Friction reduction and drag reduction device and drill string

Abstract

The present invention provides a friction-reducing and drag-reducing device and a drill string. The friction-reducing and drag-reducing device comprises: a first joint, a second joint, a blade mounting tube, and a drag-reducing blade. The first joint and the second joint are respectively connected to the two ends of the blade mounting tube. The drag-reducing blade is connected to the outer wall surface of the blade mounting tube. The outer wall surface of the drag-reducing blade is provided with a roller. The roller and the drag-reducing blade are relatively rotatably connected, and the rolling surface of the roller protrudes from the outer wall surface of the drag-reducing blade. The axis of the roller is parallel to the axis of the blade mounting tube. The friction-reducing and drag-reducing device in this application is provided with a drag-reducing blade on the outer wall surface of the blade mounting tube so that the drag-reducing blade abuts against the well wall. The drag-reducing blade is provided with a protruding roller so that the drag-reducing blade abuts against the well wall through the roller. The roller changes sliding friction into rolling friction, thereby reducing the friction between the well wall and the blade mounting tube.

Description

Technical Field

[0001] The present invention relates to the technical field of horizontal well drill strings, and in particular to a friction and resistance reducing device and a drill string. Background Art

[0002] Oil and natural gas are important natural resources, and improving their extraction efficiency has long been a research and development focus for those skilled in the art. However, during horizontal well drilling, high drill string friction is a significant issue, impacting drilling reach, efficiency, and even safety.

[0003] Reducing drill string friction can improve mining efficiency and safety. Currently, the common practice is to use stabilizers to reduce the contact area between the drill string and the wellbore wall, or to improve the lubricity of the drilling fluid to achieve local friction reduction. However, the former increases the outer diameter of the drill string, which affects subsequent drilling operations, while the latter has limited effect on reducing overall drill string friction. Summary of the Invention

[0004] The present invention provides a friction and resistance reducing device and a drill string, which are used to solve the problem of high friction resistance of the drill string in the prior art.

[0005] The present invention provides a friction reduction and drag reduction device, comprising: a first joint, a second joint, a blade mounting tube and a drag reduction blade, wherein the first joint and the second joint are respectively connected to the two ends of the blade mounting tube, the drag reduction blade is connected to the outer wall surface of the blade mounting tube, the outer wall surface of the drag reduction blade is provided with a roller, the roller and the drag reduction blade are relatively rotatably connected, and the rolling surface of the roller protrudes from the outer wall surface of the drag reduction blade, and the axis of the roller is parallel to the axis of the blade mounting tube.

[0006] According to a friction reduction and drag reduction device provided by the present invention, the blade mounting tube is provided with a mounting groove, the drag reduction blade is arranged in the mounting groove, and the depth of the mounting groove is greater than or equal to the thickness of the drag reduction blade.

[0007] According to a friction reducing and drag reducing device provided by the present invention, the drag reducing blade is hinged to the blade mounting tube, and the rotation axis of the drag reducing blade is parallel to the axis of the blade mounting tube.

[0008] According to a friction reduction and drag reduction device provided by the present invention, the friction reduction and drag reduction device also includes a transmission inner tube, a transmission gear and an ejection assembly. The transmission inner tube is arranged in the blade mounting tube, and the transmission gear is respectively engaged with the transmission inner tube and the ejection assembly. The ejection assembly is arranged in the blade mounting tube and abuts against the drag reduction blade. The transmission inner tube is used to drive the transmission gear to drive the ejection assembly to eject the drag reduction blade.

[0009] According to a friction reduction and resistance reduction device provided by the present invention, the ejection assembly includes a bearing and a ejector rod engaged with the transmission gear, the bearing is fixed in the blade mounting tube, and the ejector rod is arranged in the bearing.

[0010] According to a friction reduction and drag reduction device provided by the present invention, the friction reduction and drag reduction device also includes an elastic member, both ends of which are respectively connected to the drag reduction blade and the blade mounting tube, and the elastic member is used to drive the drag reduction blade to rotate toward the direction close to the blade mounting tube.

[0011] According to the friction reduction and resistance reducing device provided by the present invention, the roller further includes a roller, and the roller is connected to the roller pin.

