing body, two first outward-changing protruding columns axially penetrating and radially symmetrically disposed are disposed on an outer wall of the reversing body, two second outward-changing protruding columns axially penetrating and radially symmetrically disposed are further disposed on an outer wall of the reversing body, and 2 first outward-changing protruding columns and 2 second outward-changing protruding columns are disposed in a cross manner; the 2 first outward-changing convex columns are respectively provided with a reversing through groove which is radially communicated, the 2 second outward-changing convex columns are respectively provided with a positioning channel which is arranged from bottom to top, and the tops of the positioning channels are arranged in a closed manner;

the pendulum comprises a cylindrical hammer body, the outer wall of the hammer body is provided with two pendulum fan-shaped outer protruding columns which are axially communicated and radially and symmetrically arranged, the two circumferential sides of each pendulum fan-shaped outer protruding column on the side wall of the hammer body are respectively provided with a first pendulum side wall through groove and a second pendulum side wall through groove, each pendulum fan-shaped outer protruding column can be arranged in the corresponding impact cylinder fan-shaped through groove in a swinging manner, and the central angle of each impact cylinder fan-shaped through groove is larger than that of each pendulum fan-shaped outer protruding column; the inner wall of the hammer body is provided with two pendulum fan-shaped inner protruding columns which are axially communicated and radially and symmetrically arranged, the two pendulum fan-shaped inner protruding columns and the two pendulum fan-shaped outer protruding columns are arranged in a cross manner, a third pendulum side wall through groove and a fourth pendulum side wall through groove are respectively formed in the side wall of the hammer body and located on the two circumferential sides of each pendulum fan-shaped inner protruding column, the two pendulum fan-shaped inner protruding columns can be respectively sleeved in the two positioning channels in a swinging mode, and the central angle of each positioning channel is larger than that of each pendulum fan-shaped inner protruding column; the top surface of each pendulum fan-shaped inner convex column can axially abut against the top surface of each positioning channel.

In a preferred embodiment of the present invention, a first step portion with a decreasing diameter is disposed on the inner wall of the cylinder body at the bottom of the through-sector groove of the impact cylinder, and the bottom surface of the hammer body abuts against the first step portion; second step parts with the diameters being reduced are arranged below the first step parts at axial intervals, and the inner wall of the cylinder body, which is positioned below the second step parts, is abutted and sleeved on the transmission shaft; the second radial through hole is communicated with an inner cavity of the impact barrel above the second step part.

In a preferred embodiment of the present invention, an upper centering bearing is disposed between the top of the inner wall of the transmission shaft housing and the transmission shaft, a thrust bearing group is disposed below the upper centering bearing in an axial abutting manner, a lower locking nut is disposed below the thrust bearing group on the transmission shaft, a top surface of the lower locking nut and a bottom surface of an inner ring of the thrust bearing group in an axial abutting manner, a spacer sleeve is sleeved outside the lower locking nut, a top end of the torsional impact housing is sleeved in the transmission shaft housing, a top surface of the spacer sleeve and a bottom surface of an outer ring of the thrust bearing group in an axial abutting manner, and a bottom surface of the spacer sleeve and a top surface of the torsional impact housing in an axial abutting manner; a lower righting bearing is arranged between the bottom of the inner wall of the torsional impact shell and the transmission shaft.

In a preferred embodiment of the present invention, a drop-preventing assembly is connected in series between the bypass valve assembly and the motor assembly, and the drop-preventing assembly is used for preventing the motor assembly, the cardan shaft assembly and the transmission shaft assembly from dropping into a well in an accident.

From the above, the torsional impact screw drill provided by the invention has the following beneficial effects:

in the torsional impact screw drill tool provided by the invention, the screw drill tool body and the torsional impact assembly are combined together, and the torsional impact assembly generates torsional impact on the transmission shaft assembly under the action of the drilling fluid, so that the phenomena of vibration and clamping slip which possibly occur when the PDC drill bit drills can be well eliminated, the PDC drill bit can effectively shear and crush the stratum, the service life and the cutting efficiency of the drill bit are obviously improved, and the mechanical drilling speed and the drilling guidance are greatly increased; the torsional impact assembly is arranged inside the screw drill body, the compatibility of the torsional impact assembly and the screw drill body is good, the bending point of the screw drill body is not influenced, the extra length of the screw drill body is not increased, namely, the deflection and the orientation of the screw drill body are not influenced, and the application range is wider.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention.

Wherein:

FIG. 1: a schematic of the torsional impact screw drill of the present invention.

FIG. 2: is an enlarged view at I in FIG. 1.

FIG. 3: is an enlarged view at II in FIG. 1.

FIG. 4: is an enlarged view at III in FIG. 1.

FIG. 5: is a schematic diagram of the commutation architecture of the present invention.

FIG. 6: is a schematic view of the pendulum of the present invention.

