Drill string and friction reducing tool

Abstract

The application discloses a drill string and a friction-reducing tool, and the friction-reducing tool comprises a barrel shell, and an axial oscillation unit, a torsional impact unit, an eccentric excitation unit, a power generation unit and a pulse throttling unit are sequentially arranged in the barrel shell from top to bottom. The axial oscillation unit comprises a center pipe slidingly arranged in the barrel shell and a piston fixedly arranged on the center pipe; the torsional impact unit comprises a mandrel rotatably arranged in the barrel shell and a pendulum arranged on the mandrel; the eccentric excitation unit comprises an eccentric shaft rotatably arranged in the barrel shell, and the upper end of the eccentric shaft is fixedly connected with the mandrel; the power generation unit comprises a rotor driven by a liquid flow, and the upper end of the rotor is connected with the lower end of the eccentric shaft; and the pulse throttling unit comprises a movable valve fixedly connected with the lower end of the rotor and a fixed valve fixedly arranged on the barrel shell. The friction-reducing tool provided by the application can realize dynamic oscillation and impact load functions in three dimensions, achieve combined action and reduce friction.

Description

Technical Field

[0001] This application relates to the fields of oil and gas exploration, geological exploration, and geothermal well development technology, and in particular to a drill string and friction reduction tool. Background Technology

[0002] Currently, unconventional oil and gas resources such as shale oil and gas and tight oil and gas have become key areas for increasing reserves and production in China. One of the drilling models currently being developed is directional horizontal wells. Increasing the length of the horizontal section of an oil and gas well within the reservoir can significantly improve single-well productivity and final production, while reducing the number of wells and lowering investment. However, the long directional drilling cycle in the later stages of drilling the horizontal section has become a significant bottleneck restricting the speed and efficiency of development, thus reducing development timeliness.

[0003] To shorten the drilling cycle, friction-reducing tools are used in the drill string. Most existing friction-reducing tools reduce friction by using periodic axial oscillations to convert static friction between the drill string and the wellbore into dynamic friction. However, with increasing well depth, extended horizontal sections, and more frequent adjustments to the three-dimensional trajectory, existing friction-reducing tools relying solely on axial oscillations are no longer sufficient. Therefore, how to provide a composite friction-reducing tool to meet the drilling needs of deep, long horizontal wells has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a drill string and a friction-reducing tool that can simultaneously realize four dynamic oscillation impact load functions covering three dimensions, namely axial hydraulic oscillation force, centrifugal force, circumferential mechanical impact force, and torsional mechanical impact force, to achieve a combined effect and reduce friction.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A friction-reducing and drag-reducing tool includes a cylindrical shell, wherein an axial oscillation unit, a torsional impact unit, an eccentric excitation unit, a power generation unit, and a pulse throttling unit are arranged sequentially from top to bottom inside the cylindrical shell.

[0007] The axial oscillation unit includes a central tube slidably disposed within the cylindrical shell and a piston fixedly disposed at the lower end of the central tube. The upper chamber of the piston is connected to the outside through a vent hole opened in the cylindrical shell, and the lower chamber of the piston is connected to the lumen of the central tube through the lower port of the central tube. A disc spring assembly is disposed in the annular space between the central tube and the cylindrical shell.

[0008] The torsional impact unit includes a mandrel rotatably disposed within the cylindrical shell and a pendulum sleeved on the mandrel. The pendulum is provided with at least two hammer blocks evenly arranged circumferentially. The inner wall of the cylindrical shell is provided with impact blocks evenly arranged circumferentially. A swing cavity for accommodating the hammer blocks is formed between adjacent impact blocks. An upper fixed plate and a lower fixed plate are fixedly disposed within the cylindrical shell, respectively contacting the upper and lower end faces of the pendulum. An upper guide plate and a lower guide plate are fixedly sleeved on the outer surface of the mandrel, respectively cooperating with the upper and lower fixed plates. The upper guide plate has an inlet hole that cooperates with the guide hole of the upper fixed plate. The lower guide plate has a drain hole that cooperates with the flow hole of the lower fixed plate. A first radial flow hole is provided in the central flow channel of the mandrel at a position lower than the lower guide plate.

[0009] The eccentric vibration unit includes an eccentric shaft installed inside the cylindrical shell via an upper and a lower centralizing bearing. The upper end of the eccentric shaft is fixedly connected to the spindle. Axial flow holes are provided around the upper and lower centralizing bearings. A radial receiving groove is opened on the distal end of the eccentric shaft. An impact block is slidably disposed in the radial receiving groove. An elastic element for pushing the impact block outward is provided in the radial receiving groove. The inner wall of the cylindrical shell is provided with deceleration ridges distributed circumferentially.

