BACKGROUND OF THE INVENTION
1. Field of Invention
The present disclosure relates to a wellbore drilling system that includes a drill string with an outer sleeve configured to dampen vibrations in the drill string.
2. Description of Prior Art
Drilling systems employed for excavating hydrocarbon producing wellbores in a subterranean formation, and which typically include a drill string made up of a pipe string, a drill bit, a bottom hole assembly (“BHA”) containing tools for measurements and directional steering between the drill bit and the pipe string, and a collar connecting the drill bit to the pipe string. The drill string is generally made up of joints of drill pipes connected in series by engaging threads on their opposing ends. Usually, the drill string is rotated by a top drive or rotary table provided in a drilling rig on surface while drilling mud is circulated within the drill string to remove cuttings formed by rotating the drill bit in the subterranean formation.
Reactive forces from the drill bit rotating against the subterranean formation, such as rock formations can generate vibrations in the BHA and the drill string, which are generally most pronounced and damaging close to the drill bit in the BHA. Depending on the forces and physical characteristics of the drill string and the subterranean formation, the vibrations are in directions that are radial, torsional, and combinations, which can include high-frequency torsional oscillations (“HFTO”). Recent advancements in drilling technology have increased both rates of penetration through the subterranean formation and force on the drill bit (also commonly referred to as “weight on bit”), and in turn increased magnitudes of vibrational displacement in the BHA and drill strings, thereby increasing a probability of damaging the BHA and drill string. One technique for damping vibrations in a drill string include adding a free rotating inertia mass to a portion of the drill string. One drawback to this technique is the limited space available within a bottom hole assembly.
SUMMARY OF THE INVENTION
Disclosed herein is an example of a system for damping oscillations in a drill string for use in a wellbore that includes a pipe string and a damping system, where the damping system is made up of a sleeve selectively rotatable around a portion of the pipe string and selectively engaged to a sidewall of the wellbore and a coupling unit configured to vary a coupling strength between the pipe string and the sleeve. In an embodiment, the coupling unit includes one or more magnets and an electrical conduit, and the variation of the coupling strength is caused by varying an electrical current through the electrical conduit. The system further optionally includes one or more ribs on an outer surface of the sleeve that project towards the sidewall of the wellbore. The damping system optionally includes a sensor for sensing a vibration parameter indicative of a vibration of the system in the wellbore and where the coupling unit varies the coupling strength in response to the sensed vibration parameter, in an alternative, a controller is included in communication with the sensor, the controller configured to initiate the coupling unit to vary the coupling strength based on the sensed vibration parameter, and optionally, the controller is configured to split the sensed vibration parameter in a first and second vibration portion having a frequency from a first and second frequency range, respectively. In examples, the coupling unit includes a coupling that is a brake type coupling or a magnetic coupling. In an embodiment, the coupling unit includes a magnetorheological fluid, wherein the coupling strength is varied by energizing the magnetorheological fluid. Examples of the first and second frequency range include a discrete frequency value. In an alternative, the at least one of the first and second frequency range is a static frequency component.
Also disclosed is an example method for damping oscillations in a drill string operated in a wellbore, and which includes lowering into the wellbore at least a portion of a pipe string made up of a damping system including a sleeve and a coupling unit. The example method further includes engaging the sleeve to a sidewall of the wellbore, and varying, by the coupling unit, a coupling strength between the pipe string and the sleeve. The coupling unit optionally includes one or more magnets and an electrical conduit, and the variation of the coupling strength is caused by varying an electrical current through the electrical conduit. An example of the method further includes projecting one or more ribs on an outer surface of the sleeve towards the sidewall of the wellbore. The method optionally includes sensing, with a sensor in the damping system, a vibration parameter indicative of a vibration of the drill string in the wellbore and varying the coupling strength in response to the sensed vibration parameter, and in embodiments, the variation of the coupling strength by the coupling unit is initiated by a controller in communication with the sensor based on the sensed vibration parameter, and further optionally includes splitting, by the controller, the sensed vibration parameter and a first and second vibration portion having a frequency from a first and second frequency range, respectively. Embodiments include the coupling unit varying the coupling strength by at least one of a hydraulic coupling, a magnetic coupling, or an electromagnetic coupling. The coupling unit optionally includes a magnetorheological fluid, and where the variation of the coupling strength comprises energizing the magnetorheological fluid. In examples, at least one of the first and second frequency range is a discrete frequency value, and optionally, at least one of the first and second frequency range is a static frequency component.