FIG. 7: is a schematic view of the impingement cylinder of the present invention.

FIG. 8: which is schematically shown at a-a in fig. 4 in an initial state.

FIG. 9: is a schematic view at A-A in figure 4 during clockwise rotation of the reversing structure and the pendulum bob together.

FIG. 10: which is schematically shown at a-a in fig. 4 when the pendulum has reached a clockwise extreme position.

FIG. 11: which is schematically shown at a-a in fig. 4 when the reversing structure reaches the clockwise extreme position.

In the figure:

100. a torsional impact screw drill;

1. a bypass valve body; 2. a valve core; 3. a spring; 4. a sieve plate; 5. a seal ring; 6. a valve housing; 7. a circlip;

8. the lock nut is prevented from falling; 9. the joint is prevented from falling; 10. the anti-drop connecting rod;

11. a stator; 12. a rotor;

13. performing movable hinging; 14. a cardan shaft housing; 15. a ball seat; 16. a pressure bearing ball; 17. a drive ball; 18. a locking sleeve; 19. a connecting rod; 20. sealing sleeves; 21. a blocking sleeve; 22. a water cap structure; 23. a shaft sleeve;

24. an upper centering bearing; 25. a drive shaft; 250. a central hole of the transmission shaft; 251. a first radial through hole; 252. a second radial through hole; 253. a long through groove; 254. a sixth step portion; 26. a thrust bearing set; 27. a drive shaft housing; 28. a lower lock nut; 29. a spacer sleeve;

30. twisting and punching the shell; 31. an end cap; 32. a commutation structure; 320. a reversing body; 321. a first outward-shifting convex column; 322. a second outward-changing convex column; 323. reversing through the groove; 324. a positioning channel; 325. a reversing flow channel; 33. a pendulum bob; 330. a hammer body; 331. the side wall of the first pendulum bob is provided with a through groove; 332. the side wall of the second pendulum bob is provided with a through groove; 333. the side wall of the third pendulum bob is provided with a through groove; 334. a fourth pendulum through groove in the side wall; 335. a pendulum fan-shaped outer convex column; 336. a pendulum fan-shaped inner convex column; 34. an impact cylinder; 340. a cartridge body; 341. a fan-shaped through groove of the impact cylinder; 342. an impingement tube inner channel; 343. an impingement cylinder outer channel; 344. the outer channel penetrates through the groove; 345. a first step portion; 346. a second step portion; 35. and (5) lower centering bearings.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

The specific embodiments of the present invention described herein are for the purpose of illustration only and are not to be construed as limiting the invention in any way. Any possible variations based on the present invention may be conceived by the skilled person in the light of the teachings of the present invention, and these should be considered to fall within the scope of the present invention. It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Unless defined otherwise, 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 in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 to 11, the present invention provides a torsional impact screw drill 100, which includes a screw drill body, the screw drill body includes a bypass valve assembly for controlling the flow direction of drilling fluid, a motor assembly is disposed below the bypass valve assembly, the motor assembly is connected to a transmission shaft assembly through a universal shaft assembly, the motor assembly is used for converting hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around a central shaft, and the bottom of the transmission shaft assembly is used for connecting a drill bit (PDC drill bit, prior art, not shown in the figure); the lower part of the transmission shaft assembly is sleeved with an axially fixed torsional impact assembly which is used for converting the fluid energy of the drilling fluid into torsional impact force on the transmission shaft assembly.

Further, as shown in fig. 1 and 4, the transmission shaft assembly transmits the rotary power of the motor assembly to the output torque and the rotary speed of the drill bit, and simultaneously bears the axial and radial loads generated by the bit weight. The transmission shaft assembly comprises a transmission shaft 25, a transmission shaft center hole 250 which is axially communicated is formed in the transmission shaft 25, a first radial through hole 251 is radially communicated with the position, above the torsional impact assembly, on the side wall of the transmission shaft 25, a second radial through hole 252 is radially communicated with the position, below the torsional impact assembly, on the side wall of the transmission shaft 25, and a plurality of long through grooves 253 are circumferentially arranged on the side wall of the transmission shaft 25 at intervals, opposite to the torsional impact assembly; in an embodiment of the present invention, the sidewall of the transmission shaft 25 is provided with 4 first radial through holes 251 spaced 90 ° apart from each other, the sidewall of the transmission shaft 25 is provided with 6 long through grooves 253 (rectangular through grooves) spaced 60 ° apart from each other, and the sidewall of the transmission shaft 25 is provided with 4 second radial through holes 252 spaced 90 ° apart from each other. A sixth step 254 with a reduced diameter is arranged in the central hole 250 of the transmission shaft below the long through groove 253, and a contracted hole at the sixth step 254 forms a nozzle structure, where the flow passage area is suddenly reduced to generate a local pressure drop, so that a part of high-pressure fluid flows out from the first radial through hole 251 of the transmission shaft 25 or the long through groove 253 to enter the flow passage of the reversing structure 32, the pendulum 33 and the impact barrel 34.