[0010] The power generating unit includes a rotor driven by a fluid flow, the upper end of which is connected to the lower end of the eccentric shaft.

[0011] The pulse throttling unit includes a moving valve fixedly connected to the lower end of the rotor and a fixed valve fixedly disposed in the shell. The relative movement of the moving valve and the fixed valve generates a periodically changing flow area.

[0012] Optionally, in the above-mentioned friction reduction and drag reduction tool, the cross-section of the hammer block and the cross-section of the impact block are both fan-shaped, and the impact surface of the impact block is provided with guide grooves extending to the upper and lower end surfaces of the pendulum, respectively.

[0013] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the cross-section of the guide groove is an arc shape centered on the axis of the cylindrical shell.

[0014] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the first radial flow hole extends obliquely downward from the inside to the outside.

[0015] Optionally, in the above-mentioned friction reduction and drag reduction tool, the moving valve is provided with a moving valve center hole and a plurality of moving valve circumferential holes evenly distributed around the moving valve center hole, and the fixed valve is provided with a fixed valve center hole opposite to the moving valve center hole and a plurality of fixed valve circumferential holes evenly distributed around the fixed valve center hole.

[0016] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the impact block is a cylinder, and a bracket that slides with the radial receiving groove is provided between the impact block and the elastic element. The side of the bracket near the impact block is an arc surface.

[0017] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the cross-section of the deceleration ridge is fan-shaped.

[0018] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the rotor and the eccentric shaft are connected by a universal joint.

[0019] Optionally, in the above-mentioned friction-reducing and drag-reducing tool, the axial oscillation unit includes a balance sleeve located between the disc spring assembly and the piston. The balance sleeve is slidably disposed in the annular space between the central tube and the cylindrical shell. The lower cavity of the balance sleeve is connected to the lumen of the central tube through a connecting hole opened in the central tube. The cylindrical shell is provided with an oil injection hole corresponding to the upper cavity of the balance sleeve above the balance sleeve. An oil hole plug is provided in the oil injection hole.

[0020] A drill string comprising a friction-reducing tool as disclosed in any of the foregoing.

[0021] Compared with the prior art, the friction reduction and drag reduction tool provided in this application has the following beneficial effects:

[0022] The friction-reducing and drag-reducing tool provided in this application can simultaneously realize four dynamic oscillating impact load functions covering three dimensions: axial hydraulic oscillation force, centrifugal force, circumferential mechanical impact force, and torsional mechanical impact force. This is beneficial for converting the static friction state between the drill string and the well wall into a dynamic friction state during long horizontal drilling, thereby achieving the effects of friction reduction, drag reduction, and pressure relief. The axial oscillation frequency, eccentric excitation frequency, and torsional impact frequency generated by the friction-reducing and drag-reducing tool during operation are all related to the rotor speed of the power generation unit, which is conducive to the formation of a combined effect and superposition effect among these three dynamic loads. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of a friction-reducing and drag-reducing tool provided in an embodiment of this application;

[0025] Figure 2 for Figure 1 Schematic diagram of section AA in the diagram;

[0026] Figure 3 for Figure 1 Schematic diagram of the BB section in the diagram;

[0027] Figure 4 for Figure 1 Schematic diagram of the CC section in the diagram;

[0028] Figure 5 for Figure 1 Schematic diagram of the DD section in the diagram;

[0029] Figure 6 for Figure 1 Schematic diagram of the EE section in the diagram;

[0030] Figure 7 for Figure 1 Schematic diagram of the FF section in the diagram;

[0031] Figure 8 for Figure 1 Schematic diagram of the GG cross section in the image;

[0032] Figure 9 for Figure 1 A schematic diagram of the HH section.

