Intelligent adaptive bidirectional drill string shock absorber based on magneto-rheological fluid

Abstract

The application relates to the technical field of oil and gas drilling engineering, and discloses an intelligent self-adaptive bidirectional drill string shock absorber based on a magneto-rheological fluid, which comprises a driving outer cylinder, a torsional spline sleeve is threadedly connected in the driving outer cylinder, a spline mandrel is arranged on one side of the driving outer cylinder, and the bottom end of the spline mandrel is connected with the torsional spline sleeve through splines; a torsional shock absorbing unit is arranged in the driving outer cylinder and in contact with the torsional spline sleeve; an axial shock absorbing unit is connected with one end of the torsional shock absorbing unit away from the torsional spline sleeve through a limiting sleeve and an impact joint; an intelligent sensing and control unit is arranged at the bottom of the axial shock absorbing unit, and the intelligent sensing and control unit is electrically connected with the axial shock absorbing unit. Through the bidirectional structure of "mechanical passive torsional shock absorbing-mechanical-active magneto-rheological fluid pressure composite axial shock absorbing", the bidirectional drill string torsional and axial vibration is comprehensively and efficiently inhibited.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling engineering technology, and in particular to an intelligent adaptive bidirectional drill string damper based on magnetorheological fluid. Background Technology

[0002] In the field of oil and gas drilling engineering, as global oil and gas resource exploration and development extends to deep wells, ultra-deep wells, horizontal wells, and unconventional oil and gas reservoirs such as shale gas and coalbed methane, downhole conditions are becoming increasingly complex and severe. During rotary drilling, the drill string system inevitably generates strong axial, lateral, and torsional vibrations due to factors such as the interaction between the drill bit and the formation, and the friction and collision between the drill string and the wellbore. These vibrations not only significantly reduce the rate of drilling and prolong the drilling cycle, but also accelerate drill string fatigue damage, causing problems such as loose threads, failure of downhole measuring instruments, and premature drill bit wear. In severe cases, they can even lead to major downhole accidents such as drill string breakage and stuck pipe, significantly increasing the safety risks and economic costs of drilling operations. Therefore, drill string vibration dampers have become an indispensable key downhole tool in modern drilling engineering.

[0003] Currently, commonly used drill string vibration dampers both domestically and internationally are mainly classified into three categories: mechanical, hydraulic, and mechanical-hydraulic hybrid. Mechanical dampers rely on the elastic deformation of elastic elements such as disc springs and helical springs to absorb vibration energy. They have advantages such as simple structure, high temperature resistance, and high reliability. However, their damping characteristics are determined by the inherent parameters of the elastic elements, and once the design is completed, it cannot be adjusted, making it difficult to adapt to vibration suppression requirements under different working conditions. Hydraulic dampers utilize the compressibility of hydraulic oil and the throttling effect of damping orifices to dissipate vibration energy, achieving better damping performance than purely mechanical dampers. However, they also suffer from the drawback of fixed damping characteristics; their damping force is determined only by preset oil viscosity and damping orifice size, and cannot dynamically change according to downhole vibration intensity. While mechanical-hydraulic hybrid dampers combine the advantages of the former two types and improve damping performance to some extent, they are essentially still within the category of passive damping and cannot overcome the inherent limitations of passive damping technology.

[0004] When drilling through mixed hard and soft formations, gravel layers, or during directional drilling operations, the impact loads on the drill string are characterized by suddenness, wide bandwidth, and large amplitude. Passive dampers often exhibit either insufficient or excessive damping in such complex conditions: insufficient damping fails to effectively suppress severe impacts, leading to drill string damage; excessive damping hinders the effective transmission of drilling pressure, reducing rock-breaking efficiency.

[0005] To address this, a smart adaptive bidirectional drill string damper based on magnetorheological fluid is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an intelligent adaptive bidirectional drill string damper based on magnetorheological fluid, which aims to solve or improve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides an intelligent adaptive bidirectional drill string vibration damper based on magnetorheological fluid, comprising... A drive outer cylinder is provided with a torsion spline sleeve connected to its internal thread. A spline mandrel is provided on one side of the drive outer cylinder, and the bottom end of the spline mandrel is connected to the torsion spline sleeve via a spline. A torsional damping unit, one end of which is located inside the drive outer cylinder and in contact with the torsional spline sleeve; An axial damping unit is connected to the end of a torsional damping unit away from the torsional spline sleeve via a limiting sleeve and an impact joint. An intelligent sensing and control unit is located at the bottom of the axial damping unit and is electrically connected to the axial damping unit.

