System and method for damping drill string vibrations

Abstract

A viscous damper includes an inertial element including an outer surface. The viscous damper also includes a chamber having an inner surface and a volume, the inertial element being located inside the chamber. The viscous damper also includes a damping fluid in a first portion of the volume, the fluid having a viscosity and a temperature. The viscous damper also includes a gap between the outer surface of the inertial element and the inner surface of the chamber, the gap being filled with the damping fluid. The viscous damper also includes a first material in a second portion of the volume, wherein the second portion of the volume decreases or increases as the temperature of the damping fluid changes.

Description

Cross-reference to related applications

[0001] This application claims priority and interest in co-pending U.S. Provisional Application Serial No. 63 / 627,535, filed January 31, 2024, the entire contents of which are incorporated herein by reference for all purposes. Background Technology 1. Technical Field

[0003] This disclosure relates to damping drill string vibrations, and more specifically to identifying an inertial loop assembly (“IRA”) that maximizes drill string damping within a specified frequency range.

[0004] 2. Description of the prior art

[0005] Drilling systems are used to excavate hydrocarbon-producing wells in underground formations. These systems typically include a drill string, a drill bit, and collars that connect the drill bit to the drill string. The drill string is usually composed of drill pipe sections connected in series by threads at their opposite ends. Typically, the drill string is rotated by a top drive or rotary table in a drilling rig located on the surface, while drilling mud circulates within the drill string to remove drill cuttings generated by rotating the drill bit in the formation. Devices such as mud motors, mud pulse generators, turbines, and imaging units are typically installed within the drill string for use during drilling.

[0006] The reaction forces generated by the rotation of the drill bit on the underground rock formation produce vibrations in the drill string, which are typically most pronounced within the drill pipe. Depending on the stress conditions and physical properties of the drill pipe and the formation, the vibration direction can be transverse, radial, torsional, or a combination thereof. Recent advances in drilling technology have increased drilling speeds (“ROP”) and weight on bit (“WOB”) through the formation, thereby increasing the amplitude of vibrational displacements in the drill pipe; and sometimes the vibrations reach levels known as high-frequency torsional oscillations (“HFTO”). HFTO is referred to as a single-torsional mode instability. HFTO is unstable if the energy entering the system through the drill bit-rock interaction is higher than the energy output through any damping / dissipation forces. For example, when drilling through hard rock formations, resonance-induced HFTO is confined to the bottom hole assembly (“BHA”) or the lower part of the drill string. Specifically, the mode shapes of HFTO are associated with mass distribution, mass density, structural or material stiffness, damping characteristics of the drill string or BHA, and the assembly. Typically, damping (also known as material damping or structural damping) will exist in the system. For example, material damping is implemented by converting mechanical energy into thermal energy through deformation of the material of the structure. For instance, when a drilling pipe deforms, material damping is caused by the damping effect of the material of the structure (such as a damping fluid). It is possible to modify material damping by replacing one material with another that has a different damping factor. Similarly, structural damping is implemented by reducing the vibration of the structure in a threaded connection by dissipating the energy of vibrations. In some implementations, if in an unstable state, the amplitude of HFTO may increase until it is limited by a dissipating force (which rebalances the forces). In the case of HFTO, this stabilizing force is achieved when the amplitude of HFTO, measured as the rotational speed fluctuation at the drill bit, equals the average rotational speed at the drill bit provided by the top drive and mud motor, etc. In this case, the harmonic fluctuations in the drill bit rotational speed caused by HFTO result in zero or very short negative values; this jump in rotational speed triggers energy dissipation and thus stabilizes HFTO at a high amplitude. This high amplitude is referred to as a plateau, meaning the amplitude is constant at a high level and changes proportionally only with changes in the average rotational speed at the drill bit. The process by which vibration increases from near-zero values ​​(e.g., due to drilling into another formation prone to HFTO, or due to the selection of another operating parameter (e.g., higher bit pressure or lower bit speed)), along with the constant amplitude defining the plateau, is collectively referred to as HFTO. These vibrations, especially when reaching HFTO levels, can cause displacement of devices attached to the drill string that separate the lower portion of the BHA below the vibration from the upper portion above it. Therefore, reducing vibrations associated with different undesirable HFTO modes is important for preventing tool damage and reducing non-productive time (NPT) in the well.

[0007] To reduce drill string vibration (including high-frequency torque-induced rotational oscillation), a damping system is installed on the drill string above the BHA (Body Harness). The damping system typically includes a counterweight surrounding a portion of the drill string, which is sometimes submerged in fluid. HFTO is generally controlled in two different ways. One approach involves avoiding instabilities in the torsional mode that lead to high vibration amplitudes. That is, reducing the WOB (Wide Bore), increasing the rotational speed, or avoiding coupling with viscous / slippage to prevent HFTO, since the energy input is less than so-called material damping. A negative impact can be a reduction in drilling speed due to operating parameter limitations. Typically, within the range of operating parameters, HFTO may not be avoidable at at least reasonable drilling speeds. In this case, an attempt is made to limit the amplitude of the HFTO (the plateau amplitude described above), which is proportional to the average drill bit rotational speed. In this case, the amplitude is limited by reducing the rotational speed, which in turn may affect the drilling speed. Therefore, increasing damping and energy output, and thus stabilizing the system over a wider range of parameters, may thus avoid or stabilize all relevant HFTO-related destructive modes, and thus achieve high drilling speeds without compromising system reliability (which could result in excessive non-productive time due to tripping or tripping or excessive repair and maintenance costs). Summary of the Invention

[0008] A drill string with one or more inertial ring assemblies (“IRAs”) is designed using an iterative method to maximize damping within the drill string. Each IRA consists of an annular housing surrounding a portion of the drill string, with a cavity located inside the housing containing the rings and fluid. The design is optimized through an iterative process that alters the properties of the fluid and the rings and adjusts the spacing between the rings and the inner wall of the housing. Novel elements are also present in this disclosure that enable the adjustment of fluid properties. The iterative process takes into account changes in fluid properties due to different downhole conditions. The final design may have multiple IRAs with different damping characteristics. Attached Figure Description

[0009] Some features and benefits of the invention have already been set forth, and other features and benefits will become clear when described in conjunction with the accompanying drawings, wherein:

[0010] Figure 1 This is a partial side cross-sectional view of an example drilling system with a drill string that has experienced high-frequency torsional oscillations (“HFTO”).

[0011] Figure 2 yes Figure 1 A side cross-sectional view of an example of a portion of a drill string with an inertial ring assembly (“IRA”).

[0012] Figure 2 a and Figure 2 b is Figure 2A side sectional view of an alternative example of an IRA.

[0013] Figure 2 c is a side sectional view of an example of an IRA.

[0014] Figures 3a to 3f are graphs showing the variation of the damping coefficient within the natural frequency range.

[0015] Figure 4 This is a partial sectional view of the side of an example drill string equipped with an IRA designed to optimize damping.

[0016] Figure 5 yes Figure 2 A perspective sectional view of an alternative example of a drill string with a compensation device.

[0017] Figures 6a and 6b are examples of... Figure 5 A graph showing the pressure and viscosity of the damping fluid in the device.

[0018] Figures 7a and 7b are... Figure 5 A perspective sectional view of a drill string with an optional compensation device.

[0019] Figures 8a to 8f and 9a to 9f are graphs of the pressure and viscosity of the damping fluid in the apparatus of Figures 7a and 7b.

[0020] Figures 10a and 10b are Figure 5 A perspective cross-sectional view of a drill string with an alternative compensation device.

[0021] While the subject matter has been described in conjunction with the embodiments disclosed herein, it should be understood that the scope of this disclosure is not limited to any particular embodiment. Rather, it is intended to cover all alternatives, modifications, and equivalents thereof. Detailed Implementation

[0022] The methods and systems of this disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate embodiments. The methods and systems of this disclosure may take many different forms and should not be construed as limited to the exemplary embodiments listed herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete, and will fully convey its scope to those skilled in the art. Similar figures throughout the specification denote similar elements. In one embodiment, the term “about” is used to include + / - 5% of the referenced value. In one embodiment, the term “substantially” includes + / - 5% of the referenced value, comparison, or description. In one embodiment, the term “approximately” includes + / - 10% of the referenced value.

[0023] It should be further understood that the scope of this disclosure is not limited to the exact details of the architecture, operation, specific materials, or embodiments shown and described, as modifications and equivalents will be clear to those skilled in the art. Exemplary embodiments have been disclosed in the drawings and specification, and although specific terminology has been used, they are used in a general and descriptive sense only, and not for limiting purposes.

[0024] Figure 1 An example of a drilling system 10, excavating into formation 12 to form a wellbore 14, is shown in a partial side cross-sectional view. The drilling system 10 includes a drill string 16 comprising a tubing string 18 formed by multiple drill pipe segments threaded together; and a bottom hole assembly (“BHA”) 20 mounted on the lower end of the tubing string 18. The BHA 20 includes a downhole tool 102. The lower end of the BHA is connected to a drill bit 22 having teeth or composite blades (not shown) for contacting and breaking the rock in formation 12. The downhole tool 102 includes imaging devices (nuclear imaging devices, electromagnetic imaging devices, acoustic imaging devices, etc.), a mud motor, a mud pulse generator, and other currently known or later developed equipment. The tubing string 18 and the downhole tool 102 have an axial bore 108 ( Figure 2 The axial hole allows drilling fluid (mud) to pass through the drill string 16 and exit the drill bit 22 through a nozzle (not shown). The drilling fluid returns to the surface through the annulus 17 and carries drill cuttings outside the wellbore. The derrick 26 on the surface provides a structure for inserting multiple drill pipe sections into the wellbore 14 to extend the tubing string 18, and also provides a structure for driving devices (not shown) such as a top drive or rotary table for rotating the drill string 16 and drill bit 22. Optionally, a controller 28 is included, which optionally receives and records signals from within the wellbore 14, and, in another embodiment, provides command signals to devices coupled to the derrick 26 and / or located within the wellbore 14. Figure 1 In the example, a curved dashed line adjacent to drill string 16 is shown, representing an oscillation or vibration of drill string 16, which, as described above, is a high-frequency torsional oscillation (HFTO). High-frequency oscillations are induced in drill string 16 by the drilling process and the process of cutting through the formation, respectively. HFTO is a torsional oscillation typically above 50 Hz.

