Vibration damping apparatus and drill string

Abstract

The present invention relates to a vibration damping apparatus and a drill string. The vibration damping apparatus comprises a cylinder body, an elastic member and a transmission member which are provided within the cylinder body and are connected to one another, and a field-source excitation assembly. The field-source excitation assembly is provided within the cylinder body and defines, together with the transmission member, a first chamber and a second chamber which are in communication with one another. A field-controlled rheological fluid is accommodated in both the first chamber and the second chamber. The transmission member is configured to, in response to vibration, cause the elastic member to elastically deform and cause the field-controlled rheological fluid to flow between the first chamber and the second chamber. Thus, the vibration damping apparatus not only buffers vibration by means of the elastic deformation of the elastic member, but also applies, by means of the field-source excitation assembly, a variable magnetic field or electric field to the field-controlled rheological fluid, thereby adjusting the damping force generated by the field-controlled rheological fluid, and enabling the vibration damping apparatus to have good adjustability and applicability.

Description

A vibration damping device and drill string Technical Field

[0001] This invention relates to the field of drilling technology, and more particularly to a vibration damping device, especially a vibration damping device suitable for downhole tools (e.g., drill strings), and a drill string including such a vibration damping device. 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 caused by the large tonnage forces generated 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] To address the aforementioned problems in the existing technology, this invention provides a vibration damping device with good adjustability and applicability, capable of handling underground rock strata with varying lithology and complex and variable working conditions. This invention also provides a drill string including this vibration damping device.

[0005] A vibration damping device according to a first aspect of the invention includes a cylindrical body, an elastic element and a conductive element disposed within the cylindrical body and connected to each other, and a field source excitation assembly. The field source excitation assembly, disposed within the cylindrical body and together with the conductive element, defines a first chamber and a second chamber that are in communication with each other. A field-controlled rheological fluid is contained in both the first and second chambers. The conductive element is configured to cause elastic deformation of the elastic element in response to vibration, and to allow the field-controlled rheological fluid to flow between the first and second chambers.

[0006] Furthermore, the first connecting portion of the elastic element is fixedly connected to the cylinder in the circumferential direction, and the second connecting portion of the elastic element is connected to the conductive element and rotatably connected to the cylinder, so that the conductive element can respond to the first vibration component in the circumferential direction and cause the elastic element to undergo elastic deformation in the circumferential direction.

[0007] Furthermore, both the first and second ends of the conductive member are rotatably connected to the cylinder body, so that the conductive member can respond to the first vibration component and cause the elastic member to undergo elastic deformation in the circumferential direction.

[0008] Furthermore, a first blade is provided between the first and second ends of the conductor to define, together with the second blade of the field source excitation assembly, the first chamber and the second chamber arranged in the circumferential direction. The first blade is configured to change the volume of the first chamber and the second chamber in response to the first vibration component, thereby allowing the field-controlled rheological fluid to flow between the first chamber and the second chamber.

[0009] Furthermore, the field source excitation assembly includes a housing rotatably connected to the first blade, and the second blade is disposed on the inner wall of the housing. The housing and the cylinder are fixedly connected to each other in the circumferential direction so that the first blade can move relative to the second blade in response to the first vibration component, thereby changing the volume of the first chamber and the second chamber.

[0010] Furthermore, the first blade is configured to abut against the second blade in the circumferential direction in the initial state in order to apply a pre-torque to the elastic element.

[0011] Furthermore, the elastic element is a torsion bar.

[0012] Furthermore, the radial inner surface of the second blade is sealed to the conductive element, and the excitation coil of the field source excitation assembly is installed in a blind hole opened in the radial inner surface of the second blade.

[0013] Furthermore, a mandrel is provided inside the cylinder for mounting the elastic element and the field source excitation assembly. A second connector connected to the conductive element is provided on the cylinder. The conductive element is configured to reciprocate relative to the mandrel in response to a second vibration component in the axial direction.

[0014] Furthermore, the cylinder is provided with a first connector, which is configured to be fixedly connected to the mandrel in the circumferential direction, and at the same time be able to move with the cylinder in the axial direction.

[0015] Furthermore, the mandrel is provided with a first limiting part, which is configured to be fixedly connected to the second limiting part of the first connector in the circumferential direction, while allowing the second limiting part to move in the axial direction.

[0016] Furthermore, the length of the second limiting part is less than the length of the first limiting part, and the inner diameter of the second limiting part is less than the inner diameter of the body of the first connector, so that the first limiting part can be radially spaced from the body when the first connector moves.

[0017] Furthermore, the mandrel is provided with a first step and a limiting member arranged at a distance from the first step. The first step and the limiting member together restrict the stroke of the first connector as it moves with the cylinder in the axial direction.