[0012] According to a friction reduction and drag reduction device provided by the present invention, the friction reduction and drag reduction device also includes a first shock-absorbing inner tube, a first shock-absorbing outer tube and a first shock-absorbing component. The first shock-absorbing inner tube is arranged in the first shock-absorbing outer tube, the first shock-absorbing outer tube is connected between the first joint and the blade mounting tube, and the first shock-absorbing component is arranged between the first shock-absorbing inner tube and the first shock-absorbing outer tube.

[0013] According to a friction reduction and drag reduction device provided by the present invention, the friction reduction and drag reduction device also includes a connecting pipe, which is connected between the second joint and the blade mounting pipe. An avoidance groove is provided in the connecting pipe, and the second joint slides along the avoidance groove.

[0014] The present invention also provides a drill string, comprising a drill bit and the friction and resistance reducing device as described above, wherein the drill bit is connected to the second joint.

[0015] The present invention provides a friction-reducing and drag-reducing device and drill string. The device comprises a blade mounting tube disposed between a first joint and a second joint, with a rotatable roller mounted on the blade mounting tube. Because the roller protrudes from the outer wall of the blade mounting tube, it contacts the wellbore wall during drilling. Furthermore, because the roller is rotatable, rolling friction occurs between the roller and the wellbore wall when in contact. In this application, the frictional resistance experienced by the drill string is reduced by replacing sliding friction between the drill string and the wellbore wall with rolling friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1It is a structural schematic diagram of a friction and resistance reducing device provided by the present invention.

[0018] Figure 2 It is a schematic axial cross-sectional view of a friction reduction and drag reduction device provided by the present invention.

[0019] Figure 3 It is a radial cross-sectional schematic diagram of a friction reduction and drag reduction device provided by the present invention.

[0020] Figure 4 It is a schematic radial cross-sectional view of the drag reduction blades in the friction reduction and drag reduction device provided by the present invention after they are unfolded.

[0021] Figure 5 This is a working schematic diagram of a friction reduction and drag reduction device provided by the present invention.

[0022] Figure 6 This is a schematic diagram of the first joint structure of a friction reduction and resistance reduction device provided by the present invention.

[0023] Figure 7 This is a schematic structural diagram of a first gasket of a friction and drag reduction device provided by the present invention.

[0024] Figure 8 It is a schematic structural diagram of a first shock-absorbing inner tube of a friction-reducing and drag-reducing device provided by the present invention.

[0025] Figure 9 It is a schematic structural diagram of a first shock-absorbing outer tube of a friction-reducing and drag-reducing device provided by the present invention.

[0026] Figure 10 It is a schematic structural diagram of the first shock-absorbing component of a friction-reducing and drag-reducing device provided by the present invention.

[0027] Figure 11 It is a schematic diagram of the drag reduction blade structure of a friction and drag reduction device provided by the present invention.

[0028] Figure 12 It is a schematic cross-sectional view of a transmission inner tube of a friction and drag reducing device provided by the present invention.

[0029] Figure 13 It is a schematic diagram of the transmission gear structure of a friction and resistance reducing device provided by the present invention.

[0030] Figure 14 It is a schematic diagram of the blade mounting tube structure of a friction reducing and drag reducing device provided by the present invention.

[0031] Figure 15 This is a front view of a blade mounting tube of a friction reducing and drag reducing device provided by the present invention.

[0032] Figure 16 yes Figure 15 Schematic diagram of the cross section at AA in the middle.

[0033] Figure 17 It is a schematic cross-sectional view of a second shock-absorbing inner tube of a friction-reducing and drag-reducing device provided by the present invention.

[0034] Figure 18 It is a schematic cross-sectional view of a second shock-absorbing outer tube of a friction-reducing and drag-reducing device provided by the present invention.

[0035] Figure 19 This is a schematic diagram of the fourth washer structure of the friction and resistance reducing device provided by the present invention.

[0036] Figure 20 It is a schematic diagram of the bearing structure of a friction and resistance reducing device provided by the present invention.