[0033] The diagram is marked as follows:

[0034] 1. Drive shaft; 2. Upper connector; 3. Splined sleeve; 4. Disc spring assembly; 5. Disc spring sleeve; 6. Oil hole plug; 7. Punch pipe; 8. Balance sleeve; 9. Piston cylinder; 10. Piston; 11. Pressure cap; 12. Upper guide plate; 13. Upper fixed plate; 14. Pendulum cylinder; 15. Pendulum; 16. Lower guide plate; 17. Mandrel; 18. Upper centering bearing; 19. Eccentric shaft; 20. Eccentric shaft cylinder; 21. Lower centering bearing 21. Bearing; 22. Universal joint; 23. Universal joint sleeve; 24. Connecting rod; 25. Rotor; 26. Stator housing; 27. Moving valve sleeve; 28. Moving valve; 29. ​​Fixed valve; 30. Fixed valve sleeve; 31. Lower connector; 32. Upper cavity of sliding sleeve; 33. Lower cavity of sliding sleeve; 34. Connecting hole; 35. Breathing hole; 36. Lower cavity of piston; 37. Central flow channel; 38. First radial flow hole; 39. Upper axial flow hole; 40. Lower axial flow hole; 41. Second radial flow hole; 42. First inlet hole; 43. Second inlet hole; 44. First guide hole; 45. Second guide hole; 46. Third guide hole; 47. Fourth guide hole; 48. First guide groove; 49. Second guide groove; 50. Third guide groove; 51. Fourth guide groove; 52. First swing chamber zone one; 53. Second swing chamber zone two; 54. Second swing... 55. First swing chamber zone 1; 56. First flow passage hole; 57. Second flow passage hole; 58. Third flow passage hole; 59. Fourth flow passage hole; 60. First drain hole; 61. Second drain hole; 62. Moving valve center hole; 63. Moving valve circumferential hole; 64. Fixed valve center hole; 65. Fixed valve circumferential hole; 66. Impact block; 67. Elastic element; 68. Bracket; 69. Radial receiving groove; 70. Impact surface. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] See Figures 1-9 This application provides a friction reduction and drag mitigation tool, including a shell. Inside the shell, from top to bottom, are arranged an axial oscillation unit, a torsional impact unit, an eccentric excitation unit, a power generation unit, and a pulse throttling unit. It can simultaneously realize four dynamic oscillation impact load functions covering three dimensions, namely axial hydraulic oscillation force, circumferential mechanical impact force, centrifugal force, and torsional mechanical impact force. This is beneficial for converting the static friction state between the drill string and the well wall into a dynamic friction state during long horizontal drilling, thereby achieving the effects of friction reduction, drag mitigation, and pressure relief.

[0037] The axial oscillation unit includes a central tube slidably disposed within a cylindrical shell and a piston 10 fixedly disposed at the lower end of the central tube. The upper chamber of the piston 10 communicates with the outside through a breather hole 35 opened in the cylindrical shell, and the lower chamber 36 of the piston 10 communicates with the lumen of the central tube through the lower port of the central tube. A disc spring assembly 4 is disposed in the annular space between the central tube and the cylindrical shell. In this embodiment, the portion of the cylindrical shell corresponding to the axial oscillation unit includes a splined cylinder 3, a disc spring cylinder 5, and a piston cylinder 9. The central tube includes a drive shaft 1 and a punch 7. The lower end of the drive shaft 1 passes through the upper connector 2, the splined cylinder 3, and the disc spring assembly 4 sequentially from top to bottom, and the lower end of the drive shaft 1 is threadedly connected to the punch 7. The lower end of the punch 7 passes through the inner hole of the piston cylinder 9 and is threadedly connected to the piston 10. The outer side of the middle part of the drive shaft 1 is engaged with the splined cylinder 3 through a spline for transmission and can move up and down within the splined cylinder 3. The upper and lower ends of the splined cylinder 3 are threadedly connected to the upper connector 2 and the disc spring cylinder 5, respectively, and the lower end of the disc spring cylinder 5 is threadedly connected to the piston cylinder 9. The piston cylinder 9 has a vent 35 in the middle to ensure that the pressure on the upper end face of the piston 10 is consistent with the outside. The inner wall of the piston cylinder 9 fits against the outer circular surface of the piston 10 and enables the piston 10 to move up and down. The piston lower chamber 36 is formed between the inner wall of the piston cylinder 9 and the lower end face of the piston 10.