BRIEF DESCRIPTION OF DRAWINGS
Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a side partial sectional view of an example of excavating in a wellbore with a drilling system.
FIG. 2 is a side sectional view of an example of a damping system for use with the drilling system of FIG. 1.
FIG. 3 is a side partial sectional view of an example of the drilling system of FIG. 1 having the damping system of FIG. 2.
FIG. 4A is a perspective view of an alternate example of the damping system of FIG. 2.
FIG. 4B is an elevational sectional view of the damping system of FIG. 4A and taken along lines 4B-4B.
FIG. 4C is an elevational sectional view of an alternate example of the damping system of FIG. 2.
FIG. 5 is a block diagram of an example of a control scheme for damping vibration in the drilling system of FIG. 1 using the damping system of FIG. 2.
FIG. 6 is a flow chart of an example of operation of the damping system of FIG. 2.
While subject matter is described in connection with embodiments disclosed herein, it will be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents thereof.
DETAILED DESCRIPTION OF INVENTION
The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes +/−5% of a cited magnitude. In an embodiment, the term “substantially” includes +/−5% of a cited magnitude, comparison, or description. In an embodiment, usage of the term “generally” includes +/−10% of a cited magnitude.
It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.
Illustrated in a partial side sectional view in FIG. 1 is an example of a drilling system 10 forming a wellbore 12 through a subterranean formation 14. The drilling system 10 includes a drill string 16 shown inside wellbore 12, and which includes a pipe string 18 with a drill bit 20 mounted on its lower end. A bottom hole assembly (“BHA”) 21 is shown located between the pipe string 18 and drill bit 20, in examples the BHA 21 includes one or more of a tool for measurements, a tool for directional steering, a mud motor, a tool for logging while drilling, a stabilizer, a reamer, a shock absorber, and a jarring device. In alternatives, BHA 21 is on pipe string 18 and spaced away from drill bit 20. On surface S is a rotary table 22 shown providing a rotational force onto the drill string 16 to rotate drill bit 20 against the bottom of wellbore 12 and to excavate through subterranean formation 14. Further shown in the example of FIG. 1 is a wellhead assembly 24 over the opening of wellbore 12 that provides pressure control of wellbore 12 and means for accessing wellbore 12. A derrick 26 is illustrated mounted over the wellhead assembly 24 on surface S, in examples, derrick 26 provides support for the drilling operations such as raising and lowering individual pipe joints of the pipe string 18 and supporting the drill string 16 inside the wellbore 12. A controller 28 is schematically illustrated in communication downhole into wellbore 12 via communication means 30. In the example of FIG. 1, rotation of drill string 16 generates vibrations in sections 32, 34 of pipe string 18 and in the BHA 21, these vibrations are schematically illustrated by dashed lines L. In examples, these vibrations are in a direction of axis A16 of drill string 16 (i.e., axial vibration), are in a direction radial to axis A16 of drill string 16 (i.e., lateral vibration), are rotational about axis A16 (i.e., torsional vibration), or a combination of axial, radial, and torsional. In a further example, the vibrations include those that are high frequency torsional oscillations. Examples of known passive damping techniques are found in U.S. Pat. Nos. 11,448,015; 11,199,242; 11,136,834; and U.S. Patent Application Publication No. 2021/0079738, the full disclosures of which are incorporated by reference herein and for all purposes.