Drilling fluid in the central bore 250 of the drive shaft can flow from top to bottom through the first radial through-hole 251 to the torsional impact assembly, drilling fluid in the central bore 250 of the drive shaft can flow from inside to outside through the long through-groove 253 to the torsional impact assembly, and drilling fluid flowing through the torsional impact assembly flows back into the central bore 250 of the drive shaft through the second radial through-hole 252. In an embodiment of the present invention, the first radial through hole 251 is horizontally disposed, and the second radial through hole 252 is obliquely disposed from outside to inside, which facilitates the drilling fluid to flow back to the central hole 250 of the transmission shaft. Part of the drilling fluid directly flows to the drill bit through the transmission shaft center hole 250 for drilling; part of the drilling fluid flows to the torsional impact assembly through the first radial through hole 251 or the long through groove 253, and the torsional impact assembly reciprocates relative to the transmission shaft 25 under the action of the drilling fluid to generate torsional impact.

Further, as shown in fig. 1, 5, 6 and 7, the torsional impact assembly converts the fluid energy of the drilling fluid into torsional impact force, which in turn transfers the energy to the drill bit. The torsional impact assembly comprises a reversing structure 32, a pendulum bob 33 and an impact cylinder 34 which are sequentially sleeved on the transmission shaft 25 from inside to outside and are axially fixed, the lower part of the impact cylinder 34 is hermetically sleeved on the transmission shaft 25, and in the embodiment, the lower part of the impact cylinder 34 is connected on the transmission shaft 25 through threads; the pendulum bob 33 can circumferentially reciprocate under the action of the drilling fluid to impact the impact barrel 34; the inner wall of the reversing structure 32 is abutted and sleeved on the transmission shaft 25, the inner wall of the pendulum 33 is abutted with the outer wall of the reversing structure 32 in a rotating manner, and the outer wall of the pendulum 33 is abutted with the inner wall of the impact barrel 34 in a rotating manner. The impact cylinder 34 rotates synchronously with the transmission shaft 25, the reversing structure 32 and the pendulum bob 33 also rotate around the central axis of the transmission shaft 25, and simultaneously, under the action of the drilling fluid flowing out through the first radial through hole 251 or the long through groove 253, the reversing structure 32 and the pendulum bob 33 swing back and forth relative to the transmission shaft 25 and the impact cylinder 34, so that torsional impact is generated on the transmission shaft 25 and the impact cylinder 34.

Further, as shown in fig. 1, a transmission shaft shell 27 is sleeved on the outer side of the upper portion of the transmission shaft 25, a torsional impact shell 30 is connected below the transmission shaft shell 27, the bottom end of the transmission shaft 25 penetrates through the bottom end of the torsional impact shell 30 to be connected with a drill bit, and the outer wall of the impact cylinder 34 and the inner wall of the torsional impact shell 30 are rotatably abutted; as shown in fig. 7, the impact cylinder 34 includes a cylinder body 340 (hollow cylindrical structure), and 2 impact cylinder sector grooves 341 with top openings and radially symmetrical arrangement are disposed on the side wall of the cylinder body 340; the inner wall of the cylinder body 340 is provided with 2 impact cylinder inner channel channels 342 which are symmetrical in the radial direction, the 2 impact cylinder inner channel channels 342 and the 2 impact cylinder fan-shaped through grooves 341 are arranged in a cross shape, the top of each impact cylinder inner channel 342 is opened, and the bottom end of each impact cylinder inner channel 342 is flush with the bottom of each impact cylinder fan-shaped through groove 341; the outer wall of the cylinder body 340 is provided with impact cylinder outer channels 343 at two circumferential sides of each impact cylinder inner channel 342, the top of each impact cylinder outer channel 343 is open and the bottom end of each impact cylinder outer channel 343 is higher than the bottom of the impact cylinder fan-shaped through groove 341, and a radially through outer channel through groove 344 is arranged in each impact cylinder outer channel 343; the end cover 31 is hermetically sleeved below the first radial through hole 251 on the transmission shaft 25, the bottom surface of the end cover 31 is axially propped against the top surface of the cylinder body 340, the outer wall of the end cover 31 and the inner wall of the torsional impact shell 30 are rotatably propped against the end cover, and the end cover 31 is provided with an end cover flow-through groove which can be communicated with the impact cylinder outer channel 343.