[0025] Figure 2An example of an inertial ring assembly (“IRA”) 30 is shown in a side sectional view. The IRA is mounted in the downhole tool 102 within the wellbore assembly for damping high-frequency oscillations in the drill string 16. Downhole tools are also referred to herein as damping tools or viscous dampers. The IRA 30 includes an outer housing 32 with a toroidal configuration. A cavity 34 is formed within the housing 32, which is also toroidal in the drill string or BHA. Inertial elements 36 are located within the cavity 34 and pass through gaps. and The inertial element 36 is radially spaced from the inner and outer walls of the housing 34. It is shown as an annular ring-shaped member. The upper and lower surfaces of the inertial element 36 are respectively separated by gaps. and It is axially spaced from the upper and lower surfaces of the housing 34. Fluid 38 is located in the gap. , , and In one embodiment, the inertial element 36 includes a plurality of inertial elements 36. 1-n The multiple inertial elements 36 1-n Longitudinal axis A around BHA, drill string, or damping tool X Concentric arrangement, vertical or along longitudinal axis A X Stacking, in an alternative scheme, multiple inertial elements 36 1-n It is a ring-shaped component or composed of arc-shaped segments.

[0026] For example, the fluid 38 in IRA 30 includes a Newtonian fluid that is linear and has a damping factor. However, it does not have a stiffness factor. Stiffness is a measure of how well an object resists deformation in response to applied forces. It also includes non-Newtonian fluids, which have a damping factor. and stiffness factor Fluid 38 may optionally comprise silicone oil with different defined viscosities. Fluid 38 is also referred to as a damping fluid or a viscous fluid. In an embodiment, the material constituting the inertial element 36 has a viscosity of at least about 7500. Or a higher density (e.g., steel, bronze, iron, or copper) would increase the damping of the mass moment of inertia of the inertial element 36. The modal damping of each mode is proportional to the corresponding mass moment of inertia. In alternative solutions, materials with lower density offer the advantage of being able to tune to suitable frequencies, for example, by using the stiffness of the fluid based on Equation 1. and modal mass inertia Calculate the stiffness The frequency of the coupled IRA 30 Specifically, the frequency of IRA 30 Similar to the natural frequency of the system (which should be damped) based on Equation 2 .

[0027] (1)

[0028] (2)

[0029] in It is the stiffness factor of the IRA fluid 38. It is the moment of inertia of mass. It is the natural angular frequency of the BHA 20 without inertial elements. It is the natural frequency of the BHA 20 without inertial elements, and It is the frequency of an IRA with inertial elements.

[0030] As the gap decreases and the number of gaps increases, The clearance number can be increased. If the clearance number cannot be increased sufficiently (due to tolerances, changes in downhole clearance due to pressure, thermal expansion, etc.), using a lighter material is beneficial for maintaining the clearance number in a tuned state. One or more inertial elements 36 of the IRA 30 1-n Physically not attached to each other, in this sense, one or more inertial elements can rotate relative to each other. Alternatively, one or more inertial elements 36 in the IRA 30... 1-n They are spaced close to each other and have one or more gaps in the cavity to allow fluid 38 to pass through one or more different inertial elements 36 in the IRA30. 1-n The fluid flows between the cavities to fill the cavity 34. In this embodiment, multiple cavities 34 exist. 1-n One or more inertial elements 36 1-n Each inertial element resides in a cavity.

[0031] Use analytical formulas to calculate the inertial elements 36 of IRA 30. 1-n Each inertial element in the system (BHA 20 and drill string 16) provides damping. To this end, the properties of the HFTO-related modes of BHA 20 are calculated, typically using a numerical model such as the finite element model. For example, the finite element model is implemented to simulate the properties of the HFTO-related modes of BHA 20, such as multiple HFTO transient dynamic responses and their corresponding HFTO severity. In analytical methods, as an approximation, the modal properties of the oscillating modes of BHA 20 are not altered if BHA 20 interacts with the inertial elements. The modal properties of each key HFTO-related torsional mode include: mode shape. In one or more inertial elements 36 1-n The deflection at the axial position of a specific inertial element, and the natural frequency of the mode. And (if present) modal damping associated with the mode. Using this method, a semi-analytical or analytical model is used to calculate the damping provided by each inertial element placed at a specific location within the BHA 20. Typically, damping is related to the mass moment of inertia. It is beneficial to indicate high-density materials proportionally, and at that location according to the square of the amplitude relative to the mode shape ( The modal damping increases. Furthermore, modal damping is high near the tuning frequency, meaning it increases due to fluid stiffness. and mass moment of inertia The provided stiffness is used to calculate the tuning frequency based on Equation 3. .

[0032] (3)

[0033] From a trend perspective, the small damping factor It produces very high damping at and near the tuning frequency, but only within a narrow frequency range, and vice versa. Therefore, depending on the frequency range of the HFTO where damping is efficient, different... This is beneficial, and is largely influenced by the choice of fluid (the selection of damping fluid 38). According to the workflow, for each inertial element, the modal damping provided by the damping tool 102 at each relevant frequency is calculated, and finally, for all inertial elements 36... 1-n The modal damping is summed. If the damping tool 102 is placed near or at the drill bit (where the modal amplitudes are typically very high and provide efficient damping), an approximation of the modal properties can be used, thus eliminating the need to derive the modal properties from the numerical model. For this purpose, calculations are performed based on Equation 4. The value is used to describe the probability of HFTO mode shape occurrence. Specifically, The value is defined as the minimum slope of the torque characteristic when the system is in a critical steady state. It is assumed that for all critical HFTO modes, the correlation of the mode with respect to HFTO is... The value is constant. For a given natural angular frequency The amplitude of the mode shape at the drill bit is calculated based on Formula 5.

[0034] (4)

[0035] (5)

[0036] in It is the amplitude of the mode shape at the drill bit. It is in an inertial element or one or more inertial elements 36 1-n The amplitude of the mode shape at a specific inertial element in the system. It is the modal damping factor.

[0037] In the If the damping tool 102 uses an approximate treatment, then... and If neither of these is zero, the damping provided by the single inertial loop assembly at the drill bit can be approximated analytically or semi-analytically. Indeed, analytical or semi-analytical models assuming no modal changes have yielded very accurate solutions. For example, damping estimated using numerical solutions is more accurate for a specific BHA 20 and offers advantages, especially if the optimization of IRA 30 is done for a specific application and BHA 20 is known. In one example of optimizing the damping of BHA 20, IRA 30 is coupled to BHA 20, and the natural frequency of this IRA is the same as or substantially equal to the natural frequency of BHA 20. Furthermore, in this example, the design of IRA 30 is optimized, resulting in a natural frequency of IRA 30 that is closer to the natural frequency of BHA 20 than that achieved using existing methods.

[0038] In one example of the numerical solution, the numerical model of BHA 20 is coupled with the dynamic model of IRA 30, which includes a damped fluid 38 and one or more inertial elements 36. 1-n Each of the one or more inertial elements in the IRA 30 has a corresponding mass moment of inertia and a moment of inertia along axis A in the IRA 30. X The corresponding axial position. The dynamic model consists of... , and This indicates that, at the frequency of the HFTO mode, the amplitude of the specific mode shape at a point in the inertial loop assembly of BHA 20 is derived, and for specific temperatures and pressures, the following is also presented: and As discussed, specific temperatures and pressures can alter the properties of the inertial ring components. Examples of numerical models for the BHA 20 include finite element models (e.g., using beam elements), or models calculated or derived from discrete element models or transfer matrix models. This is achieved by using one or more inertial elements 36 of the IRA 30. 1-n of , and The mass matrix, damping matrix, and stiffness matrix are coupled to the numerical model of BHA 20. The numerical model of BHA 20 is then coupled with... , and The dynamic model is combined. Modal analysis is performed on the combined model to calculate modal damping from such models. One of the results is the modal damping associated with the mode and the natural frequency of the mode. This will have... , and The IRA implementation in the BHA 20 numerical model alters the natural frequencies, mode shape amplitudes, and mode-related modal damping. Furthermore, it is used for... and The value depends on the natural frequency and mode shape amplitude of placing the IRA 30 on the BHA 20. Therefore, for each natural frequency of the BHA 20 (which, for example, according to...), The criteria are crucial, necessitating the adoption of this method. Furthermore, due to the value and and This depends on the natural frequency and mode shape amplitude, thus requiring an iterative method. For example, at specific temperatures, pressures, and mode shape amplitudes derived from laboratory tests at the natural frequency of the currently considered mode, iterative methods are needed to obtain... and The value. If the IRA gap is changed, this can be used by: utilizing the gap number that takes into account the viscous shear effect in the gap. and Scaling can be performed; or an alternative, more suitable model can be used that takes into account changes in the size of the gap (gap width). Coupled with... and Inserting inertial elements into the numerical model will change the natural frequencies and mode shapes of the modes. Mode shapes are used to scale the amplitudes along BHA 20, for example, assuming a certain rotations per minute (RPM) fluctuation or angular acceleration at the drill bit, and then calculating the mode shape amplitudes at different locations in BHA 20 by the ratio of the mode shape amplitude at the drill bit to the mode shape amplitudes at the locations of one or more inertial elements of the IRA. If the natural frequencies of the modes are changed by adding inertial loop components or damping tools 102, then... and The values ​​will change because they are typically frequency-dependent (the values ​​change when the natural frequency of the BHA 20 changes) and amplitude-dependent (the values ​​change if the mode shape changes). An iterative method will be used, in which (e.g., using the Nelder Mead method) the values ​​will be changed. and The properties until derived and The assumed natural frequency and amplitude are matched with the natural frequency of BHA 20, wherein the inertial loop assembly of damping tool 102 is mounted on BHA 20, and wherein... and It is exactly at this natural frequency. According to the convergent solution of the iterative method, the modal damping is a very accurate solution without any approximations. Additionally, the temperature change of the viscous fluid (fluid 38) caused by energy dissipation in the viscous fluid can also be added as an additional parameter. The fluid temperature is different from the operating temperature and will depend on the modal damping and mode shape amplitude along BHA 20. In this sense, if parameters (such as...) and The modal damping is derived for each mode (including frequency), temperature, modal amplitude, and pressure, depending on the mode (including frequency), temperature, modal amplitude, and pressure. An alternative to the method described above for solving the problem in the frequency domain is to solve it in the time domain, where these parameters are applied to the BHA 20 model and IRA, and then the modal amplitudes varying with frequency are captured by a defined excitation. The ratio of modal amplitudes over a specific frequency range (e.g., using a half-power method) is used to calculate or approximate the damping of the achieved HFTO.

