Lateral vibration damping for a downhole component

Abstract

A system for damping lateral vibrations includes a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis, and a cavity disposed within the body. The cavity has a selected width in an at least partially lateral direction, and the at least partially lateral direction has a directional component that is orthogonal to the longitudinal axis. The system also includes a moveable element disposed in the cavity, the moveable element being free to laterally move relative to the cavity in the at least partially lateral direction in response to a lateral vibration of the body. Lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration.

Description

65DDE-511147-WO-2JNT1045PCTLATERAL VIBRATION DAMPING FOR A DOWNHOLE COMPONENTCROSS REFERENCE TO RELATED APPLICATIONSThis application claims the benefit of U.S. Application No. 63 / 733279, filed on December 12, 2024, which is incorporated herein by reference in its entirety.BACKGROUND

[0001] In the resource recovery and fluid sequestration industry, various types of components, such as drilling assemblies and measurement tools, are deployed in a borehole as part of a borehole string for purposes such as drilling, exploration and production of hydrocarbons. In the course of a downhole operation, undesirable vibrations can arise. Such vibrations include torsional vibrations, axial vibrations, and lateral vibrations due to, for example, impacts between borehole string components and a borehole wall. It is desirable to provide devices and / or systems for improved damping of lateral vibrations.SUMMARY

[0002] An embodiment of a system for damping lateral vibrations includes a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis, and a cavity disposed within the body. The cavity has a selected width in an at least partially lateral direction, and the at least partially lateral direction has a directional component that is orthogonal to the longitudinal axis. The system also includes a moveable element disposed in the cavity, the moveable element being free to laterally move relative to the cavity in the at least partially lateral direction in response to a lateral vibration of the body. Lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration.

[0003] An embodiment of a method includes deploying a borehole string in a borehole in a subterranean region, the borehole string including a damping component, the damping component including a body having a longitudinal axis, a cavity disposed within the body and a moveable element disposed in the cavity. The cavity has a selected width in an at least partially lateral direction, the at least partially lateral direction has a directional component that is orthogonal to the longitudinal axis, and the moveable element is free to laterally move in the at least partially lateral direction in response to a lateral vibration of the body. The method also includes performing a subterranean operation, and during the subterranean operation,65DDE-511147-WO-2JNT1045PCT moving in response to the lateral vibration the moveable component relative to the cavity. The lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration.

[0004] An embodiment of a system for damping lateral vibrations includes a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis, and a device housing mechanically coupled to the body. The device housing includes a cavity having a cavity volume and an inner surface. The system also includes a moveable element movably supported in the cavity and having an element volume and a mass, and an axial bearing positioned between the moveable element and the inner surface of the cavity. The element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element and the inner surface, and the interstitial volume is occupied by a fluid. The moveable element is free to laterally move relative to the device housing in an at least partially lateral direction in response to a lateral vibration of the body, the lateral direction is orthogonal to the longitudinal axis, and lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration

[0005] An embodiment of a system for damping axial vibrations includes a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis, and a device housing mechanically coupled to the body. The device housing includes a cavity having a cavity volume and an inner surface. The system also includes a moveable element movably supported in the cavity and having an element volume and a mass, and a radial bearing positioned between the moveable element and the inner surface of the cavity. The element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element and the inner surface, and the interstitial volume is occupied by a fluid. The moveable element is free to axially move relative to the device housing in an at least partially axial direction in response to an axial vibration of the body, the lateral direction is parallel to the longitudinal axis, and axial movement of the moveable element resists the axial vibration and dampens a magnitude of the axial vibration.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:65DDE-511147-WO-2JNT1045PCT

[0007] Figure 1 depicts an embodiment of a downhole system including a damping component;

[0008] Figure 2 depicts an embodiment of a damping component including a cavity enclosing a movable element, such as an inertial mass;

[0009] Figure 3 depicts an embodiment of a damping component including a cavity enclosing a movable element, such as an inertial mass;

[0010] Figure 4 depicts an embodiment of a damping component including a cavity enclosing a movable element, such as an inertial mass;

[0011] Figure 5 depicts an embodiment of a damping component including a cavity enclosing a movable element, the cavity being inclined relative to a longitudinal axis of a body of the damping component;

[0012] Figure 6 depicts an embodiment of a damping component including a cavity enclosing a movable element, the cavity including at least one lateral gap between the movable element and a wall of the cavity;

[0013] Figure 7 depicts an embodiment of a damping component including a cavity enclosing a movable element, and a feature configured to restrict or prevent rotational motion of the movable element;

[0014] Figure 8 depicts an embodiment of a damping component including a cavity enclosing a movable element, and a feature configured to restrict or prevent rotational motion of the movable element;

[0015] Figure 9 depicts an embodiment of a damping component including a cavity enclosing a movable element, and at least one compressible or deformable component disposed in the cavity;

[0016] Figure 10 depicts an embodiment of a damping component including a cavity enclosing a movable element, and at least one compressible or deformable component disposed in the cavity;

[0017] Figure 11 depicts an embodiment of a damping component including a cavity enclosing a movable element, and at least one leaf spring or flexible member configured to control or regulate lateral movement of the movable element;

[0018] Figure 12 depicts an embodiment of a damping component including a cavity enclosing a movable element, and at least one compression spring disposed between the movable component and a lateral wall of the cavity;65DDE-511147-WO-2JNT1045PCT

[0019] Figure 13 depicts an embodiment of a damping component including a cavity enclosing a movable element, at least one lateral compression spring disposed between the movable component and a lateral wall of the cavity, and at least one axial compression spring disposed between the movable component and an axial wall of the cavity;

[0020] Figure 14A-14D depict embodiments of a damping component including a cavity enclosing a movable element, and at least one compression spring disposed in the cavity, and at least one friction pad;

[0021] Figure 15 depicts an embodiment of a damping component including a cavity enclosing a movable element, and a pressure compensation system;

[0022] Figure 16 depicts an embodiment of a damping component including a cavity enclosing a movable element, and a pressure compensation system;

[0023] Figure 17 depicts an embodiment of a damping component including a cavity enclosing a movable element, the movable element including a particulate material;

[0024] Figure 18 is a flow diagram depicting an embodiment of a method of performing a subterranean operation, which includes damping lateral vibrations;|0025 | Figure 19 depicts an example of a downhole component;

[0026] Figures 20A and 20B depict measurement data collected during operation of the downhole component of Figure 19;

[0027] Figure 21 depicts a vibrational mode shape derived from the measurement data of Figures 20A and 20B, and depicts an example of a placement of a damping component;

[0028] Figures 22A and 22B depict an embodiment of one or more damping components disposed at a mud motor;

[0029] Figures 23A and 23B depict an embodiment of one or more damping components disposed at a mud motor;

[0030] Figures 24A and 24B depict an embodiment of one or more damping components disposed at a turbine motor;

[0031] Figures 25A and 25B depict an embodiment of one or more damping components disposed at a turbine motor;

[0032] Figures 26A and 26B depict an embodiment of one or more damping components disposed at a turbine motor;

[0033] Figure 27 depicts an example of a spectrogram generated from vibrational measurements performed during operation of a downhole component;65DDE-511147-WO-2JNT1045PCT

[0034] Figure 28 depicts vibrational mode shapes derived from the spectrogram of Figure 27, and depicts an example of a positions selected for placement of a damping component or components;

[0035] Figure 29 depicts an embodiment of a damping component disposed at or near a drill bit;

[0036] Figure 30 depicts an embodiment of a damping component disposed at or near a drill bit;

[0037] Figures 31 A and 31B depict an embodiment of a damping component disposed at or near a drill bit;

[0038] Figure 32 depicts an embodiment of a damping component including a cavity enclosing a movable element, and one or more axial bearing devices; and

[0039] Figure 33 depicts an embodiment of a damping component including a cavity enclosing a movable element, and one or more radial bearing devices.DETAILED DESCRIPTION|0040| A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0041] Devices, systems and methods are providing for performing subterranean operations (e.g., drilling operations) and damping vibrations. An embodiment of a damping component includes a body, and a cavity defined within the body (or attached to the body). The cavity encloses a movable element, such as an inertial mass, that is movable to damp vibrations, which may be torsional, axial and / or lateral vibrations. The damping component may be incorporated into a borehole string (e.g., as part of an existing component such as a stabilizer, steering assembly or drilling motor), or as part of a dedicated damping component.