[0018] Furthermore, a piston is provided between the first end of the conductor and the elastic element, and between the second end of the conductor and the second connector, such that the conductor and the field source excitation assembly together define the first chamber and the second chamber arranged in the axial direction. The piston forms a sliding seal with the mandrel and the cylinder. The conductor can respond to the second vibration component to cause the elastic element to undergo elastic deformation in the axial direction, and cause the field-controlled rheological fluid to flow between the first chamber and the second chamber.

[0019] Furthermore, the field source excitation component is configured to generate a magnetic field or an electric field, and the field-controlled rheological fluid is a magnetorheological fluid or an electrorheological fluid.

[0020] The drill string according to a second aspect of the invention includes at least two vibration damping devices, one of which is configured to reduce a first vibration component in the circumferential direction, and the other is configured to reduce a second vibration component in the axial direction.

[0021] The present invention achieves at least the following beneficial effects. The vibration damping device according to the present invention includes a cylindrical body, an elastic element and a conductive element disposed within the cylindrical body and connected to each other, and a field source excitation assembly. The field source excitation assembly is disposed within the cylindrical body and, together with the conductive element, defines a first chamber and a second chamber that are in communication with each other. A field-controlled rheological fluid is contained in both the first and second chambers. The conductive element is configured to cause elastic deformation of the elastic element in response to vibration, thereby allowing the field-controlled rheological fluid to flow between the first and second chambers. Thus, the vibration damping device not only buffers vibrations through the elastic deformation of the elastic element, but also applies a variable magnetic or electric field to the field-controlled rheological fluid during its flow via the field source excitation assembly, thereby adjusting the damping force generated by the field-controlled rheological fluid, resulting in improved adjustability and applicability of the vibration damping device.

[0022] Furthermore, the vibration damping device of the present invention has a uniquely designed structure, enabling it to specifically reduce vibrations in the circumferential or axial directions. Specifically, for the first vibration damping device that reduces circumferential vibration, applying a pre-torque to the torsion bar, which acts as an elastic element, not only reduces the peak torque fluctuation on the elastic element, preventing fatigue failure during vibration damping and extending its service life, but also provides a stable working condition for the drill bit. For the second vibration damping device that reduces axial vibration, by enabling the cylinder and the transmission element to respond to vibration together, the second vibration damping device can further reduce vibration using the frictional damping between the cylinder and the well wall, thus improving the vibration damping effect.

[0023] In addition, the present invention also provides a drill string comprising at least two vibration damping devices as described above, wherein one vibration damping device is configured to reduce a first vibration component in the circumferential direction, and the other vibration damping device is configured to reduce a second vibration component in the axial direction. Depending on the specific vibration conditions, the overall stiffness and damping coefficient of the two vibration damping devices can be adjusted to change the vibration mode of the drill string, avoid resonance, and optimize dynamic load and impact effects, thereby improving drilling and rock-breaking efficiency while effectively protecting the drill string. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 shows a cross-sectional view of the first vibration damping device.

[0026] Figure 2 shows a cross-sectional view of section AA of the first vibration damping device shown in Figure 1 in one state.

[0027] Figure 3 shows a cross-sectional view of section AA of the first vibration damping device shown in Figure 1 in another state.

[0028] Figure 4 shows a cross-sectional view of the second vibration damping device.

[0029] Figure 5 shows a partial enlarged view of section A of the second vibration damping device shown in Figure 4.

[0030] Figure 6 shows a partial enlarged view of section B of the second vibration damping device shown in Figure 4.

[0031] Figure 7 shows a partial enlarged view of section C of the second vibration damping device shown in Figure 4.

[0032] Figure 8 shows a cross-sectional view of the field source excitation component of the second vibration damping device shown in Figure 4.

[0033] In the figure, the reference numerals are as follows: 100, first vibration damping device; 200, second vibration damping device;

[0034] 10. Cylinder body; 11. First connector; 111. Main body; 112. Second limiting part; 12. Second connector; 13. Adaptor connector;

[0035] 20. Elastic element; 21. Elastic part; 22. First connecting part; 23. Second connecting part;

[0036] 30. Field source excitation assembly; 31. Excitation coil; 32. Housing; 33. Second blade; 34. End cap; 35. Locking seat; 36. Blind hole;

[0037] 40. Conducting element; 41. First end; 42. Second end; 42. Sealing sleeve; 43. First blade; 44. Piston component;

[0038] 50. First chamber; 60. Second chamber;

[0039] 70. Mandrel; 71. First limiting part; 711. Sealing part; 712. First step; 713. Transition part; 714. Limiting element; 72. First mounting part; 721. Second step; 73. Second mounting part; 731. Third step;

[0040] 80. Flow channel. Detailed Implementation

[0041] 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.