[0037] Figure 21 It is a schematic diagram of the structure of the sealing end cover of the shock absorbing cavity of the friction and drag reducing device provided by the present invention.

[0038] Figure 22 It is a schematic diagram of the connecting pipe structure of a friction reducing and drag reducing device provided by the present invention.

[0039] Figure 23 It is a schematic diagram of the structure of the second joint outer tube of a friction and resistance reducing device provided by the present invention.

[0040] Figure 24 It is a structural schematic diagram of a second joint of a friction reduction and resistance reduction device provided by the present invention.

[0041] Figure 25 The present invention provides a schematic diagram of the structure of a push rod sleeve of a friction and resistance reducing device.

[0042] Figure 26 It is a schematic diagram of the top rod structure of a friction reduction and resistance reduction device provided by the present invention.

[0043] Figure 27 It is a schematic structural diagram of a push rod bearing seat of a friction and resistance reducing device provided by the present invention.

[0044] Figure 28 It is a schematic diagram of the elastic component structure of a friction and resistance reducing device provided by the present invention.

[0045] Figure 29 This is a front view of a roller of a friction reduction and resistance reduction device provided by the present invention.

[0046] Figure 30 It is a schematic diagram of the roller structure of a friction reduction and resistance reduction device provided by the present invention.

[0047] Figure 31 It is a schematic diagram of the resistance reducing roller structure of a friction reducing and resistance reducing device provided by the present invention.

[0048] Reference numerals:

[0049] 1. First joint; 2. First gasket; 3. First shock-absorbing cavity inner tube; 4. First shock-absorbing cavity outer tube; 5. First shock-absorbing member; 6. Second gasket; 7. Drag-reducing blade; 8. Transmission inner tube; 9. Transmission gear; 10. Blade mounting tube; 101. Mounting groove; 11. Third gasket; 12. Second shock-absorbing inner tube; 13. Second shock-absorbing outer tube; 14. Fourth gasket; 15. Shock-absorbing bearing; 16. Shock-absorbing cavity sealing end cover; 17. Connecting tube; 18. Second joint outer tube; 19. Second joint; 20. Ejector assembly; 21. Ejector rod sleeve; 22. Ejector rod; 23. Bearing seat; 24. Bearing; 25. Elastic member; 31. Roller; 32. Roller; 33. Roller shaft. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] The following combination Figure 1 The present invention describes a friction reduction and drag reduction device, which includes: a first joint 1, a second joint 19, a blade mounting tube 10 and a drag reduction blade 7. The first joint 1 and the second joint 19 are respectively connected to the two ends of the blade mounting tube 10, and the drag reduction blade 7 is connected to the outer wall of the blade mounting tube 10. The outer wall of the drag reduction blade 7 is provided with a roller 31. The roller 31 is connected to the drag reduction blade 7 so as to be relatively rotatable, and the rolling surface of the roller 31 protrudes from the outer wall of the drag reduction blade 7. The axis of the roller 31 is parallel to the axis of the blade mounting tube 10.

[0052] Please refer to Figures 1 to 11 In this embodiment, along the drilling direction during drilling, the first joint 1 is arranged at the upper end of the blade mounting tube 10, and the second joint 19 is arranged at the lower end of the blade mounting tube 10. The first joint 1 is used to connect the drill pipe, and the second joint 19 is used to connect the drill bit.

[0053] A blade mounting tube 10 is provided between the first joint 1 and the second joint 19. A drag reducing blade 7 is provided on the outer wall of the blade mounting tube 10, and the drag reducing blade 7 contacts the well wall. A roller 31 is provided on the drag reducing blade 7, and the roller 31 protrudes from the outer wall of the drag reducing blade 7. The roller 31 is connected to the drag reducing blade 7 so as to be relatively rotatable. Figure 3 As shown, in this embodiment, the roller 31 and the resistance reducing blade 7 are connected by a pin shaft, so that after the roller 31 is installed on the resistance reducing blade 7, it can also rotate relative to the resistance reducing blade 7.