[0042] The inertial mass is free to move in one or more directions to dampen vibrations. For example, the inertial mass is free to move in a rotational direction to resist torsional vibrations, is free to move in an axial direction to resist axial vibrations, and / or free to move in a lateral direction to resist lateral vibrations.

[0043] In an embodiment, the inertial mass is free to move laterally (i.e., in a lateral or partially lateral direction) and / or in another direction relative to the cavity and the body in response to lateral and / or other vibrations. The cavity may house one or more other components or features, such as springs, compressible or deformable elements (e.g.,65DDE-511147-WO-2JNT1045PCT elastomers), and / or surfaces with a selected roughness. Such components may be provided to tune the damping component by controlling the behavior of the movable element in response to lateral vibrations. In an embodiment, the damping component includes one or more components or features for restricting or preventing rotational movement of the movable element.

[0044] The inertial mass may be composed fully or partially from a material with a high density, such as tungsten, lead, osmium, iridium, platinum, molybdenum or other high density or heavy materials, and any combination thereof.

[0045] One or more damping components may be disposed at one or more locations based on a location or locations of sources of excitation. For example, a damping component is disposed at a location where high vibration amplitudes are known to occur, such as at or near a drill bit, or at a drilling motor or other component of a bottomhole assembly. In an embodiment, a damping component is placed at a location along a borehole string that coincides with a location of a peak or local maximum associated with a given vibration mode.

[0046] Embodiments described herein provide a number of advantages and technical effects. The damping components described herein provide effective mechanisms for reducing vibrations caused by, for example, natural excitations and interactions between drilling components and a borehole wall. In addition, the damping components may be tunable in order to dampen certain vibration frequencies more than others. Furthermore, in contrast to existing devices, the damping components described herein can function over long periods of time without maintenance and with few wear components.

[0047] Figure 1 shows an embodiment of a system 10 for performing a subterranean or downhole operation (e.g., drilling, measurement, stimulation and / or production). The system 10 includes a borehole string 12 that is shown disposed in a well or borehole 14 that penetrates a subterranean region 16 (including, for example, at least one earth formation).

[0048] The borehole string 12 is operably connected to a surface structure or surface equipment 18 such as a drill rig, which includes oris connected to various surface components. In an embodiment, the borehole string 12 is a drill string extending downward into the borehole 14, and includes various downhole components, all or some of which may be incorporated in a bottomhole assembly (BHA) 20. The drill string may include one or more drill pipe sections, coiled tubing or have any other suitable structure.

[0049] The BHA 20 includes a drilling assembly including a drill bit 22, which may be driven by the surface equipment 18, e.g., by a surface drive or rotary table, or driven by a65DDE-511147-WO-2JNT1045PCT drilling motor 24 (e.g., a turbine or mud motor). The surface equipment 18 includes components to facilitate circulating fluid such as drilling mud through the borehole string 12 and through an annulus between the borehole string 12 and the wall of the borehole 14. For example, a pumping device 26 is located at the surface to circulate the fluid from a mud pit or other fluid source 28 into the borehole 14 as the drill bit 22 is rotated.

[0050] The borehole string 12 is discussed as a drill string 12, but is not so limited and can be any type of borehole string (e.g., string for hydraulic fracturing and / or other stimulation, wireline string, wellbore intervention string, fishing string, milling string, etc.)

[0051] The system 10 may include one or more of various downhole components configured to perform selected functions downhole such as controlling drilling, controlling drilling direction, performing downhole measurements, facilitating communications, performing stimulation operations and / or performing production operations. For example, the downhole components may include a logging while drilling (LWD) or measurement while drilling (MWD) tool 30, the drilling motor 24, a steering or directional control system 32 (e.g., a rotary steerable system), and other components such as a stabilizer 53 and / or vibration damping devices.

[0052] Other components may include a telemetry assembly such as a mud pulse telemetry (MPT) assembly, for communicating with the surface and / or other downhole tools or devices. The telemetry assembly includes, for example, a pulser that generates pressure signals through the fluid.

[0053] One or more downhole components and / or one or more surface components may be in communication with and / or controlled by a processor such as a downhole processor and / or a processor 38 within a surface processing unit 34. The surface processing unit 34 may control various parameters such as rotary speed, weight-on-bit, fluid flow parameters (e.g., pressure and flow rate) and others. The surface processing unit 34, in one embodiment, includes an input / output (I / O) device 36, the processor 38, and a data storage device 40 (e.g., memory, computer-readable media, etc.).

[0054] The system 10 includes at least one component 50 (referring to as a damping component or damper) that is configured to dampen lateral vibrations. The damping component 50 includes a body 52 that houses or otherwise supports one or more movable elements (also referred to as damping elements). Each movable element is allowed to move in one or more directions and resist vibrations.65DDE-511147-WO-2JNT1045PCT

[0055] In an embodiment, each movable element is allowed to move at least partially laterally (i.e., in a lateral direction or in a direction that includes a lateral directional component) in response to lateral vibrations. This creates a differential lateral motion between the moveable element and the vibrating body 52, which converts at least some vibration energy into thermal energy that is dissipated into the downhole environment. A “lateral” direction is a direction that is orthogonal to a longitudinal axis of the body 52 (and / or other component or section of the borehole string) and / or orthogonal to a rotational axis. A lateral direction may be a radial direction.

[0056] Lateral vibration typically has a lower vibration frequency than torsional vibration (which is usually a high frequency resonant oscillation), and in many cases is not a resonance phenomenon but rather is stochastic in nature. Lateral vibration is often caused by lateral shocks or forced vibration excitation from, for example, a mud motor or a stabilizer in contact with the borehole wall. Other sources of lateral vibration include forward and backward whirl.

[0057] In addition, or alternatively, the damping component 50 is configured to dampen axial and / or rotational vibrations. For example, each movable element is allowed to move at least partially axially (i.e., in an axial direction or in a direction that includes an axial directional component) in response to axial vibrations, to create a differential axial motion between the moveable element and the vibrating body 52. An “axial” direction is a direction that is parallel to a longitudinal axis of the body 52 (and / or other component or section of the borehole string) and / or parallel to a rotational axis.

[0058] Each movable element may be allowed to move rotationally (i.e., in a direction of rotation of the damping component 50) around a rotational axis in response to torsional vibrations, to create a differential rotational motion between the moveable element and the vibrating body 52. For example, a moveable element may be a ring-shaped or annular component disposed in an annular cavity, or a partially annular (arc-shaped) component. The rotational axis in an embodiment is parallel to the longitudinal axis A.

[0059] Figure 2 depicts an embodiment of the damping component 50, which may be a component of the drilling assembly or BHA 20 (e.g., a stabilizer) but is not so limited. The damping component 50 includes the body 52, which has a longitudinal axis A. The longitudinal axis A may be vertical (e.g., when in a vertical section of the borehole 14 as shown in Figure 1), horizontal as shown in Figure 2, or have any inclination.65DDE-511147-WO-2JNT1045PCT

[0060] The body 52 defines or includes a cavity 54 that has a cavity volume and houses a moveable element 56. The moveable element 56 may be an inertial mass 56 that is able to move within the cavity 54 to create differential motion when the damping component 50 is vibrating. The moveable element 56 may be permitted to move axially (i.e., parallel to the longitudinal axis A, laterally (i.e., in a lateral direction L) and / or rotationally (i.e., in a rotational direction R) around a rotational axis R,\ . In an embodiment, the rotational axis R..\ coincides in Figure 2 with the longitudinal axis A.

[0061] The differential motion generates damping energy if coupled to a dissipative force that converts lateral vibration energy into another form of energy, such as heat that is dissipated into the environment. Damping energy may be generated from the differential motion if coupled to a dissipative force created from viscous friction, coulomb friction, material deformation (e.g. elastomer), piezo or magnetorestrictive effects, eddy current effects, mechanical friction, or others, and combinations including at least one of the foregoing.

[0062] The inertial mass 56 is disposed within the cavity 54 and has freedom to move in a lateral direction L (or at least partially in the lateral direction, i.e., movement direction has a lateral component). For example, the inertial mass 56 is in the form of a ring and the cavity 54 is an annular cavity having a rectangular cross-section or other cross-sectional shape that permits differential lateral motion between the inertial mass 56 and the cavity walls. The differential motion in this example is parallel to the lateral direction L and is represented by arrow M. Alternatively, the cavity 56 may be one or more individual cavities arrayed around the axis A, each individual cavity 54 housing an individual inertial mass 56 (e.g. a bar shaped mass). In addition, or alternatively, the inertial mass 56 has freedom to move axially and / or rotationally.