[0039] Effective damping is derived from the damping curves of a specific mode that depend on the mode shape amplitude: Modal damping of a mode will generally depend on the mode shape amplitude. Therefore, energy output is dependent on the mode shape amplitude, meaning that, for example, for higher mode shape amplitudes, the modal damping coefficient will be lower or higher compared to constant modal damping for each mode shape amplitude. For example, for 2000 rad / sec at the drill bit. 2 The angular acceleration can achieve a very high value of 4% damping; however, for 2500 rad / sec... 2 The angular acceleration can be damped by 3%. Maximum modal damping or a safety factor based on the natural frequency can be used (analytical method). One approach is to use a range of modal amplitudes (e.g., for 1500 rad / sec). 2 The interval, which can be, for example, 500 rad / sec 2 Up to 2000 rad / sec 2 The damping value provided by a specific bandwidth. The lowest modal amplitude (e.g., 500 rad / sec) can be utilized. 2 ) and the maximum permissible modal amplitude (e.g., 8000 rad / sec) 2The modal amplitude range is specified using the modal mode amplitude range. Within this range, the range is defined as the maximum modal damping present within the specified modal amplitude range of the mode. The modal amplitude range is chosen to prevent the modal amplitude from "jumping" beyond the effective modal amplitude damping range into a higher modal amplitude region with lower damping. Such events can occur, for example, if an impact directs the mode to a higher modal amplitude, or if viscous / slippage (defined here as low-frequency motion throughout the BHA) is present and superimposed on the HFTO. The permissible amplitude range encompassing this range must be larger than the range itself and should be limited to the lossless modal amplitude range, for example, by scaling the modal amplitude components in the BHA 20 using modal modes, which are susceptible to the loads associated with the HFTO (which are acceleration and dynamic torsional torque).

[0040] Objective Function: The objective function defines the optimal effect of the optimized inertial loop component or damping tool 102. The properties of the inertial loop component will be modified to achieve the best result with respect to the objective function. Due to the complexity of the problem, this optimization of the objective function is accomplished using numerical optimization. Different mathematical methods exist for this purpose. For example, the NelderMead method can be used to minimize the objective function, or the same method can be used to maximize it. The objective function can also be compared to the damping to be achieved. A simple example of an objective function is:

[0041] (6)

[0042] In this paper, for a specific natural frequency, and within a specific range of temperature, pressure, and mode shape amplitudes, the minimum effective modal damping is calculated for all possible variations of these parameters. Regarding the mode shape amplitudes, the effective damping can be calculated as indicated above. The minimum damping can now be achieved within the defined frequency range. Maximize, i.e., take the maximum The objective function may include weighting functions, such as those indicating that damping should be higher at a specific frequency. For example, information about how much damping should be provided at a specific frequency or mode of BHA 20 can be extracted from downhole data used in conjunction with the model to identify which modes are sensitive to HFTO to identify the excited modes. The objective function may also require that the sum of damping over the frequency range be as high as possible, or it may combine this criterion with maximizing minimum damping over a specific frequency range. Furthermore, the so-called Sc value is a stability index that directly correlates modal properties with the damping added by the damping tool 102 to the interaction between the drill bit and the formation that excites HFTO, thus assuming a velocity-dependent characteristic of drilling torque. Similar weighting values ​​are derived to specify the objective function; these similar weighting values ​​are combinations of the achieved damping and the modal properties of the considered modes. The objective function can be maximized or minimized by changing the sign of the function by using 1 / objective function or by using a constant offset (which does not qualitatively change the outcome of the method).

[0043] In a non-limiting example of optimizing the damping of BHA 20, the damping is estimated from tests using a test apparatus (not shown) with a mechanical vibrator. and The value. Similar to the outer casing 32 ( Figure 2 A chassis with attached inertial elements 36 is mounted on a vibrator. The vibrator then vibrates the chassis and inertial elements with a certain force and frequency to generate harmonic motion of the chassis. The attached inertial elements move relative to the chassis due to the fluid transmitting the chassis motion to the inertial elements; based on the relative motion, the mass moment of inertia is measured based on the inertial elements or derived from a CAD model. Value derivation and The value of . This can be done for multiple parameter variations (e.g., different temperatures, different frequencies, different amplitudes), thereby obtaining the configuration and clearance of a specific damping fluid 38 and inertial element to generate . and A lookup table is used to determine the gaps between the inner walls of the housing (chassis) that house the inertial elements. If a temperature change is found to be relevant, the temperature change caused by the energy dissipation of the damping fluid 38 through the viscous fluid can be considered. Alternatively, a model of the damping fluid can be derived... and Such as force models; derived from simulations of force models. and The force model can also be used (e.g., using time-domain simulations, where the inertial elements are coupled to the finite element model (or similar model) of BHA 20 via a force model of the damping fluid) to directly estimate the damping in the numerical model of BHA 20. Effective modal damping can be derived from the simulation results. Or, to indicate effective modal damping Similar values ​​(such as dissipated energy). Therefore, for multiple operating parameters in a predetermined downhole design, there are multiple fluid properties of the damping fluid. For example, the force model of the damping fluid is determined by calculating the inertial / cavity interaction of multiple operating parameters in a predetermined downhole design. Therefore, the force model of the damping fluid is implemented by measuring the values ​​of multiple operating parameters in a predetermined downhole design. The values ​​are scaled to determine multiple damping fluid parameters. Similarly, the force model of the damping fluid is implemented by measuring multiple operating parameters in a predetermined downhole design. The values ​​are scaled to determine multiple damping fluid parameters. value.

[0044] The following relationships illustrate the influence and The values ​​of variables and how to derive the values ​​present in the application from laboratory test results.

[0045] (7)

[0046] (8)

[0047] (9)

[0048] in:

[0049] T: Temperature

[0050] P: Pressure

[0051] Number of gaps in the laboratory

[0052] Thermal expansion

[0053] Rotational stiffness factor in the laboratory

[0054] Rotational damping factor in the laboratory

[0055] Moment of inertia

[0056] Number of gaps S pIt is a geometric factor and mathematically represents the shear stress generated in the damping fluid 38 for a given motion (rotation) of the inertial element. The number of gaps is calculated based on the geometry of the inertial ring assembly.

[0057] (10)

[0058] In Formula 10, , , and Is it like this? Figure 2 The gap (gap dimension) shown, r o The outer radius r of the inertial element 36 is measured from axis Ax. i This is the inner radius of the inertial element 36, measured from axis Ax. The clearance can be adjusted. , , and One or more gaps or the inner radius r of the inertial element i or outer radius r o The clearance number is adjusted by the dimensions of the damping tool 102. Although the clearance number is determined by geometric parameters, it depends on the temperature and pressure applied to the damping tool 102 and present in the wellbore 14. The geometric dimensions of the inertial element 36 (such as the inner radius and outer radius (r)) are also considered. i r o ) and gaps , , and The dimensions of the inertial element (the size of the inertial ring assembly) depend on temperature and pressure, and vary due to thermal expansion / contraction, causing variations in the inner and outer radii of the inertial element and the dimensions of the gaps. In the laboratory, the number of gaps is determined for a given configuration (test setup) of the inertial ring assembly (inertial element geometry, housing, gap dimensions, material properties). More than one inertial element may exist in the inertial assembly. For each inertial element, the number of gaps is determined in the laboratory. The number of gaps is determined for each of the gaps in the inertial element. Alternatively, a number of gaps is determined for each inertial element in the housing of the inertial ring assembly, representing all gaps existing between the inertial element and the housing, such as... , , and The gap dimensions from the laboratory can be used to determine...

[0059] In some implementations, due to thermal expansion or deformation of the drilling system caused by pressure, several fluid properties of the damping fluid are temperature and pressure dependent. Therefore, a force model is used to determine several fluid properties of the damping fluid to estimate downhole conditions based on Equations 11 and 12. In this paper, the gap number S...p Used for different operation parameters and The measured values ​​are scaled. A combined model is determined using multiple fluid properties of the damping fluid by combining the numerical model of BHA 20 and the dynamic model of inertia. Based on the combined model, modal analysis is used to determine multiple optimal parameters of the IRA 30 to dampen the vibrations of BHA 20 associated with multiple HFTO-related modes by iteratively performing multiple iterations until predetermined criteria are met.

[0060] (11)

[0061] (12)

[0062] in:

[0063] T: Temperature

[0064] P: Pressure

[0065] f: Frequency

[0066] A: Amplitude

[0067] Geometric test setup (L: length, D: diameter of inertial element, etc.)

[0068] Material property testing setup ( Thermal expansion, E: Young's modulus, etc.

[0069] Number of gaps in the laboratory

[0070] The number of gaps in the potential downhole implementation.

[0071] Underground

[0072] Rotational stiffness factor for potential downhole implementation

[0073] : Potential downhole rotational damping factor

[0074] In some implementations, multiple HFTO frequencies are determined for multiple HFTO-related modes of the BHA 20 based on a predetermined Sc criterion. In one example of the numerical method, a first vector is derived from a first dynamical model of the BHA 20 without inertial elements, in which the natural frequency is... Assume a new mode shape, which has a mode shape amplitude at the inertial element. In modal damping, a second dynamic model (e.g., an FEM model) of the BHA20 with inertial elements is executed. A second vector is derived from the second dynamic model of the BHA20 with inertial elements. In one example, modal damping is calculated for the second dynamic model of the BHA20 with inertial elements to identify the optimal mode by solving the optimization problem using a pre-determined optimizer criterion based on the Modal Confidence Criterion (MAC), frequencies, and Sc values. Alternatively, relevant modes are identified using the mode closest to the mode from the previous iteration, based on the MAC criterion, the closest frequencies, and Sc values. The MAC is calculated as a normalized scalar product of the first and second vectors. The MAC is optionally used in modal analysis to indicate the similarity between the two mode shapes. In the optimal solution, the optimal mode of the second dynamic model of the BHA20 with inertial elements is derived to match the natural frequencies of the BHA20.