[0054] Because the blade mounting tube 10 rotates along with the drill pipe during drilling, the resistance-reducing blades 7 can be sleeve-shaped. The resistance-reducing blades 7 are sleeved onto the blade mounting tube 10, so that the outer wall of the blade mounting tube 10 is surrounded by resistance-reducing blades 7 to reduce resistance. At the same time, to facilitate the removal and assembly of the resistance-reducing blades 7, the resistance-reducing blades 7 can also be divided into multiple pieces, each of which is arc-shaped. The arc-shaped resistance-reducing blades 7 fit closely to the outer wall of the blade mounting tube 10, making the structure more compact.

[0055] Typically, during drilling, the outer surface of the drill string contacts the wellbore wall. As the drill string rotates, sliding friction occurs between the outer surface and the wellbore wall. This large contact area results in significant frictional resistance, impacting drilling efficiency.

[0056] In this embodiment, rollers 31 are provided on the drag-reducing blades 7 so that they protrude from the outer surface of the blades 7. This allows the rollers 31 to abut against the wellbore wall. When the drill string drives the drag-reducing blades 7 and the rollers 31 to rotate relative to the wellbore wall, the rollers 31 and the wellbore wall move relative to each other. This frictional force generates between the rollers 31 and the wellbore wall, driving the rollers 31 to rotate relative to the drag-reducing blades 7.

[0057] The axis of the roller 31 is set to be parallel to the axis of the blade mounting tube 10 so that the rolling direction of the roller 31 is consistent with the rotation direction of the blade mounting tube 10.

[0058] In this embodiment, rollers 31, mounted on drag-reducing blades 7, first abut against the wellbore wall, reducing the contact area. A rotational connection is then established between rollers 31 and drag-reducing blades 7, allowing them to rotate when subjected to friction, resulting in rolling friction between them. Furthermore, to minimize impact on the outer diameter of the drill string, rollers 31 only need to slightly protrude from the outer surface of the drag-reducing blades 7.

[0059] It can be seen that the present application reduces the friction resistance of the drill rod by reducing the contact area and changing the friction mode. Compared with the existing technology, the effect of reducing the friction resistance is greatly improved.

[0060] In one embodiment, the blade mounting tube 10 is provided with a mounting groove 101 , and the drag reduction blade 7 is disposed in the mounting groove 101 . The depth of the mounting groove 101 is greater than or equal to the thickness of the drag reduction blade 7 .

[0061] Please refer to Figures 14 to 16An annular mounting groove 101 is formed in the middle of the blade mounting tube 10 and is coaxial with the blade mounting tube 10. Installing the drag-reducing blades 7 in the mounting groove 101 ensures that the outer wall of the blade mounting tube 10 is completely encircled by the drag-reducing blades 7. This ensures that the entire outer wall of the blade mounting tube 10 is separated from the well wall by the drag-reducing blades 7, ensuring that no sliding friction occurs between the outer wall of the blade mounting tube 10 and the well wall.

[0062] At the same time, in this embodiment, the depth of the mounting groove 101 is slightly greater than the thickness of the drag-reducing blade 7, allowing the drag-reducing blade 7 to fit within the mounting groove 101 during installation. Furthermore, because the roller 31 protrudes from the drag-reducing blade 7, after the drag-reducing blade 7 is installed in the mounting groove 101, the protruding portion of the roller 31 is located within the mounting groove 101. Therefore, the distance the roller 31 protrudes from the outer wall of the drag-reducing blade 7 plus the thickness of the drag-reducing blade 7 must be greater than the depth of the mounting groove 101. This allows the roller 31 to protrude from the mounting groove 101, that is, the roller 31 protrudes from the outer wall of the blade mounting tube 10, allowing the blade mounting tube 10 to abut against the well wall through the roller 31.

[0063] In this embodiment, the drag reducing blade 7 is embedded in the installation groove 101 and only partially protrudes through the roller 31, so that the entire drill string is subjected to rolling friction through the roller 31, while the outer diameter of the drill string will not increase due to the protrusion of the drag reducing blade 7.

[0064] In one embodiment, the drag reducing blade 7 is hinged to the blade mounting tube 10 , and the rotation axis of the drag reducing blade 7 is parallel to the axis of the blade mounting tube 10 .