Referring now to FIG. 2, shown in a side sectional view is an example of a damping system 36 mounted on the pipe string 18 for damping vibrations in the drill string 16 during drilling. Damping system 36 includes a sleeve 38 shown circumscribing a portion of pipe string 18 where an annular recess 40 is formed in an outer surface of the pipe string 18. A portion of sleeve 38 is within recess 40, and an outer portion of sleeve 38 projects radially outward from recess 40 into an annulus 42 between pipe string 18 and sidewalls 44 of wellbore 12. An inner radius of sleeve 38 is spaced radially outward from an inner surface 45 of recess 40 to define a gap 46 between the two. Bearings 48 are shown in gap 46 and between opposing axial ends of sleeve 38. Sleeve 38 is selectively engaged with sidewalls 44 of wellbore 12 to be maintained substantially rotationally static with respect to wellbore 12. In the context of this disclosure, “substantially rotationally static” means that sleeve 38 is not rotatable with respect to wellbore 12 and subterranean formation 14. In examples of the sleeve 38 being “substantially rotationally static”, include the sleeve 38 linearly sliding relative to wellbore 12 and subterranean formation 14 (e.g., in an axial direction, such as in the direction of axis A16 of drill string 16). In alternate embodiments of being, “substantially rotationally static”, there is relative rotation between the sleeve 38 and wellbore 12 and subterranean formation 14, but sleeve 38 rotates relative to wellbore 12 and subterranean formation 14 with a rotational velocity that is significantly lower than the rotational velocity of drill string 16 or pipe string 18, e.g., with a rotational velocity that ranges up to about 10% of the rotational velocity of drill string 16 and pipe string 18. Further, in embodiments, the sleeve 38 being “substantially rotationally static” includes the combination of both, a rotation of sleeve 38 with respect to wellbore 12 and subterranean formation 14 with a rotational velocity that is 10% of the rotational velocity of the drill string 16 or less and a linear sliding of sleeve 38 relative to wellbore 12 and subterranean formation 14. Examples of linear sliding include movement in an axial direction, such as in the direction of axis A16 of drill string 16. Ribs 50 are shown projecting radially outward from an outer surface of sleeve 38. In the example of FIG. 2, ribs 50 have a base end 52 mounted to the outer surface of sleeve 38, a free end 54 shown protruding in the direction of or into the sidewall 44 of the wellbore 12, and lateral sides 56 extending radially between the base end 52 and free end 54. Ribs 50 of FIG. 2 are shown as elongate members with axially extending surfaces that are generally planar. In alternatives, ribs 50 have widths that decrease with distance from the base end 52 to the free end 54. Examples exist in which the number of ribs 50 in the damping system 36 range from a single rib 50 to a multiplicity of ribs 50, which are optionally spaced equidistant apart or at staggered locations around the sleeve 38. In an example of sleeve 38 being selectively engaged with sidewalls 44 of wellbore 12, one or more of ribs 50 are in contact with the sidewalls 44, where contact includes an interfering contact that prevents any relative rotation of sleeve 38 with sidewalls 44 and ranges to a frictional or scraping contact that impedes rotation of sleeve 38 relative to sidewalls 44. Ribs 50 are optionally dimensioned so have an outer diameter exceeding that of drill bit 20 (FIG. 1) so that one or more of ribs 50 extend into sidewalls 44. In embodiments, one or more of ribs 50 may be connected to an actuation device (not shown) that selectively actuates ribs 50 to selectively extend and retract thereby selectively creating or preventing the contact with sidewalls 44 of wellbore 12. Alternatives exist for engaging the sleeve 38 and sidewalls 44, such as but not limited to, a packer like member (not shown) that expands radially outward, an anchoring system, and any other means for resisting rotation of sleeve 38 with respect to the sidewalls 44.