[0042] As the drill bit interacts with the rock formation at the bottom of the well and breaks the rock, it transmits the reaction force exerted by the rock formation to the drill string, causing the drill string to vibrate. This reaction force includes both a counter-torque along the circumferential direction of the drill bit and the drill string, and a reaction force along the axial direction of the drill bit and the drill string. Therefore, the vibration of the drill string can be roughly decomposed into a first vibration component along the circumferential direction of the drill string and a second vibration component along the axial direction of the drill string.

[0043] To reduce drill string vibration, effectively protect the drill string, and extend its service life, the drill string provided by this invention includes at least a first vibration damping device 100 and a second vibration damping device 200. The first vibration damping device 100 is configured to reduce the first vibration component, and the second vibration damping device 200 is configured to reduce the second vibration component. It should be understood that, depending on the actual downhole operating conditions and the actual vibration of the drill string, the first vibration damping device 100 and the second vibration damping device 200 may be installed on the drill string simultaneously, or only the first vibration damping device 100 or the second vibration damping device 200 may be installed. One or more first vibration damping devices 100 and one or more second vibration damping devices 200 may be installed.

[0044] Referring to Figures 1 and 4, in some embodiments, both the first vibration damping device 100 and the second vibration damping device 200 include a cylindrical body 10, an elastic element 20 disposed within the cylindrical body 10, and a field source excitation assembly 30 disposed within the cylindrical body 10. The first vibration damping device 100 and the second vibration damping device 200 also include a conductive element 40 disposed within the cylindrical body 10 and connected to the elastic element 20. The conductive element 40 and the field source excitation assembly 30 together define a first chamber 50 and a second chamber 60 communicating with each other within the cylindrical body 10 for containing a field-controlled rheological fluid. The conductive element 40 is configured to respond to either the first vibration component or the second vibration component to cause elastic deformation of the elastic element 20 and to allow the field-controlled rheological fluid to flow between the first chamber 50 and the second chamber 60. In this way, on the one hand, the elastic deformation of the elastic element 20 can be used to buffer the first or second vibration component; on the other hand, the damping force of the field-controlled rheotropic fluid flowing between the first chamber 50 and the second chamber 60 can be used to dissipate the mechanical energy of the drill string vibration (e.g., convert it into heat energy), thereby achieving the purpose of vibration reduction of the drill string. It should be understood that the first chamber 50 and the second chamber 60 can be connected by a throttling channel (not shown in the figure) to increase the damping force of the field-controlled rheotropic fluid flowing between the first chamber 50 and the second chamber 60, thereby improving the vibration reduction effect.

[0045] In some embodiments, prestress, such as pretor or precompression, may be applied to the elastic element 20 so that the first damping device 100 and the second damping device 200 can better buffer the first vibration component and the second vibration component.

[0046] In some embodiments, the field source excitation component 30 is configured to generate magnetic or electric fields of varying intensities under the electrical drive of an external power source, thereby altering the flow characteristics of the field-controlled rheotropic fluid flowing between the first chamber 50 and the second chamber 60, and thus changing the damping force of the field-controlled rheotropic fluid during flow. This allows for active adjustment of the overall stiffness and damping coefficient of the first vibration damping device 100 and the second vibration damping device 200, improving their adaptability and enabling them 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. In addition, operators no longer need to frequently replace the vibration damping devices on the drill string when drilling into different rock formations, further improving drilling efficiency. Preferably, the field-controlled rheotropic fluid can be a magnetorheological fluid or an electrorheological fluid.

[0047] In some embodiments, the field source excitation assembly 30 includes an excitation coil 31. The excitation coil 31 can generate a magnetic field under the electrical drive of an external power source. Furthermore, the strength of the magnetic field generated can be changed by adjusting the current intensity within the excitation coil 31. Preferably, an iron core can be provided in the excitation coil 31 to increase the magnetic field strength while maintaining a constant current intensity and number of coil turns, thereby enabling the field source excitation assembly 30 to effectively alter the flow characteristics of the field-controlled rheotropic fluid.

[0048] In some preferred embodiments, the field source excitation component 30 can be electrically connected to a measurement-while-drilling (MSWD) device mounted on the drill string via a control module. The MSW device can collect vibration parameters such as amplitude and frequency of the drill string during drilling in real time, and then process these parameters according to a predetermined algorithm and program to obtain a processing result. The control module sends an electrical signal to the field source excitation component 30 based on the processing result to change the current intensity in the excitation coil 31, thereby changing the intensity of the excited magnetic field and thus altering the flow characteristics of the field-controlled rheotropic fluid.