[0075] In this modal analysis combined model, for multiple HFTO-related modes of BHA 20, the first multiple modal properties of the first dynamic model of BHA 20 without inertial elements are estimated. For example, the first multiple modal properties of the first dynamic model of BHA 20 without inertial elements include: the mode shape amplitude, natural frequency, and modal damping coefficient of the BHA 20 without inertial elements based on multiple operating parameters in a predetermined downhole design. Similarly, for multiple HFTO-related modes of BHA 20, the second multiple modal properties of the second dynamic model of BHA 20 with inertial elements are estimated. For example, the second multiple modal properties of the second dynamic model of BHA 20 with inertial elements include: the corresponding mode shape amplitude, corresponding natural frequency, and corresponding modal damping coefficient of each of one or more inertial elements based on multiple operating parameters in a predetermined downhole design.

[0076] Natural frequency

[0077] New mode shape Amplitude at inertial component

[0078] Dissipated energy, temperature difference with downhole temperature

[0079] The objective function is determined based on multiple HFTO frequencies, first multiple modal properties, and second multiple modal properties to achieve the maximum amount of drill string or BHA damping. Specifically, the convergence of the objective function is evaluated based on Equation 13. For example, by combining the natural frequencies of the combined model with measured... and The convergence of the objective function is evaluated by comparing the natural frequencies at the given values. Therefore, inertial elements are identified from one or more inertial elements in IRA 30 by solving the objective function based on pre-determined optimizer criteria. Specifically, inertial elements are identified from one or more inertial elements in IRA by selecting the mode shape of the inertial element that is closest to the mode shape from the previous iteration based on the modal confidence criterion (MAC), and whose frequencies and natural frequencies are... The value is also the closest.

[0080] (13)

[0081] in It is the natural frequency of BHA with an inertia number i+1, and It is the natural frequency of the inertial element i of BHA.

[0082] The new frequency derived from the combined model by adding an inertial element i+1. With the evaluation and frequency A match is found. If convergence exists according to the objective function and optimizer criteria, an inertial element is identified, and this inertial element has the optimal parameters (e.g., ring size, ring material, gap value) for the inertial element used in this iteration. , , and (Fluid properties, number of inertial elements, etc.). If convergence has not yet occurred, another iteration is performed using different inertial element parameters, which are selected by comparing the results of the objective function of multiple instances i of BHA 20 with inertial elements. Thus, a damping system for the IRA for BHA is formed by using multiple optimal parameters of the optimized inertial elements. The damping system of the IRA is installed in the drill string or BHA to penetrate the formation while reducing HFTO in BHA 20.

[0083] In this numerical method, the combined model is constructed based on the optimization problem of Equation 14 to use modal analysis to estimate the modal damping associated with the second dynamic model of the BHA 20 with inertial elements. Natural frequency and mode shape vector The natural frequencies are derived from modal analysis (the standard method). It is possible to reduce the number of degrees of freedom to improve efficiency through reduction methods (such as component modal synthesis).

[0084] (14)

[0085] (15)

[0086] (16)

[0087] (17)

[0088] , ... (18)

[0089] , ... (19)

[0090] in:

[0091] x: A vector containing degrees of freedom for the BHA and inertial components.

[0092] M: Mass matrix

[0093] C: Damping matrix, which consists of degrees of freedom belonging to both the BHA and the inertial elements (these two are coupled together).

[0094] K: Stiffness matrix, which consists of degrees of freedom belonging to the BHA and inertial elements (these two are coupled).

[0095] In some implementations, an iterative process is used to solve the optimization problem. In the initial steps of the iterative process (“Iterative Process”) used to identify the optimal IRA30 design to maximize the damping of the drill string and BHA 20, properties are assigned (or assumed) to the IRA to account for different HFTO frequencies to be damped. Examples of properties assigned include the number of gaps. The material properties, cavity geometry, coefficient of thermal expansion, number of IRAs, and the geometry of each IRA are considered. Different HFTO frequencies are identified through modal analysis (numerical model), where these modes are ranked according to their criticality based on the Sc value under the condition of additional damping in an undamped tool. These HFTO frequencies can also be constrained to a frequency range (…). to ), such as the expected range of operations. In one example, the HFTO frequency is the intrinsic frequency that is critical to the stimulus, which is estimated by, for example, the Sc criterion, and is different from the intrinsic frequency of the analytical model. In a non-restrictive example, it is assumed that there exists to The frequencies within the HFTO frequency range are assumed to be constant values ​​of Sc, or Sc values ​​are frequency-dependent. Under this assumption, the amplitude of the mode shape at the drill bit is calculated using a formula for Sc; Sc is a missing variable from the analytical formula for modal damping derived for each HFTO frequency. There are implementations where one application has three critical frequencies (e.g., one at 50 Hz, one at 200 Hz, and one at 310 Hz); and another application has a different number of critical frequencies, and these frequencies are at different values ​​(e.g., 150 Hz and 170 Hz). The HFTO frequencies in the drill string are typically between 50 Hz and 500 Hz.

[0096] In another step of the iterative process, at different tuning frequencies Considering different HFTO frequencies for the inertial element. Each of Figures 3a to 3f is illustrated graphically with curves 40, 42, 44, 46, and 48. Figure 3FA graph 50 is shown representing the sum of the damping coefficients of the inertial elements shown in Figures 3a to 3e. Each graph 40, 42, 44, 46, 48, and 50 includes a series of curves 52a-h, 54a-h, 56a-h, 58a-h, 60a-h, and 62a-h, which represent the variation of the damping coefficient (vertical axis) over the natural frequency range. Graphs 40, 42, 44, 46, 48, and 50 each have an abscissa representing the frequency (64, 68, 72, 76, 80, and 84) and a ordinate representing the damping coefficient (66, 70, 74, 78, 82, and 86). Figures 3a to 3e involve one of five different inertial elements, and each of the curves 52a-h, 54a-h, 56a-h, 58a-h, and 60a-h in each figure represents the change of the damping coefficient with frequency at a specific temperature. In this example, these curves have different properties. Furthermore, in this example, the five different inertial elements have different characteristics. In the curves of Figures 3a to 3f, the temperature increases from the top curve to the bottom curve. In each of Figures 3a to 3e, the top curve (with the largest damping coefficient value) represents the characteristics of IRA 30 at 80°C, and the bottom curve (with the smallest damping coefficient value) represents the characteristics of IRA 30 at 150°C, with a 10°C difference between adjacent curves. For the purposes of this discussion, the damping coefficient of the HFTO mode is considered as a target value. It should be noted that each frequency has a modal damping coefficient for a specific HFTO frequency. In this example, the maximum modal damping of inertial element 1 shown in Figure 3a is approximately 210 Hz, the maximum modal damping of IRA 30 shown in Figure 3b is 250 Hz, and the maximum modal damping of IRA 30 shown in Figure 3c is 340 Hz. If IRA 30 has a tuning frequency close to the HFTO frequency... At high frequencies, the damping factor will be high. Above the tuning frequency and especially below the tuning frequency, the damping factor will be low. In one example, for the defined frequency range ( to All HFTO frequencies in the IRA 30 are used, and the five inertial elements are each tuned to a different frequency within that range to cover the entire range. In this example, This is not hypothetical, as it depends on the specific fluid used in the IRA. In one example of the optimization process, the variables listed above are adjusted so that the damping of each inertial element in the inertial element is above a certain level within the HFTO frequency range considered in the design of the IRA and BHA 20. Figure 3f shows the sum of the curves shown in Figures 3a to 3e, which illustrates the total damping of the five combined inertial elements in the IRA represented by Figures 3a to 3e.

[0097] In an alternative step of the iterative process, different HFTO frequencies are correlated with the different damping properties of each inertial element ( / J) should be considered together. The lower the value, The greater the frequency influence, the more the system behaves like a fluid damper with Newtonian fluid characteristics (where...). In this alternative solution, by letting f HFTO = / 2π Configure settings to lock the HFTO frequency.

[0098] In another step of the iterative process, the optimal number of inertial elements is selected such that damping across the frequency range is optimized relative to the objective function. For example, the optimal number of inertial elements is determined by maximizing the minimum damping across the frequency range. In some implementations, the optimal damping amount is not necessarily the amount that produces the highest amplitude within a specific frequency range; rather, it is the amount that maintains damping within the expected spectrum of the operating frequency. For example, the optimal number of inertial elements is achieved when, for instance, given a limited installation space, considering all frequencies, and where adding more inertial elements would not increase damping. In an alternative, it is assumed that the design space is constant, and the number of inertial elements varies within that design space, i.e., the additional inertial elements have smaller dimensions. In examples with multiple inertial elements, additional components are included to separate adjacent inertial elements, which consume the mass moment of inertia of the inertial elements (a lower mass moment of inertia means a lower damping coefficient, and the two are linearly dependent). The example best case considers a trade-off between allocating a frequency range for each HFTO frequency and avoiding design space being consumed by elements that do not contribute to damping.

[0099] In another step of the iterative process, the properties of the IRA 30 and its included inertial elements are assigned based on the laboratory test properties of the damping fluid being tested. Alternatively, the properties of the inertial elements are adjusted or scaled according to the properties corresponding to the fluid conditions (such as temperature and / or pressure) at the time of testing to conform to the expected conditions for use in the wellbore. The properties of the inertial elements are assigned in such a way that the temperature range and the different effects of fluid properties (such as fluid viscosity, which varies with temperature) are considered based on the desired downhole temperature. and (This has an impact). Low viscosity typically results in a correspondingly narrower frequency range for HFTO and smaller gaps, which may close due to the material's response to temperature and / or pressure, as their size and manufacturing tolerances allow.

[0100] Optionally, during the iteration process, due to the modal amplitude at the downhole side of the drill bit ( IRA 30 is positioned near the drill bit. In one example, "near the drill bit" means at a distance from the drill bit where the modal amplitude is not significantly lower than that at the drill bit. The modal amplitude is not significantly lower than the modal amplitude. Examples are approximately 90% of the amplitude at the drill bit, approximately 95% of the amplitude at the drill bit, approximately 99% of the amplitude at the drill bit, and all values ​​in the range between approximately 90% and approximately 99% of the amplitude at the drill bit.

