Friction and resistance reducing device and drill string

Abstract

The invention provides a friction and resistance reducing device and a drill column, the friction and resistance reducing device comprises a first joint, a second joint, a blade mounting pipe and a resistance reducing blade, the first joint and the second joint are respectively connected to two ends of the blade mounting pipe, the resistance reducing blade is connected to the outer wall surface of the blade mounting pipe, and a roller is arranged on the outer wall surface of the resistance reducing blade; the rolling wheel and the resistance reducing blade can be connected in a relatively rotating mode, the rolling face of the rolling wheel protrudes out of the outer wall face of the resistance reducing blade, and the axis of the rolling wheel is parallel to the axis of the blade mounting pipe. According to the friction and resistance reducing device, the resistance reducing blades are arranged on the outer wall face of the blade mounting pipe, the resistance reducing blades abut against the well wall, the protruding rolling wheels are arranged on the resistance reducing blades, the resistance reducing blades abut against the well wall through the rolling wheels, sliding friction is changed into rolling friction through the rolling wheels, and therefore the friction force between the friction reducing device and the well wall is reduced.

Description

Technical Field

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

[0002] Oil and natural gas are important natural resources, and how to improve the extraction efficiency has always been the research and development direction of technicians in this field. In the process of horizontal well drilling, the problem of large drill string friction is very significant, and it affects the drilling extension capacity, drilling efficiency, and even safety construction.

[0003] If the friction of the drill string is reduced, the efficiency and safety of mining can be improved. At present, the common practice is to use stabilizers to reduce the contact area between the drill string and the well 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 will affect subsequent drilling operations, while the latter has limited effect on the overall reduction of the friction of the drill string. Summary of the invention

[0004] The 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, the transmission gear is respectively meshed 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, and 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 drag reduction device provided by the present invention, the ejection assembly includes a bearing and a ejector rod meshing 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 a friction reduction and resistance reducing device provided by the present invention, the roller further comprises 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, the connecting pipe 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 reducing and resistance reducing device as described above, wherein the drill bit is connected to the second joint.

[0015] The present invention provides a friction reduction and drag reduction device and a drill string. The friction reduction and drag reduction device is provided by arranging a blade mounting tube between a first joint and a second joint, and a rotatable roller is provided on the blade mounting tube. Because the roller protrudes from the outer wall surface of the blade mounting tube, the roller contacts the well wall during drilling. Because the roller can rotate, when the roller contacts the well wall, there is rolling friction between the roller and the well wall. In the present application, the friction resistance of the drill string is reduced by changing the sliding friction between the drill string and the well wall to 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, the following briefly introduces 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 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 reducing and drag reducing device provided by the present invention.

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

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

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

[0022] Figure 6 It is a schematic diagram of the first joint structure of a friction reducing and drag reducing device provided by the present invention.

[0023] Figure 7 It is a schematic diagram of the first gasket structure of a friction reducing and drag reducing device provided by the present invention.

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

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

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

[0027] Fig.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] Fig.12 The present invention is a schematic cross-sectional view of a transmission inner tube of a friction and drag reducing device provided by the present invention.

[0029] Fig.13 The present invention provides a schematic diagram of the transmission gear structure of a friction and resistance reducing device.

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

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

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

[0033] Fig.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] Fig.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] Fig.19 It is a schematic diagram of the fourth gasket structure of the friction and drag reducing device provided by the present invention.

[0036] Fig. 20 The present invention is a schematic diagram of a bearing structure of a friction and drag reducing device provided by the present invention.

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

[0038] Fig. 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] Fig.23 It is a schematic diagram of the structure of the second joint outer tube of a friction and drag reducing device provided by the present invention.

[0040] Fig.24 It is a structural schematic diagram of a second joint of a friction reducing and drag reducing device provided by the present invention.

[0041] Fig.25 The present invention is a schematic diagram of the structure of a top rod sleeve of a friction and resistance reducing device.

[0042] Fig.26 The present invention is a schematic diagram of a top rod structure of a friction and resistance reducing device provided by the present invention.

[0043] Fig. 27 The present invention is a schematic diagram of the structure of a push rod bearing seat of a friction and resistance reducing device.

[0044] Fig.28 It is a schematic diagram of the structure of an elastic member of a friction and drag reducing device provided by the present invention.

