Axial damping device for well drilling and drill string

Abstract

The invention relates to an axial damping device for well drilling. The axial damping device comprises a barrel, an elastic assembly and an excitation assembly, wherein a first connector and a second connector are arranged at the two ends of the barrel respectively, and the elastic assembly can generate elastic deformation in the barrel along a mandrel. The excitation assembly, the mandrel and the second connector jointly define a first cavity in the barrel, and the excitation assembly, the mandrel and the elastic assembly jointly define 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 axial direction due to elastic deformation of the elastic assembly, and therefore the rigidity and the damping coefficient of the axial 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 an axial 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 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 an axial 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 an axial vibration damping device for drilling, comprising,

[0006] A cylindrical body, with a first connector and a second connector respectively provided at both ends, and a mandrel extending from the first connector to the second connector is provided inside the cylindrical body;

[0007] An elastic component, configured to elastically deform along the mandrel within the cylinder; and

[0008] The excitation assembly, together with the mandrel and the second connector, defines a first cavity within the cylindrical body, and together with the mandrel and the elastic assembly, defines a second cavity communicating with the first cavity. Both the first and second cavities 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 axially between the first cavity and the second cavity due to the elastic deformation of the elastic component.

[0010] Furthermore, the excitation assembly includes a first mounting cylinder mounted on the mandrel, a second mounting cylinder coaxially arranged with the first mounting cylinder, and an excitation coil disposed between the first mounting cylinder and the second mounting cylinder. The excitation coil is electrically connected to a control module, which 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, the second mounting cylinder is provided with a channel connecting the first cavity and the second cavity, so that the magnetorheological fluid can flow axially between the first cavity and the second cavity.

[0012] Furthermore, a first end cap and a second end cap are respectively provided at both ends of the first mounting cylinder. A locking seat is provided on the second end cap. The locking seat is configured to work together with the first end cap to limit the excitation assembly and the spindle in the axial direction.

[0013] Furthermore, a piston is provided at the lower end of the elastic component, and the upper end of the elastic component forms an axially upward limiting position with the mandrel, so that the piston can cause the elastic component to deform in the axial direction when the magnetorheological fluid flows.

[0014] Furthermore, a force transmission cylinder is provided between the excitation assembly and the cylinder body. The two ends of the force transmission cylinder are respectively connected to the piston and the second connector, so that the second connector can directly cause the elastic assembly to deform through the piston.

[0015] Furthermore, the upper end of the mandrel is provided with a connecting part, a sealing part that is slidably and sealingly connected to the first joint, and a first limiting part provided below the sealing part. A first step is provided between the connecting part and the sealing part to limit the first joint when the axial damping device is retracted to its shortest length.

[0016] Furthermore, the first connector includes a main body that is slidably and sealingly connected to the sealing part, and a second limiting part disposed at the lower end of the main body. The second limiting part and the first limiting part form a circumferential limiting, so that the mandrel can transmit torque to the second connector through the first connector and the cylinder.

[0017] Furthermore, a transition portion, a first mounting portion for mounting the elastic component, and a second mounting portion for mounting the excitation component are sequentially provided below the first limiting portion. A second step is provided between the transition portion and the first mounting portion for limiting the elastic component, and a third step is provided between the first mounting portion and the second mounting portion for limiting the excitation component.

[0018] Furthermore, a limiting member is provided on the transition portion, the limiting member being configured to limit the first joint when the axial damping device is extended to its maximum length.

[0019] Furthermore, the mandrel is provided with a flow channel penetrating the elastic component and the excitation component, and the mandrel is slidably sealed to the first joint and the second joint, so that the mandrel can transport drilling fluid from the first joint to the second joint when the axial vibration damping device performs vibration damping.

[0020] A second aspect of the invention provides a drill string for drilling, comprising the axial vibration damping device described in any of the preceding claims, wherein a second connector of the axial vibration damping device is connected to a conversion connector, the conversion connector being configured to connect to a drill pipe, a power drill tool, a circumferential vibration damping device, or another axial vibration damping device.

