Inertial damping system and method

Abstract

A torsional damping system includes a housing having an interior space. An inertia ring is located in the interior space, and a torsional fluid is located between the inertia ring and the housing. The inertia ring is rotatably mounted relative to the housing. When the housing oscillates, the inertia ring at least dampens a portion of the oscillation. The torsional damping system can be included in a downhole tool or a bottom hole assembly and used to dampen oscillations along a drill string or along a bottom hole assembly, including oscillations between a downhole motor and a cutting tool.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to U.S. Patent Application No. 63 / 002,039, filed March 30, 2020, and U.S. Patent Application No. 63 / 022,825, filed May 11, 2020, which are incorporated herein by reference in their entirety. Background Technology

[0003] Downhole drilling systems may include one or more rotating components. During operation, these rotating components perform a variety of operations, including power generation, drilling, reaming, casing cutting, milling, steering, and other rotational operations. When rotating, the components may experience various types of vibration, including axial, lateral, and torsional oscillations. Vibration or oscillation within the tool can cause fatigue in downhole tool components (e.g., housing, shafts, etc.), increase wear, reduce tool efficiency, or damage the downhole tool. Summary of the Invention

[0004] In some embodiments, the downhole inertial damping system includes a collar with an inner surface. Multiple dampers include a housing. The inertial collar is rotatably mounted within the housing, and torsional fluid is located between the housing and the inertial collar.

[0005] In some embodiments, the inertial damping system includes a collar located between the downhole motor and the drill bit. Multiple dampers are located between the downhole motor and the drill bit. Each damper includes a housing and an inertial ring located within the housing. The inertial ring is rotatable within the housing. Torsional fluid is located between the housing and the inertial ring.

[0006] In some embodiments, the method for damping oscillation includes attaching a plurality of dampers to a collar. The method includes rotating an inertial ring within the housing of each damper, independent of and in response to movement of the collar.

[0007] This overview is provided to introduce some concepts that will be further described in the detailed description. This overview is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help limit the scope of the claimed subject matter. Additional features and aspects of embodiments of this disclosure will be set forth herein, and in part will be obvious from the description, or may be learned by practice of these embodiments. Attached Figure Description

[0008] To describe in detail the ways in which the above and other features of this disclosure can be obtained, a more specific description will be given with reference to specific embodiments of this disclosure shown in the accompanying drawings. For better understanding, the same elements are denoted by the same reference numerals in the various drawings. While some drawings may be schematic or exaggerated representations of concepts, at least some drawings are drawn to scale. It should be understood that the drawings depict some exemplary embodiments, which will be described and explained with additional features and details using the drawings, in which:

[0009] Figure 1 This is a schematic diagram of a drilling system according to at least one embodiment of the present disclosure;

[0010] Figure 2 This is a longitudinal cross-sectional view of an inertial damping system according to at least one embodiment of the present disclosure;

[0011] Figure 3-1 This is a cross-sectional view of an inertial damping system according to at least one embodiment of the present disclosure. Figure 3-2 yes Figure 3-1 Representation of the oscillation curve of an inertial damped system;

[0012] Figures 4-1 to 4-7 This is a transverse cross-sectional view of a damper according to at least one embodiment of the present disclosure under different vibration states;

[0013] Figures 5-1 to 5-4 This is a further transverse cross-sectional view of a damper according to at least one embodiment of the present disclosure under different vibration states;

[0014] Figure 6 This is a longitudinal cross-sectional view of another inertial damping system according to at least one embodiment of the present disclosure;

[0015] Figure 7 This is a longitudinal cross-sectional view of yet another inertial damping system according to at least one embodiment of the present disclosure;

[0016] Figure 8-1 This is a longitudinal cross-sectional view of another inertial damping system according to at least one embodiment of the present disclosure;

[0017] Figure 8-2 yes Figure 8-1 An enlarged view of the bearing and damper separator assembly within the inertial damping system;

[0018] Figure 8-3 yes Figure 8-1 and 8-2 End view of the bearing within the inertial damping system;

[0019] Figure 9-1 This is a transverse cross-sectional view of yet another inertial damping system according to at least one embodiment of the present disclosure;

[0020] Figure 9-2 According to at least one embodiment of this disclosure Figure 9-1 Longitudinal cross-sectional view of the inertial damping system;

[0021] Figure 9-3 According to at least one embodiment of this disclosure Figure 9-1 Another longitudinal cross-sectional view of the inertial damping system;

[0022] Figure 10-1 This is a transverse cross-sectional view of another inertial damping system according to at least one embodiment of the present disclosure;

[0023] Figure 10-2 yes Figure 10-1 A transverse cross-sectional view of an inertial damping system; and

[0024] Figure 11 This is a flowchart of a method for damping vibration according to at least one embodiment of the present disclosure. Detailed Implementation

[0025] Embodiments of this disclosure relate to apparatus, systems, and methods for damping vibrations / oscillations in downhole tools. For example, downhole systems may experience various motions, vibrations, and oscillations. In some embodiments, motion may be associated with drilling activities. For example, downhole tools may be rotated using a rotary drill bit, mill, or reamer to degrade formation or other downhole materials. Engagement of downhole tools and / or drill strings with downhole materials, flow of drilling or production fluids against or through the tool, or other conditions can cause vibrations, torsional oscillations, and other motions. For the purposes of this disclosure, the terms vibration, oscillation, and other motions may be used interchangeably unless otherwise stated. If left uncontrolled, these torsional oscillations can increase wear on downhole tools, damage downhole tools, increase fatigue of materials within downhole tools, and combinations thereof. Dampers may be mounted on downhole tools to reduce the effects of torsional oscillations or axial vibrations. For example, inertial dampers can reduce the amplitude or frequency of torsional oscillations. Of course, vibrations and oscillations can be concerns in other downhole environments besides drilling (e.g., testing, perforation, production, artificial lift, etc.), and therefore the downhole environment should not be limited to drilling systems.

[0026] Figure 1 An example of a drilling system 100 for drilling formation 101 to form wellbore 102 is shown. The drilling system 100 includes a drilling rig 103 for rotating a drilling tool assembly 104 that extends downward into wellbore 102. The drilling tool assembly 104 may include a drill string 105, a bottom hole assembly (BHA) 106, and a drill bit 110 attached to the downhole end of the drill string 105.

[0027] The drill string 105 may include several joints of the drill pipe 108 connected end-to-end via a tool joint 109. The drill string 105 transmits drilling fluid through a central bore and transmits rotational power from the drilling rig 103 to the BHA 106. In some embodiments, the drill string 105 may also include additional components such as short joints, short sections, etc. The drill pipe 108 provides a hydraulic passage through which drilling fluid is pumped from the surface. The drilling fluid exits through nozzles, nozzles, or other orifices in the drill bit 110 for cooling the drill bit 110 and its cutting structures, and for lifting drill cuttings out of the wellbore 102 during drilling.

[0028] BHA 106 may include drill bit 110 or other components. Exemplary BHA 106 may include additional or other components (e.g., coupled between drill string 105 and drill bit 110). Examples of additional BHA components include drill collars, stabilizers, measurement-while-drilling (MWD) tools, logging-while-drilling (LWD) tools, downhole motors, reamers, face cutters, hydraulic separation devices, slappers, vibration or damping tools, other components, or combinations thereof. BHA 106 may also include a Rotary Steering System (RSS). The RSS may include a directional drilling tool that alters the orientation of drill bit 110, thereby changing the wellbore trajectory. In some cases, at least a portion of the RSS may maintain a geostationary position relative to an absolute reference frame, such as gravity, magnetic north, or true north. Using a gauging system obtained from the geostationary position, the RSS can position drill bit 110, alter the path of drill bit 110, and guide the directional drilling tool along a planned trajectory.

[0029] Generally, drilling system 100 may include additional or other drilling components and accessories, such as special valves (e.g., kerb plugs, blowout preventers, and safety valves). Additional components included in drilling system 100 may be considered part of drilling tool assembly 104, drill string 105, or BHA 106, depending on their location in drilling system 100.

[0030] In some embodiments, the downhole motor 111 in BHA 106 can generate electricity for the downhole system and / or provide rotational energy for downhole components (e.g., rotating drill bit 110). The downhole motor 111 can be any type of downhole motor 111, including positive displacement pumps (e.g., screw motors) or turbines. In some embodiments, the downhole motor 111 can be powered by drilling fluid. In other words, drilling fluid pumped from the surface to the well can provide energy to rotate the rotor in the downhole motor 111. The downhole motor 111 can operate at an optimal differential pressure or within a differential pressure range. The optimal differential pressure can be the differential pressure at which the downhole motor 111 will not stall, burn out, overspeed, or otherwise be damaged. In some cases, the downhole motor 111 can rotate the drill bit so that the drill string 105 does not rotate at the surface.

[0031] Drill bit 110 in BHA 106 can be any type of drill bit suitable for degrading downhole materials. For example, drill bit 110 can be a drill bit suitable for drilling formation 101. Example types of drill bits used for drilling formations are fixed cutter or scraper bits (or PDC bits), roller cone bits, core bits, and combinations thereof (e.g., hybrid roller cone and fixed cutter bits). In other embodiments, drill bit 110 can be a mill for removing metal, composite materials, elastomers, other downhole materials, or combinations thereof. For example, drill bit 110 can be used with a directional drilling tool to drill into casing 107 lining wellbore 102. Drill bit 110 can also be a scrap mill for grinding away tools, plugs, cement, other materials, or combinations thereof within wellbore 102. Cutting chips or other debris generated by using the mill may be lifted to the surface or may fall downhole. In other embodiments, drill bit 110 may include a reamer. For example, a downhole reamer can be used in conjunction with a drill bit, which can drill into the formation while the downhole reamer enlarges the borehole size.

[0032] Operation of the rotating drill string 105 and / or downhole motor 111 may cause wholly or partially oscillation of the drill string 105 and / or BHA 106. This oscillation has various effects. For example, oscillation is generated by inputting energy into the system. Therefore, the energy used for vibration is not input into the drill bit, thereby reducing the efficient transfer of energy to the drill bit. Vibration / oscillation may also damage one or more components of BHA 106. In some embodiments, a downhole inertial damping system 112 may be used to at least partially dampen vibration. In some embodiments, the downhole inertial damping system 112 may be located between the downhole motor 111 and the drill bit 110. Using the downhole inertial damping system 112 to reduce oscillation between the downhole motor 111 and BHA 106 can reduce damage to components of BHA 106 and / or more efficiently transfer power / energy to the drill bit, thereby improving system efficiency, reducing downtime, or reducing costs. In other embodiments, the inertial damping system 112 may be within BHA 107 but above the downhole motor 111. In other embodiments, the inertial damping system may be external to the BHA 106. Furthermore, in some embodiments, the downhole motor 111 may be absent, and the inertial damping system 112 may be used. In at least some embodiments, the downhole motor 111 may include or be replaced by a steering tool (e.g., RSS), and the inertial damping system 112 may be located above, below, or inside the steering tool.