[0038] The torsional impact unit includes a spindle 17 rotatably disposed within a cylindrical shell and a pendulum 15 sleeved on the spindle 17. The pendulum 15 is provided with at least two hammer blocks evenly arranged circumferentially. The inner wall of the cylindrical shell is provided with impact blocks evenly arranged circumferentially, and a swing cavity for accommodating the hammer blocks is formed between adjacent impact blocks. An upper fixed plate 13 and a lower fixed plate are fixedly disposed within the cylindrical shell, respectively contacting the upper and lower end faces of the pendulum 15. An upper guide plate 12 and a lower guide plate 16 are fixedly sleeved on the outer surface of the spindle 17, respectively cooperating with the upper fixed plate 13 and the lower fixed plate. The upper guide plate 12 has an inlet hole that cooperates with the guide hole of the upper fixed plate 13, and the lower guide plate 16 has a drain hole that cooperates with the flow hole of the lower fixed plate. The central flow channel 37 of the spindle 17 is provided with a first radial flow hole 38 at a position lower than the lower guide plate 16. In this embodiment, the portion of the cylindrical shell corresponding to the torsional impact unit includes a pendulum cylinder 14, which is threadedly connected to the lower end of the piston cylinder 9. Figure 4 As shown, two impact blocks are symmetrically arranged on the inner wall of the pendulum cylinder 14, and two hammer blocks are symmetrically arranged on the pendulum 15. After the pendulum 15 is placed inside the pendulum cylinder 14, a first swing cavity region 52, a first swing cavity region 55, a second swing cavity region 54, and a second swing cavity region 53 are formed. That is, one hammer block moves in the first swing cavity, causing the volumes of the first swing cavity region 52 and the first swing cavity region 55 to change dynamically with each other; the other hammer block moves in the second swing cavity, causing the volumes of the second swing cavity region 54 and the second swing cavity region 53 to change dynamically with each other with each other. The upper end face of the pendulum 15 contacts the lower end face of the upper fixed plate 13, as shown. Figure 3As shown, the outer side of the upper fixed plate 13 is connected and fixed to the pendulum cylinder 14. The upper fixed plate 13 is provided with a first guide hole 44, a second guide hole 45, a third guide hole 46, and a fourth guide hole 47. The lower end face of the pendulum 15 contacts the upper end face of the lower fixed plate, as shown. Figure 5 As shown, the lower fixed plate and the pendulum cylinder 14 are an integral structure. The lower fixed plate and the upper fixed plate 13 have four flow holes corresponding to the four guide holes, namely, the first flow hole 56, the second flow hole 57, the third flow hole 58, and the fourth flow hole 59. The spindle 17 passes through the upper guide plate 12, the upper fixed plate 13, the pendulum 15, the lower fixed plate, and the lower guide plate 16 sequentially from top to bottom. The upper end of the spindle 17 is threaded to the pressure cap 11. A through-flow central flow channel 37 is provided inside the spindle 17, and a first radial flow hole 38 is provided on the lower circumference of the spindle 17. Figure 2 and Figure 6 As shown, the spindle 17 is connected to the upper guide plate 12 and the lower guide plate 16 through six aspects for transmission. The upper guide plate 12 is symmetrically provided with a first liquid inlet hole 42 and a second liquid inlet hole 43 on its circumference. The lower guide plate 16 is symmetrically provided with a first liquid outlet hole 60 and a second liquid outlet hole 61 on its circumference. The first liquid inlet hole 42 and the second liquid inlet hole 43 are respectively at a 90° angle to the first liquid outlet hole 60 and the second liquid outlet hole 61 on the circumference.

[0039] The eccentric vibration unit includes an eccentric shaft 19 mounted inside the casing via an upper centralizing bearing 18 and a lower centralizing bearing 21. The upper end of the eccentric shaft 19 is fixedly connected to a spindle 17. Axial flow holes are provided around both the upper centralizing bearing 18 and the lower centralizing bearing 21. A radial receiving groove 69 is formed on the distal end of the eccentric shaft 19. An impact block 66 is slidably disposed within the radial receiving groove 69. An elastic element 67 for pushing the impact block 66 outward is provided in the radial receiving groove 69. The inner wall of the casing is provided with deceleration ridges distributed circumferentially. In this embodiment, the portion of the casing corresponding to the eccentric vibration unit includes an eccentric shaft cylinder 20, such as... Figure 7 As shown, three fan-shaped deceleration ridges are evenly distributed on the inner side of the eccentric shaft cylinder 20. These ridges protrude from the inner wall of the eccentric shaft cylinder 20, forming an impact surface 70. The impact block 66 can move flexibly within the radial receiving groove 69 of the eccentric shaft 19. Under the thrust of the elastic element 67, the impact block 66 extends out of the eccentric shaft 19 and contacts the inner wall of the eccentric shaft cylinder 20. Figure 1 As shown, the upper centralizing bearing 18 is provided with an upper axial flow hole 39 on its circumference, and the lower centralizing bearing 21 is provided with a lower axial flow hole 40 on its circumference.