[0021] The beneficial effects of this invention are as follows: This invention provides an axial vibration damping device for drilling, comprising a cylinder with a first connector and a second connector respectively at both ends, an elastic component configured to undergo elastic deformation along a mandrel within the cylinder, and an excitation component. The excitation component, together with the mandrel and the second connector, defines a first cavity within the cylinder, and together with the mandrel and the elastic component, defines a second cavity communicating with the first cavity. The first and second cavities are filled with magnetorheological fluid. The excitation component is configured to generate magnetic fields of varying intensities, causing the magnetorheological fluid to change its flow characteristics when flowing axially between the first and second cavities due to the elastic deformation of the elastic component. This allows for adjustment of the stiffness and damping coefficient of the axial vibration damping device, thereby providing good adjustability and applicability, 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 axial vibration damping device can precisely adjust its stiffness and damping coefficient according to the drill string's vibration. This adjusted axial vibration damping device, in turn, affects the drill string's vibration at the next moment. A positive feedback loop is formed between the axial vibration damping device and the drill string, dynamically optimizing the load transfer rate and drilling pressure impact 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 shown is a cross-sectional view of the overall structure of an axial vibration damping device for drilling.

[0025] Figure 2 As shown Figure 1 A partially enlarged view of section A of the central axial vibration damping device.

[0026] Figure 3 As shown Figure 1 A partially enlarged view of section B of the central axial vibration damping device.

[0027] Figure 4 As shown Figure 1 A partially enlarged view of section C of the central axial vibration damping device.

[0028] Figure 5 As shown Figure 1 A cross-sectional view of the excitation assembly of the central axial vibration damping device.

[0029] In the figures, the reference numerals are as follows: 100, axial vibration damping device; 10, cylinder; 11, mandrel; 110, flow channel; 111, connecting part; 112, sealing part; 113, first limiting part; 114, first mounting part; 115, second mounting part; 116, first step; 117, transition part; 118, second step; 119, third step; 12, limiting element;

[0030] 20. First connector; 21. Main body; 211. Mounting groove; 22. Second limiting part;

[0031] 30. Second connector; 31. First end; 32. Second end; 33. Adapter connector;

[0032] 40. Elastic component; 41. Piston; 42. Gasket;

[0033] 50. Excitation assembly; 51. First mounting cylinder; 511. First end cap; 512. Second end cap; 513. Locking seat; 52. Second mounting cylinder; 53. Excitation coil; 54. Force transmission cylinder;

[0034] 60. First cavity; 70. Second cavity. Detailed Implementation

[0035] 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.

[0036] This invention provides a drill string (not shown) for drilling, comprising a plurality of drill pipes connected in series, a stabilizer connected to the drill pipes, an axial vibration damping device, a circumferential vibration damping device, and other components, as well as 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 100 is configured to dampen the axial vibration of the drill string, while the circumferential vibration damping device 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 axial vibration damping devices 100 and the circumferential vibration damping devices in series on the drill string as needed, or they may arrange one or more axial vibration damping devices 100 and the circumferential vibration damping devices at intervals.

[0037] refer to Figure 1 As shown, in some embodiments, the axial vibration damping device 100 includes a cylindrical body 10, a first connector 20 and a second connector 30 respectively disposed at the upper and lower ends of the cylindrical body 10, and an elastic component 40 and an excitation component 50 disposed inside the cylindrical body 10. The elastic component 40 is configured to undergo elastic deformation along the axial 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 component 50 has a first cavity 60 and a second cavity 70 that are interconnected within the cylindrical body 10, for filling with magnetorheological fluid. When the magnetorheological fluid flows along the axial 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 axial direction between the first cavity 60 and the second cavity 70, thereby achieving the purpose of vibration damping of the drill string.

[0038] 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 axially between the first cavity 60 and the second cavity 70, thus adjusting the stiffness and damping coefficient of the axial 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 axial vibration damping device 100, improving its adaptability and enabling it to better cope with diverse underground rock formations and complex and variable working conditions. Furthermore, this can also alter the vibration modes of the drill string, preventing resonance and optimizing dynamic load and impact effects, thereby improving drilling and rock-breaking efficiency while effectively protecting the drill string.

[0039] It is understood that by selecting elastic components capable of circumferential deformation, such as torsion bars, and by allowing magnetorheological fluid to flow in the circumferential direction, a corresponding circumferential vibration damping device can be designed. By mounting the axial vibration damping device 100 and the circumferential vibration damping device together on the drill string, vibrations in both the axial and circumferential 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.