[0045] Fig.29 It is a front view of a roller of a friction reducing and drag reducing device provided by the present invention.

[0046] Fig.30 The present invention is a schematic diagram of a roller structure of a friction and resistance reducing device provided by the present invention.

[0047] Fig.31 The present invention provides a friction and drag reducing device provided by the present invention.

[0048] Reference numerals: 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

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Combine the following Figure 1 The present invention describes a friction reduction and drag reduction device, comprising: 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, the drag reduction blade 7 is connected to the outer wall surface of the blade mounting tube 10, the outer wall surface of the drag reduction blade 7 is provided with a roller 31, the roller 31 and the drag reduction blade 7 are relatively rotatably connected, and the rolling surface of the roller 31 protrudes from the outer wall surface of the drag reduction blade 7, and the axis of the roller 31 is parallel to the axis of the blade mounting tube 10.

[0051] 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.

[0052] A blade installation 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 installation 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 drag reducing blade 7 are connected by a pin shaft, so that after the roller 31 is installed on the drag reducing blade 7, it can also rotate relative to the drag reducing blade 7.

[0053] Because the blade mounting tube 10 rotates with the drill pipe during the drilling process, the resistance reducing blade 7 can be sleeve-shaped, and the resistance reducing blade 7 is sleeved on the blade mounting tube 10, so that the outer wall of the blade mounting tube 10 has resistance reducing blades 7 for reducing resistance. At the same time, in order to make the disassembly and assembly of the resistance reducing blade 7 more convenient, the resistance reducing blade 7 can also be divided into multiple pieces, each of which is arc-shaped, and the arc-shaped resistance reducing blade 7 is in contact with the outer wall of the blade mounting tube 10, making the structure more compact.

[0054] Usually, during the drilling process, the outer wall of the drill string contacts the well wall. During the rotation of the drill string, there is sliding friction between the outer wall of the drill string and the well wall, and the contact area between the outer wall of the drill string and the well wall is large, so the friction resistance of the drill string is large, which affects the drilling efficiency.

[0055] In this embodiment, the roller 31 is provided on the drag reducing blade 7 so that the roller 31 protrudes from the outer wall surface of the drag reducing blade 7. Then, the roller 31 abuts against the well wall. When the drill string drives the drag reducing blade 7 and the roller 31 to rotate relative to the well wall, the roller 31 and the well wall move relative to each other, and friction is generated between the roller 31 and the well wall abutting against each other, and the roller 31 rotates relative to the drag reducing blade 7 under the driving of the friction.

[0056] The axis of the roller 31 is set to be parallel to the axis of the blade mounting tube 10 so as to make the rolling direction of the roller 31 consistent with the rotation direction of the blade mounting tube 10 .

[0057] In this embodiment, the roller 31 provided on the drag reducing blade 7 is firstly in contact with the well wall, thereby reducing the contact area with the well wall. Then, the roller 31 and the drag reducing blade 7 are set to be in rotational connection, so that the roller 31 can rotate after being subjected to friction, so that rolling friction occurs between the roller 31 and the well wall. Furthermore, in order not to affect the outer diameter of the drill string, the roller 31 only needs to slightly protrude from the outer wall surface of the drag reducing blade 7.

[0058] It can be seen that in the present application, the friction resistance of the drill rod is reduced by reducing the contact area and changing the friction mode. Compared with the prior art, the effect of reducing the friction resistance is greatly improved.

[0059] In one embodiment, the blade mounting tube 10 is provided with a mounting groove 101 , the drag reducing blade 7 is disposed 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 .

[0060] Please refer to Figures 14 to 16The middle part of the blade mounting tube 10 is provided with an annular mounting groove 101, and the annular mounting groove 101 is coaxial with the blade mounting tube 10. Then, by installing the drag reducing blade 7 in the mounting groove 101, it can be ensured that the outer wall surface of the blade mounting tube 10 is provided with drag reducing blades 7 all around, so that the entire outer wall surface of the blade mounting tube 10 is separated from the well wall by the drag reducing blades 7, and it is ensured that no outer wall surface of the blade mounting tube 10 has sliding friction with the well wall.