[0040] The power generating unit includes a rotor 25 driven by fluid flow, with its upper end connected to the lower end of an eccentric shaft 19. The pulse throttling unit includes a movable valve 28 fixedly connected to the lower end of the rotor 25 and a fixed valve 29 fixedly disposed in the cylindrical shell. The relative motion of the movable valve 28 and the fixed valve 29 generates a periodically changing flow area. In this embodiment, the portion of the cylindrical shell corresponding to the power generating unit includes a stator housing 26. The lower end of the stator housing 26 is threadedly connected to a lower connector 31. Inside the stator housing 26, from top to bottom, are a connecting rod 24, a rotor 25, a movable valve sleeve 27, a movable valve 28, a fixed valve 29, and a fixed valve sleeve 30. The rotor 25 can rotate within the stator housing 26. The upper and lower ends of the rotor 25 are threadedly connected to the connecting rod 24 and the movable valve sleeve 27, respectively. A second diameter is provided on the circumference of the movable valve sleeve 27. The moving valve sleeve 27 and the moving valve 28 are connected by an interference fit through the flow hole 41. The moving valve 28 has a through-hole 62 at its center and circumference holes 63 on its circumference. The lower end face of the moving valve 28 contacts the upper end face of the fixed valve 29. The fixed valve 29 has a through-hole 64 at its center and circumference holes 65 on its circumference. Specifically, the number of fixed valve circumference holes 65 can be the same as the number of moving valve circumference holes 63. The lower end face of the fixed valve 29 contacts the upper end face of the lower connector 31, and the outer side of the fixed valve 29 is connected and fixed to the lower connector 31 through the fixed valve sleeve 30.

[0041] During operation, the drilling fluid flows downward into the piston lower chamber 36 through the central hole of the drive shaft 1 and the flushing pipe 7. Then, a portion of the drilling fluid flows downward from the central flow passage 37 through the first radial flow hole 38, the upper axial flow hole 39, and the lower axial flow hole 40 in sequence, and then flows into the volume chamber in the stator housing 26, driving the rotor 25 to rotate and forming a rotational power source. The lower end of the rotor 25 drives the moving valve 28 to rotate through the moving valve sleeve 27, causing the moving valve circumferential hole 63 and the fixed valve circumferential hole 65 to alternately connect and close. When the moving valve circumferential hole 63 and the fixed valve circumferential hole 65 are connected, the drilling fluid can flow through both the central channel and the circumferential channel of the moving valve 28 and the fixed valve 29, resulting in a large flow area. When the moving valve circumferential hole 63 and the fixed valve circumferential hole 65 are closed, the drilling fluid can only flow through the central channel of the moving valve 28 and the fixed valve 29, resulting in a small flow area. The alternating increase and decrease of the flow area will generate periodic pressure pulse waves. The pressure pulse waves are transmitted upward to the piston lower chamber 36. Driven by the piston 10, the transmission shaft 1 and the punch pipe 7 compress the disc spring assembly 4 to form a reciprocating extension and retraction motion, generating axial hydraulic oscillation force.

[0042] At the same time, the upper end of the rotor 25 drives the eccentric shaft 19 to rotate. On the one hand, since the center of mass of the eccentric shaft 19 is not on the axis, the rotation of the eccentric shaft 19 generates a rope-like centrifugal force. On the other hand, during the movement of the impact block 66 on the inner wall of the eccentric shaft cylinder 20, it will periodically collide with the impact surface 70 to generate a circumferential mechanical impact force. After colliding with the impact surface 70, the impact block 66 will overcome the thrust of the elastic element 67 and retract into the radial receiving groove 69. It will then extend again after it is no longer in contact with the deceleration ridge.