[0040] refer to Figure 1 As shown, in some embodiments, the axial vibration damping device 100 further includes a mandrel 11 disposed within the cylinder 10, sequentially passing through the first connector 20, the elastic component 40, and the excitation component 50 in the axial direction, and then connecting to the second connector 30. The mandrel 11 has an axially extending flow channel 110 for conveying drilling fluid to the bottom of the well. The mandrel 11 has several steps for limiting the movement of the first connector 20, the elastic component 40, and the excitation component 50 during vibration damping, effectively ensuring the buffering and vibration damping performance of the axial vibration damping device 100.

[0041] refer to Figure 2-4As shown, in some embodiments, the upper end of the mandrel 11 is provided with a connecting portion 111 for connecting the drill rod or the circumferential vibration damping device. Below the connecting portion 111, there are sequentially provided a sealing portion 112 for sealingly engaging with the first connector 20, a first limiting portion 113 forming a circumferential limit with the first connector 20, a first mounting portion 114 for mounting the elastic component 40, and a second mounting portion 115 for mounting the excitation component 50. The circumferential dimension of the sealing portion 112 is smaller than the circumferential dimension of the connecting portion 111, such that a first step 116 is formed between the sealing portion 112 and the connecting portion 111 in the axial direction downward, for limiting the first connector 20 in the axial direction upward. A transition portion 117 is provided between the first limiting portion 113 and the first mounting portion 114, and the circumferential dimension of the transition portion 117 is larger than that of the first mounting portion 114, forming a second step 118 downward in the axial direction between the transition portion 117 and the first mounting portion 114, which limits the elastic component 40 upward in the axial direction. A limiting member 12 is also installed on the transition portion 117 to limit the first connector 20 downward in the axial direction. The circumferential dimension of the first mounting portion 114 is larger than that of the second mounting portion 115, forming a third step 119 downward in the axial direction between the first mounting portion 114 and the second mounting portion 115, which limits the excitation component 50 upward in the axial direction.

[0042] Combination Figure 2 As shown, in some embodiments, the first connector 20 includes a main body 21 that is slidably and sealingly connected to the sealing part 112, and a second limiting part 22 disposed at the lower end of the main body 21. A plurality of mounting grooves 211 are provided on the upper inner wall of the main body 21 for mounting sealing rings, so that when the first connector 20 is fitted onto the mandrel 11, it can form a sealing fit with the sealing part 112, thereby preventing drilling fluid, cuttings, and other impurities from entering the interior of the axial vibration damping device 100. The second limiting part 22 is used to form a circumferential limiting with the first limiting part 113 of the mandrel 11, so that the mandrel 11 can transmit the torque applied by the drill pipe or the circumferential vibration damping device above to the first connector 20.

[0043] In some embodiments, the first limiting part 113 and the second limiting part 22 can be connected by a key to form a circumferential limit. Specifically, the first limiting part 113 and the second limiting part 22 are connected by a spline, so that the first joint 20 can slide along the axial direction of the spindle 11 and transmit torque with the spindle 11 when the axial damping device 100 performs vibration damping.

[0044] In some embodiments, when the axial damping device 100 shortens axially for damping, the first joint 20 moves axially upward on the spindle 11. When the axial damping device 100 extends axially for damping, the first joint 20 moves axially downward on the spindle 11. During this process, the sealing ring installed in the mounting groove 211 of the main body 21 always forms a sealing fit with the sealing portion 112 of the spindle 11. When the axial damping device 100 is retracted to its shortest length, the upper end face of the main body 21 abuts against the first step 116. When the axial damping device 100 is extended to its longest length, the lower end face of the second limiting portion 22 abuts against the limiting member 12. Preferably, the limiting member 12 is installed in a groove provided on the transition portion 117 and protrudes radially outward from the transition portion 117.

[0045] Combination Figure 2 As shown, in some embodiments, the length of the second limiting portion 22 in the axial direction is less than the length of the first limiting portion 113 in the axial direction, and the inner diameter of the second limiting portion 22 is less than the inner diameter of the main body 21. This ensures that as the mounting groove 211 moves axially along the sealing portion 112, the inner wall of the main body 21 and the splines on the first limiting portion 113 are always radially spaced, thus preventing wear caused by mutual scraping between the inner wall of the main body 21 and the splines on the first limiting portion 113. The outer wall of the second limiting portion 22 is also provided with external threads for connecting to the cylinder 10, allowing the first connector 20 to transmit the torque transmitted from the spindle 11 to the second connector 30 through the cylinder 10.