Further, as shown in fig. 5, the reversing structure 32 includes a cylindrical reversing body 320, two first outward-changing protruding columns 321 which are axially through and radially symmetrically arranged are disposed on an outer wall of the reversing body 320, two second outward-changing protruding columns 322 which are axially through and radially symmetrically arranged are also disposed on an outer wall of the reversing body 320, and the 2 first outward-changing protruding columns 321 and the 2 second outward-changing protruding columns 322 are arranged in a cross manner; the 2 first outward-changing convex columns 321 are respectively provided with a reversing through groove 323 which is radially through, the number of the reversing through grooves 323 on each first outward-changing convex column 321 is 2, and the reversing through grooves 323 on the 2 first outward-changing convex columns 321 are radially and symmetrically arranged; the 2 second outward-changing convex columns 322 are provided with positioning channels 324 arranged from bottom to top, and the tops of the positioning channels 324 are arranged in a closed manner; an axially through reversing flow channel 325 is formed between the adjacent first reversing outer convex column 321 and the second reversing outer convex column 322;

as shown in fig. 6, the pendulum 33 includes a cylindrical hammer body 330, two pendulum fan-shaped outer protruding columns 335 are axially through and radially symmetrically disposed on an outer wall of the hammer body 330, a first pendulum side wall through groove 331 and a second pendulum side wall through groove 332 are respectively disposed on two circumferential sides of each pendulum fan-shaped outer protruding column 335 on a side wall of the hammer body 330, each pendulum fan-shaped outer protruding column 335 is swingably disposed in a corresponding impact cylinder fan-shaped through groove 341, and a central angle of the impact cylinder fan-shaped through groove 341 is greater than that of the pendulum fan-shaped outer protruding column 335; the inner wall of the hammer body 330 is provided with two pendulum fan-shaped inner convex columns 336 which are axially communicated and radially and symmetrically arranged, the two pendulum fan-shaped inner convex columns 336 and the two pendulum fan-shaped outer convex columns 335 are arranged in a cross manner, the two circumferential sides of each pendulum fan-shaped inner convex column 336 on the side wall of the hammer body 330 are respectively provided with a third pendulum side wall through groove 333 and a fourth pendulum side wall through groove 334, the two pendulum fan-shaped inner convex columns 336 can be respectively and swingably sleeved in the two positioning channels 324, and the central angle of each positioning channel 324 is larger than that of each pendulum fan-shaped inner convex column 336; the top surface of each pendulum fan-shaped inner post 336 can axially abut against the top surface of each positioning channel 324.

Further, as shown in fig. 7, a first step 345 with a reduced diameter is disposed on the inner wall of the cylinder body 340 at the bottom of the impact cylinder fan-shaped through slot 341, and the bottom surface of the hammer body 330 abuts against the first step 345, so as to realize downward axial position limitation of the pendulum 33; second step parts 346 with reduced diameters are axially arranged below the first step parts 345 at intervals, and the inner wall of the cylinder body 340 below the second step parts 346 is abutted and sleeved on the transmission shaft 25; the second radial through hole 252 communicates with the interior cavity of the impingement cylinder 34 above the second step 346. The drilling fluid which drives the torsional impact assembly to generate circumferential torsional impact reaches the inner cavity of the impact barrel 34 above the second step portion 346 and then flows back to the central hole 250 of the transmission shaft through the second radial through hole 252.

Further, as shown in fig. 1, an upper centering bearing 24 is disposed between the top of the inner wall of the transmission shaft housing 27 and the transmission shaft 25, and in the present embodiment, the upper portion of the upper centering bearing 24 is connected to the transmission shaft 25 by a thread; a thrust bearing group 26 is axially supported and arranged below the upper centering bearing 24, a lower lock nut 28 is arranged on the transmission shaft 25 and below the thrust bearing group 26, the top surface of the lower lock nut 28 is axially supported and abutted with the bottom surface of the inner ring of the thrust bearing group 26, the lower lock nut 28 is mounted on the transmission shaft 25 through threaded connection and is positioned below the thrust bearing group 26 to axially position the lower lock nut 28, a spacer sleeve 29 is sleeved outside the lower lock nut 28 and concentrically mounted and radially spaced with the lower lock nut, the top end of the torsional impact shell 30 is sleeved in the transmission shaft shell 27, the top surface of the spacer sleeve 29 is axially supported and abutted with the bottom surface of the outer ring of the thrust bearing group 26, and the bottom surface of the spacer sleeve 29 is axially supported and abutted with the top surface of the torsional impact shell 30; a lower righting bearing 35 is arranged between the bottom of the inner wall of the torsional impact shell 30 and the transmission shaft 25, and the upper part of the lower righting bearing 35 is connected into the torsional impact shell 30 through threads in the embodiment.

Furthermore, an anti-drop assembly is connected in series between the bypass valve assembly and the motor assembly and is used for preventing the motor assembly, the cardan shaft assembly and the transmission shaft assembly from dropping into a well during accidents (thread tripping and shell fracture) or facilitating fishing of a drilling tool after the drilling tool drops into the well.