[0065] Please refer to Figure 11 and Figure 14 The drag-reducing blade 7 is arc-shaped, with pin holes located at the upper and lower ends of one of its long sides. Correspondingly, pins are located at each end of the mounting groove 101. By engaging the axial holes within the mounting groove 101, the drag-reducing blade 7 is hingedly connected to the blade mounting tube 10. Furthermore, the rotation axis of the drag-reducing blade 7, i.e., the long side where the drag-reducing blade 7 is hingedly connected to the blade mounting tube 10, is parallel to the axis of the blade mounting tube 10. This ensures a closer fit between the drag-reducing blade 7 and the mounting groove 101, reducing installation space.

[0066] Because the resistance reducing blade 7 can rotate relative to the mounting tube 10 , when the roller 31 on the resistance reducing blade 7 is damaged, it can be dismantled and repaired more conveniently.

[0067] like Figure 11As shown, six rollers 31 are provided on the drag reducing blade 7, thereby reducing the pressure on a single roller 31. However, this is not limiting. In this embodiment, only six rollers 31 are provided on one drag reducing blade 7 as an example. In different embodiments, the number of rollers 31 may be increased or decreased according to actual conditions.

[0068] In one embodiment, the friction reduction and drag reduction device also includes a transmission inner tube 8, a transmission gear 9 and an ejection assembly 20. The transmission inner tube 8 is arranged in the blade mounting tube 10, and the transmission gear 9 is respectively engaged with the transmission inner tube 8 and the ejection assembly 20. The ejection assembly 20 is arranged in the blade mounting tube 10 and abuts against the drag reduction blade 7. The transmission inner tube 8 is used to drive the transmission gear 9 to drive the ejection assembly 20 to eject the drag reduction blade 7.

[0069] Please refer to Figures 1 to 13 A transmission inner tube 8 is also installed within the blade mounting tube 10. Its ends are connected to the first connector 1 and the second connector 19, respectively, to transmit the drill pipe's torque to the drill bit. An ejector assembly 20 is also installed within the blade mounting tube 10. One end of the ejector assembly 20 abuts against the drag-reducing blade 7, and the other end meshes with the transmission gear 9. The side of the transmission gear 9 opposite the ejector assembly 20 also meshes with the transmission inner tube 8.

[0070] When the drill pipe outputs torque, driving the transmission inner tube 8, drill bit, and blade mounting tube 10 to rotate, if the drill bit encounters significant resistance, the drill bit's rotational speed will decrease. However, the blade mounting tube 10 maintains contact with the wellbore wall, so the resistance and rotational speed of the blade mounting tube 10 remain unchanged. The ejector assembly 20, mounted on the blade mounting tube 10, maintains the same rotational speed as the blade mounting tube 10. However, the transmission inner tube 8 is connected to the drill bit and maintains the same rotational speed. If the drill bit's rotational speed decreases, the transmission inner tube 8's speed will also decrease.

[0071] When the speed of the transmission inner tube 8 decreases and the speed of the ejection assembly 20 remains unchanged, a speed difference is generated between the transmission inner tube 8 and the ejection assembly 20. The transmission gear 9 connected between the transmission inner tube 8 and the ejection assembly 20 then rotates due to the speed difference, and the rotation of the transmission gear 9 drives the ejection assembly 20 to eject outward. The ejection assembly 20 abuts against the drag reduction blades 7, so when the ejection assembly 20 is ejected, it also ejects the drag reduction blades 7 together. Because the drag reduction blades 7 are hinged to the blade mounting tube 10, the abutment of the ejection assembly 20 causes the drag reduction blades 7 to rotate outward. During the rotation of the drag reduction blades 7, the drag reduction blades 7, which were originally aligned with the wellbore wall, gradually deviate from the wellbore wall, further reducing the contact area between the drag reduction blades 7 and the wellbore wall, thereby reducing the friction acting on the drill string.