Damping system 36 of FIG. 2 includes a coupling unit 58 for selectively rotationally coupling the sleeve 38 with the pipe string 18. As described in more detail below, a force or torque is generated in the pipe string 18 by engaging the sleeve 38 with the sidewalls 44 while at the same time coupling the sleeve 38 to the pipe string 18 when there is relative rotation between the sleeve 38 and pipe string 18. Coupling unit 58 has a coupling 60 schematically shown in the gap 46 between the sleeve 38 and inner surface 45 of recess 40; coupling 60 is selectively rotationally coupled simultaneously with both the sleeve 38 and with the pipe string 18, which rotationally couples sleeve 38 to the pipe string 18. As discussed in more detail below, coupling 60 couples sleeve 38 to the pipe string 18 with a coupling strength that can be adjusted (e.g., switched on and off), for example by selectively increase or decrease a force or torque between sleeve 38 and pipe string 18 that prevents or reduces relative rotation between sleeve 38 and pipe string 18. Adjustment of coupling 60 may be achieved by an actuator 68 (such as a hydraulic or electromechanical means) that is configured to selectively adjust the force or torque between sleeve 38 and pipe string 18. Examples of coupling 60 include a clutch that is rotationally affixed to one of the sleeve 38 or pipe string 18, and when actuated is put into frictional contact with the other of the sleeve 38 or pipe string 18 to rotationally couple these elements with a higher coupling force. In a similar way, when disengaged, the clutch reduces frictional contact with the other of the sleeve 38 or drill pipe string 18 to rotationally decouple these elements or to reduce the coupling force between these elements. By selectively engaging or disengaging the clutch, the frictional contact, and thereby the coupling force (i.e., the coupling strength) between sleeve 38 and drill pipe string 18 can be selectively increased or reduced. For the purposes of discussion herein, the coupling unit 58 is in an activated configuration when the coupling 60 is actuated into a state with a higher coupling force between the sleeve 38 and the pipe string 18, and is in a deactivated configuration when in a state with a relatively lower coupling force between the sleeve 38 or pipe string 18. When the coupling unit 58 is in the activated configuration, the pipe string 18 is rotationally coupled with a relatively higher coupling force with the sidewalls 44 through interaction between the sidewalls 44 and sleeve 38 and interaction between the sleeve 38 and pipe string 18. In an example, during rotation of the pipe string 18, activating the coupling unit 58 generates a coupling force or forces between the sleeve 38 and pipe string 18 to result in a torque, force moment, or moment (collectively referred to as a damping force) in the pipe string 18 that dampens the vibration of the pipe string 18. In alternatives, the damping force is in a direction counter or opposite to one of the directions of vibration. An example Cartesian coordinate system with X, Y, and Z axes is shown for illustrating vibration direction. In a non-limiting example, the direction of vibration is in the YZ plane (e.g., in a Y direction), and a counterforce is applied in a direction opposite the direction of vibration. Alternatives exist in which the coupling unit 58 is periodically activated and deactivated (e.g., a clutch is engaged and disengaged) to periodically increase and decrease the damping forces and thereby the coupling force between the sleeve 38 and pipe string 18. In an alternative, when vibration is in the YZ plane and in the Y direction, a countering damping force is generated that alternately acts in the positive and the negative portion of the Y direction to counteract the vibration. Alternatively, the coupling 60 includes a permanent magnet and/or coils as discussed below, and the sleeve 38 and pipe string 18 are coupled electromagnetically, for example by directing a current through the coils. Further embodiments for an actuator include hydraulics, mechanical, and electrical, such as an electromechanical linear drive or a piezo element. In one embodiment, the coupling 60 includes a gap with electro or magneto rheological fluid in the gap 46, and the shear properties determining the shear force within the fluid and between sleeve 38 and pipe string 18 are controlled by an electrical or magnetic field, and the electrical or magnetic forces are generated by an electric motor or generator (not shown) having a rotor and stator, where the rotor is attached to the pipe string 18 and the stator is attached to the sleeve 38 or vice versa. Optionally, the coupling 60 includes an electric motor or generator (not shown) and the counterforce is controlled by, or based on, electrical current to or from the motor/generator. Coupling unit 58 of FIG. 2 further includes a sensor 62, controller 64, a line 66 connecting sensor 62 and controller 64, an actuator 68, a line 70 connecting controller 64 and actuator 68, and a connection 72 between actuator 68 and coupling 60; these elements are optionally included within damping system 36 or external of damping system 36 in the BHA 21 or pipe string 16.
Referring now to FIG. 3, shown in a side partial section view is an example of the drilling system 10 of FIG. 1 having the damping system 36 (FIG. 2) integrated into the drill string 16 or the BHA 21. Locations for placement of the damping system 36 on drill string 16 include proximate the drill bit 20, distal from the drill bit 20, and any place between. Similar to the example of FIG. 1, pipe string 18 and drill bit 20 of drill string 16 are being rotated by action of the rotary table 22 to excavate wellbore 12. In FIG. 3, the damping system 36 counters reactive forces from drilling to suppress or avoid vibrations illustrated in the example of FIG. 1. In a non-limiting example of operation, sensor 62 measures a property indicating the vibration and the torsional vibration direction, in which the property includes one or more of torsional displacement, velocity, acceleration, force, and torque relative to the sleeve 38 or sidewalls of the wellbore 12; for example, sensor 62 includes an accelerometer to sense acceleration, motion, and/or vibrations of the pipe string 18. Further devices are optionally included with sensor 62, such as, a strain gauge, a magnetometer, a gyroscope, and combinations. Sensor 62 transmits to controller 64 via line 66 a data signal that contains information about the vibration/motion, such as, direction, frequency, amplitude, torque, or any other information about or relevant to characteristics of vibrations of the pipe string 18 or drill string 16. In alternatives, the controller 64 includes logics for evaluating the information and for identifying vibration/motion that exceeds a threshold amount, and includes proportional, differential, or integral capabilities, or combinations in a PID controller or any other type of controller.