[0063] The larger the differential motion and the higher the dissipative force, the higher the damping effect will be. Thus, it is advisable to select the inertial mass 56 from a dense material, resisting inertial motion to a larger extent, given its higher mass for a given volume. The inertial mass 56 may be composed fully or partially from a material with a high density, such as tungsten, lead, osmium, iridium, platinum, molybdenum or other high density or heavy materials, and any combination thereof. The inertial mass 56 has an inertial mass volume.

[0064] A viscous fluid 58 (e.g., oil, such as silicon oil) may be included to fill the space between the inertial mass 54 and the cavity walls (interstitial volume), or the space may be empty or filled with air. A viscosity of the viscous fluid may be selected to impart desired damping behaviors (e.g., react to specific frequencies).65DDE-511147-WO-2JNT1045PCT

[0065] The cavity 54 encloses the inertial mass 56 and defines the cavity walls. The cavity walls include a pair of opposing lateral walls (an interior wall 60 and an opposing exterior wall 62), which are fully or partially orthogonal to the lateral direction L. The cavity walls also include a pair of opposing axial walls (an upper wall 64 and a lower wall 66), which are fully or partially orthogonal to the axis A. The lateral walls may be parallel to the axis A as shown in Figure 2, or inclined relative to the axis A (i.e., partially parallel to the axis A).

[0066] In an example, the body 52 includes a lower component 52a and an upper component 52b, which can be assembled or fit together to form the body 52. The body 52 may define a central bore 72 configured to, for example, provide a fluid connection to adjacent components.

[0067] The damping component 50 can be connected to other components (e.g., the directional control system 32, the LWD or MWD tool 30, etc.) via any suitable connection mechanism. For example, the lower component 52a includes a connection feature such as a threaded pin connector 68, and the upper component 52b includes a connection feature such as a threaded box connector 70. An “upper” location refers to a location along a borehole string that is closer to the surface than another location, and a “lower” location refers to a location along a borehole string that is further from the surface than another location.

[0068] The cavity 54 may be defined in any suitable manner. For example, the cavity may be formed within an integral piece of material (e.g., by casting, machining, etc.). Alternatively, the cavity may be defined by multiple components. In an embodiment, the cavity 54 is sealed to isolate the cavity 54 from materials (e.g., gases and liquids) from the surrounding environment.

[0069] In an embodiment, the lower component 52a and the upper component 52b, when connected, define the cavity 54. For example, as shown in Figure 2, the lower component 52a defines the interior lateral wall 60 and the lower axial wall 66, and the upper component 52b defines the upper axial wall 64.

[0070] The lower component 52a and / or the upper component 52b may fully define the cavity, or a cover 74 may be included to enclose the inertial mass 56. The cover 74 is configured to cover an opening or compartment formed in the lower component 52a and define the exterior lateral wall 62. If the cavity 54 is an annular cavity, the cover 74 may be a sleeve that surrounds the annular cavity. The cover 74, in addition to defining and / or sealing the cavity 54, allows for ease of installation of the inertial mass 56. If the cavity 54 is a65DDE-511147-WO-2JNT1045PCT compartment, such as a recess in the body (not an annular cavity) the cover may be a hatch cover.

[0071] The cavity 54 is configured to permit the inertial mass 56 to freely move at least in the lateral direction L between the lateral walls 60 and 62. Descriptions of “lateral movement” of the inertial mass 56, encompass movement directions that are parallel to the lateral direction L, as well as movement directions that are partially parallel to the lateral direction L (i.e., have a directional component in the lateral direction L). The inertial mass 56 may be free to move axially and / or free to rotate.

[0072] The inertial mass 56 can “freely move” in a given direction, in that there are no features or components in the cavity (besides the fluid 58 and the cavity walls 60, 62, 64, 66, and any other tuning features as described further herein) that prevent the inertial mass 56 from moving in response to a given vibration magnitude.

[0073] Figures 3-5 show the lower component 52a and show examples of alternative configurations for forming and / or sealing the cavity 54. In these examples, the cavity 54 is defined by the lower component in combination with a hatch or cover. The hatch or cover allows for ease of installation of the inertial mass 56.

[0074] In Figure 3, the lower component 52a defines the exterior lateral wall 62 and the axial walls 64 and 66. The interior lateral wall 60 is defined by an internal sleeve 76 (or cover if the cavity 54 is not fully annular, but a compartment). The internal sleeve 76 may be held in place by an internal clamp 78.

[0075] In Figure 4, the lower component 52a defines the interior lateral wall 60 and the axial walls 64 and 66. The exterior lateral wall 62 is defined by a hatch cover 80 (or sleeve).

[0076] Figure 5 shows an example in which the cavity 54 is inclined with respect to the axis A. The cavity 54 is formed within the body of the lower component 52a and has a shape that conforms to the shape of the inertial mass 56. For example, the inertial mass is a rectangular bar. It is noted that the size and shape of the inertial mass 56 is not limited to this example or other specific examples described herein. The inertial mass 56 may be, for example, a cylindrical bar.

[0077] The lateral walls 60 and 62 form an angle a with the longitudinal axis A that is greater than zero and less than 90 degrees. For example, the angle is less than 45 degrees. A plug 82 may be included to seal the cavity and define the upper wall 64.

[0078] The inclined cavity 54 facilitates installation, removal and replacement of the inertial mass 56. The inclination allows for the cavity to be easier to access and allows the65DDE-511147-WO-2JNT1045PCT inertial mass 56 to be easily slid into or out of the lower component 52a. The plug 82 may be a threaded plug.

[0079] The inertial mass 56 and the cavity 54 are shaped and sized so that there is sufficient space for the inertial mass 56 to move laterally by a selected extent. As shown in Figure 6, lateral gaps gl and g2 are defined between the inertial mass 56 and the lateral walls 60, 62 (when the inertial mass is centralized in the cavity). Any suitable gap size may be defined, such as 0.5-20 mm. gl is an exterior lateral gap and g2 is an interior lateral gap.

[0080] As shown in Figure 6, there may also be axial gaps g3 and g4 between the inertial mass and the axial walls 64 and 66. The gap g3 is an upper axial gap and g4 is a lower axial gap. The gaps g3 and g4 may have any suitable size. In an embodiment, if the damping component 50 is configured to dampen lateral vibrations, the size of the lateral gaps gl and g2 (0.5 - 5 mm) are greater than the size of the axial gaps g3 and g4 (0.1 - 1 mm). Alternatively, if the damping component 50 is configured to dampen axial vibrations, the size of the lateral gaps gl and g2 are less than the size of the axial gaps g3 and g4. The inertial mass 56 volume is less than the cavity 54 volume so that an interstitial volume is defined. The width of the gaps gl, g2, g3, and g4 is related to the size of interstitial volume.

[0081] The axial gaps g3 and g4, respectively the axial walls 64 and 66 together with the axial surfaces of the inertial mass (upper inertial mass surface 56s 1, lower inertial mass surface 56s2) may act as axial bearings, supporting the inertial mass 56 and constraining axial motion of the inertial mass 56. A bearing device (e.g., sliding or ball bearing) may be disposed between the inertial mass 56 and the upper axial wall 64, and / or between the inertial mass 56 and the lower axial wall 66 to support the inertial mass 56 and facilitate lateral and / or rotational motion. An example of such a bearing device is shown in Figure 32.

[0082] The lateral gaps gl and g2, respectively the lateral walls 60 and 62 together with the lateral surfaces of the inertial mass (interior inertial mass surface 56s3, exterior inertial mass surface 56s4) act as lateral bearings, supporting the inertial mass 56 and constraining lateral motion of the inertial mass 56. A bearing device (e.g., sliding or ball bearing) may be disposed between the inertial mass 56 and the exterior wall 62, and / or between the inertial mass 56 and the interior wall 60 to support the inertial mass 56 and facilitate axial and / or rotational motion. An example of such a bearing device is shown in Figure 33.

