Detection of high-frequency torsional oscillation by an electric machine.

Description

1 / 27 Detection of high-frequency torsional oscillation by an electric machine. CROSS-REFERENCE TO RELATED DEPOSIT REQUESTS

[0001] This application claims the benefit of a filing date prior to U.S. Patent Application Serial No. 63 / 494,333, filed April 5, 2023, and U.S. Patent Application Serial No. 18 / 627,115, filed April 4, 2024, disclosures of which are incorporated herein by reference in their entirety. BACKGROUND

[0002] In the resource recovery industry, a drill string is transported to the bottom of a well to drill a well. For drilling purposes, the drill string includes a drill bit attached to a bottom hole assembly (BHA), connected to a drill pipe that extends to a surface location. During downhole operations, high-frequency torsional oscillations (HFTOs) of the drill string can occur. The shape, frequency, and amplitude of the HFTOs (mode shape) depend primarily on the type of drill bit design, the hardness of the rock formation, and the drilling parameters applied during the drilling operation. Also relevant are the rotational frequency of the drill string, the mass distribution within the drill string, and the torsional stiffness of the drill string.An optional conventional vibration sensor (including magnetometers and accelerometers) is often placed near the drill bit to detect HFTOs. If the conventional vibration sensor is located at a torsional vibration mode node, the sensor emits only a small signal or no signal at all. However, HFTOs can still propagate upwards from the drill bit through the BHA, causing a significant presence of HFTOs at other points along the BHA. Consequently, there is a... Petition 870250086684, dated 09 / 25 / 2025, page 44 / 178 2 / 27 desire for a reliable system and method to detect HFTOs in the BHA during a drilling operation using existing technologies. SUMMARY

[0003] A method for detecting a drill string vibration in a well is disclosed in the present invention. The method includes transporting the drill string to the well, the drill string including an electric machine, the electric machine including a stator and a moving element, the moving element being movable relative to the stator, rotating the drill string in the well, determining, through a control circuit, a first amplitude of the drill string vibration by measuring a signal indicative of a movement of the moving element in the electric machine due to the rotation of the drill string and controlling, through the control circuit, a downhole operation of the drill string based on the first detected amplitude of the vibration.

[0004] Also disclosed in this document is a system for detecting vibration of a drill string in a well. The system includes an electrical machine in the drill string. The electrical machine includes an electromagnet, a stator, and a moving element that is movable relative to the stator and a control circuit. The control circuit is configured to control a magnetic field of the electromagnet, measure a signal indicative of a relative movement of the moving element with respect to the stator due to the vibration of the drill string, determine a first amplitude of the drill string vibration using the measured signal, and control a downhole operation of the drill string based on the first detected amplitude of the drill string vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The following descriptions should not be considered limiting in any respect. With reference to the attached drawings, similar elements are numbered similarly: Petition 870250086684, dated 09 / 25 / 2025, page 45 / 178 3 / 27

[0006] Figure 1 shows a drilling system in an illustrative embodiment;

[0007] Figure 1A shows a drilling BHA and a mode shape of a torsional vibration;

[0008] Figure 2 shows a detailed component section of a wellbore assembly of the drilling system;

[0009] Figure 3 shows a timeline of various parameters affected by a high-frequency oscillation; and

[0010] Figure 4 shows a detailed view of a tubular linear motor. DETAILED DESCRIPTION

[0011] A detailed description of one or more embodiments of the apparatus and method revealed by way of example, but without any limitation with reference to the Figures, is presented here.

[0012] With reference to Figure 1, a drilling system (100) is shown in an illustrative embodiment. The drilling system (100) includes a drill string (102) extending into the well (104) from a platform (106) at a surface location (108). The drill string (102) includes a drill bit (110) disposed at a lower end and a downhole assembly (BHA) (112) holed above the drill bit (110). The BHA (112) includes downhole components such as a downhole telemetry device (114) that communicates with a surface decoder device (116) on the platform (106). The downhole telemetry device (114) may be a mud pulser and transmits pressure pulse signals through a drilling fluid flowing within the drill string (102) from a downhole location to the earth surface to be received at the surface decoder device (116).Pressure pulses are created by an electrical device (120), such as an electrical machine, housed within the downhole telemetry device (114). The electrical machine may include an electric motor driving a plunger of a plunger valve or a rotating or oscillating rotor or a. Petition 870250086684, dated 09 / 25 / 2025, page 46 / 178 4 / 27 Shear valve in the mud pulsator. During drilling, drilling fluid is pumped to the bottom of the well through an internal hole in the drill string (102) to exit the drill string (102) through drill nozzles on the drill bit (110). The fluid then returns uphole through the wellbore (104) within an annular space formed between the drill string (102) and the wellbore wall (104) carrying drilling cuttings out of the well. The drill string (102) and the wellbore (104) are thus generally filled with drilling fluid. The BHA (112) may also include a mud motor (124) including a stator and a rotor, also herein called the moving element. The mud motor (124) is driven or powered by the drilling fluid flowing through the drill string (102) and the stator and generates a rotation of the rotor. The mud motor (124) is set to rotate the drill bit (110).The BHA (112) may include one or more formation evaluation devices (FE devices) (126) or components, such as a density measurement device, an acoustic displacement time device, a pressure testing device, and a resistivity measurement device. To detect the orientation of the BHA (112) in the soil formation and the drilling direction, the BHA (112) includes a measurement while drilling (MWD) tool (128) including directional sensors, such as a magnetometer configured to measure the Earth's magnetic field and an accelerometer configured to measure the force of gravity. In embodiments, the MWD tool (128) includes the telemetry device (114) and a power generator, such as an alternator.To detect drilling dynamics parameters, the BHA (112) may include a drilling dynamics measuring device (131) including sensors such as one or more accelerometers, one or more magnetometers, one or more bending sensors (e.g., extensometers), one or more axial load sensors (e.g., a load cell) and one or more temperature sensors. The sensors in the dynamics measuring device (131) are configured to detect measurement signals at a high. Petition 870250086684, dated 09 / 25 / 2025, page 47 / 178 5 / 27 sampling rate (such as at least 1,000 Hz) to resolve highly dynamic processes such as torsional vibrations. In one embodiment, the drill string (102) may include another electrical device or electrical machine (130) that performs various downhole operations, such as, for example, an alternator in a downhole power generator that converts energy from the drilling fluid flow into electrical energy. The BHA (112) may contain any number of electrical machines for various downhole operations or purposes, such as the electrical machine (120) in the mud pulsator and the electrical machine (130) in the power generator or any additional electrical machine.One or more electric machines (120, 130) may be located within the BHA (112) at any location along a longitudinal axis (A) of the BHA (112) and the drill string (102) and at a distance from the drill bit (110), wherein the locations along the longitudinal axis (A) of the electric machine (120) and the electric machine (130) or any additional electric machine are different and at different distances from the drill bit (110). That is, the electric machine (120), the electric machine (130) and an additional electric machine are not located at the same position along the longitudinal axis (A) of the BHA (112). The electric machine (120) may be at a distance D2 and the electric machine (130) may be at a distance D1 from the drill bit (110). An electric machine, as used in this application, has a housing and the housing includes an electric coil, like an electric coil in an electromagnet.An electric machine also includes a magnet, such as an electromagnet or a permanent magnet. An electric machine includes a moving part and a non-moving part, such as a rotor and a stator in an electric motor or alternator. The electric coil may be located in one of the moving or non-moving parts. The magnet may be located in the other moving or non-moving part. In some embodiments, the electric machine also includes a resolver or encoder.

