Circumferential damping device for well drilling and drill string

Abstract

The invention relates to a circumferential damping device for well drilling. The circumferential damping device comprises a barrel, an elastic piece arranged in the barrel and an excitation assembly arranged in the barrel and connected with the elastic piece. The elastic piece is configured to be capable of generating elastic deformation in the circumferential direction. The excitation assembly is internally provided with a first cavity and a second cavity communicated with the first cavity, and the first cavity and the second cavity are filled with magnetorheological fluid. The excitation assembly is constructed to be capable of generating magnetic fields with different intensities, so that the flow characteristic of the magnetorheological fluid is changed when the magnetorheological fluid flows between the first cavity and the second cavity in the circumferential direction due to elastic deformation of the elastic piece, and therefore the rigidity and the damping coefficient of the circumferential vibration reduction device are adjusted. Therefore, the axial damping device has good adjustability and applicability, and can cope with rock stratums with different underground lithology and complex and changeable working conditions.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction technology, specifically to a circumferential vibration reduction device and drill string for drilling. Background Technology

[0002] Due to complex geological structures and varying lithology and hardness, drill bits often endure significant impact loads during drilling operations. Phenomena such as drill string jamming, skipping, and resonance, resulting from the interaction between the drill bit and the drilled rock formation, can cause substantial damage to the drill bit, drill string, and even the drilling rig, leading to early failures such as drill bit cone breakage, drill string damage, or breakage. Furthermore, drill string wear and accidents caused by drill string vibration hinder the development of drilling technology towards higher speeds and higher efficiency. Therefore, eliminating or mitigating drill string vibration is crucial for improving drilling speed, shortening oil and gas resource exploration cycles, and reducing drilling costs.

[0003] Because drill string vibration and its mechanism are extremely complex, current vibration reduction systems used in drilling can only mitigate the vibrations that generate large tonnage forces when the drill string penetrates underground rock formations through their inherent damping and stiffness. Therefore, these inherently damped vibration reduction systems have poor adjustability and applicability, making them unsuitable for dealing with diverse underground rock formations and complex, variable operating conditions. Summary of the Invention

[0004] Based on the aforementioned problems in the existing technology, the present invention provides a circumferential vibration damping device for drilling, which has good adjustability and applicability, and can cope with underground rock strata with different lithologies and complex and variable working conditions.

[0005] A first aspect of the present invention provides a circumferential vibration damping device for drilling, comprising,

[0006] cylindrical body;

[0007] An elastic element is disposed within the cylinder, the elastic element being configured to elastically deform along the circumferential direction; and

[0008] An excitation assembly is connected to the elastic element inside the cylinder. The excitation assembly has a first cavity and a second cavity communicating with the first cavity. Both the first cavity and the second cavity are filled with magnetorheological fluid.

[0009] The excitation component is configured to generate magnetic fields of different intensities, which causes the magnetorheological fluid to change its flow characteristics when it flows in the circumferential direction between the first cavity and the second cavity due to the elastic deformation of the elastic element.

[0010] Furthermore, the excitation assembly includes a connecting shaft connected to the elastic element, a fixed cylinder arranged coaxially with the connecting shaft, and an excitation coil disposed on the fixed cylinder. The excitation coil is electrically connected to a control module, and the control module is configured to generate magnetic fields of different intensities in the excitation coil according to the vibration conditions, so as to change the flow characteristics of the magnetorheological fluid.

[0011] Furthermore, a first blade is provided on the connecting shaft, and a second blade is provided on the inner wall of the fixed cylinder. The first blade and the second blade together define the first cavity and the second cavity between the connecting shaft and the fixed cylinder.

[0012] The connecting shaft is configured to rotate relative to the fixed cylinder when the elastic element undergoes elastic deformation, so that the first blade moves relative to the second blade in the circumferential direction, so that the magnetorheological fluid flows between the first cavity and the second cavity.

[0013] Furthermore, the first blade or the second blade is provided with a channel connecting the first cavity and the second cavity, so that the magnetorheological fluid can flow in the circumferential direction between the first cavity and the second cavity.

[0014] Furthermore, the elastic element includes an elastic portion, and a first connecting portion and a second connecting portion respectively disposed at both ends of the elastic portion. The first connecting portion forms a circumferential limiting relationship with the cylinder, and the second connecting portion is connected to the connecting shaft.