[0083] For lateral damping, the inertial mass 56 may have an axial length selected so that the inertial mass 56 is flush with the upper and lower axial walls 64, 66 (the gaps g3 and g4 define a minimum clearance). The upper and lower axial walls 64 and 66 and / or the upper65DDE-511147-WO-2JNT1045PCT and lower axial surfaces 56sl, 56s2 of the inertial mass 56 that face the upper and lower axial walls 64 and 66, may have a surface roughness (friction coefficient) selected to tune the damping component 50.

[0084] For axial damping, the inertial mass 56 may have a width (in the lateral direction L) selected so that the inertial mass 56 is flush with the interior and exterior lateral walls 60 and 62 (the gaps gl and g2 define a minimum clearance). The lateral walls 60 and 62 and / or the interior and exterior surfaces 56s 3, 56s4 of the inertial mass 56 that face the lateral walls 60 and 62, may have a surface roughness (friction coefficient) selected to tune the damping component 50.

[0085] In an embodiment, the damping component 50 includes one or more components, elements or features (also referred to as one or more “damping control components”) configured to tune the damping component 50. Additionally or alternatively, a damping control component is configured to prevent or restrict rotational motion and / or axial motion of the inertial mass 56. Rotational motion may be fully prevented (i.e., no significant rotational motion is permitted) or partially restricted (i.e., some amount of rotational motion is permitted).

[0086] Figures 7 and 8 show examples of elements that may be included to restrict or prevent rotational motion. An anti-rotation element 84 is included, which has a first end 86 secured to the upper axial wall 64 (and / or the lower axial wall 66) of the cavity 54 as shown in Figure 7, or secured to the interior lateral wall 60 (and / or the exterior lateral wall 62) of the cavity 54 as shown in Figure 8.

[0087] A second end 88 is engaged with the inertial mass 56 such that the inertial mass 56 is prevented from moving rotationally, but is permitted to freely move laterally. The second end 88 is configured to be held at a recess or receiving portion 90 of the inertial mass 56, so that the inertial mass 56 can slide laterally (in the lateral movement direction M) along the second end 88. The receiving portion 90 may include a guide track groove or other feature that can engage the second end 88 and permit the second end 88 to slide laterally.

[0088] The anti-rotation element 84 may be tunable, to tune the damping component 50 by controlling the movement speed and / or extent of movement of the inertial mass 56 in response to lateral vibrations. For example, the lateral extent of the receiving portion is selected to control a maximum distance that the inertial mass can move in the lateral direction. In other examples, the receiving portion 90 and / or the second end 88 can have a selected surface65DDE-511147-WO-2JNT1045PCT roughness (e.g., via roughening a surface or applying a layer or coating having a selected roughness (friction coefficient)).

[0089] The surface roughness may be selected to tune the damping component 50 by providing a desired amount of frictional resistance to lateral movement. This frictional resistance (frictional coefficient) is selected to, for example, define a minimum vibration magnitude that causes lateral movement, and / or define a frequency or frequency range at which the damping component 50 is most responsive.

[0090] Figures 9-14 show examples of the damping component 50, in which one or more damping control components or features are included. A damping control component may be included to tune the damping component 50 by selecting properties of the component, such as stiffness or compressibility.

[0091] A damping control component may also function to restrict or prevent motion. For example, if the damping component is configured to dampen lateral vibrations, axial and / or rotational motion of the inertial mass 56 may be restricted.

[0092] Figures 9-14 show embodiments in which at least one flexible, compressible or otherwise deformable component is disposed between the inertial mass 56 and a wall of the cavity 54. The deformable component may be made from an elastomer (e.g., rubber or viscoelastic polymer), or any other material that can compress or otherwise deform to pennit lateral movement. Embodiments are not limited to any particular number of components, as there may be any number of components at any desired location(s).

[0093] As shown in Figure 9, at least one lateral elastomer 92 or other deformable component may be disposed within the gap gl and / or g2. For example, elastomers 92 are anayed along the exterior lateral wall 62 and / or the interior lateral wall 60. The type and properties of the elastomer (e.g., compressibility) may be selected to tune the damping component to desired lateral vibration frequencies and / or vibration magnitudes.

[0094] In addition, as shown in Figure 10, at least one axial elastomer 94 or other deformable component is disposed within the gap g3 and / or g4. The at least one axial elastomer 94 may be provided in combination with the lateral elastomers 92, or the lateral elastomers 92 may be excluded.

[0095] The at least one axial elastomer 94 may be provided to prevent or restrict axial movement of the inertial mass 56 and / or maintain the inertial mass at a central position. One or more of the axial elastomers 94 may be affixed to a wall of the cavity 54 (e.g., via an adhesive), so that the one or more axial elastomers 94 act to prevent or restrict rotational65DDE-511147-WO-2JNT1045PCT movement of the inertial mass 56. The one or more axial elastomers 94 may be tuned to damp desired axial vibration frequencies.

[0096] Figures 11-14 show embodiments in which at least one spring is provided for tuning the damping component 50. Any number of springs may be included to tune the behavior of the inertial mass 56 and / or restrict or prevent rotational movement. Embodiments are not limited to any particular number or type of springs described herein.

[0097] For example, as shown in Figure 1 1, one end of the inertial mass 56 is attached to the axial wall 64 by at least one axial leaf spring 96 (upper axial leave spring). Another axial leaf spring 96 (lower axial leaf spring) may be included to attach another end of the inertial mass 56 to the opposing axial wall 66.

[0098] The thickness and / or stiffness of each leaf spring 96 may be selected to impart specific behavioral properties to the inertial mass 56 and thereby tune the damping component 50. The spring stiffness of each leaf spring 96 may also be selected to provide a selected amount of resistance to movement of the inertial mass 56 and / or define an extent of lateral movement permitted.|0099| Figure 12 shows an example in which one or more deformable components are one or more compression springs, which may be any type of compression spring. For example, a set of lateral springs 98 is disposed in the gap gl, and / or disposed in the gap g2. The stiffness of the set of lateral springs 98 may also be selected to provide a selected amount of resistance to lateral movement of the inertial mass 56 and / or define an extent of lateral movement permitted.

[0100] The gaps g3 and g4 may be smaller than the gaps gl and g2, and may be sufficiently small so that the upper and lower axial surfaces 56sl, 56s2 of the inertial mass 56 slide along the axial walls 64 and 66. The upper and lower axial surfaces 56s 1, 56s2 of the inertial mass 56 and / or the axial walls may have a selected surface roughness (friction coefficient). The axial walls 64 and 66, together with the upper and lower axial surfaces 56s 1, 56s2 of the inertial mass and the gaps g3 and g4, act as axial bearings, supporting the inertial mass and constraining axial motion of the inertial mass 56.

[0101] As shown in Figure 13, at least one axial spring 100 may be disposed within the gap g3 and / or g4, alone or in combination with the set of lateral springs 98. There may be an upper axial spring 100 and a lower axial spring 100. The at least one axial spring 100 may be provided to prevent or restrict axial movement of the inertial mass 56 and / or centralize the inertial mass 56. The stiffness of the at least one axial spring 100 may also be65DDE-511147-WO-2JNT1045PCT selected to provide a selected amount of resistance to axial movement of the inertial mass 56 and / or define an extent of axial movement permitted. As previously noted, the damping component 50 may be tuned by providing one or more surfaces with a selected surface roughness. For example, the axial walls 64 and 66 and / or upper and lower axial surfaces 56s 1, 56s2 of the inertial mass 56 are provided with a selected surface roughness to affect lateral movement. In addition or alternatively, a component such as an elastomer may have a selected surface roughness.

[0102] Figures 14A-14D show examples in which the damping component 50 includes one or more laterally extending friction pads 102. In the example of Figure 14a, the axial springs 100 are each attached to a laterally extending friction pad 102. The upper and lower axial surfaces 56s 1, 56s2 of the inertial mass 56 slides along the friction pads 102 when moving laterally. It is noted that the friction pads (or any other surfaces having a desired surface roughness or friction coefficient) may be included in any embodiment of the damping component 50. The axial springs 100 are compressed to create a normal force on the friction pads 102 and the upper and lower axial surfaces 56s 1, 56s2 of inertial mass 56. The normal force can be adjusted to provide sufficient friction force to dampen the vibration when (lateral) differential motion between the inertial mass 56 and the friction pads 102 occurs. For such systems, the cavity may be filled with a viscous fluid 58, further supporting the damping, as shown in Figures 14A and 14D. The normal force on the friction pad 102 may be created by an axial spring 100 at each axial end by an upper laterally extending friction pad 102 and a lower laterally extending friction pad 102, as shown in the example of Figure 14A, or by an axial spring 100 at one end, as shown in the example of Figure 14B. In another example, shown in Figures 14C and 14D, the inertial mass 56 may be split in axial direction into inertial masses 56a and 56b. An axial spring 101 axially located between the inertial masses 56a and 56b exerts a force on both masses 56a and 56b, pushing the masses 56a and 56b toward respective friction pads 102.