[0013] A surface controller (118) at the surface location (108) can be used to control the operation of the drill string (102) Petition 870250086684, dated 09 / 25 / 2025, page 48 / 178 6 / 27 (e.g., a drilling operation) varying drilling parameters of the drill string (102), such as rotation speed (revolutions per minute RPM) of the drill string (102) and the drill bit (110), drilling fluid flow rate, and weight applied to the drill bit (weight on bit (WOB)). A downhole controller (119) is included in the BHA (112) and is configured to control the operation of the drill string (102) automatically without interaction from the surface controller (118) or a human. The downhole controller (119) can control the drilling direction, control downhole data capture (FE devices), and control communication with the surface controller (118).The drilling direction can be controlled by guiding an adjustable kickoff (AKO) on the downhole motor or by controlling a guidance device on the BHA (not shown), such as a rotary guidance unit. Drill string operation via the surface controller (118) or downhole controller (119) can be based on HFTO detected by the electric machine and / or conventional vibration sensor.

[0014] In one embodiment, the drill string (102) may include a conventional vibration sensor (122) disposed on or near the drill bit (110) or in any other position in the BHA (112). A conventional vibration sensor (122) is a rate sensor, an accelerometer, or a magnetometer. The conventional vibration sensor (122) is configured to detect vibrations, including high-frequency torsional oscillations (HFTOs), which may be generated during the drilling process, for example, caused by shear forces on the drill bit (110) or mass imbalances in BHA components (112), such as the mud motor (124). The impacts from HFTOs may include, but are not limited to, reduced rate of penetration (ROP), reduced quality of downhole measurements (FE data), and excessive fatigue and wear on downhole components, tools, and / or devices. If, in addition to Petition 870250086684, dated 09 / 25 / 2025, p. 49 / 178 7 / 27 conventional vibration sensor (122), if no additional vibration sensor is present in the BHA (112), the presence and magnitude of these propagated HFTOs may go unnoticed by the single conventional vibration sensor (122). For example, if the single conventional vibration sensor (122) is located at a torsional vibration mode node, the sensor (122) emits only a small signal or no signal at all, although a significant HFTO may occur at other points in the BHA (112). In one embodiment, a second vibration sensor positioned near a torsional vibration mode antinode is able to detect the HFTO. Thus, the use of at least two vibration sensors (such as a conventional vibration sensor and an additional vibration sensor of some kind) allows the detection of HFTO oscillation mode shapes propagating along the drill string (102).A specific mode format is associated with a natural frequency of the BHA (112) or drill string (102). The second vibration sensor may be another conventional vibration sensor or it may be a vibration sensor of a different type. In several embodiments, the second vibration sensor may be a device or part of a device already present in a drilling BHA (112) for another downhole operation or purpose, such as an electrical machine used within a mud pulsator or an alternator used for power generation. Electrical machines may be part of a measurement tool during drilling that commonly includes a power generation module (alternator) and a telemetry device such as a mud pulsator.In an alternative embodiment, the electric machine may be included in any other component of the BHA (112), such as a formation evaluation device (e.g., a pressure testing device) or a coring device. An electric machine in the BHA (112) has a dedicated purpose or is intended to perform a dedicated downhole operation, such as power generation, pressure pulse signal generation, coring drill rotation (coring drill motor), etc. The use of... Petition 870250086684, dated 09 / 25 / 2025, page 50 / 178 8 / 27 electric machine in a multi-purpose use or multiple downhole operation use to also detect torsional vibrations allows saving space for dedicated conventional vibration sensors. In addition, the number of devices in the BHA (112) that need to be maintained and that could potentially fail leading to costly downtime and production hours within the drill string operation is reduced.