[0043] The upper end of the eccentric shaft 19 also drives the spindle 17 to rotate. Under the drive of the spindle 17, the upper guide plate 12 and the lower guide plate 16 rotate synchronously relative to the upper fixed plate 13 and the lower fixed plate. When the first inlet hole 42 and the second inlet hole 43 of the upper guide plate 12 are connected to the first guide hole 44 and the third guide hole 46 of the upper fixed plate 13 respectively, the first outlet hole 60 and the second outlet hole 61 of the lower guide plate 16 are connected to the second flow hole 57 and the fourth flow hole 59 of the lower fixed plate respectively, so that a part of the drilling fluid flows through the first inlet hole 42 and the second outlet hole 43. A guide hole 44 flows into the first swing chamber zone 52. A portion of the drilling fluid flows into the second swing chamber zone 54 through the second inlet hole 43 and the third guide hole 46. Together, they push the pendulum 15 to rotate clockwise and collide with the impact block of the pendulum cylinder 14 to generate a clockwise torsional impact force. During the clockwise rotation of the pendulum 15, the fluid in the second swing chamber zone 53 is forced into the second flow hole 57, and at the same time, the fluid in the first swing chamber zone 55 is forced into the fourth flow hole 59. Then, the fluid is discharged through the first drain hole 60 and the second drain hole 61, respectively. Similarly, when the first inlet hole 42 and the second inlet hole 43 of the upper guide plate 12 are connected to the second guide hole 45 and the fourth guide hole 47 of the upper fixed plate 13 respectively, the first drain hole 60 and the second drain hole 61 of the lower guide plate 16 are connected to the third flow hole 58 and the first flow hole 56 of the lower fixed plate respectively. This allows a portion of the drilling fluid to flow into the second swing chamber zone 53 from the first inlet hole 42 and the second guide hole 45, and a portion of the drilling fluid to flow into the first swing chamber zone 55 from the second inlet hole 43 and the fourth guide hole 47. Together, they drive the pendulum 15 to rotate counterclockwise and collide with the impact block of the pendulum cylinder 14 to generate a counterclockwise torsional impact force. During the counterclockwise rotation of the pendulum 15, the fluid in the first swing chamber zone 52 is forced into the first flow hole 56, and the fluid in the second swing chamber zone 54 is also forced into the third flow hole 58. Then, the fluid is discharged through the second drain hole 61 and the first drain hole 60 respectively. This cycle repeats, with the spindle 17 rotating once, and the pendulum 15 generating two clockwise swings and two counterclockwise swings within the pendulum cylinder 14, thus producing two clockwise and two counterclockwise torsional mechanical impact forces.

[0044] As can be seen from the above working process, the friction reduction and drag reduction tool provided in this application can simultaneously generate four types of dynamic oscillating impact loads covering three dimensions, namely axial hydraulic oscillation force, centrifugal force, circumferential mechanical impact force, and torsional mechanical impact force, and transmit them to the drill string system at both ends to achieve the effect of reducing friction between the drill string and the well wall through a combined action.

[0045] like Figure 4 As shown, in this embodiment, the cross-section of the hammer block and the cross-section of the impact block are both fan-shaped. When the hammer block and the impact block come into contact, there is no gap between them. In order to allow the drilling fluid to flow into the swing cavity, this embodiment provides a guide groove on the impact surface of the impact block, with the upper and lower ends extending to the upper and lower ends of the pendulum 15, respectively. Specifically, the pendulum 15 is provided with a first guide groove 48, a second guide groove 49, a third guide groove 50, and a fourth guide groove 51. The first guide groove 48 is connected to the first swing cavity region 52, the upper end of the first guide groove 48 is connected to the first guide hole 44, and the lower end of the first guide groove 48 is connected to the first flow hole 56. The second guide groove 49 is connected to the second swing cavity region 53, the upper end of the second guide groove 49 is connected to the second guide hole 45, and the lower end of the second guide groove 49 is connected to the second flow hole 57. The third guide groove 50 is connected to the second swing cavity region 54, the upper end of the third guide groove 50 is connected to the third guide hole 46, and the lower end of the third guide groove 50 is connected to the third flow hole 58. The fourth guide groove 51 is connected to the first swing cavity region 55, the upper end of the fourth guide groove 51 is connected to the fourth guide hole 47, and the lower end of the fourth guide groove 51 is connected to the fourth flow hole 59. In a preferred embodiment, the cross-section of the guide channel is an arc centered on the axis of the shell, which generates a stronger thrust to drive the pendulum 15 to swing. In other embodiments, the cross-sections of the hammer block and the impact block can also be set to other shapes, such as the cross-section of the hammer block being set to an I-shape, that is, grooves are provided on both sides of the hammer block to prevent the space between the hammer block and the impact block from completely disappearing when they come into contact, thereby ensuring that the drilling fluid can flow into the swing chamber.