[0103] Any suitable component, mechanism, device or system may be included for restricting or preventing rotational motion. For example, rotational movement may be restricted or prevented by attaching a tether (not shown) to the inertial mass 56.

[0104] The damping component 50 may include one or more pressure compensation devices. Damping components can include pressure regulating devices to adapt for a certain environment or boundary condition.65DDE-511147-WO-2JNT1045PCT

[0105] Figures 15 and 16 illustrate examples of pressure regulating devices. In these examples the damping component 50 includes a pressure compensation system 140. The pressure compensation system 140 includes a compensating device, such as a moveable piston 142 abutting the fluid 58. A seal 144 prevents the fluid 58 from traversing the piston 142.

[0106] In the example of Figure 15, the piston 142 is exposed to the environment around the damping component, which may include a borehole annulus and a downhole fluid. The piston separates the fluid 58 from the downhole fluid and compensates the fluid 58 pressure with respect to the environmental pressure, such as the pressure in the borehole at a specific borehole depth.

[0107] In the example of Figure 16, the fluid 58 pressure is compensated internally, without access to the environmental pressure. The piston 142 separates the internal fluid 58 from an internal chamber 146. The internal chamber 146 and the viscous fluid 58 may be charged to any useful pressure to support the function of the damping component 50, such as a few bar to 1000 bar to adjust the fluid properties (e.g. viscosity) accordingly. The pressure inside the internal chamber 146 may be pre-charged by a compressible fluid such as a gas. The internal chamber 146, separated by the piston 142, may also compensate the thermal expansion of the internal fluid 58. The pressure in the internal chamber 146 may be selected prior to an operation of the downhole component.

[0108] The pressure compensation device is not limited to a piston. Any suitable pressure compensation device may be used, such as a membrane, a bag, bellows and others.

[0109] The damping component 50, in an embodiment, includes a particle damper. For example, as shown in Figure 17, the cavity 54 is at least partially filled with a particulate material 104. The particulate material may also be filled with a viscous fluid 106. The particulate material 104 includes particles having any suitable size and shape. In this embodiment, vibration energy is absorbed via losses occurring due to interactions between freely moving particles making up the particulate material. In an embodiment, the viscous fluid 106 may be of the same type as the fluid 58.

[0110] The damping component 50 may be an active device, adaptively adjusting parameters to optimize damping performance. The damping component 50 may therefore include sensors and active control means like actuators to for instance adjust springs in rate and / or compression. Some technologies including piezo- or magnetoresistive materials65DDE-511147-WO-2JNT1045PCT may use an electric circuit to adjust damping with respect to measured values from e. g. vibration sensors.[0011 1] During a drilling operation or other subterranean operation, the damping component 50 automatically reacts to vibrations. The vibrations cause the inertial mass 56 to move relative to the cavity 54, producing differential movement that opposes the vibration and transforms vibrational energy to heat and / or other forms of energy to dampen the vibrations.

[0112] Figure 18 illustrates a method 110 of performing a subterranean operation and damping lateral vibration of a downhole component or components. The method 110 may be performed in conjunction with the system 10 of Figure 1 and the damping component 50 of Figure 2, but is not limited thereto. The method 110 includes steps or stages represented by blocks 111-113. The method 110 includes the execution of all of the steps or stages in the order described. However, certain steps or stages may be omitted or added, or the order of the steps or stages may be changed.

[0113] At block 111, the damping component 50 is installed at a borehole string, such as the borehole string 12 of Figure 1. The damping component body 52 may be configured as a stabilizer, joint or other suitable component and connected to adjacent components via a pin-box connection or other connection mechanism. In addition, or alternatively, the damping component 50 is formed by incorporating the cavity and inertial mass (and other desired components, such as fluid, spring and / or deformable components) into a wall of the drilling motor, steering assembly and / or other part of the BHA 20.

[0114] At block 112, a downhole operation of the drill string 12 and the damping component 50 is performed, such as a drilling or directional drilling operation. The downhole operation may generate undesirable lateral vibrations.

[0115] For example, drilling is performed by rotating a drilling assembly or operating the drilling motor 24. During drilling, lateral vibrations of the drilling assembly occur due to interaction between drilling assembly components and a borehole wall.

[0116] At block 113, the damping component 50 automatically reacts to vibrations by resisting the vibrations. For example, the inertial mass 56 is causes to move laterally, axially and / or rotationally with respect to the cavity 54, generating differential motion that dampens the lateral vibrations by dissipating vibrational energy.

[0117] One or more damping components 50 and / or one or more inertial masses 56 may be positioned along a borehole string to optimize damping behavior. In an embodiment, the one or more damping components 50 are positioned at or near a drilling65DDE-511147-WO-2JNT1045PCT assembly, such as drilling components of the BHA 20 of Figure 1. Each damping component 50 is positioned at a location of the drilling assembly that corresponds to locations at which high vibrational amplitudes are excited or expected to be excited.

[0118] In addition, a damping component 50 may be tuned to a specific vibration frequency. For example, as discussed above, the width of one or more gaps gl, g2, g3, g4 and / or the viscosity of fluid 58, 106 in a cavity 54 can be selected to optimize for axial shear of the fluid, torsional shear of the fluid, and / or lateral shear of the fluid. Additional, or alternatively, the stiffness of components of a damping component (e.g., springs, compressible / deformable components, etc.) may be selected to tune the damping component to desired vibration frequencies.

[0119] Different types and modes of vibration may be excited due to behaviors of different drilling assembly components. For example, lateral vibrations may be excited by the power section of the drilling motor 24. During operation, the motor’s rotor moves with a certain eccentricity, and the lateral vibration excitation frequency is linearly dependent on the lobe configuration of a mud motor (or blade configuration of a turbine) and the rotary speed of the drill bit 22.

[0120] In coiled tubing applications, the borehole string is not rotating and therefore not contributing to the excitation frequency. The drilling motor's stator is also not rotating, since the whole bit rotary speed is driven by the drilling motor 24. The excitation mechanism is forced excitation. The force is dependent on the mass of the rotor, the radius of the rotor’s eccentricity and the frequency. The excitation force is quadratically dependent on the frequency. In the case of a mud motor, for example, the excitation frequency is the number of lobes multiplied by the rotational speed provided for the drilling motor 24 at the drill bit 22 (assuming the string / coil is not rotating).

[0121] Fluid such as drilling mud in the borehole and other liquids can provide a damping effect. However, lateral vibrations can be excessive, for example, due to high rotation speeds. Lateral vibration can also be excessive when gas is pumped through the drilling motor 24, because drilling mud is then not contributing to the damping of the system, and with an absence of damping from the mud, the forced excitation of the rotor can lead to very high vibration levels. For example, in coiled tubing, with Nitrogen exposure, the provided damping is very low and vibrations can be excessive in lateral direction.

[0122] Examples of excitation frequencies are described in "Measurement of Dynamics Phenomena in Downhole Tools - Requirements, Theory and Interpretation,"65DDE-511147-WO-2JNT1045PCT presented at the IADC / SPE Drilling Conference and Exhibition, Fort Worth, Texas, USA, March 2018 (SPE-189710-MS), the contents of which are incorporated herein by reference. Amplitudes expected for different frequencies are described in “A Combined Analytical and Numerical Approach to Analyze Mud Motor Excited Vibrations in Drilling Systems,” August 12, 2015 (GT2015-42144), and “Characterization and Mitigation of Mud Motor Vibrations” (SPE-184711-MS) the contents of which are incorporated herein by reference.

[0123] The drilling motor 24 can also be a source of axial and torsional vibrations. For example, excitation in axial direction of the BHA 20 is due to the interaction of stator blading that guides the flow and rotor blading that rotates and transforms the flow of the mud into the rotational speed and torque provided to the bit. Behind the stators is a non- uniform flow of the mud (no flow behind a stator blade, flow between the stator blades). The rotor blading is rotating through this alternating flow, which gives an excitation frequency that is dependent on the number of stator blades, and the number of rotor blades. The force is given by the pressure different and can be estimated by a stimulus.