[0015] The terms HFTO vibrations or oscillations, as disclosed herein, are used in the same broad sense as repetitive and / or periodic motions, or periodic deviations from an average value, such as an average position, an average velocity, an average acceleration, an average force, and / or an average torque. In particular, these terms are not intended to be limited to harmonic deviations, but may include all types of deviations such as, but not limited to, periodic, harmonic, and statistical deviations. As will be understood by those skilled in the art, there are different vibrations, such as lateral vibrations, axial vibrations, and torsional vibrations. For example, the adhesion / slippage of the entire drill string and HFTO are both types of torsional vibrations. Torsional vibrations can be excited by self-excitation mechanisms that occur due to the interaction of the drill bit or any other cutting structure, such as a reaming bit, and the soil formation.The main differentiator between adhesion / slip and HFTO is the frequency and typical mode shapes. For example, HFTOs have a frequency that is typically above 50 Hz compared to adhesion / slip torsional vibrations which typically have frequencies below 1 Hz. Furthermore, the excited mode shape of adhesion / slip is typically a first mode shape of the entire drill string, while the HFTO mode shape can be of a higher order and is commonly located in smaller portions of the drill string with comparably high amplitudes at the excitation point, which may be the drill bit or... Petition 870250086684, dated 09 / 25 / 2025, page 51 / 178 9 / 27 any other cutting structure (such as a reaming drill bit), or any contact between the drill bit (102) and the formation (for example, by a stabilizer). HFTO or torsional vibration, in general, is represented by an oscillating tangential acceleration, where tangential here refers to a direction tangential to a circumference of the BHA or of a downhole component in a cross-section perpendicular to the longitudinal axis (A) of the BHA or of the downhole component.

[0016] Figure 1A shows a BHA (112) of the drill string (102) in an illustrative embodiment. The BHA (112) includes the conventional vibration sensor (122) positioned in close proximity to the drill bit (110) or elsewhere in the BHA. The conventional vibration sensor (122) is capable of detecting high-frequency torsional vibration (HFTO). In various embodiments, the conventional vibration sensor (122) may be a rate sensor, an accelerometer array, a magnetometer, etc. Figure 1A further illustrates several torsional vibration modes: mode 1, mode 2, mode 3, and mode 4. Each torsional vibration mode is characterized by its mode shape (magnitude (i.e., amplitude along the BHA)) and frequency, as well as its nodes and antinodes, which occur at various locations along the BHA (112).Mode 1 and Mode 2 have high amplitudes at the location of the conventional vibration sensor (122), while Mode 3 and Mode 4 have small amplitudes (or nodes) at the location of the conventional vibration sensor (122). However, the amplitudes of Mode 3 and Mode 4 can be significant at locations far from the conventional vibration sensor (122). The electric machine (120) is located at location (132) along the longitudinal axis (A) of the BHA (112). At location (132), the amplitudes of Mode 3 (i.e., amplitude (134)) and Mode 4 (i.e., amplitude (136)) are significant. In one embodiment, the electric machine (120) is used as an additional sensor (as a second vibration sensor) to detect vibration modes such as Mode 3 and Mode 4. Petition 870250086684, dated 09 / 25 / 2025, page 52 / 178 10 / 27 which otherwise cannot be detected or identified by the single conventional vibration sensor (122) in the BHA. The electric machine (120) acts as the additional or second vibration sensor. Identifying a mode shape of a vibration mode requires at least two vibration sensors placed at different locations along the longitudinal axis (A) of the BHA (112). The second vibration sensor (electric machine 120) in combination with the conventional vibration sensor (122) (rate sensor, accelerometer or magnetometer) can verify or identify the occurrence of a specific HFTO mode (vibration mode) by matching frequency and amplitude (mode shape) with HFTO modes derived from a simulation (e.g., modal analysis) performed for a specific BHA (e.g., BHA (112)).In the simulation, the BHA (112) can be represented by a BHA model that defines the various diameters, material properties, component connection locations, specific device locations (FE devices, mud motor, guidance unit, MWD tool, stabilizers, etc.). The simulation can be performed on the ground surface before or after downhole operation. In an alternative embodiment, the simulation can be performed at the bottom hole during downhole operation using the downhole controller (119).

[0017] Figure 2 shows a detailed view of a component section (200) of the electrical machine (120) in one embodiment. The component section (200) is located within a downhole component or tool in the BHA (112), such as, for example, a telemetry device (114). The downhole component includes a body (201). The body provides an internal space, such as an internal borehole (203). The component section (200) of the electrical machine (120) is located within the internal space of the body (201) of the BHA (112). The internal space may also allow a flow of drilling fluid (232) to pass through the downhole component on its way from the earth's surface to the bottom end. Petition 870250086684, dated 09 / 25 / 2025, page 53 / 178 11 / 27 of the BHA (drill bit (110)). Drilling fluid (232) can flow around the component section (200) of the electric machine (120). An outer surface of the body (201) defines an annular space wall between the BHA (112) and the wellbore wall. The outer surface of the body (201) is in contact with the drilling fluid flowing through the annular space on the way from the bottom end of the drill bit back to the earth surface. The component section (200) includes an electric motor (202) disposed in a housing (204). An outer surface of the housing (204) can be in contact with the drilling fluid. The housing (204) is mechanically coupled to the BHA (112), as through the MWD tool or the downhole telemetry device (114). In embodiments, the electric machine (120) is coupled to the body (201) of the downhole component. The housing (204) is coupled to an inner surface of the body (201) of the wellbore component.The coupling of the electric machine (120) with the downhole component of the BHA (112) ensures the transfer of vibrations acting on the BHA (112) to the electric machine (120) where the vibrations are detected. Typically, the housing (204) of the electric machine (120) is located along a central axis of the BHA (112) or the drill string (102). The central axis is parallel to the longitudinal axis (A) and represents the axis of rotation of the BHA (112) or the drill string (102).