[0015] The fixed cylinder and the cylinder body form a circumferential limit so that the connecting shaft can rotate relative to the fixed cylinder when the elastic part undergoes elastic deformation.

[0016] Furthermore, the connecting shaft includes a first end and a second end respectively disposed at both ends of the first blade, and the first end and the second end are provided with sealing elements that form an interference fit with the cylinder body, so as to enable the first end and the second end to be rotatably and sealingly connected with the cylinder body.

[0017] Furthermore, the circumferential vibration damping device also includes a first connector and a second connector disposed at both ends of the cylinder, the first connector being connected to the elastic element and the second connector being connected to the excitation assembly.

[0018] Furthermore, the circumferential vibration damping device also includes a flow channel that passes through the first joint, the elastic element, the excitation assembly, and the second joint for conveying drilling fluid.

[0019] Furthermore, a pre-torque is applied to the elastic element to reduce the peak value of the torque fluctuation on the elastic element when the circumferential damping device performs vibration damping.

[0020] A second aspect of the present invention provides a drill string for drilling, comprising the circumferential vibration damping device described in any of the preceding claims.

[0021] The beneficial effects of this invention are as follows: This invention provides a circumferential vibration damping device for drilling, comprising a cylinder, an elastic element disposed within the cylinder, and an excitation assembly connected to the elastic element within the cylinder. The elastic element is configured to undergo elastic deformation along the circumferential direction. The excitation assembly has a first cavity and a second cavity communicating with the first cavity, both of which are filled with magnetorheological fluid. The excitation assembly is configured to generate magnetic fields of varying intensities, causing the magnetorheological fluid to change its flow characteristics as it flows circumferentially between the first and second cavities due to the elastic deformation of the elastic element. This allows for adjustment of the stiffness and damping coefficient of the circumferential vibration damping device, thereby providing better adjustability and applicability for the axial vibration damping device, enabling it to cope with diverse underground rock formations and complex and variable working conditions.

[0022] The excitation assembly is also electrically connected to the control module. The control module, based on real-time data collected from several sensors mounted on the drill string, including vibration amplitude and frequency, during drilling, sends electrical signals to the excitation assembly. This causes the excitation coil to continuously change the magnetic field strength, thereby altering the flow characteristics of the magnetorheological fluid. Therefore, the circumferential vibration damping device can precisely adjust its stiffness and damping coefficient according to the drill string's vibration. This adjusted circumferential vibration damping device, in turn, affects the drill string's vibration at the next moment. A positive feedback loop is formed between the circumferential vibration damping device and the drill string, dynamically optimizing the load transfer rate and cutting torsional effect of the drill string, thereby improving drilling and rock-breaking efficiency while effectively protecting the drill string. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 The image shows a structural cross-sectional view of a circumferential vibration damping device used in drilling.

[0025] Figure 2 As shown Figure 1 The circumferential vibration damping device shown is a cross-sectional view of section AA in one state.

[0026] Figure 3 As shown Figure 1 The circumferential vibration damping device shown is a cross-sectional view of section AA in another state.

[0027] In the figure, the following labels are used: 100, circumferential vibration damping device; 101, flow channel; 10, cylinder; 20, first joint; 30, second joint;

[0028] 40. Elastic element; 41. Elastic part; 42. First connecting part; 43. Second connecting part;

[0029] 50. Excitation assembly; 51. Connecting shaft; 511. First end; 512. Second end; 513. First blade; 514. Seal; 515. Sealing sleeve; 52. Fixing cylinder; 521. Main body; 522. Second blade; 53. Excitation coil;

[0030] 60. First cavity; 70. Second cavity. Detailed Implementation

[0031] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic structure of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] This invention provides a drill string (not shown) for drilling, comprising several drill pipes connected in series, a stabilizer connected to the drill pipes, an axial vibration damping device, a circumferential vibration damping device 100, and various joints connecting these components. The drill string transmits rotational power input from the wellhead to the drill bit at the bottom of the well, enabling the drill bit to break rocks and drill. Simultaneously, the drill string is also configured to deliver drilling fluid to the bottom of the well to remove rock cuttings generated during the drill bit's rock-breaking operation. As the drill bit interacts with the rock formation at the bottom of the well to break rocks, it transmits the reaction force exerted by the rock formation to the drill string, causing the drill string to vibrate in both the axial and circumferential directions. The axial vibration damping device is configured to dampen the axial vibration of the drill string, while the circumferential vibration damping device 100 is configured to dampen the circumferential vibration of the drill string, thereby effectively protecting the drill string and extending its service life. Technicians may arrange one or more of the axial vibration damping devices and circumferential vibration damping devices 100 in series on the drill string as needed, or they may arrange one or more of the axial vibration damping devices and circumferential vibration damping devices 100 at intervals.