[0061] At the same time, in this embodiment, the depth of the installation groove 101 is slightly greater than the thickness of the drag reducing blade 7, so that the drag reducing blade 7 can be embedded in the installation groove 101 during installation. Because the roller 31 protrudes from the drag reducing blade 7, after the drag reducing blade 7 is installed in the installation groove 101, the protruding part of the roller 31 is located in the installation groove 101. Therefore, the distance of the roller 31 protruding from the outer wall of the drag reducing blade 7 plus the thickness of the drag reducing blade 7 is greater than the depth of the installation groove 101, so that the roller 31 can protrude from the installation groove 101, that is, the roller 31 protrudes from the outer wall of the blade installation tube 10, so that the blade installation tube 10 abuts against the well wall through the roller 31.

[0062] 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.

[0063] 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 .

[0064] Please refer to Fig.11 and Fig.14 The drag reducing blade 7 is arc-shaped, and pin holes are provided at the upper and lower ends of one long side of the drag reducing blade 7. Correspondingly, pin shafts are also provided at both ends of the mounting groove 101, and the drag reducing blade 7 is hinged to the blade mounting tube 10 through the matching of the drag reducing blade 7 and the shaft hole in the mounting groove 101. And the rotation axis of the drag reducing blade 7, that is, the long side of the drag reducing blade 7 and the blade mounting tube 10 is parallel to the axis of the blade mounting tube 10, so that the drag reducing blade 7 and the mounting groove 101 are more closely fitted, reducing the installation space.

[0065] Because the drag reducing blade 7 can rotate relative to the mounting tube 10, when the roller 31 on the drag reducing blade 7 is damaged, it can be more conveniently dismantled and repaired.

[0066] like Fig.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 limited to this. In this embodiment, only six rollers 31 are provided on one drag reducing blade 7 as an embodiment, and in different embodiments, the number of rollers 31 can be increased or decreased according to actual conditions.

[0067] 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. 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.

[0068] Please refer to Figures 1 to 13 A transmission inner tube 8 is also provided in the blade mounting tube 10, and the two ends of the transmission inner tube 8 are respectively connected to the first joint 1 and the second joint 19, so as to transmit the torque of the drill pipe to the drill bit. An ejector assembly 20 is also provided in the blade mounting tube 10, and one end of the ejector assembly 20 abuts against the resistance reducing blade 7, and the other end is meshedly connected with the transmission gear 9, and the side of the transmission gear 9 opposite to the ejector assembly 20 is also meshedly connected with the transmission inner tube 8.

[0069] When the drill pipe outputs torque to drive the transmission inner tube 8, the drill bit and the blade mounting tube 10 to rotate, if the drill bit encounters an obstacle and receives a large resistance, the rotation speed of the drill bit will decrease. However, at this time, the contact between the blade mounting tube 10 and the well wall remains unchanged, so the resistance received by the blade mounting tube 10 remains unchanged, and the rotation speed of the blade mounting tube 10 remains unchanged. The ejection assembly 20 is installed on the blade mounting tube 10, and the rotation speed of the blade mounting tube 10 remains unchanged, and the rotation speed of the ejection assembly 20 remains unchanged. The transmission inner tube 8 is connected to the drill bit and maintains the same rotation speed as the drill bit. If the rotation speed of the drill bit decreases, then the rotation speed of the transmission inner tube 8 decreases.

[0070] 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. Then the transmission gear 9 connected between the transmission inner tube 8 and the ejection assembly 20 will rotate due to the speed difference, and the rotation of the transmission gear 9 drives the ejection assembly 20 to be ejected outward. The ejection assembly 20 abuts against the resistance reduction blade 7, so when the ejection assembly 20 is ejected, the resistance reduction blade 7 will be ejected together. Because the resistance reduction blade 7 is hinged to the blade mounting tube 10, the resistance reduction blade 7 rotates outward under the abutment of the ejection assembly 20. During the rotation of the resistance reduction blade 7, the resistance reduction blade 7, which was originally in the same direction as the well wall, gradually deviates from the well wall, so the contact area between the resistance reduction blade 7 and the well wall is further reduced, thereby reducing the friction force on the drill string.