[0008] Preferably, the torsional damping unit includes an upper cylinder, which is fixedly connected to the drive outer cylinder via a connecting joint. An upper mandrel is disposed through the upper cylinder, and a torsion joint is connected to the outer side of the upper end of the upper mandrel. The torsion joint is in contact with the torsion spline sleeve, and a torsional damping disc spring is disposed between the upper mandrel and the upper cylinder.

[0009] Preferably, the axial damping unit includes a lower cylinder, which is fixedly connected to the upper cylinder via a connecting joint. The impact joint and the limiting sleeve are located inside the lower cylinder. The end of the upper mandrel is connected to one end of the impact joint. An intermediate mandrel that can move axially relative to the lower cylinder is provided inside the lower cylinder. The end of the intermediate mandrel is correspondingly provided to the other end of the impact joint. An axial damping disc spring is provided between the intermediate mandrel and the lower cylinder.

[0010] Preferably, a delay mandrel is fixedly connected to the lower end of the intermediate mandrel. A delay hydraulic cylinder and a limiting piston are sleeved on the outside of the delay mandrel. The delay hydraulic cylinder is filled with magnetorheological fluid. The limiting piston is fixedly mounted on the delay mandrel. A lower mandrel is fixedly connected to the lower end of the delay mandrel. An annular groove is formed on the housing of the delay hydraulic cylinder. An electromagnetic coil is installed in the annular groove. The electromagnetic coil is electrically connected to the intelligent sensing and control unit.

[0011] Preferably, the intelligent sensing and control unit includes a lower connector fixedly connected to the delayed hydraulic cylinder. A groove is formed on the side wall of the lower connector, and a controller is installed in the groove. The controller is electrically connected to the electromagnetic coil. A sealing cover is provided at the opening of the groove, and a sealing ring is provided between the sealing cover and the inner wall of the groove. The end of the lower spindle is located inside the lower connector. An annular gap is left between the outer wall of the lower spindle and the inner wall of the lower connector. An arc-shaped magnetically attracted triaxial vibration sensor is installed in the annular gap. The base of the triaxial vibration sensor is arc-shaped, and the curvature of the base of the triaxial vibration sensor matches the outer diameter of the lower spindle. The triaxial vibration sensor is fixedly connected to the outer wall of the lower spindle by magnetic attraction through a permanent magnet on its back. The triaxial vibration sensor is electrically connected to the controller.

[0012] Preferably, a balancing hydraulic cylinder is fixedly connected between the lower cylinder and the delay hydraulic cylinder, the balancing hydraulic cylinder is provided with a balancing piston, and the delay hydraulic cylinder is installed with a buffer valve.

[0013] Preferably, the controller adopts a fuzzy PID control algorithm, using the root mean square value of the axial acceleration signal collected by the triaxial vibration sensor as the control input variable, dividing the vibration intensity into several levels, and outputting a corresponding current increment command according to the vibration intensity level. The final current command value is obtained by superimposing the output of the PID controller.

[0014] The present invention discloses the following technical effects: The torsional damping of this invention adopts a purely mechanical passive structure. It converts torsional vibration into axial displacement through a trapezoidal thread pair and uses a torsional damping disc spring to convert vibration energy into elastic potential energy. It does not require electromagnetic control, has a fast response speed and high reliability, and can effectively suppress drill string stick-slip vibration. The axial damping adopts a composite structure of axial damping disc spring and magnetorheological fluid damping in parallel. It retains the advantages of mechanical damping structure in terms of simplicity and high temperature resistance, and realizes continuous adjustment of damping force through magnetorheological effect.

[0015] The controller uses a triaxial vibration sensor to collect multi-dimensional vibration signals of the drill string in real time. It adopts a fuzzy PID control algorithm and takes the root mean square value of the axial acceleration signal as input. It can respond to changes in downhole working conditions within milliseconds and dynamically adjust the output current of the electromagnetic coil to accurately match the damping requirements of different vibration intensities. This completely avoids the problems of "insufficient damping" or "excessive damping" of traditional passive shock absorbers and ensures the effective transmission of drilling pressure.