[0072] In this embodiment, the drill pipe simultaneously outputs torque to both the transmission inner tube 8 and the blade mounting tube 10. The torque received by the transmission inner tube 8 is used to drive the drill bit, while the torque received by the blade mounting tube 10 is used to offset friction from the wellbore wall. The blade mounting tube 10 rubs against the wellbore wall through the drag-reducing blades 7. This reduces the contact area between the drag-reducing blades 7 and the wellbore wall, thereby reducing the friction experienced by the blade mounting tube 10 and, in turn, the torque output by the drill pipe to the blade mounting tube 10. While the drill pipe's torque remains constant, reducing the torque output to the blade mounting tube 10 increases the torque output to the transmission inner tube 8, thereby increasing the torque output to the drill bit. After receiving the increased torque, the drill bit has sufficient power to offset the greater resistance, increasing its rotational speed until there is no speed difference between the transmission inner tube 8 and the blade mounting tube 10.

[0073] In this embodiment, the transmission inner tube 8 is connected to the ejection assembly 20 via a transmission gear 9. The speed difference between the transmission inner tube 8 and the blade mounting tube 10 is used as a driving force to drive the drag-reducing blades 7 to reduce contact with the wellbore wall, thereby reducing wellbore friction and increasing drill bit torque. Compared to the existing method that requires an additional motor to increase drill bit torque, this embodiment uses the speed difference as a driving force, which saves resources.

[0074] In one embodiment, the ejection assembly 20 includes a bearing 24 and a push rod 22 engaged with the transmission gear 9 . The bearing 24 is fixed in the blade mounting tube 10 , and the push rod 22 is disposed in the bearing 24 .

[0075] Please refer to Figures 3 to 5 as well as Figures 25 to 27 In this embodiment, a bearing 24 is mounted within the blade mounting tube 10 via a bearing seat 23. A push rod 22 is inserted into the bearing 24, allowing the push rod 22 to rotate relative to the blade mounting tube 10 after being mounted thereon. A push rod sleeve 21 is also provided at the end of the push rod 22 facing the drag reduction blade 7. The sleeve 21 fits over the push rod 22 and is threadedly connected to the push rod 22. When a speed difference occurs between the transmission inner tube 8 and the blade mounting tube 10, the transmission gear 9 moves along the axis of the transmission inner tube 8 due to the speed difference. Because both the transmission inner tube 8 and the push rod 22 are threadedly engaged with the transmission gear 9, movement of the transmission gear 9 along the axis of the transmission inner tube 8 also drives the push rod 22 via the threads, causing the push rod 22 to drive the sleeve 21 outward against the drag reduction blade 7. Once abutted, the drag reduction blade 7 rotates outward, thereby reducing its contact area with the wellbore wall.

[0076] In this embodiment, the transmission is driven by the meshing connection between the transmission inner tube 8, the transmission gear 9 and the push rod 22, making the transmission more stable.

[0077] In one embodiment, the friction reduction and drag reduction device includes an elastic member 25 , the two ends of which are respectively connected to the drag reduction blade 7 and the blade mounting tube 10 . The elastic member 25 is used to drive the drag reduction blade 7 to rotate toward the blade mounting tube 10 .

[0078] Please refer to Figure 5 by Figure 28 In this embodiment, the elastic member 25 is a contraction spring. The elastic member 25 is connected between the resistance reduction blade 7 and the blade mounting tube 10. When the resistance reduction blade 7 has not yet rotated relative to the blade mounting tube 10, the elastic member 25 is in a free state. After the resistance reduction blade 7 is pushed out by the push rod 22, the elastic member 25 is stretched by the resistance reduction blade 7 under the drive of the resistance reduction blade 7. When the drill bit receives sufficient torque and returns to the speed before deceleration, there is no speed difference between the transmission inner tube 8 and the blade mounting tube 10, and the push rod 22 is also retracted under the drive of the transmission gear 9. At this time, the resistance reduction blade 7 loses the support of the push rod 22 and can be pulled back into the mounting groove 101 by the elastic member 25 under the elastic force of the elastic member 25, returning to a state of being in contact with the blade mounting tube 10.

[0079] In this embodiment, the pushed-out drag reduction blades 7 are pulled back by the elastic member 25 , making the structure simpler.

[0080] In one embodiment, the roller 31 further includes a roller 32 , and the roller 32 is pin-connected to the roller 31 .