As shown in fig. 1 and 2, in the present embodiment, the bypass valve assembly includes a bypass valve body 1, and the bypass valve body 1 is provided with a valve body center hole that penetrates in the axial direction; the valve core 2 is slidably sleeved in the central hole of the valve body, the valve core 2 is provided with an axially through valve core central hole, the lower part of the inner side of the bypass valve body 1 is sleeved with the valve sleeve 6, the valve sleeve 6 is provided with an axially through valve sleeve central hole, the valve core 2 can slide up and down along the valve sleeve central hole, the bottom of the valve sleeve 6 in the bypass valve body 1 is provided with an elastic retainer ring 7, and the valve sleeve 6 is axially positioned through the elastic retainer ring 7; a sealing ring 5 is arranged between the outer walls of the valve core 2 and the valve sleeve 6 and the inner wall of the bypass valve body 1, so that the sealing property is ensured; a third step part is arranged on the outer wall of the valve core 2, a fourth step part is arranged on the outer wall of the valve sleeve 6, the valve core 2 is sleeved with a spring 3, and two ends of the spring 3 respectively prop against the third step part and the fourth step part; the side wall of the valve core 2 is provided with valve core side through holes which are radially penetrated, and in a specific embodiment of the invention, the side wall of the valve core 2 is provided with 3 valve core side through holes which are mutually separated by 120 degrees; a valve port is radially arranged on the side wall of the bypass valve body 1 in a through manner, and a sieve plate 4 is arranged in the valve port; the bypass valve assembly controls the flow direction of fluid, when the flow rate and the pressure of drilling fluid do not reach standard set values, the central hole of the valve core is communicated with the valve port through the through hole at the side of the valve core, and the drilling fluid flows out through the sieve plate 4 and enters the annular space at the outer side of the bypass valve body 1; when the flow and the pressure of the drilling fluid reach standard set values, the valve core 2 moves downwards to enter the valve sleeve 6, the through hole on the side of the valve core is closed, and the drilling fluid flows into the central hole of the valve sleeve through the central hole of the valve core;

the motor assembly comprises a stator 11, a rotor 12 is arranged on the inner side of the stator 11 in a matching mode, the stator 11 and the rotor 12 are both provided with spiral lines and are meshed with each other; a rotor central hole which is axially through is arranged on the rotor 12, and a motor annular flow channel is formed between the rotor 12 and the stator 11; the motor assembly is a power part, and the rotor rotates around the axis of the stator under the driving of drilling fluid (pressure mud) to complete the conversion of liquid pressure energy to mechanical energy and provide power for the drill bit.

The anti-drop assembly comprises a hollow anti-drop joint 9, the top of the anti-drop joint 9 is connected with the bypass valve body 1, the bottom of the anti-drop joint 9 is connected in the stator 11 in a penetrating mode, an anti-drop connecting rod 10 is sleeved in the anti-drop joint 9, an anti-drop annular space is formed between the outer wall of the anti-drop connecting rod 10 and the inner wall of the anti-drop joint 9, and the anti-drop annular space is axially communicated with a valve sleeve central hole and a motor annular space flow channel; the bottom end of the anti-drop connecting rod 10 is connected in the central hole of the rotor in a penetrating way, and in one specific embodiment of the invention, the bottom end of the anti-drop connecting rod 10 is connected in the central hole of the rotor through a thread; set up the fifth step portion that the diameter is the reduction setting on the inner wall of anti-falling joint 9, the top cover of anti-falling connecting rod 10 is established and is prevented falling the lock mother 8, and in this embodiment, anti-falling lock mother 8 and anti-falling connecting rod 10 pass through threaded connection, and anti-falling lock mother 8 can block on fifth step portion.

Further, the universal shaft assembly transmits the power of the motor assembly to the transmission shaft assembly, the universal shaft assembly comprises a universal shaft shell 14, two ends of the universal shaft shell 14 are respectively connected with the stator 11 and the transmission shaft shell 27, and an inner cavity of the universal shaft shell 14 is communicated with an inner cavity of the stator 11; a movable hinge 13 is arranged in the universal shaft shell 14, the top end of the movable hinge 13 is connected in the central hole of the rotor, and in a specific embodiment of the invention, the top end of the movable hinge 13 is connected in the central hole of the rotor through threads; a connecting rod 19 is connected to a bottom end ball of the movable hinge 13, specifically, as shown in fig. 3, a blind hole is inwards formed in the center of the bottom end of the movable hinge 13, a ball seat 15 is arranged in the blind hole, a pressure bearing ball 16 is arranged at a position, corresponding to the ball seat 15, of the top end of the connecting rod 19, the pressure bearing ball 16 can be hinged in the ball seat 15, a transmission ball 17 is arranged between the top end of the outer wall of the connecting rod 19 and the inner wall of the blind hole, a sealing sleeve 20 is sleeved on the outer wall of the connecting rod 19, a blocking sleeve 21 is arranged at the top of the sealing sleeve 20, the top of the connecting rod 19 is in locking connection with the bottom end of the movable hinge 13 through a locking sleeve 18, and the locking sleeve 18 is in threaded connection with the movable hinge 13; the ball at the bottom end of the connecting rod 19 is connected with a water cap structure 22, in the embodiment, the water cap structure 22 is connected with the connecting rod 19 through threads, and the ball connection mode at the bottom end of the connecting rod 19 is the same as that at the top end of the connecting rod 19; the water cap structure 22 is provided with a water cap shaft blind hole from bottom to top, the water cap shaft blind hole is communicated with the central hole of the transmission shaft, and the side wall of the water cap structure 22 is provided with a water cap side through hole which is communicated with the inner cavity of the universal shaft shell 14 and the water cap shaft blind hole. In an embodiment of the present invention, 3 through holes spaced 120 ° apart from each other are formed on the sidewall of the water cap structure 22, and the through holes are inclined downward from outside to inside to facilitate the drilling fluid to flow into the central hole 250 of the transmission shaft.