[0049] Therefore, the first vibration damping device 100 and the second vibration damping device 200 can continuously and precisely adjust their stiffness and damping coefficient according to the vibration of the drill string. The adjusted first vibration damping device 100 and second vibration damping device 200 then affect the vibration of the drill string at the next moment. This forms a positive feedback mode, 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.

[0050] The specific structure of the first vibration damping device 100 will be described in detail below with reference to Figures 1-3.

[0051] Referring to Figure 1, in some embodiments, the elastic element 20 of the first vibration damping device 100 is configured as a hollow torsion bar coaxially arranged within the cylinder 10. The elastic element 20 includes an elastic portion 21 capable of elastic deformation in the circumferential direction, and a first connecting portion 22 and a second connecting portion 23 disposed at both ends of the elastic portion 21. The first connecting portion 22 is used to connect the cylinder 10 and the first connector 11, and the second connecting portion 23 is used to connect the conductive element 40. The first connecting portion 22 is configured to be non-rotatably connected to the cylinder 10 in the circumferential direction to prevent relative rotation between the cylinder 10 and the elastic element 20 when the conductive element 40 responds to the first vibration component. Preferably, the first connecting portion 22 and the cylinder 10 can be connected by a key, so that no movement in the circumferential direction can occur between the cylinder 10 and the elastic element 20. More preferably, the outer circumferential wall of the first connecting portion 22 and the inner wall of the cylinder 10 are connected by a spline.

[0052] In some embodiments, the first connecting portion 22 can be connected to the first joint 11 by welding or screwing. The first joint 11 is used to connect the drill bit, drill pipe, second vibration damping device 200, or another first vibration damping device 100. Preferably, the first joint 11 is configured to restrict the movement of the cylinder 10 in an axially upward direction. More preferably, the first connecting portion 22 can be connected to the first joint 11 and the cylinder 10 by welding.

[0053] In some embodiments, the second connecting portion 23 is rotatably connected to the inner wall of the cylinder 10 so that the conductive member 40 can cause the elastic portion 21 to elastically deform in the circumferential direction in response to the first vibration component.

[0054] Referring to Figures 1-3, in some embodiments, the conductive element 40 of the first vibration damping device 100 is a hollow tubular structure. The first end 41 of the conductive element 40 is used to connect to the second connecting portion 23, and the second end 42 of the conductive element 40 is used to connect to the second connector 12. As shown in Figure 2, a first blade 43 extending in both the axial and radially outward directions is provided between the first end 41 and the second end 42, which, together with the field source excitation assembly 30, defines a first chamber 50 and a second chamber 60 that are interconnected in the circumferential direction. Both the first end 41 and the second end 42 of the conductive element 40 are rotatably connected to the cylinder 10, so that the conductive element 40 can change the volume of the first chamber 50 and the second chamber 60 in response to the first vibration component via the first blade 43, thereby allowing the field-controlled rheological fluid to flow between the first chamber 50 and the second chamber 60. Preferably, a sealing element is provided on the circumferential sidewall of the first end 41 and the second end 42 of the conductive element 40 so that the first end 41 and the second end 42 are sealed to the cylinder 10 to prevent leakage of the field-controlled rheological fluid in the first chamber 50 and the second chamber 60.

[0055] As shown in Figure 1, in some embodiments, a sealing sleeve 422 is also provided between the second end 42 of the conductive member 40 and the cylinder 10. The sealing sleeve 422 can form radial support between the second end 42 and the cylinder 10, thereby enhancing the sealing between the second end 42 and the cylinder 10 and preventing drilling fluid, mud and other impurities from entering the first vibration damping device 100.

[0056] In some embodiments, the second end 42 of the conductor 40 can be connected to the second connector 12 by welding or screwing. The second connector 12 can be used to connect a drill pipe, drill string, drill bit, second vibration damping device 200, or another first vibration damping device 100. Preferably, the second connector 12 is configured to restrict the movement of the cylinder 10 in an axially downward direction.

[0057] In some embodiments, a seal is also provided on the radially outward side of the first blade 43 to enhance the sealing between the conductor 40 and the field source excitation assembly 30, ensuring that the field-controlled rheological fluid in the first chamber 50 and the second chamber 60 can only flow through the throttling channel.

[0058] Referring to Figures 2 and 3, in some embodiments, the field source excitation assembly 30 of the first vibration damping device 100 further includes a housing 32 disposed between the conductor 40 and the cylinder 10, and a second blade 33 extending axially and radially inward on the inner wall of the housing 32. The second blade 33 and the first blade 43 together define a first chamber 50 and a second chamber 60 arranged circumferentially between the first end 41 and the second end 42 of the conductor 40. Preferably, the radially inner surface of the second blade 33 is provided with a blind hole 36 for mounting an excitation coil 31. More preferably, the radially inner surface of the second blade 33 is sealed to the conductor 40 to ensure that the field-controlled rheological fluid in the first chamber 50 and the second chamber 60 can only flow through the throttling channel.