[0081] Please refer to Figures 29 to 31 In this embodiment, rollers 32 are also provided on the roller 31. During the drilling process, the blade mounting tube 10 not only rotates the drag reduction blades 7 but also moves them axially along the blade mounting tube 10. Because the roller 31 can only roll circumferentially along the wellbore wall, when the drag reduction blades 7 move axially along the blade mounting tube 10, sliding friction occurs between the roller 31 and the wellbore wall.

[0082] In this embodiment, rollers 32 are provided on the roller 31, and the rolling direction of the rollers 32 is along the axial direction of the blade mounting tube 10. Therefore, when the resistance reducing blade 7 moves along the axial direction of the blade mounting tube 10, the roller 31 abuts against the well wall through the rollers 32, causing rolling friction between the rollers 32 and the well wall, thereby reducing friction.

[0083] In one embodiment, the friction reduction and resistance reduction device also includes a first shock-absorbing inner tube 3, a first shock-absorbing outer tube 4 and a first shock-absorbing component 5. The first shock-absorbing inner tube 3 is arranged in the first shock-absorbing outer tube 4, the first shock-absorbing outer tube 4 is connected to the first joint 1, and the first shock-absorbing component 5 is arranged between the first shock-absorbing inner tube 3 and the first shock-absorbing outer tube 4.

[0084] Please refer to Figures 6 to 10The first washer 2, first shock-absorbing inner tube 3, first shock-absorbing outer tube 4, first shock-absorbing member 5, and second washer 6 collectively form a first shock-absorbing chamber. The first shock-absorbing chamber is connected between the first joint 1 and the blade mounting tube 10, providing a shock-absorbing effect for the drill pipe's transmission. The first shock-absorbing inner tube 3 is connected to the transmission inner tube 8, and the first shock-absorbing outer tube 4 is connected to the blade mounting tube 10. A first shock-absorbing member 5 is disposed between the first shock-absorbing inner tube 3 and the first shock-absorbing outer tube 4. The first shock-absorbing member 5 is preferably a disc spring, which provides vibration reduction.

[0085] Please refer to Figures 17 to 21 A second damping chamber is provided between the second joint 19 and the blade mounting tube 10 and is composed of a third washer 11, a second damping inner tube 12, a second damping outer tube 13, and a fourth washer 14. Similarly, a disc spring is provided between the second damping inner tube 12 and the second damping outer tube 13 for damping.

[0086] In this embodiment, a first shock-absorbing cavity and a second shock-absorbing cavity are respectively provided at both ends of the blade mounting tube 10 to perform shock absorption, thereby improving the anti-seismic capability of the entire device.

[0087] In one embodiment, the friction reduction and drag reducing device further includes a connecting pipe 17 connected between the second joint 19 and the blade mounting pipe 10 , an avoidance groove is provided in the connecting pipe 17 , and the second joint 19 slides along the avoidance groove.

[0088] Please refer to Figure 2 as well as Figures 22 to 24 A connecting pipe 17 is further provided between the blade mounting pipe 10 and the second joint 19. A shock-absorbing bearing 15 and a shock-absorbing cavity sealing end cover 16 are provided at one end of the blade mounting pipe 10 facing the connecting pipe 17, thereby ensuring the sealing of the connection between the blade mounting pipe 10 and the connecting pipe 17.

[0089] The connecting tube 17 is also connected to the second joint 19 via the second joint outer tube 18, wherein the diameter of the end portion of the second joint 19 connected to the connecting tube 17 is larger, thereby ensuring that the second joint 19 will not slip out of the connecting tube 17 after the second joint 19 is connected to the connecting tube 17. The end of the second joint 19 away from the connecting tube 17 is connected to a drill bit, and when the drill bit encounters resistance, it will retract inward due to the reduction in rotation speed. Therefore, in this embodiment, an avoidance groove is provided inside the connecting tube 17, and when the drill bit retracts inward, it drives the second joint 19 inward. The second joint 19 retracts inward, that is, the second joint 19 moves axially toward the connecting tube 17. At this time, the avoidance groove of the connecting tube 17 can provide sufficient sliding space for the second joint 19 to retract inward.