[0033] refer to Figure 1As shown, in some embodiments, the circumferential vibration damping device 100 includes a cylindrical body 10, a first connector 20 and a second connector 30 respectively disposed at both ends of the cylindrical body 10, and an elastic element 40 and an excitation assembly 50 disposed inside the cylindrical body 10. The elastic element 40 is configured to undergo elastic deformation in the circumferential direction when the drill string vibrates, so as to convert the mechanical energy of the drill string vibration into elastic potential energy, thereby buffering the vibration of the drill string. The excitation assembly 50 has a first cavity 60 and a second cavity 70 that are interconnected inside the cylindrical body 10 for filling with magnetorheological fluid. When the magnetorheological fluid flows in the circumferential direction between the first cavity 60 and the second cavity 70, it can generate a damping force to convert the mechanical energy of the drill string vibration into heat energy, thereby achieving the purpose of vibration damping. That is, the axial vibration damping device 100 buffers the drill string when it vibrates through the elastic component 40, and converts mechanical energy into heat energy through the damping force generated when the magnetorheological fluid flows in the circumferential direction between the first cavity 60 and the second cavity 70, thereby achieving the purpose of vibration damping of the drill string.

[0034] The excitation component 50 can generate magnetic fields of varying intensities under the electrical drive of an external power source, thereby altering the flow characteristics of the magnetorheological fluid. This changes the damping force generated when the magnetorheological fluid flows circumferentially between the first cavity 60 and the second cavity 70, thus adjusting the stiffness and damping coefficient of the circumferential vibration damping device 100. The excitation component 50 is also electrically connected to a control module (not shown in the figure) to control the intensity of the magnetic field generated by the excitation component 50. This allows the control module to actively adjust the overall stiffness and damping coefficient of the circumferential vibration damping device 100, improving its adaptability and enabling it to better cope with diverse underground rock formations and complex, variable working conditions. Furthermore, by adjusting the overall stiffness and damping coefficient of the circumferential vibration damping device 100, the vibration modes of the drill string can be altered, preventing resonance and optimizing dynamic load and torsional effects, thereby improving drilling and rock-breaking efficiency while effectively protecting the drill string.

[0035] It is understood that by selecting elastic components capable of axial deformation, such as springs or disc springs, and by allowing the magnetorheological fluid to flow axially, a corresponding axial vibration damping device can be designed. By mounting the circumferential vibration damping device 100 and the axial vibration damping device together on the drill string, vibrations in both the circumferential and axial directions of the drill string can be simultaneously damped, thereby effectively extending the service life of the drill string and reducing the risk of drill string accidents. This will not be elaborated further in this application.

[0036] Combination Figure 1As shown, in some embodiments, the circumferential vibration damping device 100 is further provided with a flow channel 101 that sequentially passes through the first joint 20, the elastic element 40, the excitation assembly 50 and the second joint 30 in the axial direction, for conveying drilling fluid to the bottom of the well.

[0037] refer to Figure 1 As shown, in some embodiments, the upper end of the first connector 20 can be connected to the drill pipe or the axial vibration damping device. The lower end of the first connector 20 extends into the cylinder 10 and is connected to the elastic element 40. In some embodiments, the first connector 20 can be connected to the drill pipe, the axial vibration damping device, or the elastic element 40 by means of screwing, bolting, or snap-fitting.

[0038] In some embodiments, the second connector 30 may be connected to the drill bit, drill rod, or axial vibration damping device by means of screwing, bolting, or snap-fitting.

[0039] Combination Figure 1 As shown, in some embodiments, the elastic member 40 includes an elastic portion 41 capable of elastic deformation in the circumferential direction, and a first connecting portion 42 and a second connecting portion 43 respectively disposed at both ends of the elastic portion 41. The first connecting portion 42 and the second connecting portion 43 are used to connect the first connector 20 and the excitation assembly 50, respectively. The first connecting portion 42 can form a circumferential limit with the cylinder 10 to prevent relative rotation between the cylinder 10 and the elastic member 40. In some embodiments, the first connecting portion 42 is keyed to the cylinder 10, thereby forming a circumferential limit between the cylinder 10 and the elastic member 40. Preferably, the outer circumferential wall of the first connecting portion 42 and the inner wall of the cylinder 10 are connected by a spline.