[0059] In some embodiments, the housing 32 and the cylinder 10 are non-rotatably connected in the circumferential direction, so that the housing 32 does not rotate relative to the cylinder 10 when the conductor 40 responds to the first vibration component, thereby ensuring relative movement between the second blade 33 and the first blade 43. Preferably, the housing 32 and the cylinder 10 are connected by a spline. In this way, the excitation coil 31 installed in the second blade 33 will not be affected by the first vibration component, thereby reducing the difficulty of electrical connection of the excitation coil 31 and improving the reliability of the excitation coil 31.

[0060] Referring to Figures 2 and 3, in some embodiments, the vibration damping device 100 is provided with two first blades 43 and two second blades 33. The two first blades 43 are arranged opposite each other in the radial direction, and the two second blades 33 are also arranged opposite each other in the radial direction. Thus, the conductor 40 and the field source excitation assembly 30 together define two first chambers 50 and two second chambers 60, and the first chambers 50 and second chambers 60 are arranged alternately in the circumferential direction.

[0061] In some embodiments, when the conductive member 40 is subjected to the first vibration component, the conductive member 40 can cause the elastic part 21 to undergo elastic deformation in the circumferential direction through the second connecting part 23, so as to convert part of the mechanical energy of the first vibration component into elastic potential energy, thereby buffering the first vibration component. Furthermore, the conductive member 40 can also change the volume of the first chamber 50 and the second chamber 60 by rotating the first blade 43, so that the field-controlled rheological fluid can flow between the first chamber 50 and the second chamber 60 through the throttling channel, thereby converting part of the mechanical energy of the first vibration component into heat energy, further reducing the first vibration component. It should be understood that the throttling channel can be provided on the first blade 43 or on the second blade 33. There can be one, two, or more throttling channels. The structure and arrangement of the throttling channels are well known to those skilled in the art, and will not be described in detail here.

[0062] As shown in Figure 3, arrow X points counterclockwise. In some embodiments, by rotating the first blade 43 and the second blade 33 to abut in the circumferential direction, a pre-torque in the counterclockwise direction can be applied to the elastic element 20. At this time, the volume of the first chamber 50 is at its maximum while the volume of the second chamber 60 is zero, as shown in Figure 3. When the drill bit rotates counterclockwise to drill and break the rock, the rock strata at the bottom of the well apply a counter-torque in the clockwise direction to the drill string through the drill bit. During normal drilling, the magnitude of the counter-torque will fluctuate due to factors such as the lithological differences of the rock strata at the bottom of the well, thereby causing the drill string to generate the first vibration component in the circumferential direction. After the counter-torque is transmitted to the first vibration damping device 100, it is superimposed and canceled by the pre-torque on the elastic element 20, thereby reducing the peak value of the torque fluctuation on the elastic element 20. In this way, fatigue failure of the elastic element 20 can be effectively prevented during vibration damping, and the service life of the elastic element 20 can be improved.

[0063] When the counter-torque is less than the pre-torque, the elastic element 20 will not twist in a clockwise direction, thus providing a stable working condition for the drill bit. When the counter-torque is greater than the pre-torque, the transmission element 40 will respond to the first vibration component and cause the elastic element 20 to twist in a clockwise direction, so as to buffer the first vibration component through the elastic element 20. At the same time, the transmission element 40 changes the volume of the first chamber 50 and the second chamber 60 through the first blade 43, so that the field-controlled rheological fluid flows between the first chamber 50 and the second chamber 60, so as to reduce the first vibration component through the damping force of the field-controlled rheological fluid during flow, thereby achieving the purpose of vibration reduction.

[0064] The specific structure of the second vibration damping device 200 will be described in detail below with reference to Figure 4-8. For the sake of brevity, components or structures in the second vibration damping device 200 that are the same as or similar to those in the first vibration damping device 100 will not be described in detail.

[0065] Referring to Figures 4-7, in some embodiments, a mandrel 70 is coaxially arranged inside the cylinder 10 of the second vibration damping device 200 for mounting the elastic element 20 and the field source excitation assembly 30. A conductor 40 is disposed between the field source excitation assembly 30 and the cylinder 10, and defines the first chamber 50 and the second chamber 60 at both ends of the field source excitation assembly 30. The upper end of the mandrel 70 is located outside the cylinder 10 and is used to connect the drill bit, drill pipe, the first vibration damping device 100, or another second vibration damping device 200. A first limiting portion 71 is provided on the mandrel 70, configured to prevent relative rotation between the mandrel 70 and the cylinder 10 only in the circumferential direction via the first connector 11, while allowing relative movement between the mandrel 70 and the cylinder 10 in the axial direction. A first mounting portion 72 and a second mounting portion 73 are also provided on the mandrel 70 for mounting the elastic element 20 and the field source excitation assembly 30, respectively.