[0046] Combination Figure 4 As shown, in some embodiments, the second connector 30 is generally a hollow cylindrical structure open at both ends, including a first end 31 facing the mandrel 11 and a second end 32 away from the mandrel 11. The second connector 30 is coaxially arranged at the lower end of the mandrel 11 through the opening of the first end 31 and is slidably sealed to the mandrel 11. This allows the excitation assembly 50, the second connector 30, and the mandrel 11 to collectively define a first cavity 60 within the cylinder 10. The second end 32 of the second connector 30 is fixedly connected to the cylinder 10 to transmit the displacement generated by the vibration of the drill string below the axial damping device 100 to the cylinder 10, so that the first connector 20, the cylinder 10, and the second connector 30 move together relative to the mandrel 11 in the axial direction.

[0047] In some embodiments, threads are provided on both the inner and outer walls of the second end 32. The threads on the outer wall of the second end 32 are used to connect to the cylinder 10, while the threads on the inner wall of the second end 32 are used to connect to the adapter 33. The adapter 33 is also generally a hollow cylindrical structure with open ends, so as to deliver drilling fluid to the bottom of the well together with the mandrel 11 and the second connector 30. The adapter 33 can be connected to the drill pipe, drill bit, or power drilling tool by means of screwing, bolting, snap-fitting, etc., or it can be connected to the circumferential vibration damping device or another axial vibration damping device 100. Further details on this are omitted here.

[0048] Combination Figure 1 and Figure 3 As shown, in some embodiments, a piston 41 fitted onto the mandrel 11 is provided at the lower end of the elastic component 40. The inner wall of the piston 41 is slidably and sealingly connected to the first mounting portion 114 of the mandrel 11, and the outer wall of the piston 41 is slidably and sealingly connected to the inner wall of the cylinder 10. This allows the elastic component 40, the excitation component 50, and the mandrel 11 to collectively define a second cavity 70 within the cylinder 10.

[0049] In some embodiments, the elastic component 40 includes a plurality of disc springs stacked on top of each other and fitted onto the first mounting portion 114. In other embodiments, the elastic component 40 may also be a spring. As long as the elastic component 40 can undergo elastic deformation in the axial direction, this application will not elaborate further.

[0050] In some preferred embodiments, gaskets 42 are provided at both ends of the elastic component 40. The gasket 42 at the upper end of the elastic component 40 abuts against the second step 118, and the gasket 42 at the lower end of the elastic component 40 abuts against the upper end surface of the piston 41.

[0051] Combination Figure 3 , Figure 4 and Figure 5 As shown, in some embodiments, the excitation assembly 50 includes a first mounting cylinder 51 disposed on the second mounting portion 115 of the spindle 11, a first end cap 511 and a second end cap 512 respectively disposed at both ends of the first mounting cylinder 51, and a second mounting cylinder 52 coaxially arranged with the first mounting cylinder 51. An excitation coil 53 electrically connected to an external power supply and the control module is disposed between the first mounting cylinder 51 and the second mounting cylinder 52. The first end cap 511 can abut against the third step 119. A locking seat 513 is disposed below the second end cap 512, which, together with the third step 119, forms an axial limit for the excitation assembly 50. In some embodiments, the locking seat 513 can be threadedly connected to the second mounting portion 115 of the spindle 11.

[0052] In some embodiments, the second mounting cylinder 52 is provided with a channel (not shown) that connects the first cavity 60 and the second cavity 70 in the axial direction, for allowing the magnetorheological fluid to flow between the first cavity 60 and the second cavity 70. The channel may be formed by a groove extending axially on the outer wall of the second mounting cylinder 52 and the inner wall of the cylinder 10, or by a through hole penetrating the second mounting cylinder 52 in the axial direction. 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 or more 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 compression valve and the rebound valve have different flow cross-sectional dimensions so that the damping of the axial damping device 100 is different during compression and rebound.

[0053] In some preferred embodiments, the second mounting cylinder 52 is further provided with several magnetic bearing seats to enhance the influence of the magnetic field generated by the excitation coil 53 on the magnetorheological fluid.