[0101] Now for reference Figure 2 a and Figure 2 Figure b shows alternative examples of IRAs 30a, 30b, which are configured to compensate for changes in the properties of fluid 38 when the fluid is exposed to conditions in the wellbore 14. In the alternative, compensation affects changes in the number of gaps during operation (such as due to thermal expansion of inertial elements and surrounding components). Fluid properties and some damping properties are temperature-dependent. Options also exist for compensating for changes in fluid 38, such as active or passive cooling (via mud) to maintain the temperature optimal for achieving optimal damping. Since fluid 38 is also pressure-dependent, this disclosure considers pressure compensation for fluid 38, which in this example allows for a smaller housing 32. In a non-limiting example, by making the gaps ( , , and To compensate for the temperature dependence of fluid 38 (including fluid properties) as it changes with temperature. and Fluid properties () , It is also affected by the gap size (through the varying shear stress distribution in fluid 38). Higher temperatures correspond to lower viscosity in fluid 38 and and The reduced value is not optimal within the expected operating temperature range. As disclosed in this article, reducing the gap ( , , and One or more gaps in the ) will increase , The value of is used to compensate for the decrease in viscosity of fluid 38 due to increased downhole temperature. In the implementation scheme, the gap ( , , and It remains present throughout the entire expected operating temperature range to prevent inertial elements from wedging inside their housing. Reduced clearance ( , , and Examples of the dimensions of one or more gaps in the well include an inertial element with a specified size and a specific coefficient of thermal expansion, such that when the ambient temperature rises during operation and because the temperature in wellbore 14A increases with increasing wellbore depth, the volume of the inertial element expands by a certain amount, thereby reducing the gap. , , and The value of one or more gaps in ); such that even if the viscosity of fluid 38 decreases due to increased temperature, , The obtained values ​​will also remain the same or substantially the same. Figure 2 In one embodiment of IRA 30a, the inertial element includes a regulating element made of a material that can be consumed with temperature. Figure 2A The example shown is a pair of adjusting elements 36Ai, 36Ao radially spaced apart from each other in an inertial element. Adjusting elements 36Ai, 36Ao are part of the inertial element 36 and are made of a different material than the rest of the inertial element. If the temperature in the IRA is rising, the adjusting elements 36Ai, 36Ao will expand. As the adjusting elements expand, the inertial element increases in size, and therefore the gap... , , and These gaps will decrease, and they are caused by G. xu 36Ao, G xu 36Ai, G ro 36Ao, G xL 36Ao, G xL 36Ai and G ri 36Ai is indicated. The regulating element may be made of a material that expands with increasing temperature (such as, for example, SMA, bimetallic, plastic, polyethylene, aluminum). An inertial coupling 90 connecting the regulating elements 36Ai and 36Ao is shown. For example, the coefficients of thermal expansion of the regulating elements 36Ai and 36Ao are selected such that one or more of the gaps Gro36Ao and Gri36Ao decrease at elevated temperatures to compensate for any temperature-induced changes in the properties of the fluid 38. Figure 2A An embodiment for adjusting the gap in an IRA comprising a single inertial element is shown. In an alternative embodiment with more inertial elements, inertial element 36... 1-n Each includes 36 connecting elements. 1-n AI and 36 1-n Ao and connecting inertial element 90 1-n .

[0102] exist Figure 2 In the alternative shown in b, IRA 30b includes an inertial element 36b located within its housing. The wall 92b of housing 32b comprises more than one layer of material, wherein these layers have different coefficients of thermal expansion. The material layers may include rubber, plastic, composite materials, or metal. Figure 2 As shown in b, when the ambient temperature rises (such as when installed in a wellbore), one or more of these layers expand by a certain amount, causing the initial gap GAxu1 to decrease by the difference ΔGAxu, becoming the reduced gap GAxu2. Adjustment is achieved by reducing the initial gap GAxu1 to the reduced gap GAxu2. , The value of is used to compensate for any decrease in viscosity of fluid 38 due to increased temperature. Optionally, wall 92b is made of a single material having a coefficient of thermal expansion that compensates for the decrease in viscosity of fluid 38 due to increased temperature. The foregoing discussion of thermal expansion is not limited to... Figure 2 The upper axial wall shown in b, and in an alternative embodiment, one or more of an inner radial wall, an outer radial wall, and a lower axial wall.

[0103] In another alternative, one or more switches (not shown) are installed, which gradually decrease the gap ( , , and One or more gaps in the fluid 38 are used to compensate for any changes in viscosity. The switch is a mechanical component that is force-driven by a spring or fluid. For example, by using a suitable material (such as rubber), the spring force can increase with thermal expansion, or the resistance to the force can decrease with temperature. If the switching mechanism is activated, the surrounding gap gradually decreases to suit the effect of temperature on the fluid. Optional materials include materials with a shape that is highly temperature-dependent, such as, but not limited to, shape memory alloys (“SMA”) or bimetals. Devices with SMA can activate a force that changes the gap geometry based on temperature.

[0104] exist Figure 2C In the alternative shown, the gap between the inertial element 36 and the housing 210 is adjusted by the adjusting mechanism 206. Wall 109 represents a barrier to the borehole 108 of the drill string. The inertial element 36 defines the gap between itself and the surrounding housing 210. , , and At least one wall 200 of the housing 210 is movable, and the position of the wall 200 is adjustable by an adjustment mechanism 206. The adjustment mechanism 206 includes an activation device 204, which is controllable by a controller (not shown). The controller can control the activation device 204 based on temperature and pressure changes encountered within the wellbore 14. The activation device 204 moves a rod 202 connected to the movable wall 200. As the temperature increases, the activation device 204 reduces the clearance. The controller controls the rod 202 in a manner that adjusts the gap number by compensating for the decrease in viscosity of the damping fluid 38 due to increased temperature. When the temperature decreases, the controller activates the device to increase the gap. This allows for adjustment of the gap number by compensating for the increased viscosity of the damping fluid 38 due to the decrease in temperature. Figure 2C Bearings 208 and 212 are also shown, which support the inertial element 36 within the housing 210 and allow the inertial element 36 to rotate smoothly relative to the housing 210. The controller can automatically control the activation device 204 without manual intervention, or it can control the activation device 204 based on control information transmitted from the surface location to the controller in the wellbore via telemetry means such as mud pulse telemetry or wired drill pipe. The activation device can be an electrically driven or hydraulically driven activation device. In an alternative embodiment, the activation device can be controlled by a material that expands with increasing temperature or contracts with decreasing temperature (e.g., SMA, bimetallic, plastic, polyethylene, aluminum). In this embodiment, the activation device is not connected to the controller and does not receive control messages. Typical clearance dimensions in damping tools range from 0.1 mm to 0.6 mm, which includes the gap between the bearing surfaces in the bearings of the inertial elements (208, 212). The clearance dimensions can vary due to thermal expansion or contraction of the housing material and the inertial element material. The clearance number S is as defined in Formula 10. p, lab The stiffness factor K of the damping fluid 38 in the gap of the inertial ring assembly d and damping factor C d (Equations 11 and 12) are scaled linearly, which can be used to determine the optimized number of gaps S under downhole conditions (downhole temperature, downhole pressure, and desired frequency of HFTO). p, dh Change the number of downhole gaps S in formulas 11 and 12. p, dh And using the number of gaps S determined in the laboratory. p, lab To calculate the stiffness factor and damping factor, use the determined stiffness factor and damping factor to calculate the damping coefficient. Then change the clearance number S again. p, dhThe updated stiffness factor and damping factor are then determined. The updated stiffness factor and damping factor are used to determine the updated damping coefficient. This process is repeated until the optimized damping coefficient for the desired frequency range of HFTO is determined. The number of gaps S belonging to the optimized damping coefficient is... p, dh This is used to adjust one or more gaps between the inertial element and the housing. This optimization process is performed on each inertial element in the inertial ring assembly. The number of gaps determined in the laboratory provides a method for scaling the stiffness factor K for different gap geometries under downhole conditions. d and damping factor C d This is a method. That is, the number of gaps in a laboratory gap configuration allows for the derivation (or scaling) of stiffness factors, damping factors, and damping coefficients for different gap configurations (such as downhole gap configurations). One or more gaps in an inertial ring assembly can be optimized using the number of gaps. The optimization of the gaps can then be achieved through one implementation of the scheme described herein.

[0105] Now for reference Figure 4 An example of a drilling system 10A with a drill string 16A is shown in a partial side sectional view. The drill string consists of a tubing string 18A and a BHA 20A located at the lower end of the drill string. Optionally, it may include... Figure 1 Similar auxiliary equipment (not shown) is included. One or more downhole tools are installed in the BHA 20A. One downhole tool is a damping tool 102 or a viscous damper. The damping tool 102 includes one or more inertial elements 120. 1-n The one or more inertial elements are designed and manufactured according to this disclosure in this example. One or more inertial elements 120 1-n Each inertial element 1 in the BHA 20A. In an alternative embodiment, a single inertial element 120 is mounted in the BHA 20A. In this example, as described above regarding... Figure 1 As described, the drill string 16A is rotated to form the wellbore 14A. Figure 4 The example illustrates that the damping tool 102 provides a certain amount of damping to the drill string 16A, thereby mitigating the formation of HFTO (high-frequency osmosis) in the drill string 16A due to the rock formation 12A. Figure 1 This can be used to offset or dampen the HFTO, thereby avoiding the undesirable effects of HFTO in the drill string.