In a non-limiting example of operation, damping of the drill string 16 or pipe string 18 is based on a comparison of the characteristics of vibrations of the pipe string 18 or drill string 16 and a threshold amount of vibration/motion of the drill string 16 or pipe string 18. Further in this example, damping is initiated when vibration/motion of the drill string 16 or pipe string 18 is less than, equal to or substantially the same, or greater than the threshold amount, and an amount of damping is applied to maintain the vibration/motion of the drill string 16 or pipe string 18 to be less than, equal to, or greater than the threshold amount. Examples of the threshold amount include a vibration/motion (such as displacement, velocity, acceleration, force, and torque) judged to be a maximum amount of vibration/motion of the drill string 16 or pipe string 18 during operation based on a design of the drill string 16 or pipe string 18 (e.g., maximum design vibration/motion), a vibration/motion below which optimizes an operating life of drilling system, a vibration/motion above which presents a probable risk of damage to a component(s) of the drill string 16 or pipe string 18 or drilling system 10, or an amount of vibration/motion of the drill string 16 or pipe string 18 at which a determination is made to apply damping. It is within the capabilities of one skilled in the art to identify a threshold amount of vibration/motion at which damping is to be applied. It is also within the capabilities of one skilled in the art to implement logics in a controller that identify vibration/motion in a drill string exceeding the threshold amount. It is further within the capabilities of one skilled in the art to determine a (magnitude of) force or torque, such as damping force or coupling strength to be exerted onto a pipe string to dampen the vibration of the pipe string 18 to below that of the threshold amount.
Controller 64 optionally includes a filter (such as a digital and/or analog filter) to analyze the vibration signal of the sensor 62 and to separate the vibration signal into two or more different bands or components, e.g., a static component (for example a mean value) and a dynamic component where the dynamic component is further distinguished in a quasi-static low frequency component (for example, 0 Hz<f<=1 Hz), a low frequency component (for example, 1 Hz<f<=50Hz), and a high frequency component (for example, 50<f<=500 Hz, where HFTO vibration generally occurs), and a ultra-high frequency component (for example, above 500 Hz). In some embodiments, the controller 64 generates commands to the actuator 68 to generate counteracting force or torque by the damping system 36 in less than all frequency bands, such as only within the high and/or ultra-high frequency bands that are transmitted to the drill string 16. An advantage of generating counteracting force or torque in only one or more of the higher frequency bands and not in the lower frequency bands is that the lower frequency band, such as the static component, is excluded from the counteracting force or moment so that the actuator 68 does not generate unnecessary drag forces that would not dampen vibration but counteract rotation of pipe string 18 within sleeve 38 which would create undesired wear on the parts, such as on one or more of bearing 48, coupling 60, and coupling unit 58. Upon identification of the vibration/motion exceeding the threshold amount, coupling 60 is activated. In an example of activating coupling 60, controller 64 generates and sends a command to actuator 68 upon identifying vibration/motion that exceeds a threshold amount. The command directs actuator 68 to actuate or energize connection 72, which activates coupling 60. In this example, connection 72 includes structure or hardware for initiating coupling between sleeve 38 and pipe string 18, such as periodic coupling with a frequency that may be higher than the static component or the quasi-static low frequency component. As noted above, rotationally coupling the sleeve 38 and pipe string 18 creates damping forces (e.g., about axis A16) due to rotational interference between ribs 50 and sidewalls 44 of wellbore 12. In embodiments, the damping forces are oppositely directed to forces generating vibration in the drill string 16, to counter the vibrational forces to dampen vibration in the drill string 16. Optionally, the damping system 36 is activated at periodic times and irrespective of sensed vibration/motion. An advantage of the system disclosed herein is that engaging the ribs 50 with the sidewalls 44 generates counteracting forces that are substantially larger than forces a restricted inertia system is capable of generating.