[0018] The electric motor (202) includes a stator (206) and a rotor (208). The stator (206) is stationary relative to the body (201). The rotor (206) is rotatable relative to the stator (206) and the body (201). The stator (206) includes an electromagnet (210) and the rotor (208) includes a magnet (such as a permanent magnet (212)). The electromagnet (210) includes one or more electrical coils. In embodiments, the electromagnet includes a magnetic core.In several embodiments, the stator (206) includes a plurality of electromagnets and the rotor (208) includes a plurality of magnets. The plurality of magnets in the rotor (208) interacts with the plurality of electromagnets in the stator (206) to generate a rotation of the rotor (208). O. Petition 870250086684, dated 09 / 25 / 2025, p. 54 / 178 The 12 / 27 electromagnet (210) is powered and controlled by a control circuit (214), which may include an electronic module, or electronic circuit or processor, a current and / or voltage measurement module, and a power supply. The control circuit (214) is located in the BHA, such as in the telemetry tool (114) or the MWD tool, and is connected to the electromagnet (210) by a first transmission line (216). In other embodiments, the stator (206) and rotor (208) may include electromagnets, or the stator (206) may include permanent magnets and the rotor may include electromagnets. A rotor shaft (222) couples the rotor (208) to additional elements, such as components for mud pulse telemetry, a rotary shear valve, or a coring drill, for example. The rotor shaft (222) is guided in bearings (230), which allow the rotor shaft (222) to rotate.The axis of rotation (B) of the rotor (208) of the electric machine (120) coincides with the central axis of the BHA (112). The rotor itself includes inertia or is connected to inertia (such as the inertia of additional elements). A tangential force caused by a torsional vibration acting on the BHA (112) is also acting on the inertia associated with the rotor (208) of the electric machine (120). Thus, the torsional vibration results in a rotation or oscillation of the rotor (208) of the electric machine (120) around the central axis of the BHA (112) and the axis of rotation of the rotor (208).

[0019] A resolver (218) (or encoder) measures an angular position of the rotor (208) relative to the stator (206) and generates a resolver signal indicating this angular position. The resolver or encoder can be a magnetic device, an optical device, or a mechanical device. The resolver (218) sends the resolver signal to the control circuit (214) via a second transmission line (220). The control circuit (214) receives the resolver signal and determines the angular position of the rotor (208) relative to the stator (206) from the resolver signal. The control circuit (214) compares the angular position to an angular position Petition 870250086684, dated 09 / 25 / 2025, page 55 / 178 13 / 27 desired and controls a current being used in the stator electromagnet (210) (206) to control, modify or adjust a timing of the electromagnet (210) to adjust an angular position of the rotor (208) to the desired angular position. The desired angular position, as used herein, refers to an angular position of a normal rotor motion in a normal use of the electric machine. A normal use is also herein referred to as first-purpose use or first operational use of the electric machine, such as actuating a pulse valve, actuating a core drill, generating power or measuring a length. An applied torque (e.g., related to torsional vibration acting on inertia) to the rotor (208) creates a deviation between an actual angular position of the rotor and a target angular position for the rotor (desired angular position).This deviation, in turn, causes an increased current which is detected by the controller and which the controller uses to bring the actual angular position of the rotor back into line with the target position. A torque can be applied to the motor for many reasons, including an inertia-induced torque. When subjected to angular acceleration (due to torsional vibration), the inertia of the additional elements and the rotor itself creates a torque on the rotor shaft (222) which results in an increase in current, which is used by the controller to control the motor, as described in this document. A tangential force caused by a torsional vibration acting on the BHA (112) is also acting on the inertia of the additional elements associated with the rotor (208) of the electric machine (120).Thus, torsional vibration results in an overlapping rotation or oscillation of the rotor (208) within the stator (206) of the electric machine (120) and around the central axis of the BHA, as well as the axis of rotation (B) of the rotor (208). The overlapping rotation or oscillation is caused by torsional vibration acting on the bottom-hole component containing the electric machine (120). The overlapping rotation or oscillation is superimposed on the rotation or oscillation of the rotor in the electric machine (120) related to use. Petition 870250086684, dated 09 / 25 / 2025, page 56 / 178 14 / 27 of the first purpose of the electric machine (120). A second purpose use (second downhole operation use) of the electric machine (120) is the detection of torsional vibration and / or the detection of torsional vibration modes. That is, the electric machine (120) is installed in the BHA (112) to serve a first purpose or to perform a first downhole operation. In a drilling operation, the electric machine serves, in addition to the first purpose, a second purpose or performs a second downhole operation, such as the detection of torsional vibration in a vibration sensor use. The additional use of the electric machine (120) as a vibration sensor is called dual purpose use or dual downhole operation use. The dual purpose use of the electric machine(s) (120) in a BHA (112) allows vibration to be detected at locations along the longitudinal axis (A) of the BHA (112) where no conventional vibration sensor is installed.

[0020] Therefore, the angular position of the rotor (208) can be altered by the presence of HFTO in the electric machine (120) housed in the downhole telemetry device (114). When HFTOs are applied to the drill string (102) and transferred to the BHA component (112) housing the electric machine (120), the resulting tangential acceleration of the inertia(s) associated with the rotor (208) creates a torque in the electric motor (202) and a torque in the rotor (208), affecting the relative angular position or movement between the stator (206) and the rotor (208). This affected relative position or motion is due, in part, to the inertia of the rotor shaft (222) and the rotor (208), as well as by additional components coupled to the rotor (208) along the rotor shaft (222) accelerated by the HFTO acting on the inertias of the additional rotor shaft components and the inertia of the rotor (208).The resolver (218) measures this relative movement of the rotor (208) with respect to the stator and the control circuit (214) corrects this relative movement by controlling a motor signal being sent to the electromagnet (210) to bring the angular position of the rotor (208) with respect to the stator. Petition 870250086684, dated 09 / 25 / 2025, page 57 / 178 15 / 27 (206) back to the desired angular position. The motor signal can be a current signal or a voltage signal. In several embodiments, the control circuit (214) controls an amplitude of a current signal. The amplitude of the current signal is proportional to the amplitude of the relative torsional acceleration and therefore to the amplitude of the HFTO. Correspondingly, the control circuit (214) can control a voltage of the motor signal transmitted to the electromagnet (210). As described, the control circuit (214) can use the resolver signal to detect the torsional vibration of the BHA (112). In an alternative embodiment, the control circuit (214) can use the voltage induced in the coil(s) of the electromagnet(s) in the stator (206) caused by the movement of the rotor (208). The rotor (208) includes magnets (permanent magnets or electromagnets).The movement of the rotor (208) includes a normal movement (desired movement) based on the primary purpose use of the electric machine (120). Superimposed on this normal movement is a movement caused by torsional vibration acting on the BHA (112) and the inertia associated with the rotor (208) and originating from the drilling process in a drilling operation. The superimposed movement of the rotor (208) within the stator (206) causes changes in magnetic flux in the stator electromagnet coils (206), resulting in an electromotive force that manifests as a voltage. The polarity of the voltage opposes that of the applied voltage controlled by the control circuit (counter-electromotive force (cemf)). Therefore, the cemf modifies the voltage of the control circuit (214) to the electromagnet of the electric machine (120). This effect allows the control circuit (214) to detect the torsional vibration through the control signal to the stator electromagnet (206).