[0033] Figure 2This is a cross-sectional view of an example downhole inertial damping system 212 according to at least one embodiment of the present disclosure. The downhole inertial damping system 212 includes a collar 214 having an inner surface 216. In some embodiments, the collar 214 can be any collar. For example, the collar 214 can be a drill collar, MWD collar or housing, LWD collar or housing, housing or body of a steering tool (e.g., RSS), housing or body of a downhole tool (e.g., stabilizer, reamer, casing cutter, mill), any other downhole tool, short joint, collar or housing of any other downhole element, and combinations thereof. One or more dampers 218 can be coupled to the inner surface 216 of the collar 214. While embodiments of the present disclosure show and discuss dampers 218 as coupled to the inner surface 216 of the collar 214, it should be understood that one or more dampers 218 can be coupled to the outer surface 217 of the collar 214 (shown in dashed lines), between components, or coupled to other components that may experience oscillation.

[0034] The damper 218 can be a torsional damper that reduces or limits the torsional oscillation of the collar 214, or a downhole tool or other component connected to the collar 214. Figure 2 In this configuration, dampers 218 (e.g., viscous dampers) are located between the downhole motor 211 and the drill bit 210. In some embodiments, the oscillations of the BHA may be the largest, most intense, or potentially cause the greatest damage between the downhole motor 211 and the drill bit 210. For example, even if the oscillation amplitude is not the largest, they may resonate, thereby increasing damage, or they may be at high frequencies, resulting in rapid cycling and fatigue failure. Therefore, by positioning multiple dampers 218 between the downhole motor 211 and the drill bit 210, the dampers 218 can be placed where they can dampen potentially destructive oscillations in the BHA. One or more of the multiple dampers 218 are configured to dampen high-frequency torsional oscillations (HFTO). Although some systems are configured to reduce or mitigate relatively low-frequency oscillations (e.g., less than about 1 Hz, less than about 5 Hz) or mid-frequency oscillations (e.g., between about 5 Hz and about 40 Hz), the embodiments of dampers 218 with torsional fluid and / or particulate materials discussed below can be configured to dampen HFTO. It should be understood that the HFTO may include torsional oscillations greater than about 40 Hz or greater than about 50 Hz. Furthermore, the damper 218 discussed below can be configured to dampen the HFTO to about 250 Hz, about 300 Hz, or about 350 Hz. Additionally, the system described herein may have one or more dampers 218 configured to dampen one or more HFTO frequencies in the BHA.

[0035] Figure 2The damper 218 includes a housing 220. The housing 220 may be a portion of the damper 218 coupled to the collar 214. Some or each of the plurality of dampers 218 may share the housing 220, although in other embodiments, one or more dampers 218 have separate housings 220. The housing 220 may be coupled to the collar 214 and, in some embodiments, is rotatably, longitudinally, or radially fixed to the collar 214. Thus, in at least some embodiments, the housing 220 may not move relative to the collar 214. In some embodiments, the housing 220 is integrally formed as part of the collar 214.

[0036] The collar 214 may be axially positioned between the downhole motor 211 and the drill bit 210, and may extend its full length between the downhole motor 211 and the drill bit 210. In some embodiments, the collar 214 includes multiple segments / collars connected end-to-end between the downhole motor 211 and the drill bit 210. Therefore, vibrations, oscillations, and other movements of the collar 214 between the downhole motor 211 and the drill bit 210 can be transmitted along the collar 214. One or more dampers 218 installed between the downhole motor 211 and the drill bit 210 can reduce vibration not only at the location of the damper 218, but also along the collar 214 between the downhole motor 211 and the drill bit 210, within the drill bit 210, and above the downhole motor 211.

[0037] Figure 2 The shell 220 defines an internal space 222. The internal space 222 may be defined by an inner wall 228, an outer wall 230, a lower wall 232, and an upper wall 233. Figure 2 In this design, housing 220 is shown as having an annular structure with an axis surrounding collar 214. Inertial element 224 may be located (e.g., placed) within internal space 222. In some cases, the inertial element is a ring with an annular shape; in others, it may be a rod or a partial ring. Therefore, although the description refers to inertial ring 224, it should be understood that inertial element 224 may have other configurations. Inertial ring 224 may be rotatably mounted within internal space 222 inside housing, thus allowing free rotation within internal space 222. With this configuration, when housing 220 or collar 214 rotates or oscillates, inertial ring 224 can move or rotate at different rates of rotation or potentially in different ways or directions.

[0038] The torsional fluid 226 may be located within the internal space 222 and may at least partially fill the gap between the inertia ring 224 and the walls (e.g., inner wall 228, outer wall 230, lower wall 232, and upper wall 233) defining the internal space 222 of the housing 220. The torsional fluid 226 may prevent the inertia ring 224 from rotating within the internal space 222. For example, the viscosity and density of the torsional fluid 226 may affect the rotational resistance of the inertia ring 224, and therefore different torsional fluids 226 may alter the damping effect of the damper 218. Fluids with higher viscosity or density may have higher resistance to the rotation / motion of the inertia ring 224, while fluids with lower viscosity or density may have lower resistance to the rotation / motion of the inertia ring 224. In some embodiments, the torsional fluid 226 may comprise a silicon-based fluid, an oil-based fluid, a water-based fluid, a magnetorheological fluid, an electrorheological fluid, having other components, or a combination thereof. In some embodiments, the torsional fluid 226 comprises or is replaced by particulate material, such as ceramic or graphite beads or flakes. In some embodiments, the torsional fluid 226 may include a combination of fluid and solid. In some embodiments, different dampers 218 in the same drill string may include different torsional fluids 226, or each damper 218 may include the same torsional fluid 226.

[0039] The inertial ring 224 can have various configurations and, in some embodiments, includes one or more holes, cavities, channels, or other pathways. For example, the inertial ring 224 may include one or more cavities, and torsional fluid 226 may be located in and / or flow into and out of one or more cavities in the inertial ring 226. This flow can reduce torsional oscillation or reduce / dissipate the heat generated by the inertial ring 226.

[0040] In some embodiments, the inertial ring 224 rotates asynchronously with the collar 214 by rotating relative to a common reference frame at a different rate of rotation or in a different direction of rotation than the collar 214. Therefore, the rotation or other motion of the inertial ring 224 may not be synchronized with the collar 214. During the oscillation of the collar 214, the collar 214 may rotate in a first direction and a second direction (or rotate at a first speed and a second speed in the first direction). When rotating in the first direction (or at the first speed), the collar 214 may cause the housing 220 to rotate accordingly. The torsional fluid 226 and the inertial ring 224 may rotate independently of the housing 220 (including rotating asynchronously with the housing 220). As the housing 220 rotates, the walls of the housing 220 may apply frictional shear forces to the torsional fluid 226 and / or the inertial ring 224, or the torsional fluid 226 may apply frictional / shear forces to the inertial ring 224, thereby applying torque to the inertial ring 224. This may cause the inertial ring 224 to rotate in the first direction. The collar 214 and housing 220 can then oscillate, thereby moving in a second direction (or moving at a different speed in the first direction). This can result in opposing or decreasing rotational forces, or decreasing or increasing rotational forces, on the torsional fluid 226 and the inertia ring 224. However, because the inertia ring 224 rotates at a given speed in the first direction, it can resist rotation in the second direction or resist increases / decreases in speed. This resistance to changes in rotation can apply a counter-torque to the housing 220 and collar 214. This counter-torque can reduce the oscillation amplitude or frequency of the collar 214, which can reduce fatigue, damage, and wear of the components connected to the collar 214, extend the life of the components connected to the collar 214, or more efficiently transfer energy to the drill bit 210 through the collar 214.

[0041] In some embodiments, the mass of the inertia ring 224 affects the rotational drag and damping effect of the inertia ring 224. The mass of the inertia ring 224 may be influenced by its physical dimensions and structure or density. For example, a larger inertia ring 224 has a greater mass than a smaller inertia ring 224 of the same material, which can alter the damping effect of the inertia ring 224. Figure 2In this configuration, the inertial ring 224 has a height 234, which is the distance between the axial lower surface 235 and the axial upper surface 236 of the inertial ring 224. In some embodiments, the height 234 can be within a range having a lower limit, an upper limit, or both, including any one of 1 inch (2.54 cm), 2 inches (5.01 cm), 3 inches (7.62 cm), 5 inches (12.7 cm), 7.5 inches (19.05 cm), 10 inches (25.4 cm), 12 inches (30.48 cm), 2 feet (0.61 m), 5 feet (1.52 m), 10 feet (3.05 m), 20 feet (6.10 m), 30 feet (9.14 m), or any value between these values. For example, the height 234 can be greater than 1 inch (2.54 cm). In another example, the height 234 can be less than 30 feet (9.14 m). In other examples, height 234 can be any value within the range of 1 inch (2.54 cm) to 30 feet (9.14 m), such as between 2 inches (5.01 cm) and 10 inches (25.4 cm) or between 2 inches (5.01 cm) and 7.5 inches (19.05 cm). In other examples, height 234 can be greater than 30 feet (9.14 m) or less than 1 inch (2.54 cm).

[0042] The inertia ring 224 also has a cross-sectional width, which is the difference between the inner radius 238 and the outer radius 240 of the inertia ring 224. In some embodiments, the inner radius 238 can be within a range having a lower limit, an upper limit, or both, including any one of 1.0 inch (2.54 cm), 1.5 inch (3.81 cm), 2.0 inch (5.08 cm), 2.5 inch (6.35 cm), 3.0 inch (7.62 cm), 3.5 inch (8.89 cm), 4.0 inch (10.16 cm), 5.0 inch (12.7 cm), 5.5 inch (13.97 cm), 6.0 inch (15.24 cm), 10 inch (25.4 cm), 15 inch (38.1 cm), or any value between them. For example, the inner radius 238 can be greater than 1.5 inch (3.81 cm). In another example, the inner radius 238 can be less than 15 inches (38.1 cm). In other examples, the inner radius 238 can be any value between 1.0 inch (2.54 cm) and 15 inches (38.1 cm), and can be between 2.0 inches (5.8 cm) and 6.0 inches (15.24 cm), or between 2.5 inches (6.35 cm) and 5.0 inches (12.7 cm). In some examples, the inner radius 238 can be less than 1.0 inch (2.54 cm) or greater than 15 inches (38.1 cm).