[0016] By effectively suppressing vibration, it can significantly reduce the risk of drill bit fatigue damage, thread loosening and downhole instrument failure, extend drill bit service life, increase mechanical drilling speed, and reduce downhole complexities and accidents. It is suitable for drilling projects of deep wells, ultra-deep wells, horizontal wells and unconventional oil and gas resources such as shale gas and coalbed methane. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a front view of the bidirectional drill string damper of the present invention; Figure 2 This is a schematic diagram of the bidirectional drill string vibration damper of the present invention; Figure 3 This is a schematic diagram of the structure of the torsion spline sleeve of the present invention; Figure 4 This is a schematic diagram of the cooperation between the drive outer cylinder and the torsional damping unit of the present invention; Figure 5 This is a schematic diagram showing the cooperation between the torsional damping unit and the axial damping unit of the present invention; Figure 6 This is a schematic diagram showing the cooperation between the axial damping unit and the intelligent sensing and control unit of the present invention; The components are as follows: 1. Splined mandrel; 2. Drive outer cylinder; 3. Torsion spline sleeve; 4. Torsion joint; 5. Upper mandrel; 6. Connecting joint; 7. Upper cylinder; 8. Impact joint; 9. Limiting sleeve; 10. Lower cylinder; 11. Intermediate mandrel; 12. Balance hydraulic cylinder; 13. Balance piston; 14. Buffer valve; 15. Delay hydraulic cylinder; 16. Delay mandrel; 17. Limiting piston; 18. Lower mandrel; 19. Controller; 20. Triaxial vibration sensor; 21. Lower joint; 22. Electromagnetic coil; 23. Sealing cover; 24. Axial damping disc spring; 25. Torsional damping disc spring. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figures 1-6 This invention provides an intelligent adaptive bidirectional drill string vibration damper based on magnetorheological fluid, comprising: The drive outer cylinder 2 is internally threaded with a torsion spline sleeve 3, forming a trapezoidal thread pair, which is used to convert the torsional vibration of the drill string into an axial load. This axial load is compressed by the torsion joint 4 to the torsional damping disc spring 25 set between the upper mandrel 5 and the upper cylinder 7, thereby achieving passive absorption of torsional vibration. A spline mandrel 1 is provided on one side of the drive outer cylinder 2. The bottom end of the spline mandrel 1 is connected to the torsion spline sleeve 3 through a spline. The upper end of the spline mandrel 1 is provided with an API standard thread for connecting the upper drill string.

[0022] Torsional damping unit, one end of which is located inside the drive outer cylinder 2 and in contact with the torsion spline sleeve 3; An axial damping unit is connected to the end of a torsional damping unit away from a torsional spline sleeve 3 via a limiting sleeve 9 and an impact joint 8. The intelligent sensing and control unit is located at the bottom of the axial damping unit and is electrically connected to the axial damping unit.

[0023] Further optimization of the design involves a torsional vibration damping unit comprising an upper cylinder 7, which is hollow inside. The upper cylinder 7 is fixedly connected to the drive outer cylinder 2 via a connecting joint 6. An upper mandrel 5 is inserted through the upper cylinder 7, and a torsion joint 4 is connected to the outer upper end of the upper mandrel 5. The torsion joint 4 contacts a torsion spline sleeve 3. A torsional vibration damping disc spring 25 is positioned between the upper mandrel 5 and the upper cylinder 7. When the drill string generates torsional vibration, the spline mandrel 1 drives the torsion spline sleeve 3 to rotate via the spline. Due to the side effects of the thread, the rotational motion is converted into axial movement of the torsion spline sleeve 3, pushing the torsion joint 4 to compress the torsional vibration damping disc spring 25. This converts the torsional vibration energy into the elastic potential energy of the disc spring, achieving passive absorption of the torsional vibration. This unit does not rely on electromagnetic control and features fast response and high reliability.

[0024] Further optimization of the scheme: The axial damping unit includes a lower cylinder 10, which is fixedly connected to an upper cylinder 7 via a connecting joint 6. An impact joint 8 and a limiting sleeve 9 are located inside the lower cylinder 10. The end of the upper mandrel 5 is connected to one end of the impact joint 8. An intermediate mandrel 11, capable of axial movement relative to the lower cylinder 10, is installed inside the lower cylinder 10. The end of the intermediate mandrel 11 corresponds to the other end of the impact joint 8. An axial damping disc spring 24 is installed between the intermediate mandrel 11 and the lower cylinder 10. When the drill string generates axial vibration, the intermediate mandrel 11 moves axially relative to the lower cylinder 10 in the direction of vibration. The limiting structure on the intermediate mandrel 11 compresses the axial damping disc spring 24, converting some of the axial vibration energy into elastic potential energy. When the drill string generates axial vibration, the limiting piston 17 moves relative to the delayed hydraulic cylinder 15, compressing the magnetorheological fluid and causing it to flow through the damping gap. By adjusting the current of the electromagnetic coil 22 to generate a controllable magnetic field, the viscosity of the magnetorheological fluid is changed, thereby adjusting the damping force on the limiting piston 17 in real time. The axial damping disc spring 24 works in parallel with the magnetorheological fluid damper to absorb axial vibration energy. The magnetorheological fluid damper can be actively adjusted according to the working conditions to achieve the best damping effect.