[0021] In one embodiment, the electric machine (120) is an alternator and is used to generate electrical energy in the BHA (112). The electrical energy can be used by a mud pulsator to power an electric motor to drive a pulsating valve, to power an electric motor of a drill bit. Petition 870250086684, dated 09 / 25 / 2025, page 58 / 178 16 / 27 witnessing or to power hydraulic pumps in the BHA (112). Electrical energy can also be used to power electronic boards used in the BHA (112) to control downhole operation, process data, store acquired data provided by downhole sensors, control hydraulic units and other similar operations. As the alternator is similarly designed as a motor, it can be used in the same way to detect vibration as described previously with the electric machine (120) (Figure 2). The alternator includes a rotor and a stator (206). The stator (206) may include one or more coils as part of an electromagnet and the rotor (208) may include one or more permanent magnets or electromagnets. In an alternative embodiment, the rotor includes one or more coils as part of an electromagnet and the stator (206) may include one or more permanent magnets or electromagnets. A turbine is connected to the rotor (208).When the turbine is rotated, as by the flowing drilling fluid (232), the rotor (208) is rotated and induces a voltage in the electromagnet coil(s) in the stator (206). If a rotation or oscillation of the rotor (208) caused by vibration (e.g., torsional vibration) is superimposed on the rotation of the turbine, a counter-electromotive force can be detected in the coil(s) in the stator (voltage or current in the coil). A control circuit (214) is used to analyze the voltage or current in the coil(s) and to detect the vibration. In Figure 1, the electric machine (120) can be a pulse motor and the electric machine (130) can be an alternator. Both electric machines can be used in a dual-purpose use mode. The electric machine (120) is used as a pulse motor (electric motor) and is used as a vibration sensor and the electric machine (130) is used as a power generator (alternator) and as a vibration sensor.Together with the conventional vibration sensor (122) in Figure 1, three vibration sensors would be in the BHA (112) at three different locations along the longitudinal axis (A) of the BHA (112), allowing to detect not only the occurrence of torsional vibration, but also to identify forms of. Petition 870250086684, dated 09 / 25 / 2025, page 59 / 178 17 / 27 Torsional vibration mode. Two vibration sensors are used to identify a vibration mode by analyzing the vibration data acquired by the two vibration sensors. Therefore, the electric machine (120) and the electric machine (130) used in dual-purpose use mode are sufficient to detect and identify a vibration mode. Alternatively, the electric machine (120) in dual-purpose use together with the conventional vibration sensor (122), or the electric machine (130) in dual-purpose use together with the conventional vibration sensor (122), are sufficient to detect and identify a vibration mode.

[0022] Figure 3 shows a timeline (300) of various parameters affected by a high-frequency oscillation. A first graph (302) shows the motor current in amperes (A) (also here called the vibration signal detected by the electric machine) along its ordinate axis. A second graph (304) shows a tangential acceleration in units of gravitational acceleration (g) (also here called the vibration signal detected by a conventional vibration sensor) along its ordinate axis. The conventional vibration sensor here is an acceleration sensor. The first graph (302) and the second graph (304) share the same abscissa, which shows the time (e.g., in seconds (s)). The duration of the time interval shown in Figure 3 is 190 minutes or 11,400 seconds. The left vertical line corresponds to 0 seconds, the right vertical line refers to 100 minutes or 6000 seconds.The vibration signal detected by the electric machine and the vibration signal detected by the conventional vibration sensor are stored in a memory and analyzed by the control circuit (214).

[0023] With reference to the second graph (304), the time period shown includes regions of low tangential vibration (306) with zero or relatively small HFTO amplitude (low tangential acceleration) and regions of high tangential vibration (308) in which HFTOs are present at significant HFTO amplitude (high tangential acceleration). The regions Petition 870250086684, dated 09 / 25 / 2025, page 60 / 178 18 / 27 low tangential vibration (306) can be one or more regions and the high tangential vibration regions can be one or more regions.

[0024] With reference now to the first graph (302), a raw or unfiltered dataset (310) of the current signal and a filtered dataset (312) of the current signal are shown. The filtered dataset may include filtered data for noise reduction. A low amplitude for the current signal corresponds to regions of low tangential vibration (306). A high amplitude for the current corresponds to regions of high tangential vibration (308). This amplitude difference can be seen in both the unfiltered dataset (310) and the filtered dataset (312). An average current without HFTO or without vibration (314) shows an average of the current amplitude corresponding to the low vibration regions (306). This average current (314) may correspond to the typical or normal operation of the electrical machine (130), such as actuating a slurry pulse telemetry valve. It is assumed that normal operation does not have HFTO acting on the electrical machine (120).This average can be used as a baseline current signal, also referred to here as a baseline signal. The baseline signal can be used to calculate a threshold (e.g., a threshold current) that can be used to indicate the need for HFTO mitigation, such as performing a mitigation operation. The threshold current can be defined experimentally using torsional vibration data recorded in a drilling operation and correlated to a wear state or a failure occurrence. The threshold current is then related to a torsional vibration amplitude that causes wear or failure of components in the BHA (112). In an alternative embodiment, the threshold current can be related to the amplitude of the baseline signal. The threshold current can be defined as being a multiple of the baseline signal. In one embodiment, the threshold can be defined as being twice the current amplitude of the baseline signal.If, for example, the current measured in a region of high tangential vibration exceeds twice the amplitude of the signal current. Petition 870250086684, dated 09 / 25 / 2025, page 61 / 178 19 / 27 baseline, then HFTO is defined as being detected. In some modes, the current threshold can be defined as any multiple of the amplitude of the baseline signal current (1.5 times, 3 times, 10 times, etc.). In another mode, the threshold is related to the standard deviation for the baseline signal amplitude. HFTO mitigation may include adapting drilling operations, such as adjusting operational parameters. Operational parameters adjusted to mitigate HFTO may include weight on the drill bit (WOB), rotational speed (RPM), drilling fluid flow rate, or drilling direction.