[0043] In some embodiments, the outer radius 240 can be within a range having a lower limit, an upper limit, or both upper and lower limits, including any one of 1.5 inches (3.81 cm), 2.0 inches (5.08 cm), 2.5 inches (6.35 cm), 3.0 inches (7.62 cm), 3.5 inches (8.89 cm), 4.0 inches (10.16 cm), 5.0 inches (12.7 cm), 6.0 inches (15.24 cm), 10 inches (25.4 cm), 15 inches (38.1 cm), 20 inches (50.8 cm), or any value between them. For example, the outer radius 240 can be greater than 1.5 inches (3.81 cm). In another example, the outer radius 240 can be less than 20 inches (50.8 cm). In other examples, the outer radius 240 can be any value between 1.5 inches (3.81 cm) and 20 inches (50.8 cm), such as between 1.5 inches (3.81 cm) and 12.5 inches (31.75 cm), or between 3.5 inches (8.98 cm) and 10 inches (25.4 cm). In some examples, the outer radius 240 can be less than 1.5 inches (3.81 cm) or greater than 20 inches (50.8 cm).

[0044] The mass of the inertia ring 224 is determined by its shape, size, and material density. In some embodiments, the inertia ring 224 comprises, or is made of, a tungsten alloy, a steel alloy, an aluminum alloy, any other metal alloy, a ceramic, a carbide, other non-metallic materials, or a combination of the foregoing. In some embodiments, the inertia ring 224 is an integral component.

[0045] In the illustrated embodiment, the inertia ring 224 can be passively rotated, meaning that the inertia ring 224 rotates in response to the movement of the collar 214 or the housing 220. For example, frictional or shear forces on the fluid 226 can cause the inertia ring 224 to rotate. In some embodiments, the passively rotating inertia ring 224 can reduce the overall length of the inertia damping system 212 and can be installed relatively easily at a reduced cost. This can increase the number of locations where the inertia damping system 212 can be used. Furthermore, because the inertia ring 224 can be passively rotated, a single inertia ring 224 can be placed in or on different downhole tools without requiring tool extensions or BHAs. In other embodiments, the active or actuated inertia ring 224 can even rotate without the collar 214 or the housing 220 moving.

[0046] In some embodiments, the internal space 222 may be larger than the inertia ring 224. Torsional fluid 226 may fill the space or gap 242 between the walls of the internal space 222 and the inertia ring 224. In some embodiments, the gap 242 may help determine the amount of vibration damping provided by the torsional fluid 226. The gap 242 is shown as a radial gap and is relatively constant between the inertia ring 224 and the inner wall 228 and outer wall 230. However, in some embodiments, the gap 242 may not be constant. For example, when the BHA (e.g., BHA 106) bends during directional application, the gap 242 may change and cause some portions of the inertia ring 224 to become closer to the outer wall 230. Therefore, the gap 242 should be considered as an average gap, or half the difference between the width of the inertia ring 224 and the width of the internal space 222. Furthermore, although the inertial ring 224 and the interior space 222 are schematically shown as having linear surfaces in cross-section, such as when the inertial ring 224 is formed as a rectangular ring, in other embodiments, any or all such surfaces may be curved or wavy (e.g., the inertial ring 224 may be a toroidal surface).

[0047] In some embodiments, the gap 242 may be within a range having a lower limit, an upper limit, or both, including 0.0001 inches (2.54 micrometers), 0.0005 inches (12.7 micrometers), 0.001 inches (25.4 micrometers), 0.002 inches (50.8 micrometers), 0.003 inches (76.2 micrometers), 0.004 inches (101.6 micrometers), 0.005 inches (127.0 micrometers), 0.006 inches (152.4 micrometers), and 0.007 inches. The gap can be any one of the following: (177.8 micrometers), 0.008 inches (203.2 micrometers), 0.009 inches (228.6 micrometers), 0.010 inches (254.0 micrometers), 0.050 inches (0.127 centimeters), 0.10 inches (0.25 centimeters), 0.5 inches (1.27 centimeters), 1 inch (2.54 centimeters), 2 inches (5.08 centimeters), 3 inches (7.62 centimeters), 4 inches (10.2 centimeters), 5 inches (12.7 centimeters), or any value in between. For example, a gap of 242 can be greater than 0.0001 inches (2.54 micrometers). In another example, a gap of 242 can be less than 5 inches (12.7 centimeters). In other examples, the gap 242 can be any value in the range of 0.0001 inches (2.54 micrometers) to 5 inches (12.7 centimeters), such as between 0.0005 inches (12.7 micrometers) and 0.25 inches (6.35 millimeters).

[0048] As described herein, the inertial element 224 contributes to the torsional oscillation of the damped housing 214. The damping of the torsional oscillation can be modeled as the energy dissipated in a single oscillation cycle. The energy dissipated in a single oscillation (Eloss) can be modeled according to Equation 1.

[0049]

[0050] Among them, C tor It is the torsional damping coefficient, v hsg It is the rotational speed of the shell, angular velocity, and J. r This is the moment of inertia of inertial element 224. Torsional damping coefficient (C) tor It can be determined according to Equation 2.

[0051]

[0052] Where μ is the viscosity of the torsional fluid 226, D is the height 234, r1 is the inner radius 238, r2 is the outer radius 240, and h is the gap 242. Moment of inertia (e.g., J) r It can be determined according to Equation 3.

[0053]

[0054] Where m is the mass of inertial element 224. Analysis of equations 2 and 3 shows that changing the dimensions of inertial element 224 can change its inertia. For example, increasing r2 can increase C. tor and J r In some embodiments, it is possible to do so without affecting C tor In this case, m can be changed. For example, the density of inertial element 224 can be increased. For inertial element 224 of the same size, this will increase m, thereby increasing J. r And C tor It remains unchanged. Furthermore, changing the properties of the inertial fluid 226 can alter C. tor , and J r It remains unchanged. For example, increasing μ can increase C. tor .

[0055] Analysis of Equation 1 shows that C can be changed tor and J r One or two to change E loss If the energy of the oscillation is known or predictable, the energy loss of the inertial damping system 212 can be optimized to account for the oscillation energy. In this way, the operator can modify the characteristics of the inertial damping system 212 (e.g., the size and / or density of the inertial element 224, the characteristics of the inertial fluid 226) to optimize the energy loss for a given application. loss .

[0056] In at least one embodiment, the inertial element 224 has a D of 6 inches (15.2 cm), r1 of 1.3 inches (3.3 cm), r2 of 2 inches (5.1 cm), h of 0.005 inches (0.127 mm), and μ of 2400 cSt. Plugging these values ​​into Equations 1, 2, and 3 yields an E of approximately 0.25 lbf-ft·s / rad. loss If μ is changed to 12,000 cSt, then E loss Approximately 1.25 psi-fts per radian.

[0057] The drill bit has drill bit energy (e.g., W). bit This is the amount of energy that the drill bit adds to the oscillating system.

[0058] The drill bit energy can be determined according to Equation 4.

[0059]

[0060] Where T amp It is the amplitude of the oscillating torque, v bit It is the amplitude of the drill bit's oscillation speed. Based on E loss and W bit The system has an energy dissipation ratio, which can be determined according to Equation 5.

[0061]

[0062] In some embodiments, the energy dissipation ratio may be represented by the amount of torsional oscillation energy damped by the inertial damping system 212. In some embodiments, the energy dissipation ratio may be within a range having a lower limit, an upper limit, or both, including any one of 1%, 5%, 10%, 15%, 20%, 25%, 50%, 75%, 95%, or any value between these values. For example, the energy dissipation ratio may be greater than 1%. In some examples, the energy dissipation ratio may be less than 95%. In some examples, the energy dissipation ratio may be any value within the range of 1% to 95%, such as between 1% and 10%, or between 5% and 20%. In other embodiments, the energy dissipation ratio may be less than 1% or greater than 95%.

[0063] In the illustrated embodiment, the inertial damping system 212 includes two dampers 218. However, it should be understood that the inertial damping system 212 may include more or fewer than three dampers. For example, the inertial damping system 212 may include one, two, three, four, five, six, seven, eight, nine, ten or more dampers 218.

[0064] In the illustrated embodiment, each damper 218 is longitudinally adjacent to the other damper 218. In other words, the upper wall 233 of the first damper 218 contacts the lower surface 232 of the second damper. In some embodiments, the wall 233 of the first damper 218 may be the lower surface 232 of the second damper 218. In other embodiments, there may be a space or gap between the dampers 218 (see FIG. 3).

[0065] According to at least one embodiment of this disclosure, Figure 3 (by Figure 3-1 and 3-2 The components include a torsional damping system 312. Figure 3-1 Cross-sectional view of ) and downhole tools ( Figure 3-2 The torsional oscillation curve 350 represents the oscillation amplitude 352 as the rotational rate increases along the x-axis and the distance 354 from the drill bit 310 as the y-axis increases. An undamped oscillation curve 356 can represent the oscillation curve of the sample collar. The undamped oscillation curve 356 may have an oscillation peak 358, which represents the maximum oscillation amplitude of the undamped oscillation curve 356. A damped oscillation curve 364 can represent the oscillation curve of the sample collar after damping. As shown in the damped oscillation curve 364, the oscillation of the collar can be reduced along the length of the curve by using one or more dampers compared to the undamped oscillation curve 356.

[0066] The oscillation peak 358 of the undamped curve may occur at a peak distance 361 from the drill bit 310. The drill bit position is represented as point 362 in curve 350. The peak distance 361 may be expressed as a percentage of the motor distance 363, which is the distance between the drill bit position 362 and the downhole motor position 360. The percentage of the motor distance can be determined by dividing the peak distance 361 by the motor distance 363. In some embodiments, the peak position percentage may be within a range having a lower limit, an upper limit, or both limits, including any one of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or any value in between. For example, the peak percentage may be greater than 10%. In some examples, the peak percentage may be less than 90%. In some examples, the peak percentage may be any value within the range of 10% to 90%, such as between 20% and 80%, or between 50% and 70%. In some embodiments, the peak percentage may be 0% (i.e., the oscillation peak 358 is located at drill bit position 362). In some embodiments, the peak percentage may be 100% (i.e., the oscillation peak 358 is located at downhole motor position 360). In some embodiments, the undamped oscillation curve 356 may include more than one oscillation peak 358.