[0090] Another embodiment of the present invention provides a drill string comprising a drill bit, a drill pipe, and the aforementioned friction and drag reduction device. The drill pipe is connected to a first connector 1, and the drill bit is connected to a second connector 19. The drill pipe outputs torque that drives the friction and drag reduction device and the drill bit to rotate. During the rotation of the drill string, the rollers 31 on the drag reduction blades 7 contact the wellbore wall, converting sliding friction into rolling friction, significantly reducing friction from the wellbore wall.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A friction reducing and resistance reducing device, characterized in that: include: A first joint (1), a second joint (19), a blade mounting tube (10), and a resistance reducing blade (7), wherein the first joint (1) and the second joint (19) are respectively connected to both ends of the blade mounting tube (10), the resistance reducing blade (7) is connected to the outer wall surface of the blade mounting tube (10), the outer wall surface of the resistance reducing blade (7) is provided with a roller (31), the roller (31) and the resistance reducing blade (7) are connected to each other so as to be relatively rotatable, and the rolling surface of the roller (31) protrudes from the outer wall surface of the resistance reducing blade (7), and the axis of the roller (31) is parallel to the axis of the blade mounting tube (10); the resistance reducing blade (7) and the resistance reducing blade (7) are connected to each other so as to be relatively rotatable. The blade mounting tube (10) is hinged, and the rotation axis of the drag reducing blade (7) is parallel to the axis of the blade mounting tube (10); the friction reducing and drag reducing device further comprises a transmission inner tube (8), a transmission gear (9) and an ejection assembly (20); the transmission inner tube (8) is arranged in the blade mounting tube (10), the transmission gear (9) is respectively engaged with the transmission inner tube (8) and the ejection assembly (20), the ejection assembly (20) is arranged in the blade mounting tube (10) and abuts against the drag reducing blade (7), and the transmission inner tube (8) is used to drive the transmission gear (9) to drive the ejection assembly (20) to eject the drag reducing blade (7).

2. The friction reducing and resistance reducing device according to claim 1, characterized in that: The blade mounting tube (10) is provided with a mounting groove (101), the drag reducing blade (7) is arranged in the mounting groove (101), and the depth of the mounting groove (101) is greater than or equal to the thickness of the drag reducing blade (7).

3. The friction reducing and resistance reducing device according to claim 1, characterized in that: The ejection assembly (20) includes a bearing (24) and a push rod (22) meshed with the transmission gear (9), wherein the bearing (24) is fixedly arranged in the blade mounting tube (10), the push rod (22) is arranged in the bearing (24), and the push rod (22) is meshed with the transmission gear (9).

4. The friction reducing and drag reducing device according to claim 1, characterized in that: The friction and resistance reducing device further comprises an elastic member (25), the two ends of the elastic member (25) being respectively connected to the resistance reducing blade (7) and the blade mounting tube (10), and the elastic member (25) being used to drive the resistance reducing blade (7) to rotate in a direction close to the blade mounting tube (10).

5. The friction reducing and drag reducing device according to claim 1, characterized in that: The roller (31) further comprises a roller (32), and the roller (32) is pin-connected to the roller (31).

6. The friction reducing and drag reducing device according to claim 1, characterized in that: The friction and resistance reducing device further comprises a first shock-absorbing inner tube (3), a first shock-absorbing outer tube (4), and a first shock-absorbing component (5); the first shock-absorbing inner tube (3) is arranged in the first shock-absorbing outer tube (4); the first shock-absorbing outer tube (4) is connected between the first joint (1) and the blade mounting tube (10); and the first shock-absorbing component (5) is arranged between the first shock-absorbing inner tube (3) and the first shock-absorbing outer tube (4).

7. The friction reducing and drag reducing device according to claim 1, characterized in that: The friction reduction and resistance reducing device further comprises a connecting pipe (17), wherein the connecting pipe (17) is connected between the second joint (19) and the blade mounting pipe (10), and an avoidance groove is provided in the connecting pipe (17), and the second joint (19) slides along the avoidance groove.

8. A drill string, characterized in that: It comprises a drill bit and the friction reducing and resistance reducing device according to any one of claims 1 to 7, wherein the drill bit is connected to the second joint (19).

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