In the present embodiment, a bushing 23 is disposed between the bottom of the water cap structure 22 and the top of the upper centering bearing 24.

In summary, the bypass valve assembly comprises a bypass valve body 1, a valve core 2, a spring 3, a sieve plate 4, a sealing ring 5, a valve sleeve 6 and an elastic retainer ring 7; the anti-falling assembly comprises an anti-falling lock nut 8, an anti-falling joint 9 and an anti-falling connecting rod 10; the motor assembly comprises a stator 11 and a rotor 12; the universal shaft assembly comprises a movable hinge 13, a universal shaft shell 14, a ball seat 15, a pressure bearing ball 16, a transmission ball 17, a locking sleeve 18, a connecting rod 19, a sealing sleeve 20 and a blocking sleeve 21; the transmission shaft assembly comprises a water cap structure 22, a shaft sleeve 23, an upper centering bearing 24, a transmission shaft 25, a thrust bearing group 26, a transmission shaft shell 27, a lower lock nut 28, a spacer bush 29 and a lower centering bearing 35; the torsional impact assembly includes a torsional impact housing 30, an end cap 31, a reversing structure 32, a pendulum 33, and an impact barrel 34. The bypass valve body 1, the anti-drop joint 9, the stator 11, the universal shaft shell 14, the transmission shaft shell 27 and the torsional impact shell 30 are connected through threads to form the shell structure of the invention.

After the drilling fluid enters the valve body central hole, when the flow rate and the pressure of the drilling fluid reach standard set values, the main channel of the drilling fluid is a valve core central hole, a valve sleeve central hole, an anti-drop annulus, a motor annulus flow channel, an inner cavity of the universal shaft shell 14, a water cap side through hole, a water cap shaft blind hole and a transmission shaft central hole 250, part of the drilling fluid in the transmission shaft central hole 250 flows to a torsional impact assembly through a first radial through hole 251 or a long through groove 253, the torsional impact assembly is enabled to perform torsional impact and then flows downwards and back to the transmission shaft central hole 250 through a second radial through hole 252, and all the drilling fluid flows to a drill bit through the transmission shaft central hole 250.

The torsional impact screw drill 100 takes drilling fluid as a driving medium, the drilling fluid flows into a valve core central hole of a valve core 2 from a valve body central hole of a bypass valve body 1, when the flow rate and the pressure of the drilling fluid do not reach standard set values, the valve core central hole is communicated with a valve port through a valve core side through hole, the drilling fluid flows out through a sieve plate 4, enters an annular space at the outer side of the bypass valve body 1 and is in a bypass state; when the flow and the pressure of the drilling fluid reach standard set values, the valve core 2 moves downwards to enter the valve sleeve 6, the through hole on the side of the valve core is closed, and the drilling fluid flows into the central hole of the valve sleeve through the central hole of the valve core;

the drilling fluid flows out from the valve sleeve central hole of the valve sleeve 6, flows into a motor annular flow channel (spiral sealing cavity) between the stator 11 and the rotor 12 through the anti-drop joint 9, the rotor 12 rotates, the whole universal shaft assembly also rotates, the universal shaft assembly transmits the rotating speed and the torque to the transmission shaft 25 and finally to the drill bit, and the working principle of the conventional screw drilling tool is that.

The drilling fluid flows from the motor annulus flow path to the inner cavity of the cardan shaft housing 14 and then flows from the water cap side through hole and the water cap shaft blind hole of the water cap structure 22 to the transmission shaft center hole 250 (i.e., the middle flow path) of the transmission shaft 25.

The flow path area at the sixth step 254 in the central bore 250 of the drive shaft is abruptly reduced, creating a localized pressure drop, causing a portion of the high pressure fluid to flow out of the first radial through hole 251 or slot 253 of the drive shaft 25 into the flow path of the reversing structure 32, the pendulum 33, and the impact barrel 34. Drilling fluid flows into the twisting and impacting assembly, and the twisting and impacting assembly starts to operate.