[0067] Figure 3-1 The torsional damping system 312 is shown in Figure 3-2 The torsional damping system 312 is located to the left of the oscillation curve 350 and has the same longitudinal dimensions as the oscillation curve 350. Although the torsional damping system 312 shown includes a downhole motor 311, a drill bit 310, and three dampers 318-1, 318-2, and 318-3 (collectively referred to as dampers 318), it should be understood that the torsional damping system 312 may include additional or different downhole tools, different numbers of dampers, etc., that may be found in the BHA or drill string.

[0068] In the illustrated embodiment, the first damper 318-1 is positioned between the drill bit 310 and the motor 311. For example, the first damper 318-1 may be positioned at or near the oscillation peak 358 on the oscillation curve 350. When positioned near the oscillation peak 358, the distance between the axial center of the first damper 318-1 and the oscillation peak 358 may be less than 2%, 5%, or 10% of the motor distance 363. In some embodiments, placing the first damper 318-1 at (or near) the oscillation peak 358 can minimize the frequency or amplitude of the oscillation. As seen in the oscillation curve 356, in this embodiment, the oscillation peak 358 is closer to the downhole motor position 360 of the downhole motor 311 than the drill bit position 362 of the drill bit 310. Therefore, the first damper 318-1 may be positioned closer to the downhole motor 311 than the drill bit 310. To further reduce oscillations near the oscillation peak 358, a second damper 318-2 may be positioned between the first damper 318-1 and the downhole motor 311 (and therefore closer to the downhole motor 311 than to the drill bit 310). By concentrating the dampers 318 at or near the oscillation peak 358, the amplitude or frequency of the vibration can be further reduced. In some embodiments, a third damper 318-3 may be positioned between the downhole motor 311 and the drill bit 310. For example, the third damper 318-3 may be positioned closer to the drill bit 310 than closer to the downhole motor 311, or even closer to the drill bit 310 than closer to the first damper 318-1. Furthermore, in some embodiments, any number of dampers 318 may be positioned between the drill bit 310 and the downhole motor 311. The spacing between the dampers 318 may be irregular, as shown in Figure 3, or the dampers may have a regular interval / spacing. In some embodiments, the irregular spacing between the dampers 318 can typically reflect the oscillation curve 350. For example, the greater the distance 354 and amplitude 352 between points on the oscillation curve 350, the greater the separation distance in the torsional damping system 312.

[0069] As described herein, in some embodiments, the first damper 318-1 may be positioned near the oscillation peak 358, with the peak damper placement defined as a percentage of the motor distance 363. In some embodiments, the peak damper placement may be within a range having a lower limit, an upper limit, or both, including any one of 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, or any value between these values. For example, the peak percentage may be greater than 0.5%. In some examples, the peak damper placement may be less than 25%. In some examples, the peak damper placement may be any value within the range of 0.5% to 25%, such as between 0.5% and 10%, or between 1% and 7%. In some embodiments, the peak damper placement may be 0% (i.e., the first damper 318-1 is located at the oscillation peak 358). In some embodiments, placing the peak damper within 10% to dampen the oscillation peak 358 is crucial for the performance of the torsional damping system 312. In some embodiments, a single damper 318 may be placed within the peak damper placement. In other embodiments, multiple dampers 318 may be placed within the peak damper placement to further dampen the oscillation peak 358.

[0070] In some embodiments, placing the damper 318 at or near the oscillation peak 358 can cause the oscillation peak 358 to change position and potentially change size. For example, the damper 318 can reduce oscillation at the location of the oscillation peak 358, allowing different locations to experience the highest oscillation on the BHA or drill string. In some embodiments, the oscillation peak 358 can be identified during downhole drilling operations or through simulation. The damper 318 located at or near the peak can comprise a magnetorheological torsional fluid, an electrorheological torsional fluid, or any other suitable fluid. In some embodiments, by applying a magnetic field to the magnetorheological fluid (or an electric field to the electrorheological fluid), the density of the torsional fluid can be changed, which can change (and potentially increase) the oscillation damping.

[0071] In some embodiments, the dampers 318 may be uniformly positioned between the drill bit 310 and the downhole motor 311, or uniformly spaced along a portion of the distance between the drill bit 310 and the motor 311. Uniformly spaced dampers 318 can help dampen oscillations over the entire distance between the downhole motor 311 and the drill bit 310, or over the entire distance covered. In some embodiments, the uniformly spaced dampers 318 may be used for an oscillation curve 356 that varies depending on the downhole tool used or the drilling conditions.

[0072] In some embodiments, the oscillation peak 358 may be located above the downhole motor 311. In some embodiments, the damper 318 may be placed anywhere along the drill string, including above the downhole motor 311. Of course, in some embodiments, the damper 318 may be used in a BHA or drill string that does not include a downhole motor. In this case, the position of the damper relative to the oscillation peak can be measured relative to other components (e.g., the distance between the drill bit and LWD, the distance between the drill bit and the reamer, the distance between the drill bit and the RSS, etc.).

[0073] Figure 4-1 This is a transverse cross-sectional view of the first damper 418-1 and the second damper 418-2 according to some embodiments. It can be seen that the collars 414-1 and 414-2 (collectively referred to as 414), the housing 420, and the inertia rings 424-1 and 424-2 (collectively referred to as 424) can have annular cross-sectional shapes. In this way, the inertia ring 424 can rotate freely within the housing 420. Of course, the inertia ring 424 can have different shapes, including the partial rings described herein.

[0074] The housing 420 may define or include a central aperture 444. Drilling fluid may flow through the central aperture 444. In some embodiments, as the inertia ring 424 rotates, heat is generated in the torsional fluid 426, the housing 420, or the inertia ring 424. The drilling fluid flowing through the central aperture 444 may cool the housing 420, the inertia ring 424, and the torsional fluid 426, and may also act as a heat sink for the torsional damping system 412.

[0075] The first damper 418-1 may be located at a different longitudinal position than the second damper 418-2. For example, the first damper 418-1 may be located at or near the oscillation peak (e.g., oscillation peak 358 in FIG. 3). The collar 414 may oscillate in response to downhole conditions and operations, and the first damper 418-1 and the second damper 418-2 may be connected to the same collar 414; however, the position of the collar 414-1 may oscillate with oscillation energy, including amplitude, frequency, or direction, different from that at the position of the collar 414-2. In some embodiments, the first damper 418-1 and the second damper 418-2 may have the same construction (e.g., the same mass, fluid, size, density, etc.), although in other embodiments they may have different constructions.

[0076] During operation, the collar 414 can swing and rotate in the first collar direction 437. The first collar direction 427 is shown in a reference frame relative to the surrounding strata. Figure 4-1The inertial ring 424 is fixed to the housing 420 or the collar 414 without rotation and therefore cannot rotate synchronously with the collar 414. As the collar 414 and housing 420 rotate, the housing 420 can apply a frictional / shear torque along the first collar direction 437 on the torsional fluid 426, which can transmit the frictional torque along the first collar direction 437 to the inertial ring 424. However, the inertial ring 424 initially resists rotation, causing the collar 414 to rotate while the inertial ring 424 remains stationary or has a relatively stationary position.

[0077] In some embodiments, the first inertial ring 424-1 may rotate or otherwise move with a different rotational energy than the second inertial ring 424-2. This may be a result of the oscillation energy of the collar 414-1 at the first inertial ring 424-1 being different from the oscillation energy of the collar 414-2 at the second inertial ring 424-2. For example, in Figure 4-1 In the illustrated embodiment, by applying at least some energy to the first inertial ring 424-1 through the housing 420 and the torsional fluid 426, the oscillation and movement of the collar 414-1 have caused the first inertial ring 424-1 to rotate relative to the surrounding formation along the first ring direction 439. This can reduce the oscillation amplitude and / or frequency of the collar 414-1. In the illustrated embodiment, the collar 414-2 rotates along the first collar direction 437 at the second damper 418-2, but the collar 414-2 does not cause the second inertial ring 424-2 to rotate. Therefore, the first inertial ring 424-1 can rotate while the second inertial ring 424-2 can not rotate, can rotate at different magnitudes, or can rotate in different directions. It should be understood that in some embodiments, the first inertial ring 424-1 may not rotate / move, while the second inertial ring 424-2 may rotate / move.

[0078] exist Figure 4-2 In this configuration, the oscillation of the collar 414-2 at the second damper 418-2 causes the second inertial ring 424-2 to rotate in the first collar direction 439. The collar 414-1 at the first damper 418-1 can still rotate in the first collar direction 439, transferring at least a portion of its energy to the first inertial ring 424-1, which can rotate in the first collar direction 439 at the same or different rotational rates as the second inertial ring 424-2.

[0079] exist Figure 4-3In this configuration, the oscillation of the collar 414 at the first damper 418-1 and the second damper 418-2 has stopped. For example, the oscillation of the collar 414 may occur at some point between the directions of rotation. However, the masses of the first inertial ring 424-1 and the second inertial ring 424-2 can cause the first inertial ring 424-1 and the second inertial ring 424-2 to continue rotating in the first collar direction 439. In this way, the first inertial ring 424-1 and the second inertial ring 424-2 can continue to apply energy to the collar 414 for a period of time, even after the collar 414 has stopped rotating.

[0080] exist Figure 4-4 In this configuration, the second inertia ring 424-2 has stopped rotating, while the first inertia ring 424-1 is still rotating. This is likely because the collar 414-1 transmits more energy to the first inertia ring 424-1 than the collar 414-2 transmits to the second inertia ring 424-2. In this way, including multiple dampers 418 allows the dampers 418 to dampen different oscillating energies at different locations. This can potentially help dampen oscillations across the collar, drill string, or BHA.

[0081] exist Figure 4-5 In the middle, the collar 414 at the first damper 418-1 and the second damper 418-2 swings in the second collar direction 441, which is the same as... Figure 4-1 and 4-2 The first ring direction 437 is opposite to the direction of the second ring. The first inertial ring 424-1 can retain at least a portion of the rotational energy transferred by the ring 414-1 before the ring 414-1 oscillates and causes rotation along the direction 441 of the second ring. Therefore, the ring 414-1 can transfer at least a portion of its rotational energy to the first inertial ring 424-1, and the first inertial ring 424-1 can transfer at least a portion of its rotational energy to the ring 414-1. This can reduce the oscillation energy of the ring 414-1, thereby reducing the amplitude or frequency of the oscillation of the ring 414-1. Figure 4-5 In the second damper 418-2, the collar 414-2 may not yet have caused the second inertia ring 424-2 to rotate. Therefore, the collar 414-2 can transfer at least a portion of its rotational energy to cause the second inertia ring 424-2 to rotate, thereby damping at least a portion of the oscillation of the collar 414-2.