[0071] In this embodiment, the drill pipe outputs torque to the transmission inner tube 8 and the blade mounting tube 10 at the same time, wherein the torque received by the transmission inner tube 8 is used to drive the drill bit to drill, and the torque received by the blade mounting tube 10 is used to offset the friction from the well wall. The blade mounting tube 10 rubs against the well wall through the resistance reduction blade 7, so the contact area between the resistance reduction blade 7 and the well wall is reduced, which can reduce the friction received by the blade mounting tube 10, thereby reducing the torque output by the drill pipe to the blade mounting tube 10. When the torque output by the drill pipe remains unchanged, the drill pipe reduces the torque output to the blade mounting tube 10, which will increase the torque output to the transmission inner tube 8, that is, increase the torque output to the drill bit. After receiving a larger torque, the drill bit can have enough power to offset the larger resistance, so that the rotation speed of the drill bit increases until there is no speed difference between the transmission inner tube 8 and the blade mounting tube 10.

[0072] In this embodiment, the transmission inner tube 8 is connected to the ejection assembly 20 through the transmission gear 9, and the speed difference between the transmission inner tube 8 and the blade mounting tube 10 is used as power to drive the resistance reduction blade 7 to reduce the contact with the well wall, thereby reducing the friction of the well wall and increasing the torque of the drill bit. Compared with the prior art, which requires an additional motor to increase the torque of the drill bit, the method of using the speed difference as power in this embodiment can save resources.

[0073] In one embodiment, the ejector assembly 20 includes a bearing 24 and a push rod 22 meshing 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 .

[0074] Please refer to Figures 3 to 5 as well as Figure 25 to Figure 27 In this embodiment, the bearing 24 is installed in the blade mounting tube 10 through the bearing seat 23. The push rod 22 is inserted into the bearing 24, so that the push rod 22 can rotate relative to the blade mounting tube 10 after being installed in the blade mounting tube 10. A push rod sleeve 21 is also provided at one end of the push rod 22 facing the resistance reducing blade 7. The push rod sleeve 21 is sleeved on the push rod 22 and is threadedly connected with 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 under the action of the speed difference. Because the transmission inner tube 8 and the push rod 22 are both engaged with the transmission gear 9 through threads, when the transmission gear 9 moves along the axis of the transmission inner tube 8, it will also drive the push rod 22 to move through the threads, so that the push rod 22 drives the push rod sleeve 21 to push the resistance reducing blade 7 outward. After being pushed, the resistance reducing blade 7 rotates outward, thereby reducing the contact area with the well wall.

[0075] 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, so that the transmission is more stable.

[0076] In one embodiment, the friction reduction device includes an elastic member 25 , both ends of which are respectively connected to the drag reduction blade 7 and the blade mounting tube 10 , and the elastic member 25 is used to drive the drag reduction blade 7 to rotate toward the direction close to the blade mounting tube 10 .

[0077] Please refer to Figure 5 by Fig.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. When 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 enough torque and returns to the speed before speed reduction, 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 to the mounting groove 101 by the elastic member 25 under the elastic force of the elastic member 25, and returns to the state of being in contact with the blade mounting tube 10.

[0078] In this embodiment, the pushed-out drag-reducing blades 7 are pulled back by the elastic member 25, so that the structure is simpler.

[0079] In one embodiment, the roller 31 further includes a roller 32 , and the roller 32 is pin-connected to the roller 31 .

[0080] Please refer to Figure 29 to Figure 31 In this embodiment, a roller 32 is further provided on the roller 31. During the entire drilling process, the blade mounting tube 10 not only drives the resistance reducing blade 7 to rotate, but also drives the resistance reducing blade 7 to move along the axial direction of the blade mounting tube 10. Since the roller 31 can only roll along the circumferential direction of the well wall, when the resistance reducing blade 7 moves along the axial direction of the blade mounting tube 10, there is sliding friction between the roller 31 and the well wall.

[0081] In this embodiment, a roller 32 is provided on the roller 31, and the rolling direction of the roller 32 is along the axial direction of the blade mounting tube 10. Then, 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 roller 32, so that rolling friction occurs between the roller 32 and the well wall, thereby reducing the friction force.

[0082] In one embodiment, the friction reduction and drag 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.