An alternate example of a damping system 36A for damping vibration in the pipe string 18 is shown in a perspective view in FIG. 4A and in an elevational sectional view in FIG. 4B. Damping system 36A includes an annular hub 74A, which circumscribes and is fixedly coupled to pipe string 18. Mounted on an outer surface of hub 74A is a magnetic field source 76A. In the example of FIG. 4A, a magnetic field source 76A includes a number of magnets attached along the outer surface of hub 74A. Examples of the magnets include permanent magnets, and electromagnets, such as those having a coil wound around magnetic material (such as ferromagnetic material). As shown, the magnetic field sources 76A have elongated lengths that are generally aligned with an axis of hub 74A and substantially parallel with axis A16. Widths of the magnets each span a portion of the outer circumference of hub 74A. Magnetic field sources 76A are shown spaced angularly apart from one another, and in examples, successive magnetic field sources 76A are in contact with one another along their respective elongate edges. Circumscribing magnetic field source 76A is a ring 78A having an inner diameter spaced radially outward from an outer diameter of magnetic field source 76A, the spacing forms a gap 79A between magnetic field sources 76A and ring 78A. The gap 79A provides for rotation of the ring 78A with respect to the magnetic field sources 76A and the hub 74. In the embodiment shown, ring 78A is a generally monolithic member and that is made up of one or more of metal, a metal alloy, a ceramic, a composite, and combinations. Examples include other configurations, such as the ring 78A being segmented. The body of ring 78A has windings 80A embedded within, which includes one or more electrically conducting members. In the example of FIG. 4A, connection 72A is made up of elongated electrically conducting members, such as wires, and actuator 68A is a switch that selectively provides electrical communication from an electrical source (not shown) to the electrically conducting members of connection 72A. Examples of an electrical source include controller 28 (FIG. 1), controller 64 (FIG. 2), a battery, a generator, and any other device that provides electrical power either downhole or on surface. Ring 78A is inserted within and is rotationally coupled to sleeve 38. Ribs 50 are shown extending radially outward from sleeve 38 and penetrating subterranean formation 14, interaction between ribs 50 and subterranean formation 14 couples sleeve 38 and ring 78A to subterranean formation 14.
In a non-limiting example of operation of the damping system 36A of FIGS. 4A and 4B, initiation of damping system 36A occurs upon identification of the vibration/motion exceeding the threshold amount, or optionally initiation occurs periodically. An example of initiation of the damping system 36A includes providing electricity to the windings 80A via actuator 68A and connection 72A, which due to the arrangement of the windings 80A creates a magnetic field surrounding the magnetic field source 76A. Interaction between the magnetic field and magnetic field source 76A results in a torque t being applied to the magnetic field source 76A, which impedes relative rotation between the sleeve 38 and the pipe string 18. The torque t is applied to the pipe string 18 via coupling between the magnetic field source 76A and hub 74 and the coupling between hub 74A and pipe string 18. Applying a particular amount of electricity to actuator 68A and through connection 72A results in the torque t having a designated magnitude, where the designated magnitude is determined sufficient for damping HTFO in the pipe string 18 to below the threshold amount. In the example of FIGS. 4A and 4B, the coupling 60A includes hub 74A, magnetic field source 76A, and ring 78A. An example of coupling 60A is available from WITTENSTEIN cyber motor, Walter-Wittenstein-Strasse 1, 97999 Igersheim, Germany (www.wittenstein-cyber-motor.com).