[0054] Combined again Figure 3 and Figure 4 As shown, in some embodiments, a force transmission cylinder 54 is also provided between the excitation assembly 50 and the cylinder 10. The two ends of the force transmission cylinder 54 are connected to the piston 41 and the second connector 30, respectively, so that the second connector 30 can directly transmit the displacement caused by the vibration of the drill string to the piston 41, allowing the elastic assembly 40 to directly convert the mechanical energy of the vibration into elastic potential energy, thereby enhancing the buffering effect. The magnetorheological fluid flowing between the first cavity 60 and the second cavity 70 can not only convert the mechanical energy of the drill string vibration into heat energy during this process, but also effectively suppress the oscillation of the elastic assembly 40 during the interconversion of mechanical energy and elastic potential energy, thereby further enhancing the vibration reduction effect.

[0055] In some embodiments, when the axial damping device 100 contracts axially to dampen vibration, the second connector 30, while pushing the first connector 20 to move axially upward via the cylinder 10, also pushes the piston 41 to move axially upward via the force transmission cylinder 54. During this process, the volume of the first cavity 60 decreases while the volume of the second cavity 70 increases. The magnetorheological fluid in the first cavity 60 flows into the second cavity 70 through the channel. Due to the limitation of the flow cross-sectional size of the channel, the magnetorheological fluid in the first cavity 60 does not immediately and completely flow into the second cavity 70. Therefore, while the magnetorheological fluid in the first cavity 60 flows into the second cavity 70, it also to some extent prevents the second connector 30 from moving axially upward, thereby effectively mitigating the oscillations generated by the elastic component 40 when converting mechanical energy into elastic potential energy.

[0056] When the axial damping device 100 extends axially to dampen vibration, the elastic component 40 pushes the piston 41 to move axially downwards. The piston 41, through the force transmission cylinder 54, pushes the second connector 30 to move axially downwards. During this process, the volume of the first cavity 60 increases while the volume of the second cavity 70 decreases. The magnetorheological fluid in the second cavity 70, while flowing into the first cavity 60, also partially prevents the piston 41 from moving axially downwards, thus effectively mitigating the oscillations generated by the elastic component 40 when converting elastic potential energy into mechanical energy.

[0057] Therefore, the flow rate of the magnetorheological fluid between the first cavity 60 and the second cavity 70 is inevitably affected by the flow cross-section of the channel and the flow characteristics of the magnetorheological fluid. Thus, during the axial elongation and shortening of the axial damping device 100, the flow of the magnetorheological fluid through the channel between the first cavity 60 and the second cavity 70 effectively suppresses the oscillations of the elastic component 40 during the interconversion of mechanical energy and elastic potential energy, thereby further enhancing the buffering effect. Furthermore, when the magnetorheological fluid flows through the channel between the first cavity 60 and the second cavity 70, it can convert mechanical energy into heat energy, and conduct the heat to the drilling fluid downhole through the mandrel 11 and the cylinder 10.

[0058] In some embodiments, the excitation coil 53 of the excitation assembly 50 generates a magnetic field under the electrical drive of an external power source, altering the flow characteristics of the magnetorheological fluid and adjusting the viscous and Coulomb resistance of the fluid flowing between the first cavity 60 and the second cavity 70. This effectively changes the stiffness and damping coefficient of the axial vibration damping device 100, making it adjustable and thus broadening its applicability. The axial vibration damping device 100 can then better cope with diverse underground rock formations and complex, variable working conditions. Technicians also no longer need to frequently replace the axial vibration damping device 100 when drilling into different rock formations, improving drilling efficiency.

[0059] 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, so that the excitation coil 53 continuously changes the magnetic field strength, thereby continuously changing the flow characteristics of the magnetorheological fluid. Therefore, the axial 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 axial vibration damping device 100 will affect the vibration of the drill string at the next moment. A positive feedback mode is formed between the axial vibration damping device 100 and the drill string, thereby dynamically optimizing the load transfer rate and drilling pressure impact effect of the drill string, so as to improve the drilling rock breaking efficiency while effectively protecting the drill string.

[0060] 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.

[0061] 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.