[0046] like Figure 1As shown, to facilitate the passage of drilling fluid, this application preferably makes the first radial flow hole 38 extend obliquely downward from the inside to the outside. Similarly, the second radial flow hole 41 can extend obliquely upward from the inside to the outside. In this embodiment, the rotor 25 is a screw rotor. Depending on the drilling conditions, the rotor 25 can be configured as a hollow screw rotor. Of course, the rotor 25 can also be configured as other types, such as an impeller rotor. In order to enable the components in the friction reduction tool to rotate more stably, this embodiment connects the rotor 25 and the eccentric shaft 19 through a universal joint 22. The part of the shell corresponding to the universal joint 22 includes a universal joint cylinder 23. The upper end of the universal joint cylinder 23 is threadedly connected to the lower end of the eccentric shaft cylinder 20, and the lower end of the universal joint cylinder 23 is threadedly connected to the upper end of the stator housing 26. The lower end of the universal joint 22 is threadedly connected to the connecting rod 24, and the upper end of the universal joint 22 is threadedly connected to the eccentric shaft 19. The upper end of the rotor 25 drives the eccentric shaft 19 to rotate sequentially through the connecting rod 24 and the universal joint 22.

[0047] like Figure 7 As shown, in this embodiment, the impact block 66 is a cylinder, and a bracket 68 that slides in conjunction with the radial receiving groove 69 is provided between the impact block 66 and the elastic member 67. The side of the bracket 68 near the impact block 66 is an arc surface. In other embodiments, the impact block 66 can also be configured as other shapes, such as a sphere or a cuboid with a blunt, rounded tip. The cross-section of the deceleration ridge can be configured as a sector shape or other shapes, such as a semicircle. The number of deceleration ridges can also be set to other values ​​as needed, for example, two or four.

[0048] In a preferred embodiment, the axial oscillation unit includes a balance sleeve 8 located between the disc spring assembly 4 and the piston 10. The balance sleeve 8 is slidably disposed in the annular space between the central tube and the cylindrical shell. The lower cavity 33 of the balance sleeve 8 is connected to the cavity of the central tube through a connecting hole 34 opened in the central tube. The cylindrical shell has an oil injection hole corresponding to the upper cavity 32 of the balance sleeve 8, and an oil hole plug 6 is provided in the oil injection hole. Figure 1 As shown, an oil hole plug 6 is provided on the circumference of the middle part of the disc spring cylinder 5. A stepped surface is provided at the lower end of the interior of the disc spring cylinder 5. The inner hole of the balance sleeve 8 is in contact with the outer circular surface of the punch tube 7. The outer circular surface of the balance sleeve 8 is in contact with the inner wall of the disc spring cylinder 5. The upper end face of the balance sleeve 8 forms a closed upper cavity 32 between the drive shaft 1, the spline cylinder 3, the disc spring cylinder 5, and the punch tube 7. The lower end face of the balance sleeve 8 forms a lower cavity 33 between the disc spring cylinder 5 and the piston cylinder 9. A connecting hole 34 is provided in the middle of the punch tube 7 and communicates with the lower cavity 33 of the sleeve.

[0049] Before using the friction-reducing tool, first remove the oil hole plug 6, inject oil (such as gear oil) into the upper cavity 32 of the sleeve, and push the balance sleeve 8 downward along the outer surface of the punch tube 7, finally hooking it against the lower step surface inside the disc spring cylinder 5. This ensures that the disc spring assembly 4 and the transmission spline that mates with the spline cylinder 3 are completely immersed in the oil medium environment, thereby reducing the wear rate and improving the oscillation propulsion efficiency. After filling with oil, tighten the oil hole plug 6 to secure it. During tool use, the balance sleeve 8 can ensure that the oil pressure inside the upper cavity 32 of the sleeve remains dynamically stable. That is, after a period of use, if a small leak occurs from the annular mating surface of the transmission shaft 1 and the upper connector 2, causing a decrease in pressure inside the upper cavity 32 of the sleeve, the balance sleeve 8 can slide upward under the fluid pressure of the lower cavity 33 of the sleeve, restoring the pressure by reducing the volume of the upper cavity 32 of the sleeve, thus ensuring the working environment of the disc spring assembly 4 and the transmission spline.