[0025] Furthermore, both the axial damping disc spring 24 and the torsional damping disc spring 25 are mating disc spring assemblies.

[0026] In a further optimized design, a delay spindle 16 is fixedly connected to the lower end of the intermediate spindle 11. A delay hydraulic cylinder 15 and a limiting piston 17 are sleeved on the outside of the delay spindle 16. The delay hydraulic cylinder 15 is filled with magnetorheological fluid. The limiting piston 17 is fixedly mounted on the delay spindle 16. A lower spindle 18 is fixedly connected to the lower end of the delay spindle 16. An annular groove is provided on the housing of the delay hydraulic cylinder 15. An electromagnetic coil 22 is installed in the annular groove. The electromagnetic coil 22 is electrically connected to the intelligent sensing and control unit.

[0027] Furthermore, the cross-section of the annular groove inside the housing of the time-delay hydraulic cylinder 15 is rectangular or U-shaped, and the depth and width of the groove are determined according to the dimensions of the electromagnetic coil 22. After the electromagnetic coil 22 is wound, it is embedded into the groove as a whole, and then filled and fixed with high-temperature resistant, high-strength epoxy resin or ceramic potting material, so that the coil and the housing become one, while improving the insulation and sealing performance.

[0028] Further optimizing the scheme, the intelligent sensing and control unit includes a lower connector 21 fixedly connected to the time-delay hydraulic cylinder 15. A groove is provided on the side wall of the lower connector 21, and a controller 19 is installed in the groove. The controller 19 is electrically connected to the electromagnetic coil 22. A sealing cover 23 is provided at the opening of the groove, and a sealing ring is provided between the sealing cover 23 and the inner wall of the groove to prevent drilling fluid from entering the groove. The end of the lower mandrel 18 is located inside the lower connector 21. An annular gap is left between the outer wall of the lower mandrel 18 and the inner wall of the lower connector 21. An arc-shaped magnetically attracted triaxial vibration sensor 20 is installed in the annular gap. The base of the triaxial vibration sensor 20 is arc-shaped, and the curvature of the base of the triaxial vibration sensor 20 matches the outer diameter of the lower mandrel 18. The triaxial vibration sensor 20 is fixedly connected to the outer wall of the lower mandrel 18 by magnetic attraction through a permanent magnet on its back. The triaxial vibration sensor 20 is electrically connected to the controller 19. The triaxial vibration sensor 20 monitors drill string vibration in real time and transmits the vibration signal to the controller 19. The controller 19 analyzes and processes the signal to identify vibration characteristics. Subsequently, for torsional vibration, the torsional damping unit passively absorbs the vibration mechanically. For axial vibration, the controller 19 calculates and outputs a corresponding current to the electromagnetic coil 22 in real time based on the intensity level of the axial vibration. The electromagnetic coil 22 generates a controllable magnetic field, changing the viscosity of the magnetorheological fluid. The change in the viscosity of the magnetorheological fluid causes the axial damping force on the limiting piston 17 to change in real time. This damping force works in conjunction with the axial damping disc spring 24 to absorb axial vibration energy. Throughout the process, torsional vibration is absorbed autonomously by the mechanical structure without the participation of the electromagnetic system; axial vibration is controlled actively in a closed loop of "sensing-decision-execution".

[0029] Furthermore, the controller 19 integrates a signal processing unit and an electromagnetic control module: the signal processing unit is used to filter, amplify, and extract features from the vibration signal; the electromagnetic control module is used to precisely adjust the output current according to the instructions output by the signal processing unit.

[0030] Furthermore, the triaxial vibration sensor 20 is internally encapsulated with a triaxial MEMS accelerometer chip and a permanent magnet, which enables it to be firmly attached to the outer surface of the lower spindle 18.

[0031] Furthermore, a shallow groove is pre-machined on the outer wall of the lower mandrel 18, the curvature of which matches the curvature of the curved base. The triaxial vibration sensor 20 is attracted to the shallow groove by a permanent magnet on its back, while a high-temperature resistant adhesive is applied to the contact surface between the sensor and the shallow groove. This dual fixing method ensures both ease of installation and reliable sensor fixation under severe vibration conditions.