As shown in fig. 8, when the pendulum 33 rotates counterclockwise to the extreme position as an initial state, at this time, the pendulum fan-shaped inner convex post 336 of the pendulum 33 abuts against one clockwise side of the positioning channel 324 on the reversing structure 32, the through slot 253 on the transmission shaft 25 communicates with the reversing through slot 323 of the first outward convex post 321 on the reversing structure 32, high-pressure drilling fluid flows in, the drilling fluid pushes the pendulum 33 and the reversing structure 32 to rotate clockwise together, and the state of the rotation process is as shown in fig. 9;

as shown in fig. 10, when the pendulum 33 rotates clockwise to the limit position, a violent collision is generated on the impact barrel 34 and stops at the moment that the pendulum fan-shaped outer convex column 335 of the pendulum 33 contacts the impact barrel 34, at this moment, the positioning channel 324 of the reversing structure 32 is communicated with the impact barrel outer channel 343 (a passage of high-pressure drilling fluid) through the third pendulum side wall through groove 333 and the outer channel through groove 344, and the high-pressure drilling fluid flows into the positioning channel 324 to drive the reversing structure 32 to rotate clockwise to the limit position (the pendulum fan-shaped inner convex column 336 abuts against the counterclockwise side of the positioning channel 324 on the reversing structure 32) and stops.

At this time, as shown in fig. 11, the pendulum 33 and the reversing structure 32 rotate clockwise to the limit position, the first pendulum sidewall through slot 331 at the clockwise side of the pendulum fan-shaped outer boss 335 communicates with the reversing through slot 323 of the first reversing outer boss 321, and the high-pressure fluid flows in, pushing the pendulum 33 and the reversing structure 32 to rotate counterclockwise together until both the pendulum 33 and the reversing structure 32 reach the limit position (the aforementioned initial state, as shown in fig. 8), and completing a torsional impact motion cycle.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.

Claims

1. A torsional impact screw drill is characterized by comprising a screw drill body, wherein the screw drill body comprises a bypass valve assembly for controlling the flow direction of drilling fluid, a motor assembly is arranged below the bypass valve assembly and is connected with a transmission shaft assembly through a universal shaft assembly, the motor assembly is used for converting hydraulic power of the drilling fluid into mechanical energy for driving the transmission shaft assembly to rotate around a central shaft, and the bottom of the transmission shaft assembly is used for connecting a drill bit; the lower part of the transmission shaft assembly is sleeved with an axially fixed torsional impact assembly, and the torsional impact assembly is used for converting fluid energy of drilling fluid into torsional impact force on the transmission shaft assembly;

the transmission shaft assembly comprises a transmission shaft, an axially-through transmission shaft center hole is formed in the transmission shaft, a first radial through hole is radially arranged on the side wall of the transmission shaft above the torsional impact assembly in a through mode, a second radial through hole is radially arranged on the side wall of the transmission shaft below the torsional impact assembly in a through mode, a plurality of long through grooves are circumferentially arranged on the side wall of the transmission shaft at intervals in a position opposite to the torsional impact assembly, a sixth step portion with the diameter reduced is arranged in the transmission shaft center hole below the long through grooves, and a nozzle structure is formed by shrinkage cavities at the sixth step portion; the drilling fluid in the central hole of the transmission shaft can flow to the torsional impact assembly from top to bottom through the first radial through hole, the drilling fluid in the central hole of the transmission shaft can flow to the torsional impact assembly from inside to outside through the long through groove, and the drilling fluid flowing through the torsional impact assembly flows back into the central hole of the transmission shaft through the second radial through hole.

2. The torsional impact screw drill of claim 1, wherein the torsional impact assembly comprises a reversing structure, a pendulum and an impact barrel, which are sequentially sleeved on the transmission shaft from inside to outside and are axially fixed, the lower part of the impact barrel is hermetically sleeved on the transmission shaft, and the pendulum can circumferentially reciprocate to impact the impact barrel under the action of drilling fluid; the inner wall of the reversing structure is abutted to and sleeved on the transmission shaft, the inner wall of the pendulum bob is rotated and abutted to the outer wall of the reversing structure, and the outer wall of the pendulum bob is rotated and abutted to the inner wall of the impact barrel.