[0106] Figure 5 The example is a perspective sectional view of drilling tool 102, which is a wellbore 14A used for underground excavation. Figure 4 Drill string 16A and BHA 20A ( ) Figure 4Part of the drilling tool 102. The drilling tool 102 is also referred to as a downhole damping tool. The downhole tool is also referred to herein as a damping tool. Tool 102 has a body 106 and an axially extending bore 108A through the body 106. Drilling fluid or mud 110 flows through the axial bore 108A to the BHA 20A (which is installed). Figure 4 The drill bit, and through the drill string 16A and the wellbore 14A ( Figure 4 The annular space between the walls of 17A ( Figure 4 The drilling tool 102 is transferred back to the ground outside the drill string 16A. The annulus 17A between the drilling tool and the wellbore wall (…) Figure 4 The downhole pressure P in ) 环空 180. Pressure P in axial hole 108A 孔 The influence of 188 and downhole temperature T. In the example shown, the damping fluid 112 is located inside a chamber 114 formed within the body 106. The chamber 114 has a volume V. 腔室 The chamber 114 may be formed annularly around the axial bore 108A. An inner wall 116 is defined between the chamber 114 and the axial bore 108A, and an outer wall 118 is defined between the chamber 114 and the outer surface 119 of the drilling tool 102, and the wellbore 14A. Figure 4 ) Circum-17A ( Figure 4 Between the inertial ring 120 and the chamber 114. An inertial ring 120 is also disposed in the chamber 114 and immersed in fluid 112; in the example shown, there is a pair of rings 120, alternative embodiments include a single inertial ring or three or more inertial rings. The inertial rings 120 are axially spaced from each other, radially spaced from sidewalls 116 and 118, and immersed in damping fluid 112. A gap 124 is shown in the axial space between the inertial ring 120 and the stator 122. An annular gap 125 is shown in the annular space between the inertial ring 120 and the outer sidewall 118 and between the inertial ring 120 and the inner sidewall 116. In the example shown, depending on the viscosity of the damping fluid 112, the inertial ring 120 is capable of circumferential rotation around axis A. XThe inertial ring 120 is rotatable and movable relative to the body 106. An annular stator 122 extends radially inward from the outer wall 118 into the chamber 114 and extends between the inertial rings 120. The combination of the inertial rings 120, stator 122, axial clearance 124, annular clearance 125, and damping fluid 112 is optionally referred to herein as an inertial ring assembly 126. Axial clearances exist on both sides of the individual inertial ring 120. One clearance is located on the upper side of the individual inertial ring 120, and a second axial clearance is located on the lower side of the individual inertial ring 120. Each inertial ring is supported by at least one axial bearing and one radial bearing (not shown). The radial bearing is preferably located between the inertial ring 120 and the inner wall 116. The annular clearance between the inertial ring 120 and the inner wall is provided by the gap between the support surfaces. In one embodiment, the radial bearing may be located between the inertial ring and the outer wall 118. The inertial ring is supported by two axial bearings. One axial bearing is located between the inertia ring 120 and the stator 122 on the inertia ring well, and another axial bearing is located between the inertia ring 120 and the stator 122 below the inertia ring well.

[0107] Furthermore, an example of damping fluid 112 is silicone oil, which has a defined density (density value) and viscosity (viscosity value) under surface conditions. Both properties change if temperature and pressure are applied to damping fluid 112. Deviations in viscosity and density from target values ​​negatively impact the damping properties of the inertia ring assembly 126 because the shear rate values ​​of the fluid in the annular and axial gaps depend on the viscosity value of the silicone oil. Inertia ring 120 is coupled to body 106 when the viscosity of damping fluid 112 exceeds the target value by a certain amount, causing the shear force generated by the movement of inertia ring 120 within damping fluid 112 in gap 124 to exceed the torque applied by the rotation of drill string 16A. Conversely, when the viscosity is below the target value, the thickness of damping fluid 112 in gap 124 lacks sufficient cohesion or friction to transmit torque from drilling tool body 106 to inertia ring 120. During drilling operations, the downhole temperature T applied to drilling tool 102... 环空 182 and downhole pressure P 环空 180 typically increases with depth and frequently affects the pressure in chamber 114. The pressure level or value in chamber 114 depends on the downhole temperature T applied to the drilling tool 102. 环空 182, T 孔 190 and pressure P 环空 180, P 孔 The values ​​of 188, the stiffness of the materials constituting the inner wall 116 and the outer wall 118, the difference in thermal volume expansion between the damping fluid 112 and the materials of the inner wall 116 and the outer wall 118 of the drilling tool 102, and the compressibility of the damping fluid 112 are all considered. The viscosity and density values ​​of the damping fluid 112 also depend on the internal pressure P in the chamber 114. 腔室184 and temperature T 腔室 186. Therefore, during drilling operations, the viscosity and density values ​​of fluid 112 will deviate from target values; this, in turn, affects the damping of the inertia ring assembly 126 and the drilling tool 102. For example, the damping fluid 112 has a sufficiently high viscosity to ensure proper damping, but not so viscous that the inertia member 120 can still move relative to the drilling tool body 106. Typically, increased temperature causes a decrease in the viscosity value of the damping fluid, while increased pressure causes an increase in the viscosity value of the damping fluid; although these changes differ in magnitude. Therefore, it is necessary to maintain the viscosity of the damping fluid within the operating range for efficient operation of the damping tool 102 (efficient damping of HFTO). For the purposes of this discussion, the operating range of the viscosity value of the damping fluid 112 describes the viscosity range of the damping fluid 112 within which the inertia ring assembly 126 damps high-frequency torsional oscillations (HFTO) in the drill string during drilling. The operating range of viscosity is determined by laboratory experiments and / or mathematical simulations.

[0108] Although the temperature-dependent viscosity change of the damping fluid 112 is related to the internal pressure P in chamber 114 腔室 Regardless of the specific properties, the internal pressure and the associated viscosity change depend on several properties of the damping fluid 112 and the stiffness of the inner wall 116 and the outer wall 118. The following effects influence the internal pressure in chamber 114: the compressibility of the damping fluid 112 (its effect is greater for high-viscosity oils), and the resulting pressure-induced volume reduction of the chamber depends on the applied pressure P. 环空 178. P 孔 188 itself. In an example where the coefficients of thermal expansion of the body 106 and the damping fluid 112 are different, there is a difference in volume expansion due to temperature rise; this difference affects the pressure inside the chamber 114. In an alternative embodiment where the damping fluid 112 is viscous (such as a highly viscous oil), the thermal volume expansion of the body 106, made of steel, is relatively small, which results in a pressure P inside the chamber 114. 腔室 184 increased. The main body 106 is supported by well shaft 14A ( Figure 4 The pressure P in ) 环空 178. P 孔 188. Pressure P in axial hole 108A 孔 The pressure P inside chamber 188 and chamber 114 腔室 The stress generated by the difference between 184 and 118 will cause corresponding deformation of sidewalls 116 and 118, and the direction of deformation depends on which of these pressures is greater. The pressure P in the chamber caused by the resulting volume contraction or expansion of chamber 114... 腔室 The change in 184 depends on the stiffness of the materials used in sidewalls 116 and 118. (Annular P) 环空The pressure in 178 is primarily defined by the wellbore depth and is referred to as downhole pressure in this paper. The temperature in the annulus is mainly determined by the rock layer 12A (…). Figure 4 The temperature limit for this is based on depth and is referred to as downhole temperature in this paper.

[0109] As described in more detail below, drilling tool 102 has fluid viscosity maintenance or fluid viscosity regulation features that maintain or regulate the viscosity of damping fluid 112 within these values, ensuring sufficient damping for the operation of inertia ring assembly 126 within the expected pressure and temperature range inside the wellbore. An example of such features includes sidewalls 116 and 118 with sufficient mechanical integrity to prevent deformation under desired downhole conditions from causing the viscosity of fluid 112 to exceed its operating range (i.e., pressure-induced deformation). Examples of sidewalls 116 and 118 with sufficient mechanical integrity include those that resist pressure-induced deformation due to their radial thickness and / or being made of a specific material. Another example of fluid viscosity maintenance features includes compensating for pressure increases within chamber 114 in response to tool 102 exposure to downhole conditions (increased temperature and pressure compared to surface conditions). Examples of pressure compensation include the volume V of chamber 114. 腔室 One or more parts of the device have a substance that is compressible differently from fluid 112 (e.g., a gas, an elastic component, or a medium that is more compressible than fluid 112). This can be used to regulate the level of internal pressure by adjusting the viscosity level (viscosity value) of the oil (damping fluid) in chamber 114 to a target value range (the operating range of the viscosity of the inertia ring assembly). In this example, chamber 128 is shown located within chamber 112, which includes gas 130 or its volume V. 128 Other substances that change in response to pressure changes. Further optionally, a cavity 132 having substance 134 is included, the volume of which changes in response to temperature changes. Cavity 132 has a volume V. 132 Cavity 128 occupies a chamber volume V. 腔室 Part 1 V 128 Cavity 132 occupies a chamber volume V. 腔室 Part 2 V 132 The volume V of the chamber 腔室 Part 3 V 流体The chamber 114 is occupied by a damping fluid. Material 134 can be a solid or liquid material. Examples of material 134 include: paraffin wax, which has a large coefficient of thermal expansion compared to the high-viscosity oil (damping fluid 112) in chamber 114; and materials with highly nonlinear thermal volume expansion, causing a phase change (e.g., from solid to liquid, or vice versa) over the applicable temperature range. Those skilled in the art can identify materials and volumes suitable for the intended operating conditions in the borehole. Optionally, an accumulator (not shown) is located inside chamber 114, filled with air (or other gas) and initially preloaded by a specified pressure (e.g., multiples of 100 bar). In one embodiment, gas 130 in chamber 128 and material 134 in chamber 132 are in contact with damping fluid 112. That is, there are no barriers confining gas 130 in chamber 128 or material 134 in chamber 132. Gases can move freely within chamber 114 or damping fluid 112. The same applies to material 14. The gas can dissolve in a damped fluid volume V. 流体 In an alternative embodiment, a barrier may be present between the damping fluid 112 and the gas 130 and / or between the damping fluid 112 and the material 134. The barrier separates the gas 130 or material 134 from the damping fluid 112. The barrier is a flexible barrier (such as a bellows). The bellows may be made of rubber, elastomer, or metal. The barrier allows the gas and material to compress or expand. The volume of the gas, the volume of the material, and the volume of the fluid define the volume of the chamber.