[0040] In some embodiments, the elastic part 41 is made of a highly elastic metal material, so that the elastic element 40 can convert the mechanical energy of the drill string vibrating in the circumferential direction into elastic potential energy.

[0041] refer to Figure 1-3 As shown, in some embodiments, the excitation assembly 50 includes a connecting shaft 51 connecting the elastic member 40 and the second connector 30, and a fixed cylinder 52 coaxially arranged with the connecting shaft 51. The connecting shaft 51 includes a first end 511 connected to the second connecting portion 43, a second end 512 connected to the second connector 30, and a first blade 513 extending axially between the first end 511 and the second end 512. Sealing members 514 are provided on the circumferential outer walls of both the first end 511 and the second end 512 to form an interference fit with the inner wall of the cylinder 10, thereby achieving a rotatable sealed connection between the first end 511 and the second end 512 of the connecting shaft 51 and the inner wall of the cylinder 10.

[0042] In some embodiments, a sealing sleeve 515 is also provided between the second end 512 and the cylinder 10. The sealing sleeve 515 can form radial support between the second end 512 and the cylinder 10, thereby enhancing the sealing between the second end 512 and the cylinder 10 and preventing drilling fluid, mud and other impurities from entering the circumferential vibration damping device 100.

[0043] Combination Figure 2 and Figure 3 As shown, in some embodiments, the fixed cylinder 52 includes a main body 521 disposed on the inner wall of the cylinder 10, and a second blade 522 extending axially on the inner wall of the main body 521. A circumferential restraint is formed between the main body 521 and the cylinder 10, preventing relative rotation between them. Preferably, the main body 521 and the cylinder 10 are connected by a spline. The second blade 522 extends radially inward and seals with the connecting shaft 51, while the first blade 513 extends radially outward and seals with the inner wall of the main body 521, such that the first blade 513 and the second blade 522 together define a first cavity 60 and a second cavity 70 between the connecting shaft 51 and the main body 521.

[0044] In this embodiment, two first blades 513 are provided on the connecting shaft 51, and the two first blades 513 are arranged opposite each other in the radial direction. Similarly, two second blades 522 are provided on the main body 521, and the two second blades 522 are arranged opposite each other in the radial direction. This results in the excitation assembly 50 having two first cavities 60 and two second cavities 70 internally, and the first cavities 60 and second cavities 70 are arranged alternately in the circumferential direction.

[0045] In some embodiments, the first blade 513 or the second blade 522 is provided with a channel (not shown) communicating circumferentially with the first cavity 60 and the second cavity 70, so that the magnetorheological fluid can flow between the first cavity 60 and the second cavity 70. There may be one, two, or more channels. In some preferred embodiments, a compression valve and a rebound valve are respectively provided in the two channels. The compression valve is configured to allow the magnetorheological fluid to flow only from the first cavity 60 to the second cavity 70, and the rebound valve is configured to allow the magnetorheological fluid to flow only from the second cavity 70 to the first cavity 60. The flow cross-sections of the compression valve and the rebound valve are different to provide different damping of the circumferential damping device 100 during compression and rebound.

[0046] In some embodiments, when the circumferential vibration damping device 100 dampens the circumferential vibration of the drill string, the elastic element 40 undergoes circumferential torsion, causing energy to be converted between the mechanical energy of the drill string vibration and the elastic potential energy of the elastic element 40. During torsion, the elastic element 40 causes the connecting shaft 51 to rotate relative to the fixed cylinder 52, resulting in relative movement of the first blade 513 and the second blade 522 in the circumferential direction. This increases the volume of the first cavity 60 and decreases the volume of the second cavity 70, or vice versa. Therefore, the magnetorheological fluid can flow circumferentially between the first cavity 60 and the second cavity 70 through the channel. During this process, the damping force generated by the magnetorheological fluid as it passes through the channel converts the mechanical energy of the drill string vibration or the elastic potential energy of the elastic element 40 into heat energy, which is then conducted to the drilling fluid in the form of heat through the connecting shaft 51 and the cylinder 10. This achieves circumferential vibration damping of the drill string.