[0082] exist Figure 4-6In this configuration, the collar 414-2 has transferred sufficient oscillating energy to the second inertial ring 424-2, causing the second inertial ring 424-2 to rotate in the second ring direction 243. The first inertial ring 424-1 may still rotate in the first ring direction 439. Therefore, depending on the different oscillating energies of the collar 414 at the first damper 418-1 and the second damper 418-2, the first inertial ring 424-1 and the second inertial ring 424-2 can rotate in different directions.

[0083] exist Figure 4-7 In this configuration, the collar 414-1 located at the position of the first damper 418-1 can oscillate in a different rotational direction than the collar 414-2 located at the position of the second damper 418-2. In other words, the collar 414-1 can vibrate in a manner that causes rotation along the first collar direction 437, while the collar 414-2 can vibrate in a manner that causes rotation along the second collar direction 441. As described herein, the collar 414-1 and the first inertial ring 424-1 can transfer at least a portion of their energy to each other, thereby at least partially reducing the oscillation of the collar 414-1. Similarly, the collar 414-2 and the second inertial ring 424-2 can transfer at least a portion of their energy to each other, thereby at least partially reducing the oscillation of the collar 414-2. Because the first damper 418-1 and the second damper 418-2 are independent dampers 418, each damper 418 can dampen the oscillation of the collar 414 in a manner unique to the position of the damper 418. In this way, including multiple dampers 418 can reduce the sway of the collar 414 along its length. Collars 414-1 and 414-2 can also be the same collar, but can reflect different axial / longitudinal positions along the collar.

[0084] Now for reference Figure 5-1 In some embodiments, the first inertial ring 524-1 of the first damper 518-1 may have a different mass than the second inertial ring 524-1 of the second damper 518-2. For example, due to the use of materials with different densities or different sizes or shapes, the first inertial ring 524-1 may have a larger mass than the second damper 518-2. Therefore, when the collar 514 rotates in the torsional fluid 526 along the first collar direction 537, the first inertial ring 524-1 may take longer to begin rotating than the second inertial ring 524-2. Consequently, the second inertial ring 524-2 may begin rotating along the first collar direction 539 before the first inertial ring 524-1. This may be because the first inertial ring 524-1 may expend more energy to begin rotating than the second inertial ring.

[0085] like Figure 5-2As shown, the collar 514 can transfer sufficient rotational energy to the first inertial ring 524-1, causing the first inertial ring 524-1 to begin rotating along the first ring direction 539. Because the first inertial ring 524-1 is heavier than the second inertial ring, the collar 514 can transfer more energy to the first inertial ring 524-1 (or can use more energy to cause the first inertial ring 524-1 to move), therefore the first inertial ring 524-1 can dampen the oscillation of the collar 514 to a greater extent than the second inertial ring 524-2.

[0086] exist Figure 5-3 In this configuration, the rotation of collar 514 has stopped, and the second inertial ring 524-2 has transferred all its energy to collar 514 and has also stopped rotating. In some embodiments, because the first inertial ring 524-1 is heavier than the second inertial ring, the first inertial ring 524-1 may require a longer time to stop rotating in the first ring direction 539. In this way, the first inertial ring 524-1 can continue to transfer its rotational energy to collar 514.

[0087] exist Figure 5-4 In this configuration, the collar 514 oscillates in the second collar direction 541. The first inertial ring 524-1 can continue to rotate in the first ring direction 539. In some embodiments, the collar 514 can cause the second inertial ring 524-2 to rotate in the second ring direction 543. The first and second inertial rings 524-1 and 524-2 can transfer their respective rotational energy to the collar 514 to dampen the collar's oscillation. Because the first inertial ring 524-1 has a different mass than the second inertial ring 524-2, even when experiencing the same oscillation, the first inertial ring 524-1 can rotate in a different direction than the second inertial ring 524-2 at a given moment. This can increase the damping of the magnitude or frequency of the collar's oscillation. This can reduce damage to downhole tools, thereby saving time and money associated with tool maintenance.

[0088] It should be understood that oscillation can include any variation in rotational energy. Variations in rotational energy can include changes in rotational direction, rotational rate, oscillation frequency, oscillation amplitude, and combinations thereof. Therefore, embodiments of this disclosure can include oscillations from the first ring direction to the first ring direction at different rotational rates, oscillations from the first ring direction to no rotation, oscillations from the first ring direction to the second ring direction, oscillations from the second ring direction to the second ring direction at different rotational rates, oscillations from the second ring direction to no rotation, and oscillations from the second ring direction to the first ring direction. Similarly, these varying oscillations in the ring can cause the inertial ring to change direction from the first ring direction to the second ring direction, change the rotational rate of the inertial ring in the first ring direction, change the rotation of the inertial ring from the first ring direction to no rotation, change the rotational rate of the inertial ring in the second ring direction, change the rotation of the inertial ring from the second ring direction to no rotation, or change the rotation of the inertial ring from the second ring direction to the first ring direction.

[0089] Figure 6 This is a representation of a torsional damping system 612 according to at least one additional embodiment of the present disclosure. In the illustrated embodiment, a plurality of dampers 618 are longitudinally separated from each other. In other words, a damper spacing 646 exists between the first damper 618-1 and the second damper 618-2 (collectively referred to as dampers 618), which may be a percentage of the total inertial damper height 648. In some embodiments, the damper spacing 646 may be within a range having a lower limit, an upper limit, or both, including any one of 0%, 2.5%, 5%, 10%, 25%, 50%, 75%, 100%, 150%, 200%, 300%, or any value between these values. For example, the damper spacing 646 may be less than 300% of the damper height 648. In some examples, the damper spacing 646 may be greater than 0%, 5%, 10%, or 300% of the damper height 648. When the dampers 618 have different heights 648, the damper spacing 646 can be determined based on the damper 618 with the smaller height 648.

[0090] In some embodiments, the damper spacing 646 may be determined based on the location of the maximum oscillation. In some embodiments, at least three dampers 618 may be uniformly spaced along the collar 614 (e.g., having the same damper spacing 646). In some embodiments, the dampers 618 may be non-uniformly spaced (e.g., having different damper spacings 646). In some embodiments, the dampers 618 may be spaced based on the oscillation curve of the collar 614 to place the dampers 618 at the location of the highest oscillation or where the peak is observed or expected.

[0091] Figure 7This is a representation of a torsional damping system 712 according to at least one additional embodiment of the present disclosure. In the illustrated embodiment, a single housing 714 includes a plurality of inertial rings 724-1, 724-2 (collectively referred to as 724). The housing 714 includes an internal space 722. The plurality of inertial rings 724 may be mounted in the internal space 722. For example, a first inertial ring 724-1 may be located within the internal space 722 at a longitudinal well above a second inertial ring 724-2. Torsional fluid 726 may be located in the internal space 722 between the housing 714 and the inertial rings 724. In some embodiments, the torsional fluid 726 may be located between the first inertial ring 724-1 and the second inertial ring 724-2. Optionally, one or more spacers 729 may be used to separate the first and second inertial rings 724-1, 724-2. Including a plurality of inertial rings 724 in a single housing 714 simplifies the torsional damping system 712, which simplifies installation and maintenance. Of course, there may also be multiple internal spaces 722 defined by a single housing 714, and each internal space 722 may include one or more inertial rings 724.

[0092] In some embodiments, the first inertial ring 724-1 and the second inertial ring 724-2 may rotate independently relative to each other at different rotational rates or directions. The first inertial ring 724-1 and the second inertial ring 724-2 may have the same or different masses, shapes / structures, etc. For example, the first inertial ring 724-1 may be larger than the second inertial ring 724-2 or comprise a denser material. In some examples, the first inertial ring 724-1 may be smaller than the second inertial ring 724-2 or comprise a less dense material.

[0093] In some embodiments, the inertial ring 724 may include one or more grooves or channels 731 on the surfaces of the inertial rings 724-1 and 724-2. These grooves or channels may facilitate the movement of the torsional fluid 726 throughout the space between the housing 714 and the inertial ring 724, and between the first inertial ring 724-1 and the second inertial ring 724-2. Including grooves or channels on the inertial ring 724 may further facilitate heat transfer between the torsional fluid 726 and the inertial ring 724. In some embodiments, a pressure differential may exist between portions of the interior space 722. The grooves or channels 731 in the inertial ring 724 or the spacer 729 may contribute to pressure compensation throughout the interior space 722.

[0094] Figure 8-1 This is a cross-sectional view of another torsional damping system 812 according to at least one additional embodiment of the present disclosure. In the illustrated embodiment, the torsional damping system 812 includes a collar 814 and six inertial elements 824, which may optionally be configured as rings as described herein. The number of inertial elements 824 is merely illustrative and may include more or fewer than six inertial elements 824.

[0095] The torsional damping system 812 is conceptually similar to Figure 7 The torsional damping system 712, schematically illustrated, comprises multiple inertial elements 824 enclosed within a housing, but additional features and various alternatives are also shown. For example, the housing of the multiple inertial elements 824 is not constructed using a single integral element; the housing may be formed from multiple components that collectively define an internal space for torsional fluid and the inertial elements 824. In particular, in this embodiment, the internal space is radially defined between the inner surface of the inner shaft or spindle 853 and the collar 814.

[0096] Figure 8-1 The internal space shown also extends axially between the locking element 857 and the fluid-filled fixing device 861. Example locking element 857 could be a locking nut or other element that engages the spindle 853 or other parts of the housing to the collar 814. For example, locking element 857 could be engaged to the spindle 853 and load internal components (including the spindle 853 and the inertial element 824) onto the shoulder of the outer collar 814.

[0097] Optional fluid filling fixing device 861 can limit Figure 8-1 The upper end of the internal space, and can also be used to fill the internal space with torsional fluid 826 (see Figure 8-2 This can be accomplished through one or more fluid ports 879. Alternatively or additionally, one or more other ports may be used. For example, one or more ports 880 in the collar 814 may be used to help fill or remove the torsional fluid 826.

[0098] The torsional fluid 826 contained within the housing (or, in this embodiment, an internal component that, together with the collar 814, defines the housing) can be separated from other fluids in the torsional damping system 812. For example, drilling fluid may flow through a bore in the mandrel 853 for delivery to the drill bit or other downhole tools, while the torsional fluid 826 (which may optionally be different from the drilling fluid) is contained in the space surrounding the inertial element 824. One or more plugs, valves, etc., may be used in ports 879, 880 to maintain separation between the inertial fluid 826, drilling fluid, production fluid, or other fluids.