[0110] Referring now to Figure 6a, curve 136 is shown, which has an abscissa representing the downhole temperature value, a ordinate representing the downhole pressure value, and an origin O where the abscissa and ordinate intersect. Line 138 on curve 136 1-8 This indicates the corresponding downhole pressure P. 环空 and temperature T 环空 Below, the fluid 112 in chamber 114 is at a constant pressure contour line 138. 1-8 Each line in the diagram represents a prediction job scenario for a different implementation of tool 102 as described above. For simplicity, line 138... 1-8 Only the range of downhole temperature and pressure is shown; this range is referred to as the operating range and is illustrated by ellipse 140 in the dashed outline. This indicates pressures greater than and less than those corresponding to line 138. 1-8 The pressure line (not shown) is substantially parallel to line 138. 1-8 Extending this line, the line representing higher pressure is farther from the origin O, while the line representing lower pressure is closer to the origin O. Similarly, in Figure 6b, curve 142 includes contour lines 144. 1-8 The contour lines represent the fluid 112 in chamber 114 at different downhole pressures P.环空 and temperature T 环空 The constant viscosity is as shown in Figure 6a, line 144. 1-8 Located within the working domain inside ellipse 140. Line 144 1-8 Each line represents the target viscosity used for the operation. Lines for higher viscosities (not shown) typically have a similar viscosity to line 144. 1-8 The same profile, but with a correspondingly larger downhole pressure.

[0111] In Figures 6a and 6b, based on the following conditions, according to the wellbore pressure P 环空 and wellbore temperature T 环空 To generate contour lines 1381 and 1441: The damping fluid 112 in chamber 114 is a high-viscosity silicone oil, and the inner wall 116 and outer wall 118 are rigid, causing the inner and outer walls to undergo minimal deformation under the expected downhole pressure. Here, the increase in internal pressure is primarily driven by the volume expansion caused by the temperature of the damping fluid 112 within chamber 114. Contour lines 1382 and 1442 illustrate a scenario where the stiffness of the sidewalls 116 and 118 is relatively low, resulting in increased internal pressure and making deformation more dependent on downhole pressure. Temperature dependence is reduced because the deformation of the sidewalls 116 and 118 partially compensates for the temperature-induced volume expansion. Lines 1381 (high stiffness) and 1382 (medium stiffness), representing internal pressure, are more horizontally oriented in the medium stiffness region compared to the high stiffness region. A similar effect is observed for viscosity, as illustrated in 1441 (high stiffness) and 1442 (medium stiffness). Within the operating domain (the temperature and pressure range encountered inside the wellbore (operating conditions)), the viscosity levels of the sidewalls 116 and 118 with moderate stiffness exhibit less dependence on temperature (curve 1442). For the operating domain shown, the viscosity range (viscosity change) caused by temperature changes at moderate stiffness is smaller than that at high stiffness. Typically, the viscosity range is adjusted according to the shape of the operating domain by adjusting the stiffness of the sidewalls 116 and 118. Lines 1383 and 1443 represent a scenario where the compartment (cavity) 128 contains a gas (e.g., air), the fluid 112 in the chamber 114 is a high-viscosity silicone oil for HFTO damping, and the sidewalls 116 and 118 have moderate stiffness. Alternatively, the compartment 128 comprises a separate volume region, and optionally, the gas is dissolved within the fluid 112 inside the chamber 114. That is, the gas 130 is not only located in the cavity 128 but also distributed throughout the volume V of the chamber 114. 腔室 In the middle. Based on the ratio of the volume of chamber 114 to the volume of compartment 128, the internal pressure level in chamber 114 (illustrated by lines 1383 and 1443) is adjusted by changing the following: filled with damping fluid V. 流体 The volume of the chamber (V) 腔室), the volume (V) of the chamber filled with gas 130 128 ), the volume (V) of the chamber filled with material 134 132 ). Increasing the volume V of gas by 130 (or compartment 128) 128 In this case, the pressure level in chamber 114 shifts to a lower value within the operating range. That is, as the pressure and temperature in the wellbore increase, the pressure change in the chamber is small. This also leads to a shift in the viscosity level, which also shifts to a lower value within the operating range. That is, as the pressure and temperature in the wellbore increase, the viscosity change is small. For example, if the viscosity level is too high due to an increase in pressure introduced by the moderate stiffness of the sidewalls 116, 118, this method is used to adjust the viscosity level. Optionally, the viscosity range deviating from the target level is adjusted, and the target viscosity level itself shifts more towards the center of the operating range. However, the viscosity still has a temperature dependence, which leads to excessively high viscosity at low temperatures and high pressures, and excessively low viscosity at high temperatures and low temperatures. The temperature rise in the chamber due to the temperature rise in the borehole causes the temperature of the damping fluid 112 to rise. Therefore, the viscosity of the damping fluid decreases, resulting in improper operation of the inertia ring assembly 126 (or damping tool 102). Using a material with reduced stiffness for the sidewalls of chamber 114, compared to standard downhole equipment material (steel), will cause the sidewalls to deform under increased pressure in the wellbore, resulting in a reduction in the volume of chamber 114. This will lead to increased pressure in chamber 114, thereby increasing the viscosity of the damping fluid, at least partially compensating for the viscosity decrease caused by increased temperature. Material 134 exhibits a volume increase due to increased temperature, leading to a similar effect. The volume V of material 134 132 The increased volume will lead to increased pressure and viscosity in chamber 114, thus at least partially compensating for the viscosity decrease in response to temperature rise. While increased temperature inside the wellbore may result in excessively low viscosity of the damping fluid, increased pressure in the chamber due to increased pressure in the wellbore may result in excessively high viscosity, which could also cause the inertia ring assembly to drift out of its operating range. The volume V of gas in chamber 128 or dissolved in the compressible damping fluid 112 (such as air) 128 It can compensate for the increase in pressure in chamber 114, thereby maintaining the viscosity of the damping fluid within the target viscosity range (operating range).

[0112] Referring again to Figures 6a and 6b, lines 1385 and 1445 represent a scenario where compartment 128 contains gas, and lines 1386 and 1446 illustrate a scenario where compartment 128 contains gas and compartment 132 contains material 134, wherein material 134 has a coefficient of thermal expansion (or coefficient function) much larger than that of the damping fluid 112 in chamber 114. Furthermore, in this example, the compressibility of material 134 is within the range of the compressibility of the damping fluid 112 in chamber 114. Material 134 in this example may optionally be paraffin wax. If the temperature increases, the thermal volume expansion of compartment 132 filled with material 134 will increase the pressure in chamber 114. Thus, the temperature-dependent viscosity loss of fluid 112 in chamber 114 is compensated by the pressure increase depicted by 1446. In this example, the internal pressure remains within acceptable ranges at low and moderate downhole pressures, meaning that the pressure-induced viscosity increase is within the same range as the viscosity increase at higher temperatures. Thus, the viscosity is adjusted to a value that is approximately linear or changes little with respect to pressure and temperature changes encountered in the operating region. Compared to the behavior without viscosity adjustment characteristics (volume of material 134, volume of gas 130), the smaller viscosity variation within the operating region enables the inertial ring assembly 126 to operate efficiently.

[0113] For oil-immersed HFTO downhole drilling tools (damped tools), the viscosity-dependent damping properties become more uniform (with less variation) in the operating domain under the following conditions: the options discussed above for tool 102 (such as, but not limited to, the stiffness of the sidewalls 116, 118, the characteristics of the damping fluid 112, the characteristics of the gas 130, and the volumes of the compartments 128, 132 (gas volume V)). 128 And the volume V of material 134 134 The properties of material 134 are balanced, and the viscosity is controlled as indicated by line 1446. The properties of material 134 are determined by compressibility, coefficient of thermal expansion, and the presence of a phase change at the temperatures encountered in the wellbore (operating area). The properties of gas 130 are determined by compressibility and coefficient of thermal expansion. In one example, the internal pressure and viscosity in chamber 114 are influenced by compartment 132 or volume V. 132The influence of material 134, which exhibits nonlinear thermal volume expansion due to phase change in the temperature range encountered by the downhole tool 102 within the wellbore and during drilling. In one example, the damping fluid 112 is silicone oil, and material 134 is paraffin wax with a phase change from solid to liquid, in one embodiment with a phase change temperature range up to about 100°C. Examples of paraffin wax undergo large thermal volume expansion at the phase change temperature (~100°C), which can optionally increase the internal pressure in chamber 114 at the phase change temperature to maintain the viscosity value at a target value or shift the viscosity toward a target value. Examples of this response are illustrated by lines 1387 and 1388. As depicted by lines 1447 and 1448, the viscosity also undergoes an increase. In an alternative embodiment, combining material 134 as paraffin wax (or one or more substances with similar properties) with damping fluid 112 as a gas, further linearization of the viscosity level in the working domain is achieved. Typically, the characteristic of rapid thermal volume expansion due to phase transition is also used to rapidly increase or maintain a defined viscosity level at a given temperature. This is particularly applicable if the viscosity is acceptable at higher temperatures but too low at lower temperatures (e.g., line 1442).

[0114] Typically, increased internal pressure also leads to increased viscosity, and excessive viscosity increase can adversely affect the damping capability of a viscous damping tool. Figures 7a and 7b show, in perspective cross-sectional views, an operational example of an alternative embodiment of a damping tool 102A configured to limit increases in internal pressure, thereby maintaining the viscosity of the damping fluid 112 within a specified range. Tool 102A includes a wall or barrier 146 located in the rear portion of tool 102A and away from the inertia ring 120. Wall 146 is an annular member having an outer diameter (which conforms to the inner surface of sidewall 118) and projecting radially inward into chamber 114 such that the inner diameter of the wall is radially spaced outward from sidewall 116 to define a gap 148 between inner sidewall 116 and wall 146. In an alternative embodiment, wall 146 projects radially outward from inner sidewall 116. Gap 148 is then defined between outer sidewall 118 and wall 146. Membrane 150 extends along the rear radial surface of wall 146, across gap 148, and axially along inner sidewall 116. Opposite ends of membrane 150 are sealingly attached to the inner surface 121 of sidewall 118 and the rear wall 152 at one end of chamber 114 to define space 154 in the rear end of chamber 114. In the example shown, gas 156 is trapped in space 154 (volume V) by membrane 150 and walls 118, 152. 154In the process of entrapment, gas 156 (e.g., air) is pre-compressed to a specified level, as shown, which is equal to or greater than the pressure of fluid 112. The gas pressure may be at room temperature and atmospheric pressure between 1 bar and 200 bar. The surface of membrane 150 opposite to gas 156 is in direct communication with damping fluid 112 in chamber 114 via gap 148. The combination of membrane 150 and entrapped gas 156 defines accumulator 158, which compensates for pressure changes within chamber 114. The dimensions of wall 146 are optionally designed to prevent membrane 150 from being squeezed into chamber 112 due to pressure difference between space 154 and chamber 114, particularly at lower pressures of damping fluid 112 present at ground level and when damping tool 102A is assembled. In a non-limiting example of the operation, Figure 7b illustrates that the pressure in chamber 114 (such as due to exposure to conditions in the wellbore as described above (the operating area)) increases to a level higher than that depicted in Figure 7a and exceeds the pressure in space 154, thereby creating a pressure differential across membrane 150. This pressure differential causes damping fluid 112 to flow through gap 148, thereby deforming membrane 150 (as shown in Figure 7b), which in turn compresses gas 156 and reduces the volume V of space 154. 154 Those skilled in the art are capable of designing an accumulator 158 that compensates for pressure increases in the fluid 112, keeping the fluid viscosity within a target range and allowing for continued damping of the inertia ring assembly 126. In an embodiment, the accumulator or volume V... 154 It can be located anywhere in the chamber 114, and the wall 146 can take any form, as long as it supports the membrane 150.