[0124] Accordingly, the excitation frequency of axial vibration is a multiple of the bit rotary speed, where the multiple is a number N of rotor blades. For example, a mud motor typically operates to provide rotary speed values between about 1-15 Hz (60 - 900 RPM).

[0125] Torsional, axial and lateral vibrations can be excited close to the drill bit 22 and along the drill string 12. In some cases, for example to control and suppress lateral bit whirl, inertia elements could be installed close to the bit 22, where the mode shape of such vibration has a maximum. Bit whirl can be forward whirl or backward whirl. Forward whirl typically has the same frequency as the rotary speed, while backward whirl can have much higher frequency and acceleration. Backward whirl is known to be very destructive and can reach much higher frequencies than the bit rotary frequency, depending on the diameter difference of the bit and the borehole. During backward whirl, the bit kinematicly rolls along the borehole wall opposite to the drill string sense of rotation. In an exemplary case, the bit has a diameter db of 8.5”, the borehole has a diameter dh of 8.6”, and the backward whirl frequency fwhiri is 85 times the bit frequency fbit (fwhiri = - fbit x db / (dh-db)). Lateral dampers can be designed and tuned to be effective at such frequencies.

[0126] Other factors can contribute to excitation of vibrations. For example, due to lateral shocks excited by the interaction of stabilizers and a borehole, or by the65DDE-511147-WO-2JNT1045PCT interaction of a drill bit and the borehole, certain elements could be excited in their natural frequency.

[0127] Accordingly, one or more damping components 50 may be placed at a location or locations that correspond to locations or positions where vibration amplitude is known or expected to be above a threshold amplitude or at a maximum amplitude. In an embodiment, the selected location of a damping component is at or near a location of a maximum amplitude of a given vibration mode shape.

[0128] Figure 19 shows an example of a downhole component at which a damping component or parts thereof may be disposed. In this example, the downhole component is an electronics assembly such as a probe component (e.g., sub) 120, which includes an electronics package 122 supported between two supports 124. A lateral acceleration sensor 126 was used to measure lateral vibrations. Such probe components 120 can be easily excited by lateral shocks and vibrations. The excitation for such probe structures can be from shocks (e. g. stabilizer rib wall contact), mud flow (turbulences of the fluid flow), mud motor imbalance, drill bit whirl, BHA whirl, stabilizer whirl, multiples of drilling rpm, etc.

[0129] Figures 20A and 20B illustrate lateral acceleration measurements associated with the probe component 120. Figure 20A illustrates a graph 150 of lateral acceleration amplitude (in units of gravitational acceleration g) as a function of time; vibrational measurements are represented by curves 152 and 154. Figure 20B illustrates a frequency-domain graph 156 of amplitude as a function of vibrational frequency, where vibrational measurements are represented by a plot 158.

[0130] Figure 21 shows an example of a location along which the damping component 50 may be positioned. The body 52 of the damping component 50 may be defined by a housing of the probe component 120, or the damping component 50 may have a body 52 attached to the probe component 120. In this example, the damping component 50 is positioned at a location of a maximum of a normalized lateral mode shape of a first natural frequency (represented by curve 159 of amplitude as a function of longitudinal position x of the probe component 120) derived from the above measurements.

[0131] The following are examples of placement of a damping component 50 or components along the BHA 20. In the following, the downhole components of BHA 20, respectively drilling motor 24 has a longitudinal axis in an x-axis direction (axial direction). The following figures show a side cross-sectional view in a plane defined by the axial direction65DDE-511147-WO-2JNT1045PCT and a lateral direction ( -axis direction). The figures also show a cross-sectional view in a plane defined by lateral directions (y-axis and --axis and perpendicular to the x-axis).

[0132] Figures 22A, 22B, 23A and 23B show examples of damping elements for damping lateral vibrations excited in one or more downhole components of the BHA 20 and / or the drilling motor 24, which is configured as a mud motor and includes a motor power section 130 in a tubular housing 132.

[0133] In the example of Figures 22A and 22B, a damping component 50 is disposed at a plurality of axial locations A along the drilling motor, which are selected to correspond to a lateral vibration mode due to eccentric motion of a rotor in the motor power section 130. Each damping component 50 includes a plurality of discrete cavities 54 defined within the housing 132 and arrayed circumferentially around the motor power section 130. Each cavity 54 houses an inertial mass 56 and may have any suitable axial length (length in the x-axis direction). As shown, the body 52 of a damping component 50 is defined by a portion of the housing 132. In an embodiment, the housing 132 may be the stator of the drilling motor 24.100134] For a given location, each cavity 54 is optimized by tuning the cavity 54 and damping control components therein for an excitation frequency of the motor power section 130. Each cavity 54 may be tuned by selecting appropriate gap widths, fluid viscosity and / or stiffness of springs or deformable elements. It is noted that damping components at different locations A may be tuned differently.

[0135] Figures 23 A and 23B show an example in which the damping component 50 includes an annular or ring-shaped cavity 54 and inertial mass 56. The cavity and inertial mass may be fully annular as shown, or broken into multiple discrete arc-shaped cavities and associated inertial masses.

[0136] In other examples, one or more damping components 50 are disposed relative to a turbine motor 26 and includes a turbine power section 134 in a tubular housing 136.

[0137] As shown in Figures 24A, 24B, a damping component 50 is disposed at a plurality of axial locations A along the drilling motor 24 which is configured as a turbine motor, which are selected to correspond to one or more peaks of a lateral vibration mode excited, for example, by the flow of fluid and interaction between stator blades and rotor blades of the turbine power section 134.65DDE-511147-WO-2JNT1045PCT

[0138] One or more damping components 50 may include a plurality of discrete cavities 54 defined within the housing 136 and arrayed circumferentially around the turbine power section 134, as shown in Figures 24A and 24B. As shown in Figures 25A and 25B, one or more damping component 50 includes an annular or ring-shaped cavity 54 and inertial mass 56. The cavity 54 and inertial mass 56 may be fully annular as shown, or broken into multiple discrete arc-shaped cavities and associated inertial masses.

[0139] As noted above, each damping component 50 of the drilling motor 24 (turbine motor) may be tuned to the same frequency or to different frequencies. In addition, it is noted that the damping components 50 may have the same configuration (e.g., discrete cavities, an annular cavity or multiple arc-shaped cavities), or there may be a combination of damping components having different configurations (e.g., at least one damping component 50 includes discrete cavities and at least one damping component 50 includes an annular cavity).

[0140] Each damping component 50 may be tuned for damping of specific vibration frequencies associated with the turbine motor, mud motor or any other downhole components of BHA 20. For example, the size of the inertial mass, gap size, spring rate, spring pretension, viscosity of fluid in the cavity and / or extent of each cavity is selected based on known or expected vibration frequencies, which may be axial, lateral and / or torsional.

[0141] In an embodiment, the mass or mass moment of inertia in a given vibration direction is maximized, for example, with geometric constraints. For example, as shown in Figures 26A and 26B, a damping component is incorporated into the housing 136 around the turbine power section 134, motor or any other downhole components. The damping component 50 may include a plurality of discreet cavities as shown, or may include a single annular cavity. Each cavity 54 and inertial mass 56 has an axial extent that corresponds to the entire length of the turbine power section 134, or any other suitable axial extent.

[0142] The embodiments of Figures 22-26 are not limited to a turbine power section, motor or any other specific downhole component. The embodiments may be applicable to any downhole component or components, and any type of borehole string.

[0143] Figures 27 and 28 show another example of placement of a damping component or components 50. In this example, a portion of the BHA 20, such as a drill collar, was excited via operation of a mud motor.

[0144] A spectrogram 160 (Figure 27) shows vibrational measurements taken during a time period of 3000 seconds, where high-speed data was captured continuously with 1000 Hz in sliding mode. The spectrogram 160 shows amplitudes at various frequencies,65DDE-511147-WO-2JNT1045PCT where the amplitude is represented by a color-coding or shading. Lighter shades correspond to higher amplitudes.