[0050] This application also provides a drill string that includes the friction-reducing and drag-reducing tool disclosed in the above embodiments. Since the friction-reducing and drag-reducing tool disclosed in the above embodiments has the aforementioned technical effects, the drill string with this tool also has the aforementioned technical effects, which will not be repeated here.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A friction-reducing and drag-reducing tool, comprising a cylindrical shell, characterized in that, The cylindrical shell is provided with an axial oscillation unit, a torsional impact unit, an eccentric excitation unit, a power generation unit, and a pulse throttling unit arranged sequentially from top to bottom. The axial oscillation unit includes a central tube slidably disposed within the cylindrical shell and a piston fixedly disposed at the lower end of the central tube. The upper chamber of the piston is connected to the outside through a vent hole opened in the cylindrical shell, and the lower chamber of the piston is connected to the lumen of the central tube through the lower port of the central tube. A disc spring assembly is disposed in the annular space between the central tube and the cylindrical shell. The torsional impact unit includes a mandrel rotatably disposed within the cylindrical shell and a pendulum sleeved on the mandrel. The pendulum is provided with at least two hammer blocks evenly arranged circumferentially. The inner wall of the cylindrical shell is provided with impact blocks evenly arranged circumferentially. A swing cavity for accommodating the hammer blocks is formed between adjacent impact blocks. An upper fixed plate and a lower fixed plate are fixedly disposed within the cylindrical shell, respectively contacting the upper and lower end faces of the pendulum. An upper guide plate and a lower guide plate are fixedly sleeved on the outer surface of the mandrel, respectively cooperating with the upper and lower fixed plates. The upper guide plate has an inlet hole that cooperates with the guide hole of the upper fixed plate. The lower guide plate has a drain hole that cooperates with the flow hole of the lower fixed plate. A first radial flow hole is provided in the central flow channel of the mandrel at a position lower than the lower guide plate. The eccentric vibration unit includes an eccentric shaft installed inside the cylindrical shell via an upper and a lower centralizing bearing. The upper end of the eccentric shaft is fixedly connected to the spindle. Axial flow holes are provided around the upper and lower centralizing bearings. A radial receiving groove is opened on the distal end of the eccentric shaft. An impact block is slidably disposed in the radial receiving groove. An elastic element for pushing the impact block outward is provided in the radial receiving groove. The inner wall of the cylindrical shell is provided with deceleration ridges distributed circumferentially. The power generating unit includes a rotor driven by a fluid flow, the upper end of which is connected to the lower end of the eccentric shaft. The pulse throttling unit includes a moving valve fixedly connected to the lower end of the rotor and a fixed valve fixedly disposed in the shell. The relative movement of the moving valve and the fixed valve generates a periodically changing flow area.

2. The friction-reducing and drag-reducing tool according to claim 1, characterized in that, The cross-section of the hammer block and the cross-section of the impact block are both fan-shaped, and the impact surface of the impact block has guide grooves extending to the upper and lower ends of the pendulum, respectively.

3. The friction-reducing and drag-reducing tool according to claim 2, characterized in that, The cross-section of the guide channel is an arc centered on the axis of the cylindrical shell.

4. The friction-reducing and drag-reducing tool according to claim 1, characterized in that, The first radial flow hole extends obliquely downward from the inside to the outside.

5. The friction-reducing and drag-reducing tool according to claim 1, characterized in that, The moving valve is provided with a moving valve center hole and a plurality of moving valve circumferential holes evenly distributed around the moving valve center hole, and the fixed valve is provided with a fixed valve center hole opposite to the moving valve center hole and a plurality of fixed valve circumferential holes evenly distributed around the fixed valve center hole.

6. The friction-reducing and drag-reducing tool according to claim 1, characterized in that, The impact block is a cylinder, and a bracket that slides in cooperation with the radial receiving groove is provided between the impact block and the elastic element. The side of the bracket closest to the impact block is an arc surface.

7. The friction-reducing and drag-reducing tool according to claim 6, characterized in that, The cross-section of the deceleration ridge is fan-shaped.

8. The friction-reducing and drag-reducing tool according to claim 1, characterized in that, The rotor is connected to the eccentric shaft via a universal joint.

9. The friction-reducing and drag-reducing tool according to any one of claims 1 to 8, characterized in that, The axial oscillation unit includes a balance sleeve located between the disc spring assembly and the piston. The balance sleeve is slidably disposed in the annular space between the central tube and the cylindrical shell. The lower cavity of the balance sleeve is connected to the lumen of the central tube through a connecting hole opened in the central tube. The cylindrical shell is provided with an oil injection hole corresponding to the upper cavity of the balance sleeve above the balance sleeve, and an oil hole plug is provided in the oil injection hole.

10. A drill string, characterized in that, Includes the friction-reducing and drag-reducing tools as described in any one of claims 1 to 9.

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