[0115] Figures 8a to 8f graphically illustrate the effects of the embodiments of Figures 7a and 7b combined with the embodiments represented by graphs 136 (Figure 6a) and 142 (Figure 6b) (cavities 132 and 128 filled with material 134 and gas 130). In this example, levels p3 and p4 (Figure 8a) shift towards higher temperatures in Figure 8b, while p1 or p2 remains unchanged. This results in viscosity levels v3 and v4 (Figure 8d) shifting towards higher pressure levels, as shown in Figure 8e. Within the operating range, viscosity increases above v2 are limited, and the viscosity remains close to the target viscosity within this range. This is shown in Figure 8f and provides advantages during drilling operations with a wide range of temperatures and pressures. Optionally, the initial pressure level in space 154 can be adjusted to adapt the viscosity level of fluid 112 to the defined operating range. Figures 9a through 9f provide curves illustrating the pressure and viscosity of fluid 112 in damping tool 102A at initial pressures of 200 bar, 280 bar, and 350 bar in space 154. As shown in Figure 9a, the initial pressure of accumulator 158 is below p2, therefore the pressure above p2 in chamber 114 activates accumulator 158 to compensate for fluid expansion in chamber 114 throughout the working domain. Figure 9b shows that the target viscosity is not in the center of the working domain. In an alternative embodiment, the initial pressure level in space 154 is increased to approximately p3; this compensates for the viscosity reduction of damping fluid 112 at higher temperatures. In this example, a wide range covered by the target viscosity exists within the working domain. In embodiments where the working domain shifts towards lower downhole pressures due to different operating conditions, the viscosity level can be easily adjusted by increasing the initial pressure (space 154) to approximately p4, as shown in Figure 9e. In an alternative, the initial pressure is regulated outside the wellbore, such as in a surface maintenance workshop, or via additional devices located in drilling tool 102A (e.g., a pressure pump (not shown) that pumps gas from a second pressure vessel into space 156, and an adjustable pressure relief valve (not shown) for reducing pressure in space 154). This device is operated above ground and via a downlink, or controlled by a control unit in drilling tool 102, which is sensor-driven (e.g., a temperature sensor and / or a pressure sensor that measures pressure in space 154 or the borehole). The downlink is transmitted using downhole telemetry techniques such as mud pulse telemetry, electromagnetic telemetry, acoustic telemetry, or telemetry via wired connections.

[0116] Figure 10a shows a perspective cross-sectional view of another alternative tool 102B, which includes an accumulator 158B made of a membrane 150B having an end attached to the rear wall 152B of the chamber 112. In this example, the opposite ends of the membrane 150B are attached to the rearward-facing surface of the wall 146B, and a rupture disc 160B is disposed in a gap 148B between the wall 146B and the sidewall 116. A first space 1541B is defined between the membrane 150B and the sidewall 116, and a second space 1542B is defined between the membrane 150B, the rear surface of the wall 146B, the sidewall 118, and the rear wall 152B. Gas 156B is located in the first space 1541B, and a substance, which may have the same or different properties and conditions as gas 156B, is located in the second space 1542B. In a non-limiting example, the fracture disk 160B ruptures under a specified pressure difference between chamber 112 and the first space 1541B, causing fluid 112 to flow into the first space 1541B through gap 148B, thereby compensating for the pressure increase within chamber 112, as described above. The fracture disk ruptures under a pressure significantly greater than 1 bar (e.g., between 50 and 100 bar), such that the fracture disk at the surface will not rupture during the assembly of the damping tool 102B. When the fracture disk ruptures, gas will move freely within the volume of the chamber. The material in the second space 1542B is either solid or fluid. In one embodiment, the material 1542B comprises phase changes within the temperature range encountered by the downhole tool 102B in the wellbore and during drilling. The material 1542B may be paraffin.

[0117] An optional accumulator 162 is shown in the example of tool 102B in Figures 10a and 10b. Accumulator 162 includes a housing 164, within which a cylinder 166 is located. As shown, fluid 168 (such as gas) and a spring 170 are located inside the cylinder 166. A piston 172 is located in a portion of the cylinder 166 and has an outer periphery that seals against the inner surface of the cylinder 166. The larger diameter end of piston 172 contacts an end of spring 170 opposite the bottom or closed end of cylinder 166. The smaller diameter end of piston 172 protrudes from the larger diameter end in a direction away from spring 170 and through an opening in housing 164. A diaphragm 174 (e.g., a rubber diaphragm) spans the smaller diameter end of piston 172 and the opening in housing 164 and serves as a barrier to prevent fluid communication between fluid 168 in cylinder 166 and damping fluid 112 in the space outside cylinder 166. Return to Reference Figure 10AThe diagram shows a pair of accumulators 162 mounted inside chamber 114 and submerged in fluid 112. In one example, accumulators 162 operate in a manner similar to accumulators 158 (Figures 7a and 7b), i.e., piston 172 is pushed into cylinder 166 when the pressure of damping fluid 112 is at a level required to compress gas 168 and overcome the force required to compress spring 170. Options available through the use of accumulators 162 include placing one or more rubber elements (e.g., O-rings (not shown)) on the larger or smaller diameter portion of piston 172 to regulate the force (due to the pressure exerted by fluid 112 on the corresponding surface area of ​​the larger or smaller diameter portion of piston 172). Another option is to adjust the spring constant of spring 170.

[0118] Therefore, the invention described herein is well-suited to achieving these objectives and realizing the mentioned objectives and advantages, as well as other objectives and advantages inherent therein. While only currently preferred embodiments of the invention are given for purposes of disclosure, many variations exist in the details of the procedures for achieving the desired results. For example, there are embodiments in which the inertial loop assembly 30 and the inertial loop assembly 126 are the same or substantially the same. There are embodiments of a downhole tool 102 having the optimized inertial loop assembly (or multiple assemblies) 30, 126 as described herein, and also having... Figure 5 The compensation device is illustrated in Figures 7a, 7b, 10, and 10b. These and other similar modifications will be apparent to those skilled in the art and are intended to be covered within the spirit of the invention disclosed herein and the scope of the appended claims.

Claims

1. A viscous damper, the viscous damper comprising: An inertial element, the inertial element including an outer surface; A chamber, the chamber including an inner surface and a volume, wherein the inertial element is located inside the chamber; The damping fluid in the first portion of the volume, the fluid having viscosity and temperature; The gap between the outer surface of the inertial element and the inner surface of the chamber is filled with the damping fluid; The first material in the second part of the volume, wherein the second part of the volume decreases or increases with the change of the temperature of the damping fluid.

2. The viscous damper of claim 1, wherein the second portion of the volume decreases with increasing temperature, and the pressure in the chamber decreases with increasing temperature.

3. The viscous damper according to claim 1, wherein the first material comprises a gas.

4. The viscous damper according to claim 3, wherein the gas comprises air.

5. The viscous damper of claim 1, wherein the first material is in contact with the damping fluid and is free to move within the chamber.

6. The viscous damper according to claim 1, wherein: The first material is a solid or a fluid, and The first material is different from the damping fluid.

7. The viscous damper of claim 1, further comprising a second material different from the damping fluid and different from the first material, the second material being located in a third portion of the volume of the chamber.

8. The viscous damper of claim 7, wherein the second material is either a solid or a fluid.

9. The viscous damper of claim 8, wherein the second material comprises paraffin wax.

10. The viscous damper of claim 8, wherein the second material comprises a phase transition at the intended operating temperature of the viscous damper.

11. The viscous damper of claim 1, wherein the second portion of the volume is separated from the first portion of the volume by a flexible barrier.

12. The viscous damper of claim 1, wherein the second portion of the volume is separated from the first portion of the volume by a rupture disc.

13. The viscous damper of claim 1, wherein the chamber includes a sidewall, and the sidewall is formed of a material having a stiffness value less than that of steel.

14. A method for manufacturing a viscous damper, the method comprising: A receiving inertial element, the inertial element having an outer surface; The inertial element is placed inside a cavity, the cavity including an inner surface and a volume; A damping fluid, having viscosity and temperature, is contained in a first portion of the volume. The damping fluid is used to fill the gap between the outer surface of the inertial element and the inner surface of the chamber; A first material is filled into a second portion of the volume, wherein the second portion of the volume decreases or increases with changes in the temperature of the damping fluid.

15. The method of claim 14, wherein the second portion of the volume decreases as the temperature increases, and the pressure in the chamber decreases as the temperature increases.

16. The method of claim 14, wherein the first material comprises a gas.

17. The method of claim 14, wherein the first material is in contact with the damping fluid and is free to move within the chamber.

18. The method of claim 14, wherein: The first material is a solid or a fluid, and The first material is different from the damping fluid.

19. The method of claim 14, further comprising: A second material, different from the damping fluid and different from the first material, is filled into a third portion of the volume of the chamber.

20. The method of claim 20, wherein the second material is either a solid or a fluid.

Images