[0066] Referring to Figure 5, in some embodiments, a sealing portion 711 is provided above the first limiting portion 71 for sliding sealing engagement with the first connector 11. The upper end of the sealing portion 711 has a first step 712 for abutting against the upper end face of the first connector 11 when the second vibration damping device 200 is in its shortest length state. A spline is provided on the circumferential outer wall of the first limiting portion 71 to engage with the first connector 11, so that the mandrel 70 and the cylinder 10 can not rotate relative to each other in the circumferential direction but can move relative to each other in the axial direction via the first connector 11. This not only allows the mandrel 70 and the cylinder 10 to move relative to each other in the axial direction under the action of the second vibration component, but also allows torque to be transmitted between the mandrel 70 and the cylinder 10. A transition portion 713 is provided between the first limiting portion 71 and the first mounting portion 72 for mounting the limiting member 714. The limiting member 714 protrudes radially outward from the transition portion 713 so as to abut against the lower end face of the first joint 11 when the second vibration damping device 200 is at its longest length. Therefore, the limiting member 714 and the first step 712 cooperate with each other to limit the movement stroke of the first joint 11 and the maximum amplitude of the second vibration damping device 200 under the action of the second vibration component.

[0067] In some preferred embodiments, the first connector 11 includes a main body 111 that slides with the sealing part 711, and a second limiting part 112 disposed below the main body 111. The inner wall of the second limiting part 112 is provided with a spline that engages with the first limiting part 71. The axial length of the second limiting part 112 is less than the axial length of the first limiting part 71, and the inner diameter of the second limiting part 112 is less than the inner diameter of the main body 111. Thus, during the axial movement of the main body 111, the inner wall of the main body 111 and the spline on the first limiting part 71 are always radially spaced, thereby preventing wear caused by mutual scraping between the inner wall of the main body 111 and the spline on the first limiting part 71. The outer wall of the second limiting part 112 is also provided with an external thread for connecting the cylinder 10, so that torque can be transmitted between the mandrel 70 and the cylinder 10 through the first connector 11.

[0068] Referring to Figures 5 and 6, in some embodiments, the circumferential dimension of the transition portion 713 is larger than the circumferential dimension of the first mounting portion 72, forming a second step 721 axially downward between the transition portion 713 and the first mounting portion 72, which abuts against the upper end of the elastic member 20 and forms a limiting position. The circumferential dimension of the first mounting portion 72 is larger than the circumferential dimension of the second mounting portion 73, forming a third step 731 axially downward between the first mounting portion 72 and the second mounting portion 73, which abuts against the upper end of the field source excitation assembly 30 and forms a limiting position. This allows the radial dimension of the mandrel 70 to gradually decrease in the axially downward direction, thereby facilitating the installation of the elastic member 20 and the field source excitation assembly 30.

[0069] It should be understood that the first vibration damping device 100 may also be provided with a spindle 70 connected to the first joint 11, so as to better install the elastic element 20 and the conductive element 40 without affecting the torsion of the elastic element 20 and without affecting the response of the conductive element 40 to the first vibration component.

[0070] Referring to Figures 4-6, in some embodiments, the elastic element 20 of the second vibration damping device 200 is a disc spring assembly. It is easy to understand that the elastic element 20 of the second vibration damping device 200 can also be a spring or other components capable of elastic deformation in the axial direction.

[0071] Referring to Figures 6 and 7, in some embodiments, the conductive element 40 of the second vibration damping device 200 is a hollow tubular structure. The first end 41 of the conductive element 40 is used to connect to the elastic element 20, and the second end 42 of the conductive element 40 is used to connect to the second connector 12. A piston element 44 is provided between the first end 41 and the elastic element 20, which slides and seals with the spindle 70 and the cylinder 10. A piston element 44 is also provided between the second end 42 and the second connector 12, which slides and seals with the spindle 70 and the cylinder 10. Thus, the conductive element 40, through the piston elements 44 at both ends, together with the field source excitation assembly 30 located on the second mounting portion 73, defines the first chamber 50 and the second chamber 60 arranged in the axial direction. It should be understood that the piston element 44 can be connected to the elastic element 20, the conductive element 40, or the second connector 12.