[0099] Multiple inertial elements 824 are located in an annular space between the spindle 853 and the collar 814, and are rotatable within the housing and the collar 814. Specifically, as described herein, as the collar 814 rotates and oscillates, a torsional fluid 826 (see...) surrounds the inertial elements 824. Figure 8-2A frictional shear force can be applied to the inertial element to cause the inertial element 824 to rotate. As the collar 814 undergoes various changes in its rotational speed or direction (e.g., during torsional oscillation), the inertial element 824 may rotate asynchronously with the collar 814. Since the spindle 853 is coupled to the collar 814 (e.g., via locking element 857, fluid-filled fixing device 861, or both), the spindle 853 can rotate synchronously with the collar 814.

[0100] To facilitate the rotation of the inertial element 824, one or more friction-reducing elements can be used within the internal components and housing of the torsional damping system 812. For example, in Figure 8-1 In the middle, end bearing 851-1 is axially positioned between the uppermost inertial element 824 and the fluid filling fixing device 861. Similarly, another end bearing 851-2 is axially positioned between the lowermost inertial element 824 and the locking element 857.

[0101] While a single inertial element 824 may be located within the housing, and in this embodiment between end bearings 852-1 and 851-2, multiple inertial elements 824 are included in some embodiments. In such embodiments, one or more spacer bearings 849 may optionally be axially positioned between adjacent inertial elements 824. The spacer bearings 849 may be used as thrust bearings, radial bearings, or both.

[0102] Figure 8-2 An enlarged view of an exemplary separator bearing 849 located between two inertial elements 824 is provided. As shown, the separator bearing 849 has a T-shaped cross-section, although other shapes may also be used. For example, Figure 8-1 The end bearings 851-1 and 851-2 can have an L-shaped cross-section. Figure 8-2 In the T-shaped part, the head extends axially along the inner radial surface of the adjacent inertial element 824, while the column of the T-shaped part extends radially between the collar 814 and the spindle 853, and extends along the axial ends of the adjacent inertial element 824 separated by the separator bearing 849.

[0103] In the illustrated embodiment, bushing 847 is fitted to the inner surface of each axial end of inertial element 824 and mates with the head of separator bearing 849 to reduce friction as inertial element 824 rotates relative to collar 814, spindle 852, and separator bearing 849. Bushing 847 may be press-fitted, mechanically attached, or otherwise secured to inertial element 824. Bushing 847 may be formed of any suitable material, and bushing 847 and inertial element 824 may be formed of the same or different materials. For example, if inertial element 824 is formed of steel, the bushing may be or include steel, brass, bronze, titanium, tungsten, composite materials, alloys, polymers, etc. Of course, inertial element 824 may be formed of other materials discussed herein.

[0104] The design of bushing 847 (or the inertial element 824 itself when bushing 847 is absent) and separator bearing 849 may include one or more predetermined bearing clearances. Such clearances may define a gap and may include a radial clearance 845-1 between the inner surface of bushing 857 (or the inner surface of inertial element 824) and the outer surface of the head of separator bearing 849. Additionally or alternatively, an axial clearance 845-2 may be formed between the axial end of bushing 847 (or the axial end of inertial element 824) and the radially extending surface of the head or column of separator bearing 849.

[0105] In some embodiments, the clearances 845-1 and 845-2 (collectively referred to as bearing clearance 845) may be within a range having a lower limit, an upper limit, or both, including 0.0001 inches (2.54 micrometers), 0.0005 inches (12.7 micrometers), 0.001 inches (25.4 micrometers), 0.002 inches (50.8 micrometers), 0.0025 inches (63.5 micrometers), 0.003 inches (76.2 micrometers), and 0.004 inches (1... The bearing clearance 845 can be any one of the following: 0.001.6 micrometers (127.0 micrometers), 0.006 inches (152.4 micrometers), 0.007 inches (177.8 micrometers), 0.008 inches (203.2 micrometers), 0.009 inches (228.6 micrometers), 0.010 inches (254.0 micrometers), 0.050 inches (0.13 centimeters), 0.10 inches (0.25 centimeters), 0.25 inches (0.64 centimeters), or any value in between. For example, the bearing clearance 845 can be greater than 0.0001 inches (2.54 micrometers). In another example, the bearing clearance 845 is less than 0.25 inches (0.64 centimeters). In other examples, gap 242 can be any value in the range of 0.0001 inches (2.54 micrometers) and 0.25 inches (0.64 centimeters), such as between 0.001 inches (25.4 micrometers) and 0.005 inches (127.0 micrometers), or between 0.002 inches (50.8 micrometers) and 0.010 inches (254.0 micrometers). Furthermore, although radial gap 845-1 can be the same as axial gap 845-2, they can differ in other embodiments. For example, radial gap 845-1 can be larger or smaller than axial gap 845-2.

[0106] The inertial element 824 can have a width smaller than the width of the internal space (e.g., radially measured). Figure 8-2 In this configuration, the internal space is defined between the collar 814 and the outer surface of the spacer 855, which is coupled to the outer surface of the spindle 853. As shown, the spacer 855 is mounted to the spacer bearing 849 (e.g., using a pin). This serves to restrict rotation of the spacer 855, thereby coupling the spacer 855 and the spacer bearing 849, which is also rotatably coupled to one or both of the spindle 853 or the collar 814. In other embodiments, the spacer 855 may be removed or may be integral with the spindle 853 or the spacer bearing 849, and the spindle 853 or the spacer bearing 849 may define the internal space.

[0107] The reduced width of the inertial element 824 relative to the internal space allows for the formation of various radial clearances 842-1, 842-2 on the inner and outer surfaces of the inertial element 824. Simultaneously, the length of the inertial element 824 can be less than the length of the internal space between opposing separator bearings 842 (or between separator bearings 842 and end bearings 851-1, 851-2, or between other components defining the internal space). Thus, axial clearances 842-3, 842-4 can be formed at the upper and lower ends of the inertial element 824.

[0108] Radial clearances 842-1 and 842-2 and axial clearances 842-3 and 842-4 collectively define a fluid clearance 842, which can be used to define the frequency response of the torsional damping system 812. For example, by changing the dimensions of the fluid clearance 842, the frequency response can be tailored to different vibration ranges. Furthermore, the fluid clearance 842 can provide at least four surfaces on which the torsional fluid 826 can apply frictional / shear forces to each inertial element 824 to change the rotational speed or direction of the inertial element 824. Similar to the bearing clearance 845, the fluid clearance 842 can be varied. For example, the radial clearances 842-1 and 842-2 can be equal to, less than, or greater than the axial clearances 842-3 and 842-4.

[0109] In some embodiments, different inertial elements 824 can provide different frequency responses for different vibration ranges. For example, inertial elements 824 can have different shapes, sizes, or materials, or different fluid clearances 842 or bearing clearances 845, compared to another inertial element 824 within the same torsional damping system 812—or even within the same housing. Furthermore, the fluid clearances 842 and bearing clearances 845 can not only be different, but can be different so that one or both can be varied to accommodate a customized set of frequencies or vibration ranges. Different configurations can be arranged in any suitable manner. For example, the damping stages (e.g., the inertial elements 824 and the corresponding bearing clearance and fluid clearance configurations) at one or both axial ends of the torsional damping system 812 can differ from one or each of the end stages. In other embodiments, these stages can be configured alternately. Of course, other configurations are also possible, including those described herein. Figure 3-1 and 3-2 The aforementioned approach targets the desired oscillation curve at different locations. Variations in inertial elements and bearing materials, fluid clearances, bearing clearances, and torsional fluid composition allow the torsional damping device to be adjusted for specific oscillation curves, downhole conditions, and operations.

[0110] Bearings (including spacer bearing 849 and end bearings 851-1, 851-2) may also have any number of other features or constructions. For example, Figure 8-3This is an end view of an exemplary separator bearing 849 configured to allow torsional fluid 826 to flow between different stages and optionally expel trapped air. Specifically, the separator bearing 849 includes one or more openings 881 that allow torsional fluid 826 or air to flow from a space around an inertial element 824 through the separator bearing 849 and into a space around an adjacent inertial element 824. Optionally, channels 883 in one or more axial or radial surfaces of the separator bearing 849 may also facilitate fluid flow between stages. This can facilitate filling the inner chamber, for example, using a fluid-filled retaining device 861 or a collar port 880, such that the torsional fluid 826 can flow throughout the entire inner chamber within the housing of the torsional damping system 812.

[0111] In other embodiments, each stage can be separate and independent, such that fluid is contained around one inertial element 824 and does not flow into the space around another inertial element 824. This can allow, for example, different torsional fluids 826 to be used for different stages to target different vibration frequencies.

[0112] although Figure 8-2 and 8-3 The separator bearing 849 is shown, but those skilled in the art will understand that the end bearings 851-1 and 851-2 can be constructed similarly. For example, end bearings 851-1 and 851-2 may include bearing clearances, fluid clearances, etc., to allow the inertial element 824 to rotate while providing the desired frequency response. Similarly, openings, channels, or other fluid flow pathways may be provided to allow fluid to flow within a single damper stage or between different stages.

[0113] Figure 9-1 This is a representation of a cross-sectional view of a torsional damping system 912 according to at least one additional embodiment of the present disclosure. The torsional damping system 912 includes a housing 914 having one or more housing extensions 978-1, 978-2 (collectively referred to as housing extensions 978). A torsional shaft 971 is located inside the housing 914. The torsional shaft 971 is rotatable relative to the housing 914. The torsional shaft 971 includes one or more damping members 973. The torsional damping members 973 may extend (e.g., project) from the central axis 975 of the torsional shaft 971. In the illustrated embodiment, the torsional shaft 971 includes four torsional damping members 973. However, it should be understood that the torsional shaft 971 may include more or fewer than four torsional damping members 973. For example, the torsional shaft 971 may include one, two, three, four, five, six, seven, eight, nine, ten, or more torsional damping members 973. Furthermore, the torsional members 973 may be spaced apart at equal or unequal angles around the circumference of the torsional shaft 971.

[0114] Elastic members 977-1 and 977-2 (collectively referred to as 977) extend between adjacent housing extensions 978 and torsional damping members 973. In some embodiments, a first elastic member 977-1 may extend from a first side 980-1 of the torsional damping member 973 to the first housing extension 978-1, and a second elastic member 977-2 may extend from a second side 980-2 of the damping member 973 to the second housing extension 978-2. In some embodiments, the torsional damping system 912 may include a single elastic member 977 (or a plurality of elastic members 977 coupled to one side of the damping member 973) connected to the torsional damping member 973. In some embodiments, the elastic members 977 may bias the torsional damping member 973 toward a center or other defined location between the first housing extension 978-1 and the second housing extension 978-2.