[0025] A high vibration average current (316) shows an average of the current amplitude corresponding to the tangential high vibration regions (308). The high vibration average current (316) can be compared to the baseline signal. When the high vibration average current (316) exceeds the current threshold, the presence of HFTO is detected. Furthermore, when an HFTO is present, both its presence and its amplitude and frequency can be detected. Using a high current signal detection sampling rate (e.g., 1000 Hz), the instantaneous amplitude and frequency of the HFTO can be derived by filtering the current signal and subtracting the average of the current signal when no HFTO is present from the filtered signal. The control circuit (214) analyzes the recorded current signal (vibration signal detected by the electric machine) to determine the frequency content.The analysis may include a Fast Fourier Transform (FFT), a Power Spectrum Density (PDS) analysis, or alternative frequency analysis techniques. When the average high vibration current (316) exceeds the limit current established by the baseline signal, an alert may be transmitted from the downhole telemetry device (114) to the surface decoder device (116). In another embodiment, the controller may detect an amplitude and frequency. Petition 870250086684, dated 09 / 25 / 2025, page 62 / 178 20 / 27 instantaneous HFTO values ​​are transmitted to the surface. In response, the controller (118) or an operator can control or adjust a drilling parameter applied to the drill string (102) to reduce the magnitude or presence of HFTO (mitigation operation). For example, the controller (118) or the operator can reduce the RPM or the WOB or a combination of these.

[0026] In several embodiments, the current signal corresponding to the high tangential vibration regions (308) can be compared to the current signal corresponding to the low vibration regions (306) in a time domain or a frequency domain (FFT). When the comparison is made in the frequency domain, the frequency of the HFTO in the high tangential vibration regions can also be detected.

[0027] Figure 4 shows a detailed view of another type of electrical machine, such as a tubular linear motor (400), located in a drill string (102). The tubular linear motor (400) is used to detect vibration in a drill string. Depending on its orientation relative to the longitudinal axis of the drill string, the linear motor can detect axial or lateral vibration in a manner similar to how a rotary motor is able to detect torsional vibration. The linear motor includes a stator (402) and a converter (401), also here called the moving element. The stator (402) surrounds the converter, and the converter is movable within the stator (402). The stator (402) is stationary relative to the drill string (102). The converter includes a plurality of magnets (403), commonly permanent magnets. The stator (402) includes a plurality of electromagnets (404), each including an electric coil (405) and a magnetic core.The electromagnets are located in a stator iron (406). The orientation of the magnetic poles of the magnets (403) in the converter creates a magnetic field of 90 degrees relative to the magnetic field created by the plurality of electromagnets (404). Linear motors commonly operate on a three-phase power supply to provide current to. Petition 870250086684, dated 09 / 25 / 2025, page 63 / 178 21 / 27 plurality of electromagnets (404) in the stator (402). The varying phases between neighboring electromagnets (404) and the consequent change in orientation of the resulting magnetic fields in the stator (402) interact with the magnetic fields of the magnets (403) in the converter (401) and move the converter (401) relative to the stator (402). An acceleration acting on the inertia of the converter (401) due to the vibration of the drill string leads to a variation in the current (emf) supplied to the electromagnets (404) in the stator (402) provided by a power supply. A control circuit (406), connected to the plurality of electromagnets (404) via transmission lines (407), controls the current supplied to the plurality of electromagnets (404). The control circuit (406) is configured to measure a current or a voltage and detect variations in current or voltage in the energy supplied to the plurality of electromagnets (404), providing a current signal or a voltage signal.Analysis of the current or voltage signal allows for the detection of drill string vibration and the determination of vibration amplitude and frequency, as described previously. The linear motor may include an encoder (408) monitoring the movement of the converter relative to the stator (402). In one embodiment, the control circuit (406) may detect drill string vibration by measuring and analyzing the encoder signal. There are other types of linear motors, such as an iron-core motor or a U-channel motor, which may be used alternatively to a tubular linear motor for vibration detection. The converter (401) may be coupled to additional elements, such as components that must be moved by the converter. The additional elements (not shown) increase the inertia of the converter, making it more sensitive to vibration. As described with the rotary motor, the linear motor located in a drill string is used in a dual-purpose application.The primary uses of a linear motor can be to power a downhole robot arm, actuate a plunger valve, handle and store rock cores after they have been drilled, and measure a... Petition 870250086684, dated 09 / 25 / 2025, page 64 / 178 22 / 27 displacement, enabling various downhole operations, such as extracting sandpaper or blades. A secondary use is as a vibration sensor. The linear motor converter includes a longitudinal shaft (T). Axial vibration can be detected by the linear motor when the longitudinal shaft of the converter (T) extends along the longitudinal axis (A) of the drill string. The longitudinal shaft (T) of the converter can be parallel to the longitudinal axis (A) of the drill string or it can be at a small angle to the longitudinal axis (A) of the drill string, such as between 0.1 degrees and 10 degrees. Lateral vibration can be detected by the linear motor when the longitudinal axis (T) of the linear motor converter extends perpendicular to the longitudinal axis (A) of the drill string.The longitudinal axis (T) of the converter may be 90 degrees relative to the longitudinal axis (A) of the drill string or may deviate slightly from being perpendicular to the longitudinal axis (A) of the drill string, such as between 0.1 degrees and 10 degrees off the perpendicular direction. The tubular linear motor (400) is located within a housing (not shown). The housing including the tubular linear motor may be located within the drill string and within a body of a downhole component (not shown), such as within the inner bore of the downhole component. In this case, the housing with the linear motor is in contact with the downhole fluid flowing through the inner bore. In an alternative embodiment, the linear motor may be located in a collar of a downhole component of the drill string (not shown).In this case, the linear motor is housed in a collar pocket and can be isolated from the downhole environment by a hatch cover. In another embodiment, a solenoid surrounding a magnet or magnetic material, as used with plunger-based mud pulsator valves (solenoid valve), can be used to detect drill string vibration. In this embodiment, the current supplied to the solenoid to move the magnet to close or open the valve is monitored by the... Petition 870250086684, dated 09 / 25 / 2025, page 65 / 178 23 / 27 control circuit for detecting and analyzing vibration. In this embodiment, the primary purpose of the solenoid valve is valve movement, while the secondary purpose is vibration detection. In yet another embodiment, a linear variable differential transformer (LVDT) can be used to detect vibration. In this embodiment, the primary purpose of the LVDT is the measurement of linear displacements, while the secondary purpose of the LVDT is vibration detection by observing the back electromotive force (EMF) caused by the vibration of the drill string transferred to the moving component of the LVDT.