[0072] In some embodiments, the second connector 12 is used to connect the drill pipe, drill string, drill bit, first vibration damping device 100, or another second vibration damping device 200. Preferably, the second connector 12 can be connected to the aforementioned equipment via an adapter 13. The second connector 12 can be fixedly connected to the cylinder 10 by means of screwing, welding, etc., so that when the second connector 12 causes the transmission element 40 to respond to the second vibration component, the cylinder 10 can also reciprocate in the axial direction. In particular, when the second vibration damping device 200 is applied to directional or horizontal well drilling, the cylinder 10 of the second vibration damping device 200 can rub against the well wall during reciprocating movement. Therefore, the second vibration damping device 200 further reduces the second vibration component by enabling frictional damping between the cylinder 10 and the well wall, thereby improving the vibration damping effect of the second vibration damping device 200.

[0073] Referring to Figures 6, 7, and 8, in some embodiments, the field source excitation assembly 30 of the second vibration damping device 200 further includes a housing 32 disposed on the second mounting portion 73, and end caps 34 disposed at both ends of the housing 32. The housing 32 is configured as a hollow structure for mounting the excitation coil 31. The end cap 34 at the upper end of the housing 32 abuts against the third step 731, and the end cap 34 at the lower end of the housing 32 can be threaded to the spindle 70. This fixes the field source excitation assembly 30 on the spindle 70, ensuring that the excitation coil 31 is not subjected to the second vibration component, thereby reducing the difficulty of electrical connection of the excitation coil 31 and improving the reliability of the excitation coil 31. It is easy to understand that the housing 32 can be an integral structure or a split structure. Preferably, the field source excitation assembly 30 further includes a locking seat 35 disposed below the housing 32. The locking seat 35 can also be threaded to the spindle 70 to enhance the reliability of the installation of the field source excitation assembly 30.

[0074] In some embodiments, the housing 32 is also provided with the throttling channel (not shown) to connect the first chamber 50 and the second chamber 60.

[0075] In some embodiments, when the conductive member 40 responds to the action of the second vibration component via the second connector 12, the conductive member 40 can cause the elastic member 20 to undergo elastic deformation in the axial direction via the piston member 44, so as to convert part of the mechanical energy of the second vibration component into elastic potential energy, thereby buffering the second vibration component. Furthermore, the conductive member 40 can also change the volume of the first chamber 50 and the second chamber 60 via the piston members 44 at both ends, so that the field-controlled rheological fluid flows between the first chamber 50 and the second chamber 60 through the throttling channel, thereby converting part of the mechanical energy of the second vibration component into heat energy, further reducing the second vibration component.

[0076] In some embodiments, a preload can be applied to the elastic element 20. At this time, the piston 44 at the upper end of the housing 32 abuts against the end cap 34, the second chamber 60 has the smallest volume, and the first chamber 50 has the largest volume. When the drill bit drills and breaks rock at a certain drilling pressure, the rock formation at the bottom of the well applies an axial reaction force to the drill string through the drill bit. After the reaction force is transmitted to the second vibration damping device 200, the piston 44 at the upper end of the housing 32 moves away from the end cap 34, and the elastic element 20 is further compressed and shortened. During normal drilling, the magnitude of the reaction force 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 generate the second vibration component in the axial direction. When the magnitude of the reaction force changes, the elastic element 20 can immediately respond to the change in reaction force by contracting or extending under the action of the transmission element 40, thereby improving the response speed and vibration damping effect of the second vibration damping device 200.

[0077] As shown in Figures 1-7, both the second vibration damping device 200 and the first vibration damping device 100 are also provided with flow channels 80 for conveying drilling fluid to the drill bit at the bottom of the well to clean up rock cuttings generated during drill bit rock breaking. The flow channel 80 of the second vibration damping device 200 is constructed within the mandrel 70, while the flow channel 80 of the first vibration damping device 100 is constructed within the elastic member 20 and the conductive member 40. It should be understood that if the first vibration damping device 100 is also provided with a mandrel 70 connected to the first connector 11, then the flow channel 80 of the first vibration damping device 100 can also be constructed within the mandrel 70.

[0078] It is easy to understand that although the vibration damping device of the present invention is optimally applied to drill strings, it can also be applied to other downhole tools and other equipment that may be subjected to circumferential and / or axial motion.

[0079] 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.

[0080] It should be understood that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not used to describe a specific order or sequence. Such terms can be used interchangeably where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. The terms "length," "width," "upper," "lower," "front and back," "left and right," "vertical," "horizontal," "top," "bottom," "inner," and "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 the 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, and therefore should not be construed as a limitation of the invention.

[0081] 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 vibration damping device for downhole tools, comprising, Cylinder (10); An elastic element (20) and a conductive element (40) disposed within the cylinder (10) and connected to each other; and A field source excitation component (30) is disposed within the cylindrical body (10) and, together with the conductive member (40), defines a first chamber (50) and a second chamber (60) that are in communication with each other. Both the first chamber (50) and the second chamber (60) contain field-controlled rheological fluid. The conductive element (40) is configured to cause the elastic element (20) to undergo elastic deformation in response to vibration, and to allow the field-controlled rheological fluid to flow between the first chamber (50) and the second chamber (60).