[0047] Furthermore, when the magnetorheological fluid flows between the first cavity 60 and the second cavity 70, it also prevents relative rotation between the connecting shaft 51 and the fixed cylinder 52 to a certain extent through the first blade 513 and the second blade 522. This can effectively reduce the oscillation of the elastic element 40 connected to the connecting shaft 51 during the conversion of mechanical energy and potential energy, thereby further enhancing the buffering effect.

[0048] In some embodiments, an excitation coil 53 electrically connected to an external power source and the control module is disposed within the first blade 513 and / or the second blade 522. The excitation coil 53 can generate a magnetic field under the electrical drive of the external power source, altering the flow characteristics of the magnetorheological fluid and adjusting the viscous resistance and Coulomb resistance of the magnetorheological fluid flowing between the first cavity 60 and the second cavity 70. This effectively changes the stiffness and damping coefficient of the circumferential vibration damping device 100, making it adjustable and thus broadening its applicability. The circumferential vibration damping device 100 can then better cope with underground rock strata of varying lithology and complex and changing working conditions. Technicians also no longer need to frequently replace the circumferential vibration damping device 100 when drilling into different rock strata, improving drilling efficiency.

[0049] Preferably, the excitation coil 53 is only disposed within the second blade 522. Since the connecting shaft 51 is fixedly connected to the elastic element 40, the connecting shaft 51 will also undergo a certain degree of torsional deformation during the vibration damping process of the circumferential damping device 100. Not disposing of the excitation coil 53 within the first blade 513 effectively ensures the integrity of the first blade 513, guarantees its strength, and prevents damage to the first blade 513 after frequent torsional deformation.

[0050] In some preferred embodiments, a magnetic shielding sheet is also provided on the second blade 522 to prevent the excitation coil 53 from generating magnetic leakage and to improve the magnetic control effect of the excitation coil 53.

[0051] In some preferred embodiments, a technician may apply a pre-torque to the elastic element 40 during the assembly of the circumferential damping device 100 in order to counteract the counter-torque applied by the drill bit to the drill string, thereby reducing the peak torque fluctuation of the elastic element 40 during the damping of the circumferential damping device 100.

[0052] exist Figure 3 As shown, arrow X in the diagram points counterclockwise. After applying a counterclockwise pre-torque to the elastic element 40, the first blade 513 on the connecting shaft 51 engages with the second blade 522 on the fixed cylinder 52. At this time, the volume of the second cavity 70 is zero, while the volume of the first cavity 60 is at its maximum. That is, as... Figure 3 As shown in the diagram, when the drill string rotates counterclockwise to drive the drill bit to drill and break the rock, the rock formation at the bottom of the well applies a counter-torque in the clockwise direction to the drill string through the drill bit. During normal drilling, the magnitude of this counter-torque fluctuates due to factors such as differences in the lithology of the rock formation at the bottom of the well, causing the drill string to vibrate in the circumferential direction. This counter-torque is transmitted through the drill string to the circumferential vibration damping device 100, where it is superimposed on and canceled out by the pre-torque on the elastic element 40, thus reducing the peak value of the torque fluctuation on the elastic element 40. This effectively prevents fatigue failure of the elastic element 40 when the circumferential vibration damping device 100 is in operation, improving the service life of the elastic element 40.

[0053] When the value of the counter-torque is less than the value of the pre-torque, the volume of the second cavity 70 is less than the volume of the first cavity 60. When the value of the counter-torque is approximately equal to the value of the pre-torque, the volumes of the second cavity 70 and the first cavity 60 are also approximately the same. That is, as... Figure 2 The state is shown. When the value of the counter-torque is approximately greater than the value of the pre-torque, the volume of the second cavity 70 is greater than the volume of the first cavity 60. When the drill string drills relatively smoothly into the bottom rock formation through the drill bit, the value of the counter-torque fluctuates smoothly within a certain range, and the volumes of the first cavity 60 and the second cavity 70 also fluctuate smoothly within a certain range.

[0054] In some preferred embodiments, the excitation coil 53 of the excitation assembly 50 can continuously change the strength of the magnetic field under the control of the control module. The control module can use several sensors installed on the drill string to collect vibration indicators such as amplitude and frequency of the drill string during drilling in real time, and then process the indicators according to a predetermined algorithm and program to obtain the processing result. The control module sends an electrical signal to the excitation assembly 50 according to the processing result, causing the excitation coil 53 to continuously change the magnetic field strength, thereby continuously changing the flow characteristics of the magnetorheological fluid. Therefore, the circumferential vibration damping device 100 can continuously and accurately adjust its stiffness and damping coefficient according to the vibration of the drill string, and the adjusted circumferential vibration damping device 100 will affect the vibration of the drill string at the next moment. A positive feedback mode is formed between the circumferential vibration damping device 100 and the drill string, dynamically optimizing the load transfer rate and cutting torsional effect of the drill string, so as to improve the drilling and rock breaking efficiency while effectively protecting the drill string.