[0028] Below, some modalities of the aforementioned revelation will be presented:

[0029] Embodiment 1. A method for detecting a vibration of a drill string in a well, wherein the method includes transporting the drill string to the well, the drill string including an electric machine, the electric machine including a stator and a moving element, the moving element being movable relative to the stator, rotating the drill string in the well, determining, through a control circuit, a first amplitude of the vibration of the drill string by measuring a signal indicative of a movement of the moving element in the electric machine due to the rotation of the drill string and controlling, through the control circuit, a downhole operation of the drill string based on the first detected amplitude of the vibration.

[0030] Modality 2. The method of any previous embodiment, in which the detection of the first amplitude of the drill string vibration includes measuring at least one of: (i) a current; and (ii) a voltage supplied to a coil located inside the electrical machine.

[0031] Modality 3. The method of any previous embodiment, in which the detection of the first amplitude of the drill string vibration includes detecting a signal from at least one of: (i) a resolver; and (ii) an encoder associated with the moving element in the electrical machine. Petition 870250086684, dated 09 / 25 / 2025, p. 66 / 178 24 / 27

[0032] Modality 4. The method of any previous modality, in which the control of the downhole operation includes performing a mitigation operation when the first detected amplitude of the vibration exceeds a limit.

[0033] Embodiment 5. The method of any previous embodiment, wherein the drill string includes a longitudinal axis and the electric machine and a vibration sensor are located in the drill string at different locations along the longitudinal axis, further comprising determining a second amplitude of the drill string vibration using the vibration sensor and using the first amplitude of the drill string vibration and the second amplitude of the drill string vibration to identify a vibration mode of the drill string vibration.

[0034] Modality 6. The method of any previous embodiment, in which the vibration sensor is one of an accelerometer and a magnetometer.

[0035] Modality 7. The method of any previous embodiment, in which the vibration sensor is another electrical machine in the drill string.

[0036] Modality 8. The method of any previous embodiment, in which the identification of the vibration mode of the drill string includes the use of a simulation.

[0037] Modality 9. The method of any previous modality, in which the electric machine is one of a motor and an alternator.

[0038] Modality 10. The method of any previous modality, in which the vibration of the drill string is a high-frequency torsional oscillation (HFTO).

[0039] Modality 11.0 method of any previous modality, which additionally includes determining a frequency of the first detected amplitude of the drill string vibration using the control circuit. Petition 870250086684, dated 09 / 25 / 2025, page 67 / 178 25 / 27

[0040] Modality 12. A system for detecting a vibration of a drill string in a well. The system includes an electrical machine in the drill string and a control circuit. The electrical machine includes an electromagnet, a stator, and a moving element that is movable relative to the stator. The control circuit is configured to control a magnetic field of the electromagnet, measure a signal indicative of a relative movement of the moving element with respect to the stator due to the vibration of the drill string, determine a first amplitude of the drill string vibration using the measured signal, and control a downhole operation of the drill string based on the first detected amplitude of the drill string vibration.

[0041] Mode 13. The system of any previous mode, in which the measured signal is one of at least: (i) a current; and (ii) a voltage supplied to the electromagnet.

[0042] Modality 14. The system of any previous modality, which additionally includes a resolver or an encoder, in which the measured signal is at least one of: (i) a resolver signal; and (ii) an encoder signal.

[0043] Modality 15.0 system of any previous embodiment, in which the moving element is one of a rotor and a converter.

[0044] Mode 16.0 system of any previous mode, in which the vibration is a high-frequency torsional oscillation (HFTO).

[0045] Modality 17.0 system of any previous modality, in which the electric machine is one of a motor and an alternator.

[0046] Modality 18. The system of any previous embodiment, additionally including a vibration sensor in the drill string, the electric machine and the vibration sensor being located at different locations along a longitudinal axis of the drill string, wherein the control circuit is configured to determine a second amplitude of the drill string vibration using the vibration sensor. Petition 870250086684, dated 09 / 25 / 2025, page 68 / 178 26 / 27 and use the first amplitude of the drill string vibration and the second amplitude of the drill string vibration to identify a vibration mode of the drill string vibration.

[0047] Modality 19.0 system of any previous modality, in which the vibration sensor is one of an accelerometer and a magnetometer.