[0115] When the torsional damping system 912 undergoes torsional oscillation / vibration, the housing 914 can rotate (e.g., in the first housing direction 937). This can cause the second elastic member 977-2 to compress, while the first elastic member 977-1 expands. The compression and expansion of the elastic member 977 can cause the torsion shaft 971 to rotate in the same direction as the housing 914 (e.g., in the first housing direction 937), and can transfer at least a portion of the energy of the housing 914 to the torsion shaft 971. During the oscillation, the housing 914 can change its rotational rate and / or rotational direction. However, the torsion shaft 971 can continue to rotate in the first housing direction 937 until the opposing force on the torsional damping member 973 causes the torsion shaft 971 to stop rotating and / or rotate in the opposite direction. This movement can transfer at least a portion of the energy of the torsion shaft 971 to the housing 914. In this way, the expansion and contraction of the elastic member 977 can reduce the energy of the housing 914, thereby damping the magnitude and / or frequency of the oscillation.

[0116] In some embodiments, the elastic member 977 can be any elastic or biasing member. For example, the elastic member 977 can be made of one or more springs, such as coil springs, wave springs, leaf springs, Belville springs, etc. In some examples, the elastic member 977 can be made of elastically deformable and / or compressible materials, such as rubber, silicone, plastics, etc. In some examples, the elastic member 977 can be made of a combination of springs and elastically deformable / compressible materials.

[0117] Figure 9-2 yes Figure 9-1 A longitudinal cross-sectional view of the torsional damping system 912 along A-A'. The torsional damping system 912-1 shown includes a defined torsional cavity 982 (e.g., Figure 9-1The housing 914 is the space between the first housing extension 978-1 and the second housing extension 978-2. A torsional damping member 973-1 extends into the torsional cavity 982. An elastic member 977-1 is connected to the torsional damping member 973 along its longitudinal length. In some embodiments, the elastic member 977-1 extends along the entire longitudinal length of the torsional damping member 973-1. In some embodiments, the elastic member extends along a certain percentage of the torsional damping member 973-1. In some embodiments, the percentage of extension can be within a range having a lower limit, an upper limit, or both limits, including any one of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value between these limits. For example, the percentage of extension can be greater than 10%. In another example, the percentage of extension can be less than 100%. In yet another example, the percentage of extension can be any value between 10% and 100%. Figure 9-2 In the illustrated embodiment, the elastic member 977-1 is made of a block of elastically deformable material, such as rubber or silicone. However, the elastic member 977-1 may be made of a wave spring, leaf spring, or any other elastic or biasing member.

[0118] Figure 9-3 It is along Figure 9-1 Another longitudinal cross-sectional view of another embodiment of the torsional damping system 912-2, taken along line A-A'. In the illustrated embodiment, the torsional damping member 973-2 includes a plurality of elastic members 977-4 along the illustrated height of the torsional damping member 973-2. In the illustrated embodiment, the torsional damping member 973-2 includes three elastic members 977-4; however, it should be understood that the torsional damping member 973-2 may include more or fewer than three elastic members 977-4. For example, the torsional damping member 977-4 may include one, two, three, four, five, six, seven, eight, nine, ten or more elastic members aligned or otherwise positioned longitudinally along the torsional damping member 973-2.

[0119] In the illustrated embodiment, the torsional damping member 973-2 includes a plurality of torsional fluid paths 984. In this embodiment, the torsional fluid paths 984 include orifices or openings through which torsional fluid in the cavity 982 can pass. The torsional fluid flowing through the torsional fluid paths 984 can alter the inertia of the torsional damping member 973. For example, a greater number of torsional fluid paths 984 can reduce the rotational resistance of the torsional damping member 973. A smaller number of torsional fluid paths 984 can increase the rotational resistance of the torsional damping member 973. The torsional fluid paths 984 may include through holes or blind holes, or may include grooves or channels in the surface of the torsional shaft 971.

[0120] Figure 10-1 This is a representation of a torsional damping system 1012 according to at least one additional embodiment of the present disclosure. The torsional damping system 1012 shown includes a housing 1020 coupled to the inner surface 1016 of a collar 1014. Although the housing 1020 is shown extending along the inner surface 1016, in some embodiments, the collar 1014 itself may define the housing for the torsional damping system, as referenced herein. Figure 8-1 and 8-2 As stated above.

[0121] In some embodiments, the internal space 1022 of the housing 1020 may be partially or completely filled with granular material, such as a plurality of inertial beads 1066. When the collar 1014 or the housing 1020 rotates in a first direction, the inertial beads 1066 in the internal space 1022 may rotate in the first direction. When the collar 1014 or the housing 1020 oscillates and rotates in a second direction (or at a different rate in the first direction), some or all of the inertial beads 1066 may continue to rotate in the first direction (or at the first rate). Furthermore, the inertial beads 1066 may include movement toward the surface and downhole in response to axial vibrations in the collar 1014. In some embodiments, the inertial beads 1066 may move inconsistently (e.g., simultaneously, at the same speed). Individual inertial beads 1066 may impact, contact, collide, and push against each other. The mutual impacts and friction between the individual inertial beads 1066 can dissipate energy from torsional oscillations and axial or lateral vibrations. This energy dissipation can reduce the amplitude or frequency of the oscillation of the collar 1014.

[0122] In some embodiments, the inertial bead 1066 may be made of a metal alloy, including tungsten alloy, steel alloy, aluminum alloy, lead, any other metal, ceramic, carbide, sand (e.g., silica or quartz sand), other non-metallic materials, or combinations thereof.

[0123] In some embodiments, a gas, such as atmospheric gas, completely or partially fills the space between the inertial beads 1066. In some embodiments, a liquid, such as a torsional fluid, water, oil, drilling mud, or other fluid, completely or partially fills the space between the inertial beads 1066. The liquid may be a Newtonian fluid or a non-Newtonian fluid. In some embodiments, a liquid may partially fill the space between the inertial beads 1066, and a gas or a different liquid may fill the remaining space between the inertial beads 1066. The material used to fill the space between the inertial beads 1066 can help determine the damping effect of the inertial beads 1066. For example, a fluid (gas or liquid) with a lower density between the inertial beads 1066 may result in a larger damping effect, while a fluid with a higher density between the inertial beads 1066 may result in a smaller damping effect.

[0124] Figure 10-2 It is along Figure 10-1 The line B-B' intercepts Figure 10-1 A cross-sectional view of the torsional damping system 1012. In some embodiments, the internal space 1022 of the housing may include one or more chambers 1069. A chamber may include one or more radial or axial features, including walls or baffles 1069. Inertia beads 1066 may engage or contact the radial or axial walls, which may help to further dampen rotational oscillations and / or vibrations. In some embodiments, the walls 1069 may be longitudinal (e.g., extending in a direction parallel to the longitudinal axis). Longitudinal walls 1069 may help dampen rotational vibrations and oscillations. In some embodiments, the walls 1069 may be radial (e.g., extending radially from the central bore to the collar 1014). Radial walls 1069 may help dampen vertical vibrations and oscillations.

[0125] Figure 11 This is a flowchart depicting a method 1168 for damping torsional oscillation. Method 1168 includes coupling a first damper to a collar at 1170. As discussed herein, this may include coupling the damper to the collar. In some embodiments, this includes coupling the housing of the damper to the collar such that the housing and the collar move synchronously. The damper may be coupled to an inner or outer surface of the collar, or it may be coupled to an above-well or down-well portion of the collar.

[0126] At 1172, a second damper is optionally coupled to the collar. The second damper may be coupled in the same or different manner as the first collar. At 1174, the collar may rotate in the downhole environment. In some embodiments, rotating the collar downhole may include or cause vibration / oscillation of the collar. For example, the collar may oscillate in response to downhole drilling or production activities, such as drilling, generating electricity with a downhole motor, reaming, fracturing, lifting production fluids, or performing other downhole activities.

[0127] In response to the rotating collar, at 1176, one or more inertial elements of the first or second damper may move. The inertial elements may be located inside or outside the internal space of the housing of each damper and may move asynchronously with the collar. For example, the inertial collar may rotate at a different rate of rotation or in a different direction of rotation than the collar. Similarly, the inertial beads may rotate within the housing at a different rate of rotation or in a different direction of rotation than the oscillating collar. Moving the inertial element in response to the rotation of the collar may include rotating the inertial element based on the rotation of the collar. For example, the rotating collar may include a torsional fluid that transmits frictional / shear torque or force to the internal space of the housing. The torsional fluid may transmit at least a portion of the frictional / shear force to the inertial element, which may cause the inertial element to rotate.

[0128] The inertial element may rotate or otherwise move out of sync with the collar. This can cause the inertial element to transfer at least a portion of its energy to the collar, or the collar to transfer at least a portion of its rotational energy to the inertial element. In this way, the inertial element can reduce the amount of rotational energy of the oscillating collar, which can reduce the torsional oscillation of the collar. This can help reduce damage to downhole components caused by torsional oscillation. In some embodiments, rotating the inertial ring out of sync with the collar is a result of torsional oscillation. For example, when torsional oscillation (i.e., a change in the direction or magnitude of rotation experienced by the collar) occurs, the first and / or second dampers may not respond simultaneously with the corresponding positions on the collar, causing the inertial elements in the first and second dampers to rotate at a different speed or direction than the corresponding positions on the collar.

[0129] Therefore, method 1168 may include moving a first inertial element (e.g., a ring or granular material in the first housing of a first damper) at a first rotational rate or direction. A second inertial element (e.g., a ring or granular material in the second housing of a second damper, or a second location in the same housing) moves at a second rotational rate or direction. In some embodiments, the first rotational rate differs from the second rotational rate. In some embodiments, the first rotational direction differs from the second rotational direction. Therefore, method 1168 may include moving the first inertial element (and optionally, compared to a collar) at a different rotational rate or direction than the second inertial element. This could be due to the inertial element being placed at different locations along the length of the BHA (e.g., between the downhole motor and the drill bit), different structures of the inertial element, etc.

[0130] In some embodiments, method 1168 may further include flowing a fluid stream through a central orifice in the housing and cooling the plurality of dampers with the fluid stream. Moving the inertial element within the housing may cause the housing, the inertial element, or the torsional fluid to heat up, which could damage these components. In some embodiments, heating the torsional fluid may reduce the fluid viscosity and alter the torsional damping characteristics of the dampers. Therefore, cooling the plurality of dampers may improve the torsional damping characteristics of the plurality of dampers, or at least improve the consistency of the dampers.