[0083] Please refer to Figures 6 to 10The first washer 2, the first shock-absorbing inner tube 3, the first shock-absorbing outer tube 4, the first shock-absorbing member 5 and the second washer 6 together form a first shock-absorbing chamber. The first shock-absorbing chamber is connected between the first joint 1 and the blade mounting tube 10 to provide a shock-absorbing effect for the transmission of the drill pipe. 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 provided 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, and shock absorption is performed through the first shock-absorbing member 5.

[0084] Please refer to Figures 17 to 21 A second damping cavity composed of a third washer 11, a second damping inner tube 12, a second damping outer tube 13 and a fourth washer 14 is provided between the second joint 19 and the blade mounting tube 10. Similarly, a disc spring is also provided between the second damping inner tube 12 and the second damping outer tube 13 for damping.

[0085] In this embodiment, a first shock absorbing chamber and a second shock absorbing chamber are respectively provided at both ends of the blade mounting tube 10 to perform shock absorption, thereby improving the shock resistance of the entire device.

[0086] In one embodiment, the friction reduction and drag reduction device further comprises 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.

[0087] Please refer to Figure 2 as well as Figure 22 to Figure 24 A connecting pipe 17 is also provided between the blade installation 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 installation pipe 10 facing the connecting pipe 17, thereby ensuring the sealing of the connection between the blade installation pipe 10 and the connecting pipe 17.

[0088] The connecting tube 17 is also connected to the second joint 19 through 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 relatively large, thereby ensuring that after the second joint 19 is connected to the connecting tube 17, the second joint 19 will not slip out of 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 shrink 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 shrinks inward, it drives the second joint 19 to shrink inward. The second joint 19 shrinks inward, that is, the second joint 19 moves axially toward the connecting tube 17, and at this time, the avoidance groove of the connecting tube 17 can provide sufficient sliding space for the second joint 19 to shrink inward.

[0089] Another embodiment of the present invention further provides a drill string, comprising a drill bit, a drill rod, and the friction and drag reducing device as described above. The drill rod is connected to the first joint 1, and the drill bit is connected to the second joint 19. The drill rod outputs torque to drive the friction and drag reducing device and the drill bit to rotate. During the rotation of the drill string, the roller 31 on the drag reducing blade 7 contacts the well wall, which can change the sliding friction into rolling friction, thereby greatly reducing the friction from the well wall.

[0090] 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 embodiments of the present invention.

Claims

1. A friction reduction and drag reduction device, characterized in that: include: A first joint (1), a second joint (19), a blade mounting tube (10), and a drag reducing blade (7), wherein the first joint (1) and the second joint (19) are respectively connected to two ends of the blade mounting tube (10), the drag reducing blade (7) is connected to an outer wall surface of the blade mounting tube (10), a roller (31) is provided on the outer wall surface of the drag reducing blade (7), the roller (31) and the drag reducing blade (7) are connected to each other so as to be relatively rotatable, and a rolling surface of the roller (31) protrudes from the outer wall surface of the drag reducing blade (7), and an axis of the roller (31) is parallel to an axis of the blade mounting tube (10).

2. The friction reducing and drag 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 drag reducing device according to claim 1, characterized in that: The drag reduction blade (7) is hinged to the blade mounting tube (10), and the rotation axis of the drag reduction blade (7) is parallel to the axis of the blade mounting tube (10).

4. The friction reducing and drag reducing device according to claim 3, characterized in that: The friction 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 meshed with the transmission inner tube (8) and the ejection assembly (20) respectively; the ejection assembly (20) is arranged in the blade mounting tube (10) and abuts against the drag reducing 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 reducing blade (7).

5. The friction reducing and drag reducing device according to claim 4, characterized in that: The ejector assembly (20) comprises a bearing (24) and a push rod (22) meshed with the transmission gear (9); the bearing (24) is fixedly disposed in the blade mounting tube (10); the push rod (22) is disposed in the bearing (24); and the push rod (22) is meshedly connected with the transmission gear (9).

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

7. 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).

8. 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 member (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 member (5) is arranged between the first shock absorbing inner tube (3) and the first shock absorbing outer tube (4).

9. The friction reducing and drag reducing device according to claim 1, characterized in that: The friction reduction and drag reduction 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.

10. A drill string, characterized in that: It comprises a drill bit and the friction reducing and drag reducing device according to any one of claims 1 to 9, wherein the drill bit is connected to the second joint (19).

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