3. The torsional impact screw drill tool of claim 2, wherein a transmission shaft shell is sleeved on the outer side of the upper part of the transmission shaft, a torsional impact shell is connected below the transmission shaft shell, the bottom end of the transmission shaft penetrates out of the bottom end of the torsional impact shell and is used for connecting a drill bit, and the outer wall of the impact cylinder and the inner wall of the torsional impact shell are rotatably abutted; the impact barrel comprises a barrel body, and 2 impact barrel fan-shaped through grooves with openings at the tops and arranged radially and symmetrically are formed in the side wall of the barrel body; the inner wall of the cylinder body is provided with 2 impact cylinder inner channels which are radially symmetrical, the 2 impact cylinder inner channels and the 2 impact cylinder fan-shaped through grooves are arranged in a cross manner, the top of each impact cylinder inner channel is opened, and the bottom of each impact cylinder inner channel is flush with the bottom of each impact cylinder fan-shaped through groove; the outer wall of the cylinder body is provided with impact cylinder outer channels at two circumferential sides of each impact cylinder inner channel, the top of each impact cylinder outer channel is opened, the bottom of each impact cylinder outer channel is higher than the bottom of the impact cylinder fan-shaped through groove, and a radially through outer channel through groove is arranged in each impact cylinder outer channel; the end cover is arranged below the first radial through hole in a sealing sleeved mode on the transmission shaft, the bottom face of the end cover is axially abutted to the top face of the barrel body, the outer wall of the end cover and the inner wall of the torsional impact shell are rotatably abutted to the end cover, and the end cover which can be communicated with the outer channel of the impact barrel is arranged on the end cover and flows through the through groove.

4. The torsional impact screw drill of claim 3, wherein the reversing structure comprises a cylindrical reversing body, two first outward-changing convex columns which are axially through and radially symmetrically arranged are arranged on the outer wall of the reversing body, two second outward-changing convex columns which are axially through and radially symmetrically arranged are also arranged on the outer wall of the reversing body, and 2 first outward-changing convex columns and 2 second outward-changing convex columns are arranged in a cross manner; the 2 first outward-changing convex columns are respectively provided with a reversing through groove which is radially communicated, the 2 second outward-changing convex columns are respectively provided with a positioning channel which is arranged from bottom to top, and the tops of the positioning channels are arranged in a closed manner;

the pendulum comprises a cylindrical hammer body, two pendulum fan-shaped outer protruding columns are arranged on the outer wall of the hammer body, the two pendulum fan-shaped outer protruding columns are axially communicated, the two pendulum fan-shaped outer protruding columns are radially and symmetrically arranged, a first pendulum side wall through groove and a second pendulum side wall through groove are respectively formed in the two circumferential sides of each pendulum fan-shaped outer protruding column on the side wall of the hammer body, each pendulum fan-shaped outer protruding column can be arranged in the corresponding impact cylinder fan-shaped through groove in a swinging mode, and the central angle of each impact cylinder fan-shaped through groove is larger than that of each pendulum fan-shaped outer protruding column; the inner wall of the hammer body is provided with two pendulum fan-shaped inner protruding columns which are axially communicated and radially and symmetrically arranged, the two pendulum fan-shaped inner protruding columns and the two pendulum fan-shaped outer protruding columns are arranged in a cross manner, the two circumferential sides of each pendulum fan-shaped inner protruding column on the side wall of the hammer body are respectively provided with a third pendulum side wall through groove and a fourth pendulum side wall through groove, the two pendulum fan-shaped inner protruding columns can be respectively sleeved in the two positioning channels in a swinging manner, and the central angle of each positioning channel is larger than that of each pendulum fan-shaped inner protruding column; the top surface of each pendulum fan-shaped inner convex column can axially abut against the top surface of each positioning channel.

5. The torsional impact screw drill of claim 4, wherein a first step portion with a decreasing diameter is provided on the inner wall of the barrel body at the bottom of the fan-shaped through slot of the impact barrel, and the bottom surface of the hammer body abuts against the first step portion; second step parts with the diameters being reduced are arranged below the first step parts at axial intervals, and the inner wall of the cylinder body, which is positioned below the second step parts, is abutted and sleeved on the transmission shaft; the second radial through hole is communicated with an inner cavity of the impact barrel above the second step part.

6. The torsional impact screw drill tool of claim 4, wherein an upper centering bearing is arranged between the top of the inner wall of the transmission shaft shell and the transmission shaft, a thrust bearing group is arranged under the upper centering bearing in an axial abutting manner, a lower locking nut is arranged on the transmission shaft and is positioned under the thrust bearing group, the top surface of the lower locking nut is in an axial abutting manner with the bottom surface of the inner ring of the thrust bearing group, a spacer sleeve is sleeved on the outer side of the lower locking nut, the top end of the torsional impact shell is sleeved in the transmission shaft shell, the top surface of the spacer sleeve is in an axial abutting manner with the bottom surface of the outer ring of the thrust bearing group, and the bottom surface of the spacer sleeve is in an axial abutting manner with the top surface of the torsional impact shell; a lower righting bearing is arranged between the bottom of the inner wall of the torsional impact shell and the transmission shaft.

7. The torsional impact screw drill of claim 4, wherein a drop prevention assembly is connected in series between the bypass valve assembly and the motor assembly, the drop prevention assembly being used to prevent the motor assembly, the cardan shaft assembly and the transmission shaft assembly from dropping into the well in the event of an accident.