2. The vibration damping device according to claim 1, characterized by The first connecting portion (22) of the elastic element (20) is fixedly connected to the cylinder (10) in the circumferential direction, and the second connecting portion (23) of the elastic element (20) is connected to the conductor (40) and rotatably connected to the cylinder (10) so that the conductor (40) can respond to the first vibration component in the circumferential direction and cause the elastic element (20) to generate elastic deformation in the circumferential direction.

3. The damping device according to claim 1 or 2, characterized in that The first end (41) and the second end (42) of the conductive member (40) are rotatably connected to the cylinder (10) so that the conductive member (40) can cause the elastic member (20) to undergo elastic deformation in the circumferential direction in response to the first vibration component.

4. The vibration damping device according to claim 3, characterized by A first blade (43) is disposed between the first end (41) and the second end (42) of the conductor (40) for defining, together with the second blade (33) of the field source excitation assembly (30), the first chamber (50) and the second chamber (60) arranged in the circumferential direction. The first blade (43) is configured to change the volume of the first chamber (50) and the second chamber (60) in response to the first vibration component, thereby allowing the field-controlled rheological fluid to flow between the first chamber (50) and the second chamber (60).

5. The vibration damping device according to claim 4, characterized by The field source excitation assembly (30) includes a housing (32) rotatably connected to the first blade (43), and the second blade (33) is disposed on the inner wall of the housing (32). The housing (32) and the cylinder (10) are fixedly connected to each other in the circumferential direction so that the first blade (43) can move relative to the second blade (33) in response to the first vibration component, thereby changing the volume of the first chamber (50) and the second chamber (60).

6. The vibration damping device according to claim 4 or 5, characterized by The first blade (43) is configured to abut against the second blade (33) in the circumferential direction in the initial state in order to apply a pre-torque to the elastic element (20).

7. The vibration damping device according to any one of claims 1 to 6, characterized by The elastic element (20) is a torsion bar.

8. The vibration damping device according to any one of claims 4 to 6, characterized by The radial inner surface of the second blade (33) is sealed to the conductive element, and the excitation coil (31) of the field source excitation assembly (30) is installed in a blind hole (36) opened in the radial inner surface of the second blade (33).

9. The vibration damping device according to claim 1, characterized by The cylinder (10) is provided with a mandrel (70) for mounting the elastic element (20) and the field source excitation assembly (30). The cylinder (10) is provided with a second connector (12) connected to the conductor (40). The conductor (40) is configured to reciprocate relative to the mandrel (70) in response to a second vibration component in the axial direction.

10. The vibration damping device according to claim 9, characterized by The cylinder (10) is provided with a first connector (11), which is configured to be fixedly connected to the mandrel (70) in the circumferential direction and can move with the cylinder (10) in the axial direction.

11. The vibration damping device according to claim 10, characterized by The spindle (70) is provided with a first limiting part (71), which is configured to be fixedly connected to the second limiting part (112) of the first connector (11) in the circumferential direction, while allowing the second limiting part (112) to move in the axial direction.

12. The vibration damping device according to claim 11, characterized by The length of the second limiting part (112) is less than the length of the first limiting part (71), and the inner diameter of the second limiting part (112) is less than the inner diameter of the body (111) of the first connector (11), so that the first limiting part (71) can be spaced apart from the body (111) in the radial direction when the first connector (11) moves.

13. Damping device according to any of claims 9-12, characterized in that The mandrel (70) is provided with a first step (712) and a limiting member (714) spaced apart from the first step (712). The first step (712) and the limiting member (714) together restrict the stroke of the first connector (11) as it moves with the cylinder (10) in the axial direction.

14. Damping device according to any of claims 9-13, characterized in that A piston (44) is provided between the first end (41) of the conductor (40) and the elastic member (20), and between the second end (42) of the conductor (40) and the second connector (12), such that the conductor (40) and the field source excitation assembly (30) together define the first chamber (50) and the second chamber (60) arranged in the axial direction. The conductor (40) is able to cause the elastic member (20) to elastically deform in the axial direction in response to the second vibration component, and cause the field-controlled rheological fluid to flow between the first chamber (50) and the second chamber (60).

15. The vibration damping device according to any one of claims 1 to 14, characterized by The field source excitation component (30) is configured to generate a magnetic field or an electric field, and the field-controlled rheological fluid is a magnetorheological fluid or an electrorheological fluid.

16. A drill string, characterized by It includes at least two vibration damping devices, one of which is a vibration damping device (100) according to any one of claims 2-8, and the other is a vibration damping device (200) according to any one of claims 9-14.

Images