[0032] Furthermore, the controller 19 is electrically connected to the triaxial vibration sensor 20, and to the electromagnetic coil 22, through through holes located inside the components. These through holes are several millimeters in diameter and are filled with high-temperature resistant insulating sealant or equipped with glass sintered sealing joints to ensure the reliability and sealing of the electrical connections under high-pressure drilling fluid conditions.

[0033] The triaxial vibration sensor 20 continuously acquires axial, lateral, and torsional acceleration signals of the drill string at a high-frequency sampling rate. The signals are transmitted to the controller 19 via wires inside the through-hole, where the signal processing unit filters and reduces noise, extracting characteristic parameters such as vibration amplitude and frequency. The control algorithm determines the severity of the current vibration based on these parameters and calculates the optimal axial damping force to be applied, thereby generating a current command. The electromagnetic control module outputs a corresponding current to the electromagnetic coil 22, generating a controllable magnetic field. This magnetic field directly acts on the magnetorheological fluid within the time-delay hydraulic cylinder 15, causing a change in its viscosity, thereby altering the damping force experienced by the limit piston 17 during its movement.

[0034] For torsional vibration, the aforementioned electromagnetic system does not participate in the regulation; the vibration is entirely absorbed mechanically and passively by the threaded reversing mechanism and torsional damping disc spring 25 in the torsional damping unit. For axial vibration, the axial damping disc spring 24 works in parallel with the magnetorheological fluid damping: when the axial vibration is small, the controller 19 outputs a small current, the magnetorheological fluid viscosity is low, and the axial damping disc spring 24 plays the main damping role; when drilling encounters a hard interlayer causing severe impact vibration, the controller 19 detects a sudden increase in vibration amplitude, rapidly increases the output current, strengthens the magnetic field, increases the viscosity of the magnetorheological fluid, increases the damping force, and effectively suppresses drill string bouncing; when drilling encounters a homogeneous formation and the vibration is stable, the controller 19 automatically reduces the current, reduces the damping force, ensures effective transmission of drilling pressure, and improves rock breaking efficiency. The entire adjustment process requires no manual intervention and is completely automatic in adapting to changes in downhole conditions.

[0035] In a further optimized design, a balancing hydraulic cylinder 12 is fixedly connected between the lower cylinder 10 and the delay hydraulic cylinder 15. A balancing piston 13 is installed inside the balancing hydraulic cylinder 12, and a buffer valve 14 is installed inside the delay hydraulic cylinder 15. The balancing hydraulic cylinder 12 and the balancing piston 13 are used to compensate for the hydrostatic pressure outside the wellbore, ensuring that the internal pressure of the shock absorber is balanced with the external pressure, preventing high pressure from damaging the seals. The buffer valve 14 is used to limit the maximum movement speed of the limit piston 17 to avoid impact damage.

[0036] Further optimizing the scheme, controller 19 employs a fuzzy PID control algorithm. It uses the root mean square value of the axial acceleration signal collected by the triaxial vibration sensor 20 as the control input variable, dividing the vibration intensity into several levels. Based on the vibration intensity level, the fuzzy controller 19 outputs a corresponding current increment command, which is then superimposed with the output of the PID controller 19 to obtain the final current command value. This control strategy can adjust the current in real time according to the vibration intensity, theoretically responding to impact loads within milliseconds, causing the vibration amplitude to decay rapidly, and automatically reducing the damping force after the operating condition returns to stability, thus avoiding excessive vibration damping.

[0037] Furthermore, the spline mandrel 1, drive outer cylinder 2, torsion spline sleeve 3, torsion joint 4, upper mandrel 5, connecting joint 6, upper cylinder 7, impact joint 8, limit sleeve 9, lower cylinder 10, intermediate mandrel 11, balance hydraulic cylinder 12, balance piston 13, buffer valve 14, delay hydraulic cylinder 15, delay mandrel 16, limit piston 17, lower mandrel 18, and lower joint 21 are connected sequentially along the axial direction.

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "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, and are only for the convenience of describing this invention, 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, and therefore should not be construed as a limitation of this invention.