[0131] Industrial applicability

[0132] Embodiments of this disclosure relate to apparatus, systems, and methods for inertial damping in downhole tools. Downhole systems may include numerous motions, vibrations, oscillations, and other movements. In some embodiments, these movements may be associated with drilling, remediation, or production activities. For example, during drilling operations, the downhole tool may rotate to degrade the formation. The engagement of the downhole tool with the formation can result in vibrations, torsional oscillations, and other movements. For the purposes of this disclosure, the terms vibration, oscillation, and other movements may be used interchangeably unless otherwise stated. If left uncontrolled, these torsional oscillations can increase wear on the downhole tool, damage the downhole tool, increase fatigue of the materials within the downhole tool, and combinations thereof. Dampers may be mounted on the downhole tool to reduce the effects of torsional oscillations. For example, a damper may reduce the amplitude and / or frequency of torsional oscillations.

[0133] In some embodiments, the characteristics and structure of the inertial damping system discussed above can be combined, altered, and / or modified to optimize the inertial damping system for a particular application. In some embodiments, altering the characteristics and / or structure of the inertial damping system can widen or narrow the range of magnitude and / or frequency of the inertial damping provided by the inertial damping system.

[0134] In some embodiments, the material used to manufacture the inertia ring can be changed to alter the magnitude and / or frequency of torsional oscillation damping. Changing the inertia ring material can include changing the density of the inertia ring, which can alter the mass of the inertia ring and thus its vibration damping characteristics.

[0135] In some embodiments, the torsional fluid can be modified to reduce the magnitude and / or frequency of torsional oscillation damping. For example, the viscosity of the torsional fluid can be changed to alter its resistance to the rotation of the inertial ring. This may change the frequency and / or magnitude of the inertial damping provided by the inertial ring. In some embodiments, the torsional fluid can be converted into a granular material, such as multiple small torsional beads discussed herein.

[0136] In some embodiments, the gap between the inner wall of the housing or collar and the inertial ring can be varied to alter the size and / or frequency of the inertial damping system. This can include increasing the gap, decreasing the gap, and variations in the gap (e.g., by modifying the texture and / or curves of the inner wall surface of the housing).

[0137] In some embodiments, the inertial damping system can allow different oscillation damping mechanisms at different oscillation positions. For example, the material and / or size of the inertial ring can vary along the length of the inertial ring, or different inertial rings within the same housing or in different dampers can have different materials and / or sizes. This can help to vary the magnitude and / or frequency bandwidth of the damped oscillation.

[0138] In some embodiments, the damper may be separable and / or segmented to have one or more inertia rings at any or every oscillation location. In some embodiments, the inertia rings may be separated within the same internal space of the housing to allow the inertia rings to rotate independently within the housing. In some embodiments, the properties of the separable and / or segmented dampers and / or inertia rings may differ. For example, the first inertia ring may be made of a first material, and the second inertia ring may be made of a second material. In another example, the first inertia damper may be used with a first type of torsional fluid, while the other inertia damper uses a different type of torsional fluid. Other variations may also be made, including fluid friction / shear clearance around the torsional ring, bearing clearance, torsional ring shape, etc. These options allow the inertial damping system to provide damping of different magnitudes and / or frequencies (or magnitude and frequency ranges) based on the oscillation curve of the downhole tool. In this way, the downhole drilling system can experience reduced oscillation and / or vibration along the length of the downhole drilling system (or its entirety). In some cases, different components may be interchangeable to facilitate tool changes on the surface to accommodate different conditions anticipated during individual operations.

[0139] In some embodiments, separating and / or segmenting the damping system and / or inertia ring can allow for different levels of stiffness in the downhole tool. For example, the downhole tool may need to bend to complete a dogleg maneuver, such as through directional drilling, using a directional drilling rig, or other dogleg mechanisms. By dividing the damper and / or inertia ring into multiple pieces, the bendability of the inertial damping system can be matched to the flexibility of the downhole drilling system.

[0140] Embodiments of the torsional oscillation system have been described primarily with reference to wellbore drilling operations; however, the torsional oscillation system described herein can be used in applications other than wellbore drilling, including wellbore production or repair. In other embodiments, the torsional oscillation system according to this disclosure can be used outside of wellbore or other downhole environments used for exploration or production of natural resources. For example, the torsional oscillation system of this disclosure can be used in boreholes for placing utility pipelines. Therefore, the terms “wellbore,” “borehole,” etc., should not be construed as limiting the tools, systems, components, or methods of this disclosure to any particular industry, field, or environment.

[0141] This document describes one or more specific embodiments of the present disclosure. These described embodiments are examples of the technology currently disclosed. Additionally, to provide a concise description of these embodiments, not all features of an actual embodiment may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, many embodiment-specific decisions will be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which may vary from embodiment to embodiment. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but remain routine tasks of design, fabrication, and manufacturing for those skilled in the art who benefit from this disclosure.

[0142] Furthermore, it should be understood that references to "one embodiment" or "an embodiment" in this disclosure are not intended to be construed as excluding the existence of additional embodiments that also incorporate the described features. For example, any element described with respect to the embodiments herein may be combined with any element of any other embodiment described herein. Numbers, percentages, ratios, or other values ​​used herein are intended to include such values, as well as other values ​​that are "about" or "approximate" to said values, as will be understood by one of ordinary skill in the art as covered by the embodiments of this disclosure. Therefore, the values ​​should be interpreted broadly enough to include values ​​that are at least sufficiently close to said values ​​to perform the desired function or achieve the desired result. The values ​​include at least the variation expected in a suitable manufacturing or production process and may include values ​​within 5%, 1%, 0.1%, or 0.01% of said values.

[0143] In view of this disclosure, those skilled in the art should recognize that equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made to the embodiments disclosed herein without departing from the spirit and scope of this disclosure. Equivalent constructions, including the functional "device plus function" clause, are intended to cover structures described herein that perform the functions described, including structural equivalents that operate in the same manner and equivalent structures that provide the same functionality. The applicant's explicit intent is not to invoke device plus function or other functional claims for any claim, except for claims that include "for…device" with the associated function. Every addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims will be included in the claims.

[0144] The terms “approximately,” “about,” and “substantially” as used herein refer to quantities that are close to the stated amount, which are within standard manufacturing or process tolerances, or that still perform the desired function or achieve the desired result. For example, the terms “about,” “approximately,” and “substantially” can refer to quantities that are less than 5%, less than 1%, less than 0.1%, and less than 0.01% of the stated amount. Furthermore, it should be understood that any direction or frame of reference in the foregoing description is only relative direction or movement. For example, any reference to “up” and “down,” or “above” or “below,” is only a description of the relative position or movement of the relevant element. As used herein, the term “axial” refers to a direction measured along an axis (e.g., the longitudinal axis of a tool), while the term “radial” refers to a direction perpendicular to that axis (e.g., extending from the longitudinal axis toward the housing, collar, etc.).

[0145] This document describes various features in alternative forms to emphasize that these features can be combined in any number of combinations. Each feature should be considered as being combinable with other features unless those features are mutually exclusive. The term "or" as used herein is not exclusive unless the opposite is clearly expressed. For example, having A or B includes A alone, B alone, or a combination of A and B. Conversely, having only A or B includes A alone or B alone, but not a combination of A or B. Even if not explicitly stated in multiple independent forms, the claims should be considered as being combinable with each of the other claims (or any combination of other claims).

[0146] The invention may be practiced in other specific forms without departing from the spirit or characteristics thereof. The described embodiments are to be considered illustrative rather than restrictive. Therefore, the scope of this disclosure is indicated by the appended claims rather than the foregoing description. Variations within the meaning and scope of equivalents of the claims will be included within their scope.

Claims

1. A downhole inertial damping system, comprising: A collar that is axially positioned between the downhole tool and the drill bit; and A damper connected to the collar, the damper comprising: A mandrel is disposed in a collar, and the mandrel and collar define an inner chamber between them; A first inertial ring is disposed in the inner chamber around a mandrel and is rotatable relative to a collar within the inner chamber. A second inertial ring is disposed in the inner chamber around a mandrel and can rotate relative to the collar within the inner chamber; A bearing element is disposed in an inner chamber around a spindle and extends between the spindle and a collar to separate a first inertial ring from a second inertial ring. A bushing disposed on a first inertia ring or a second inertia ring, the bushing being configured to contact the bearing element; and The torsional fluid is contained within an internal chamber and contacts a first inertial ring, and contacts a second inertial ring via multiple openings in the bearing element.

2. The downhole inertial damping system according to claim 1, wherein the torsional fluid comprises silicone resin.

3. The downhole inertial damping system according to claim 1, wherein the torsional fluid comprises granular material.

4. The downhole inertial damping system according to claim 1, wherein the torsional fluid comprises liquid and particulate material.

5. The downhole inertial damping system according to claim 1, wherein the torsional fluid comprises at least one of magnetorheological or electrorheological fluids.

6. The downhole inertial damping system according to claim 1, wherein the first inertial ring and the second inertial ring comprise tungsten.

7. The downhole inertial damping system according to claim 1, wherein the damper is positioned closer to the downhole tool than closer to the drill bit.

8. The downhole inertial damping system according to claim 1, wherein the central axis comprises an outer surface and an inner surface, the inner surface defining a hole.

9. The downhole inertial damping system according to claim 1, wherein the bearing element engages with the inner surface of the collar and the outer surface of the mandrel.

10. The downhole inertial damping system of claim 1, wherein the damper further comprises a spacer connected to the mandrel.

11. The downhole inertial damping system of claim 1, wherein the bearing element further includes a surface defining a plurality of channels facing one of the first inertial ring or the second inertial ring.

12. A method for damping oscillation, comprising: A downhole rotating collar is coupled to a damper and axially positioned between the downhole tool and the drill bit, the damper comprising: A mandrel disposed in a collar, the mandrel including a first surface, the first surface and the collar defining an inner chamber therebetween; A first inertial ring is disposed in the inner chamber around a mandrel and is rotatable relative to a collar within the inner chamber. A second inertial ring is disposed in the inner chamber around a mandrel and can rotate relative to the collar within the inner chamber; A bearing element is disposed in an inner chamber around a spindle and extends between the spindle and a collar to separate a first inertial ring from a second inertial ring. A bushing disposed on a first inertia ring or a second inertia ring, the bushing being configured to contact the bearing element; and A torsional fluid, contained within an internal chamber and in contact with a first inertial ring, and in contact with a second inertial ring via multiple openings in a bearing element; and In response to the rotation of the collar, the first inertial ring and the second inertial ring rotate asynchronously with the rotation of the collar.

13. The method of claim 12, further comprising: The first inertial ring rotates at a first rotational speed; and The second inertial ring is rotated at a second rotational speed, which is different from the first rotational speed.

14. The method according to claim 12 or claim 13, further comprising: Drilling fluid is allowed to flow through a central hole in the mandrel defined by a second surface of the mandrel, and the drilling fluid is separated from the inner chamber by the wall of the mandrel.

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