[0055] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0057] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A circumferential vibration damping device for drilling, comprising: Cylinder (10); An elastic element (40) is disposed inside the cylinder (10), and the elastic element (40) is configured to be elastically deformable in the circumferential direction; as well as An excitation assembly (50) is connected to the elastic element (40) inside the cylinder (10). The excitation assembly (50) has a first cavity (60) and a second cavity (70) communicating with the first cavity (60). The first cavity (60) and the second cavity (70) are filled with magnetorheological fluid. The excitation component (50) is configured to generate magnetic fields of different intensities, which causes the magnetorheological fluid to change its flow characteristics when it flows in the circumferential direction between the first cavity (60) and the second cavity (70) due to the elastic deformation of the elastic element (40).

2. The circumferential vibration damping device for drilling according to claim 1, characterized in that, The excitation assembly (50) includes a connecting shaft (51) connected to the elastic member (40), a fixed cylinder (52) coaxially arranged with the connecting shaft (51), and an excitation coil (53) disposed on the fixed cylinder (52). The excitation coil (53) is electrically connected to a control module. The control module is configured to generate magnetic fields of different intensities in the excitation coil (53) according to the vibration conditions, so as to change the flow characteristics of the magnetorheological fluid.

3. The circumferential vibration damping device for drilling according to claim 2, characterized in that, A first blade (513) is provided on the connecting shaft (51), and a second blade (522) is provided on the inner wall of the fixed cylinder (52). The first blade (513) and the second blade (522) together define the first cavity (60) and the second cavity (70) between the connecting shaft (51) and the fixed cylinder (52). The connecting shaft (51) is configured to rotate relative to the fixed cylinder (52) when the elastic member (40) undergoes elastic deformation, so that the first blade (513) moves in the circumferential direction relative to the second blade (522) so that the magnetorheological fluid flows between the first cavity (60) and the second cavity (70).

4. The circumferential vibration damping device for drilling according to claim 3, characterized in that, The first blade (513) or the second blade (522) is provided with a channel connecting the first cavity (60) and the second cavity (70) so that the magnetorheological fluid can flow in the circumferential direction between the first cavity (60) and the second cavity (70).

5. The circumferential vibration damping device for drilling according to claim 2, characterized in that, The elastic element (40) includes an elastic portion (41) and a first connecting portion (42) and a second connecting portion (43) respectively disposed at both ends of the elastic portion (41). The first connecting portion (42) forms a circumferential limiting with the cylinder (10), and the second connecting portion (43) is connected to the connecting shaft (51). The fixed cylinder (52) and the cylinder body (10) form a circumferential limit so that the connecting shaft (51) can rotate relative to the fixed cylinder (52) when the elastic part (41) undergoes elastic deformation.

6. The circumferential vibration damping device for drilling according to claim 5, characterized in that, The connecting shaft (51) includes a first end (511) and a second end (512) respectively disposed at both ends of the first blade (513). The first end (511) and the second end (512) are provided with sealing elements (514) that form an interference fit with the cylinder (10) so that the first end (511) and the second end (512) are rotatably and sealingly connected with the cylinder (10).

7. The circumferential vibration damping device for drilling according to any one of claims 1-6, characterized in that, The circumferential vibration damping device (100) further includes a first connector (20) and a second connector (30) disposed at both ends of the cylinder (10), wherein the first connector (20) is connected to the elastic element (40) and the second connector (30) is connected to the excitation assembly (50).

8. The circumferential vibration damping device for drilling according to claim 7, characterized in that, The circumferential vibration damping device (100) further includes a flow channel (101) that passes through the first joint (20), the elastic element (40), the excitation assembly (50) and the second joint (30) for conveying drilling fluid.

9. The circumferential vibration damping device for drilling according to any one of claims 1-6, characterized in that, A pre-torque is applied to the elastic element (40) to reduce the peak value of the torque on the elastic element (40) when the circumferential damping device (100) performs damping.

10. A drill string for drilling, characterized in that, Includes the circumferential vibration damping device (100) as described in any one of claims 1-9.

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