[0039] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A smart adaptive bidirectional drill string vibration damper based on magnetorheological fluid, characterized in that: include Drive outer cylinder (2), the drive outer cylinder (2) is internally threaded with a torsion spline sleeve (3), a spline spindle (1) is provided on one side of the drive outer cylinder (2), and the bottom end of the spline spindle (1) is connected to the torsion spline sleeve (3) through a spline; Torsional damping unit, one end of which is located inside the drive outer cylinder (2) and in contact with the torsion spline sleeve (3); An axial damping unit is connected to the end of a torsional damping unit away from the torsional spline sleeve (3) via a limiting sleeve (9) and an impact joint (8). An intelligent sensing and control unit is located at the bottom of the axial damping unit and is electrically connected to the axial damping unit.

2. The intelligent adaptive bidirectional drill string damper based on magnetorheological fluid according to claim 1, characterized in that: The torsional damping unit includes an upper cylinder (7), which is fixedly connected to the drive outer cylinder (2) via a connecting joint (6). An upper mandrel (5) is provided through the upper cylinder (7), and a torsion joint (4) is connected to the outer side of the upper end of the upper mandrel (5). The torsion joint (4) is in contact with the torsion spline sleeve (3), and a torsional damping disc spring (25) is provided between the upper mandrel (5) and the upper cylinder (7).

3. The intelligent adaptive bidirectional drill string damper based on magnetorheological fluid according to claim 2, characterized in that: The axial damping unit includes a lower cylinder (10), which is fixedly connected to the upper cylinder (7) via a connecting joint (6). The impact joint (8) and the limiting sleeve (9) are located inside the lower cylinder (10). The end of the upper spindle (5) is connected to one end of the impact joint (8). An intermediate spindle (11) that can move axially relative to the lower cylinder (10) is provided inside the lower cylinder (10). The end of the intermediate spindle (11) is correspondingly provided to the other end of the impact joint (8). An axial damping disc spring (24) is provided between the intermediate spindle (11) and the lower cylinder (10).

4. The intelligent adaptive bidirectional drill string vibration damper based on magnetorheological fluid according to claim 3, characterized in that: The lower end of the intermediate mandrel (11) is fixedly connected to a delay mandrel (16). The delay mandrel (16) is fitted with a delay hydraulic cylinder (15) and a limiting piston (17). The delay hydraulic cylinder (15) is filled with magnetorheological fluid. The limiting piston (17) is fixedly mounted on the delay mandrel (16). The lower end of the delay mandrel (16) is fixedly connected to a lower mandrel (18). The housing of the delay hydraulic cylinder (15) is provided with an annular groove. An electromagnetic coil (22) is installed in the annular groove. The electromagnetic coil (22) is electrically connected to the intelligent sensing and control unit.

5. The intelligent adaptive bidirectional drill string damper based on magnetorheological fluid according to claim 4, characterized in that: The intelligent sensing and control unit includes a lower connector (21) fixedly connected to the delayed hydraulic cylinder (15). A groove is provided on the side wall of the lower connector (21), and a controller (19) is installed in the groove. The controller (19) is electrically connected to the electromagnetic coil (22). A sealing cover (23) is provided at the opening of the groove, and a sealing ring is provided between the sealing cover (23) and the inner wall of the groove. The end of the lower spindle (18) is located inside the lower connector (21), and the outer side of the lower spindle (18) is... An annular gap is left between the wall and the inner wall of the lower connector (21). An arc-shaped magnetic triaxial vibration sensor (20) is installed in the annular gap. The base of the triaxial vibration sensor (20) is arc-shaped. The curvature of the base of the triaxial vibration sensor (20) matches the outer diameter of the lower spindle (18). The triaxial vibration sensor (20) is fixedly connected to the outer wall of the lower spindle (18) by magnetic attraction through the permanent magnet on its back. The triaxial vibration sensor (20) is electrically connected to the controller (19).

6. The intelligent adaptive bidirectional drill string damper based on magnetorheological fluid according to claim 1, characterized in that: A balance hydraulic cylinder (12) is fixedly connected between the lower cylinder (10) and the time-delay hydraulic cylinder (15). A balance piston (13) is provided inside the balance hydraulic cylinder (12), and a buffer valve (14) is installed inside the time-delay hydraulic cylinder (15).

7. The intelligent adaptive bidirectional drill string vibration damper based on magnetorheological fluid according to claim 1, characterized in that: The controller (19) adopts a fuzzy PID control algorithm, using the root mean square value of the axial acceleration signal collected by the triaxial vibration sensor (20) as the control input variable, and divides the vibration intensity into several levels. According to the vibration intensity level, the fuzzy controller (19) outputs the corresponding current increment command, which is superimposed with the output of the PID controller (19) to obtain the final current command value.

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