[0062] 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. An axial vibration damping device for drilling, comprising, A cylindrical body (10) is provided with a first connector (20) and a second connector (30) at its two ends respectively. A mandrel (11) extending from the first connector (20) to the second connector (30) is provided inside the cylindrical body (10). The elastic component (40) is configured to elastically deform along the mandrel (11) within the cylinder (10); and The excitation assembly (50) defines a first cavity (60) within the cylinder (10) together with the mandrel (11) and the second connector (30), and defines a second cavity (70) communicating with the first cavity (60) together with the mandrel (11) and the elastic assembly (40). The first cavity (60) and the second cavity (70) are filled with magnetorheological fluid. in, 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 axial direction between the first cavity (60) and the second cavity (70) due to the elastic deformation of the elastic component (40).

2. The axial vibration damping device for drilling according to claim 1, characterized in that, The excitation assembly (50) includes a first mounting cylinder (51) mounted on the mandrel (11), a second mounting cylinder (52) coaxially arranged with the first mounting cylinder (51), and an excitation coil (53) disposed between the first mounting cylinder (51) and the second mounting 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 axial vibration damping device for drilling according to claim 2, characterized in that, The second mounting cylinder (52) is provided with a channel connecting the first cavity (60) and the second cavity (70) so that the magnetorheological fluid can flow in the axial direction between the first cavity (60) and the second cavity (70).

4. The axial vibration damping device for drilling according to claim 2, characterized in that, The first mounting cylinder (51) is provided with a first end cap (511) and a second end cap (512) at its two ends respectively. A locking seat (513) is provided on the second end cap (512). The locking seat (513) is configured to work together with the first end cap (511) to limit the excitation assembly (50) and the spindle (11) in the axial direction.

5. The axial vibration damping device for drilling according to claim 1, characterized in that, The lower end of the elastic component (40) is provided with a piston (41), and the upper end of the elastic component (40) forms an axially upward limiting position with the mandrel (11), so that the piston (41) can cause the elastic component (40) to deform in the axial direction when the magnetorheological fluid flows.

6. The axial vibration damping device for drilling according to claim 5, characterized in that, A force transmission cylinder (54) is also provided between the excitation assembly (50) and the cylinder (10). The two ends of the force transmission cylinder (54) are respectively connected to the piston (41) and the second connector (30) so that the second connector (30) can directly cause the elastic assembly (40) to deform through the piston (41).

7. The axial vibration damping device for drilling according to any one of claims 1-6, characterized in that, The upper end of the spindle (11) is provided with a connecting part (111), a sealing part (112) that is slidably and sealingly connected to the first joint (20), and a first limiting part (113) provided below the sealing part (112). A first step (116) is provided between the connecting part (111) and the sealing part (112) for limiting the first joint (20) when the axial damping device (100) is contracted to its shortest length.

8. The axial vibration damping device for drilling according to claim 7, characterized in that, The first connector (20) includes a main body (21) that is slidably and sealingly connected to the sealing part (112), and a second limiting part (22) disposed at the lower end of the main body (21). The second limiting part (22) and the first limiting part (113) form a circumferential limiting, so that the spindle (11) can transmit torque to the second connector (30) through the first connector (20) and the cylinder (10).

9. The axial vibration damping device for drilling according to claim 7, characterized in that, Below the first limiting part (113), there are sequentially arranged a transition part (117), a first mounting part (114) for mounting the elastic component (40), and a second mounting part (115) for mounting the excitation component (50). A second step (118) is provided between the transition part (117) and the first mounting part (114) for limiting the elastic component (40). A third step (119) is provided between the first mounting part (114) and the second mounting part (115) for limiting the excitation component (50).

10. The axial vibration damping device for drilling according to claim 9, characterized in that, A limiting member (12) is provided on the transition portion (117), the limiting member (12) being configured to limit the first joint (20) when the axial damping device (100) is extended to its longest length.

11. The axial vibration damping device for drilling according to any one of claims 1-6, characterized in that, The mandrel (11) is provided with a flow channel (110) that passes through the elastic component (40) and the excitation component (50), and the mandrel (11) is slidably sealed to the first connector (20) and the second connector (30) so that the mandrel (11) can transport drilling fluid from the first connector (20) to the second connector (30) when the axial vibration damping device (100) performs vibration damping.

12. A drill string for drilling, characterized in that, Includes the axial vibration damping device (100) as described in any one of claims 1-11, wherein the second joint (30) of the axial vibration damping device (100) is connected to a conversion joint (33), the conversion joint (33) being configured to connect to a drill pipe, a power drill, a circumferential vibration damping device or another axial vibration damping device (100).

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