[0048] Modality 20. The system of any previous modality, in which the vibration sensor is another electrical machine in the drill string.

[0049] The use of the terms a, an, and similar references in the context of describing the invention (especially in the context of the following claims) should be interpreted as encompassing both the singular and the plural, except where otherwise indicated in the present invention or clearly contradicted by the context. Additionally, it should be considered that the terms first, second, and similar in the present invention do not denote any order, quantity, or importance, but are instead used to distinguish one element from another. The terms approximately, substantially, and generally are intended to include the degree of error associated with measuring the specific quantity based on the equipment available at the time of filing the application. For example, approximately and / or substantially and / or generally may include a range of ±8% or 5% or 2% of a given value.

[0050] The learnings from this disclosure can be used in a variety of well operations. These operations may involve the use of one or more treatment agents to treat a formation, the fluids residing in a formation, an oil well, and / or equipment in the oil well, such as a production pipeline. Treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, signaling agents, flow improvers, etc. Petition 870250086684, dated 09 / 25 / 2025, page 69 / 178 27 / 27 Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, signal injection, cleaning, acidification, steam injection, water injection, cementing, etc.

[0051] Although the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various alterations may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Additionally, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its essential scope. Therefore, it is intended that the invention is not limited to the specific embodiment disclosed as the best contemplated mode for carrying out the present invention, but that the invention includes all embodiments that fall within the scope of the claims.Furthermore, in the drawings and description, exemplary embodiments of the invention have been disclosed, and although specific terms may have been employed, they are used, unless otherwise stated, only in a generic and descriptive sense and not for the purpose of limitation; therefore, the scope of the invention is not thus limited. Petition 870250086684, dated 09 / 25 / 2025, page 70 / 178

Claims

1 / 3 CLAIMS 1. Method for detecting a vibration of a drill string (102) in a well (104), the method being characterized by: transporting the drill string (102) to the well (104), the drill string (102) including an electric machine (120, 130), the electric machine (120, 130) including a stator (206, 402) and a moving element (208, 401), the moving element (208, 401) being movable relative to the stator (206, 402); rotating the drill string (102) in the well (104); to determine, by means of a control circuit (214), a first amplitude of the vibration of the drill string (102) by measuring a signal indicating a movement of the moving element (208,401) in the electric machine (120, 130) due to the rotation of the drill string (102); and to control, by means of the control circuit (214), a downhole operation of the drill string (102) based on the first detected amplitude of the vibration.

2. Method according to claim 1, characterized in that the detection of the first amplitude of the vibration of the drill string (102) includes measuring at least one of: (i) a current; and (ii) a voltage supplied to a coil (405) located inside the electrical machine (120, 130).

3. Method according to claim 1, characterized in that the detection of the first amplitude of the vibration of the drilling column (102) includes detecting a signal from at least one of: (i) a resolver (218); and (ii) an encoder (408) associated with the moving element (208, 401) in the electric machine (120, 130).

4. Method, according to claim 1, characterized in that the downhole operation control includes performing a mitigation operation when the first detected vibration amplitude exceeds a limit. Petition 870250086684, dated 09 / 25 / 2025, p. 71 / 178 2 / 3 5. Method according to claim 1, wherein the drill string (102) includes a longitudinal axis (A) and the electric machine (120, 130) and a vibration sensor (122) are located in the drill string (102) at different locations along the longitudinal axis (A), further characterized by determining a second amplitude of the vibration of the drill string (102) using the vibration sensor (122) and using the first amplitude of the vibration of the drill string (102) and the second amplitude of the vibration of the drill string (102) to identify a vibration mode of the vibration of the drill string (102).

6. Method according to claim 5, characterized in that the vibration sensor (122) is one between an accelerometer and a magnetometer.

7. Method according to claim 1, characterized in that the electric machine (120, 130) is one of a motor (202) and an alternator.

8. Method according to claim 1, further characterized by determining a frequency of the first detected amplitude of the drill string vibration (102) using the control circuit (214).

9. System for detecting a vibration of a drill string (102) in a well (104), the system being characterized by: an electric machine (120, 130) in the drill string (102), the electric machine (120, 130) including an electromagnet (210), a stator (206, 402) and a moving element (208, 401) being movable relative to the stator (206, 402); a control circuit (214) configured to: control a magnetic field of the electromagnet (210); measure a signal indicating a relative movement of the moving element (208, 401) relative to the stator (206, 402) due to the vibration of the drill string (102); Petition 870250086684, dated 09 / 25 / 2025, p. 72 / 178 3 / 3 determine a first amplitude of the drill string vibration (102) using the measured signal; and control a downhole operation of the drill string (102) based on the first detected amplitude of the drill string vibration (102).

10. System according to claim 9, characterized in that the measured signal is one of at least: (i) a current; and (ii) a voltage supplied to the electromagnet (210).

11. System according to claim 9, further characterized by a resolver (218) or an encoder (408), wherein the measured signal is at least one of: (i) a resolver signal; and (ii) an encoder signal.

12. System according to claim 9, characterized in that the moving element (208, 401) is one of a rotor (208) and a converter (401).

13. System according to claim 9, characterized in that the electric machine (120,130) is one of a motor (202) and an alternator.

14. System according to claim 9, further characterized by a vibration sensor (122) in the drill string (102), the electric machine and the vibration sensor (122) being located at different locations along a longitudinal axis of the drill string (102), wherein the control circuit (214) is configured to: determine a second amplitude of the vibration of the drill string (102) using the vibration sensor (122); and use the first amplitude of the vibration of the drill string (102) and the second amplitude of the vibration of the drill string (102) to identify a vibration mode of the vibration of the drill string (102).

15. System according to claim 14, characterized in that the vibration sensor (122) is one among an accelerometer and a magnetometer. Petition 870250086684, dated 09 / 25 / 2025, p. 73 / 178

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