[0145] A linearly increasing excitation frequency (denoted as element 162) of excitation can be clearly identified between 8 Hz excitation frequency at 0 seconds and 14 Hz at 1400 seconds. As shown, the amplitudes generally increase with the excitation frequency, which can also be observed in the time based measurements. The high quality of the data enables the identification of multiples of the rotor excitation frequency as well as multiples of the motor rotary speed.

[0146] The spectrogram 160 reveals high acceleration amplitude levels at excitation frequencies (due to rotor imbalance) between 8 Hz and 9.5 Hz, between 10 Hz and 12 Hz, and between 13 Hz and 14 Hz.

[0147] Normalized mode shapes in the corresponding drilling environment are shown in Figure 28, as a graph 164 of normalized mode amplitude as a function of distance along the BHA from the drill bit 22. A first mode at 8.56 Hz is shown as curve 166, a second mode at 11.78 Hz is shown as curve 168, and a third mode at 13.27 Hz is shown as curve 170.100148] A section of the BHA 20 is also shown, as well as positions along the BHA 20 at which damping components 50 would be optimized to counteract these modes. The positions are represented by shaded regions 172. These positions correspond to locations along the BHA where one or more modes have high amplitudes.

[0149] Figures 29-31 show examples of a damping component 50 placed at or near the drill bit 22, and may be configured to dampen axial, torsional and / or lateral vibrations. Figure 29 shows an example of the damping component 50, in which two cavities (each having an inertial mass therein) are positioned symmetrically about a longitudinal axis of the BHA 20 and / or drill bit 22. In the example of Figure 30, the damping component 50 includes a rectangular cavity 54 centrally located relative to the axis. Figures 31 A and 3 IB show an example in which the damping component 50 includes cavities 54 arrayed circumferentially around the axis. The damping component 50 may be tuned for vibration frequencies associated with natural self-excitation modes, backward whirl, forced excitation and shocks. All damper embodiments as described above in respective Figures 2 - 17 can alternatively be used at or near the drill bit 22. Such at or near the drill bit 22 devices would be beneficial to suppress or dampen bit induced lateral vibrations, such as bit induced backward or forward whirl or bit induced axial vibrations, such as bit bounce.65DDE-511147-WO-2JNT1045PCT

[0150] As noted above, the cavity 54 may include or define a bearing structure or a bearing system for facilitating axial, rotational and / or lateral differential motion. The bearing system may be formed by surfaces of the inertial mass 56 and walls of the cavity 54. A bearing device may be included to further facilitate movement.

[0151] Figures 32 and 33 depict embodiments of the damping component 50, in which the cavity 54 houses one or more bearing devices, denoted as axial bearings 180 and radial bearings 182. Each bearing may be any suitable device or structure, such as a journal bearing or sliding bearing. Bearing gaps may be selected (e.g., between 0.01 mm and 0.5 mm) to support and constrain motion. Suitable bearing materials include plastic, brass, copper, steel, coatings such as HVOF, CVD, PTFE, and others. Other examples of suitable bearing devices or structures include ball or roller bearings, which can be used to further decrease bearing gap and minimize friction between the inertial mass 56 and the cavity 54.

[0152] In the embodiment of Figure 32, an axial bearing 180 is coupled to the inertial mass 54. There may be an axial bearing 180 disposed in the gap g3 and coupled to the upper axial wall 64, and / or an axial bearing 180 disposed in the gap g4 and coupled to the lower axial wall 66. The axial bearing 180 acts to facilitate lateral movement of the inertial mass 56 and constrain axial movement.

[0153] In the embodiment of Figure 33, a radial bearing 182 is coupled to the inertial mass 54. There may be a radial bearing 182 disposed in the gap g2 and coupled to the interior wall 60, and / or a lateral bearing 182 disposed in the gap gl and coupled to the exterior wall 62. The lateral bearing 182 acts to facilitate axial movement of the inertial mass 56 and constrain lateral movement.

[0154] Set forth below are some embodiments of the foregoing disclosure:

[0155] Embodiment 1 : A system for damping lateral vibrations, comprising: a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis; a cavity disposed within the body, the cavity having a selected width in an at least partially lateral direction, the at least partially lateral direction having a directional component that is orthogonal to the longitudinal axis; and a moveable element disposed in the cavity, the moveable element being free to laterally move relative to the cavity in the at least partially lateral direction in response to a lateral vibration of the body, wherein lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration.65DDE-511147-WO-2JNT1045PCT

[0156] Embodiment 2: The system of any prior embodiment, wherein the cavity is sealed from a downhole environment around the body.

[0157] Embodiment 3: The system of any prior embodiment, wherein a space in the cavity is filled with a viscous fluid.

[0158] Embodiment 4: The system of any prior embodiment, further comprising a damping control component, the damping control component disposed in the cavity and configured to perform at least one of: restricting a rotational movement of the movable element, and controlling the lateral movement.

[0159] Embodiment 5: The system of any prior embodiment, wherein the damping control component is selected from at least one of: a compressible component, a compression spring, a leaf spring and an elastomer component.

[0160] Embodiment 6: The system of any prior embodiment, wherein the damping control component is attached to the body and connected to the movable element to restrict the rotational movement.

[0161] Embodiment 7: The system of any prior embodiment, wherein at least one of a wall of the cavity, a surface of the moveable element and an internal component in the cavity has a surface roughness selected to regulate the lateral movement.

[0162] Embodiment 8: The system of any prior embodiment, wherein the cavity defines a pair of opposing axial walls, and a pair of opposing lateral walls, the opposing lateral walls being orthogonal to the at least partially lateral direction, and the cavity includes a lateral gap between the movable element and a lateral wall of the cavity, and an axial gap between the movable element and an axial wall of the cavity, the lateral gap being larger than the axial gap.

[0163] Embodiment 9: The system of any prior embodiment, wherein the movable element is made at least partially from a material selected from at least one of tungsten, lead, and molybdenum.

[0164] Embodiment 10: The system of any prior embodiment, wherein the cavity is disposed at a selected location along the borehole string based on a mode shape of the lateral vibration, the selected location corresponding to a position of a maximum amplitude of the mode shape.

[0165] Embodiment 11: The system of any prior embodiment, wherein the movable element is supported by an axial bearing configured to facilitate lateral movement and constrain axial movement of the inertial mass in an axial direction, the axial direction being parallel to the longitudinal axis.65DDE-511147-WO-2JNT1045PCT

[0166] Embodiment 12: The system of any prior embodiment, further comprising a compensating device configured to compensate a pressure of the viscous fluid with respect to at least one of: an environmental pressure; and a fluid pressure of a fluid in an internal chamber, the fluid pressure of the internal chamber having a selected pressure level defined prior to operation of the downhole component.

[0167] Embodiment 13: The system of any prior embodiment, wherein the pressure compensating device is selected from at least one of a piston, a bellows, a bag, and a membrane.

[0168] Embodiment 14: A method comprising: deploying a borehole string in a borehole in a subterranean region, the borehole string including a damping component, the damping component including a body having a longitudinal axis, a cavity disposed within the body and a moveable element disposed in the cavity, the cavity having a selected width in an at least partially lateral direction, the at least partially lateral direction having a directional component that is orthogonal to the longitudinal axis, the moveable element being free to laterally move in the at least partially lateral direction in response to a lateral vibration of the body; performing a subterranean operation; and during the subterranean operation, moving in response to the lateral vibration the moveable component relative to the cavity, wherein the lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration.

[0169] Embodiment 15: The method of any prior embodiment, wherein the damping component includes a damping control component, and damping the lateral vibration includes at least one of: restricting a rotational movement of the movable element by the damping control component, and controlling the lateral movement by the damping control component.

[0170] Embodiment 16: The method of any prior embodiment, wherein the damping control component is attached to the body and connected to the movable element to restrict the rotational movement.

[0171] Embodiment 17 : The method of any prior embodiment, wherein at least one of a wall of the cavity, a surface of the moveable element and an internal component in the cavity has a surface roughness selected to regulate the lateral movement.

[0172] Embodiment 18: The method of any of any prior embodiment, wherein the movable element is made at least partially from a material selected from tungsten, lead, molybdenum65DDE-511147-WO-2JNT1045PCT

[0173] Embodiment 19: A system for damping lateral vibrations, comprising: a body configured to be connected to a downhole component of a system for performing a subterranean operation, the body having a longitudinal axis; a device housing mechanically coupled to the body, wherein the device housing includes a cavity having a cavity volume and an inner surface; a moveable element movably supported in the cavity and having an element volume and a mass; and an axial bearing positioned between the moveable element and the inner surface of the cavity, wherein: the element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element and the inner surface, and wherein the interstitial volume is occupied by a fluid; and the moveable element is free to laterally move relative to the device housing in an at least partially lateral direction in response to a lateral vibration of the body, the lateral direction being orthogonal to the longitudinal axis, wherein lateral movement of the moveable element resists the lateral vibration and dampens a magnitude of the lateral vibration

[0174] Embodiment 20: A system for damping axial vibrations, comprising: a body configured to be connected to a downhole component of a system for perfonuing a subterranean operation, the body having a longitudinal axis; a device housing mechanically coupled to the body, wherein the device housing includes a cavity having a cavity volume and an inner surface; a moveable element movably supported in the cavity and having an element volume and a mass; and a radial bearing positioned between the moveable element and the inner surface of the cavity, wherein: the element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element and the inner surface, and wherein the interstitial volume is occupied by a fluid; and the moveable element is free to axially move relative to the device housing in an at least partially axial direction in response to an axial vibration of the body, the lateral direction being parallel to the longitudinal axis, wherein axial movement of the moveable element resists the axial vibration and dampens a magnitude of the axial vibration.

[0175] In connection with the teachings herein, various analyses and / or analytical components may be used, including digital and / or analog systems. The system may have components such as a processor, storage media, memory, input, output, communications link (wired, wireless, pulsed mud, optical or other), user interfaces, software programs, signal processors (digital or analog) and other such components (such as resistors, capacitors, inductors and others) to provide for operation and analyses of the apparatus and methods disclosed herein in any of several manners well-appreciated in the art. It is considered that65DDE-511147-WO-2JNT1045PCT these teachings may be, but need not be, implemented in conjunction with a set of computer executable instructions stored on a computer readable medium, including memory (ROMs, RAMs), optical (CD-ROMs), or magnetic (disks, hard drives), or any other type that when executed causes a computer to implement the method of the present invention. These instructions may providefor equipment operation, control, data collection and analysis and other functions deemed relevant by a system designer, owner, user or other such personnel, in addition to the functions described in this disclosure.

[0176] One skilled in the art will recognize that the various components or technologies may provide certain necessary or beneficial functionality or features. Accordingly, these functions and features as may be needed in support of the appended claims and variations thereof, are recognized as being inherently included as a part of the teachings herein and a part of the invention disclosed.

[0177] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and / or “substantially” and / or “generally” can include a range of ± 8% of a given value.

[0178] The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and / or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

[0179] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without65DDE-511147-WO-2JNT1045PCT departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.

Claims

65DDE-511147-WO-2JNT1045PCTCLAIMSWhat is claimed is:

1. A system for damping lateral vibrations, characterized by: a body (52) configured to be connected to a downhole component of a system (10) for performing a subterranean operation, the body (52) having a longitudinal axis; a cavity (54) disposed within the body (52), the cavity (54) having a selected width in an at least partially lateral direction, the at least partially lateral direction having a directional component that is orthogonal to the longitudinal axis; and a moveable element (56) disposed in the cavity (54), the moveable element (56) being free to laterally move relative to the cavity (54) in the at least partially lateral direction in response to a lateral vibration of the body (52), wherein lateral movement of the moveable element (56) resists the lateral vibration and dampens a magnitude of the lateral vibration.

2. The system of claim 1, wherein the cavity (54) is sealed from a downhole environment around the body (52).

3. The system of claim 1 or 2, wherein a space in the cavity (54) is filled with a viscous fluid (58).

4. The system of claim 1, further comprising a damping control component (92,94,96,98,100,102), the damping control component disposed in the cavity (54) and configured to perform at least one of: restricting a rotational movement of the movable element (56), and controlling the lateral movement.

5. The system of claim 4, wherein the damping control component is selected from at least one of: a compressible component, a compression spring (98,100), a leaf spring (96) and an elastomer component (92,94).

6. The system of claim 4, wherein the damping control component is attached to the body (52) and connected to the movable element (56) to restrict the rotational movement.

7. The system of claim 1, 2, or 4, wherein at least one of a wall of the cavity (54), a surface of the moveable element (56) and an internal component (102) in the cavity (54) has a surface roughness selected to regulate the lateral movement.

8. The system of any of claims 1-4, wherein the cavity (54) defines a pair of opposing axial walls (64,66), and a pair of opposing lateral walls, the opposing lateral walls (64,66) being orthogonal to the at least partially lateral direction, and the cavity (54) includes a lateral gap between the movable element (56) and a lateral wall (64,66) of the cavity (54),65DDE-511147-WO-2JNT1045PCT and an axial gap between the movable element (56) and an axial wall (64,66) of the cavity (54), the lateral gap being larger than the axial gap.

9. The system of any of claims 1-8, wherein the movable element (56) is made at least partially from a material selected from at least one of tungsten, lead, and molybdenum.

10. The system of any of claims 1-9, wherein the cavity (54) is disposed at a selected location along a borehole string (12) based on a mode shape of the lateral vibration, the selected location corresponding to a position of a maximum amplitude of the mode shape.1 1. The system of any of claims 1-10, wherein the movable element (56) is supported by an axial bearing (64,66,56sl,56s2,180) configured to facilitate lateral movement and constrain axial movement of the moveable element (56) in an axial direction, the axial direction being parallel to the longitudinal axis.

12. The system of claim 3, further comprising a compensating device (140) configured to compensate a pressure of the viscous fluid with respect to at least one of: an environmental pressure; and a fluid pressure of a fluid in an internal chamber (146), the fluid pressure of the internal chamber (146) having a selected pressure level defined prior to operation of the downhole component.

13. A method characterized by: deploying aborehole string (12) in aborehole (14) in a subterranean region (16), the borehole string including a damping component (50), the damping component (50) including a body (52) having a longitudinal axis, a cavity (54) disposed within the body (52) and a moveable element (56) disposed in the cavity (54), the cavity (54) having a selected width in an at least partially lateral direction, the at least partially lateral direction having a directional component that is orthogonal to the longitudinal axis, the moveable element (56) being free to laterally move in the at least partially lateral direction in response to a lateral vibration of the body (52); performing a subterranean operation; and during the subterranean operation, moving in response to the lateral vibration the moveable element (56) relative to the cavity (54), wherein the lateral movement of the moveable element (56) resists the lateral vibration and dampens a magnitude of the lateral vibration.65DDE-511147-WO-2JNT1045PCT14. A system for damping lateral vibrations, characterized by: a body (52) configured to be connected to a downhole component of a system (10) for performing a subterranean operation, the body (52) having a longitudinal axis; a device housing mechanically coupled to the body (52), wherein the device housing includes a cavity (54) having a cavity volume and an inner surface; a moveable element (56) movably supported in the cavity (54) and having an element volume and a mass; and an axial bearing (64,66,56sl ,56s2, 180) positioned between the moveable element (56) and the inner surface of the cavity (54), wherein: the element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element (56) and the inner surface, and wherein the interstitial volume is occupied by a fluid (58); and the moveable element (56) is free to laterally move relative to the device housing in an at least partially lateral direction in response to a lateral vibration of the body (52), the lateral direction being orthogonal to the longitudinal axis, wherein lateral movement of the moveable element (56) resists the lateral vibration and dampens a magnitude of the lateral vibration.

15. A system for damping axial vibrations, characterized by: a body (52) configured to be connected to a downhole component of a system (10) for performing a subterranean operation, the body (52) having a longitudinal axis; a device housing mechanically coupled to the body (52), wherein the device housing includes a cavity (54) having a cavity volume and an inner surface; a moveable element (56) movably supported in the cavity (54) and having an element volume and a mass; and a radial bearing (60,62,56s3,56s4,182) positioned between the moveable element (56) and the inner surface of the cavity (54), wherein: the element volume is less than the cavity volume so that an interstitial volume is defined between the moveable element (56) and the inner surface, and wherein the interstitial volume is occupied by a fluid (58); and the moveable element (56) is free to axially move relative to the device housing in an at least partially axial direction in response to an axial vibration of the body (52), the lateral direction being parallel to the longitudinal axis, wherein axial movement of the moveable element (56) resists the axial vibration and dampens a magnitude of the axial vibration.

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