Another example embodiment of a damping system 36B with coupling 60B is shown in a sectional plan view in FIG. 4C. In this example, an inner protrusion 82B, such as a cylinder or annular ring or ring segment, is mounted on an inner surface of sleeve 38. A piston 84B projects laterally from protrusion 82B and is moveable in a reciprocating motion in a direction generally parallel with axis A16. In an example, protrusion 82B is hydraulically powered, and line 70B is a flow line for selectively transporting hydraulic fluid to the protrusion 82B. In an alternative example, protrusion 82B is electrically powered, and line 70B is an electrically conductive member for communicating electricity to protrusion 82B from an electrical source, the same as or similar to that described above regarding connection 72A in FIG. 4A. Coupling 60B includes an annular stator 86B shown circumscribing pipe string 18 and disposed adjacent an end of piston 84B distal from cylinder 82. A slot 88B is formed axially through stator 86B at its outer periphery. An elongated rail 90B is attached to an inner surface of sleeve 38 and shown substantially parallel with axis A16. Stator 86B is oriented so that slot 88B and rail 90B are aligned and rail 90B is inserted into slot 88B. Inserting rail 90B into slot 88B rotationally couples stator 86B with sleeve 38. Slot 88B has a width that exceeds a width of rail 90B by an amount so that stator 86B is slidable with respect to rail 90B and along axis A16. Alternatively, coupling 60B includes multiple slots 88B and rails 90B spaced angularly apart respectively along the outer periphery of the stator 86B and inner surface of sleeve 38. Coupling 60B further includes a rotor 92B shown circumscribing and mounted onto an outer surface of pipe string 18. Rotor 92B is rotationally and axially attached to pipe string 18 and spaced a distance from stator 86B along axis A16 on a side opposite piston 84B. For the purposes of discussion herein, the coupling 60B of FIG. 4C is referred to herein as a braking type coupling.
In a non-limiting example of operation of damping system 36B of FIG. 4C, initiation of damping system 36B occurs upon identification of the vibration/motion exceeding the threshold amount, or optionally initiation occurs periodically. In embodiments in which protrusion 82B is hydraulically powered, initiating damping system 36B includes flowing hydraulic fluid through line 70B to protrusion 82B; and in embodiments in which protrusion 82B is electrically powered, initiating damping system 36B includes transmitting electricity through line 70B to protrusion 82B. Powering protrusion 82B, either by application of electricity or a flow of hydraulic fluid, causes protrusion 82B to apply a force onto piston 84 to urge piston 84B further outward from protrusion 82B in a direction as represented by arrow A84B. For example, in embodiments in which protrusion 82B is electrically powered, electricity through line 70B may be received by one or more piezo-elements that in response apply the force onto piston 84 to urge piston 84B outward. Continued urging of piston 84B in the direction of arrow A84B causes piston 84B to contact stator 86B. As stator 86B is moveable along rail 90B, further application of force onto piston 84B from protrusion 82B pushes stator 86B into sliding contact with rotor 92B. When the stator 86B and rotor 92B are in sliding contact, friction between stator 86B and rotor 92B generates a damping force the same or similar to that described above, in the pipe string 18 that dampens the vibration of the pipe string 18.
Shown in block diagram in FIG. 5 is an example of a control scheme 500 for damping vibration in the pipe string 18 with the damping system 36 of FIG. 2. In the control scheme 500 is a feedback loop 502 illustrating the coupling 60 (FIG. 2) applying a counter moment to the drill string 18 based on torsional motion sensed in the damping system (FIG. 3) or elsewhere in the drill string 16, which as described above maintains torsional motion of the BHA 21 to within a designated amount. At point 504 a counter moment that is created by the coupling is added to the vibration that are excited in the drill string 16 when the vibration level is above a pre-selected threshold value to compensate for vibrations induced into the pipe string 18 resulting from interaction of the drill bit 20 with rock in the formation 14.
Shown in FIG. 6 is a flow chart 600 of an example of operation of the damping system of FIG. 2. In step 601, after the pipe string 18 is lowered into wellbore 12, ribs 50 are coupled to sidewalls 44 of wellbore 12. In step 602 motion of the BHA 21 or other portions of drill string 16 is sensed with a sensor 62 (FIG. 2), for example by sensing the relative motion of pipe string 18 relative to sleeve 38. In alternatives, the sensed motion is converted into a signal representing the motion, examples of which include one or more values or ranges of amplitude, and frequency. In step 604, a counter acting moment is calculated based on the sensed motion. As illustrated in FIG. 6, in one embodiment, step 604 two steps: in step 606, portions of the signal representing the motion of the BHA 21 are divided or separated based on their frequency to split the sensed motion into two or more frequency components or bands, such as low frequency signals, medium frequency signals, and high frequency signals. In step 608, one or more counter acting force or torque is calculated for each of the two or more frequency components or bands and converted to one or more signals indicative of the counter acting force or torque for one or more of the two or more frequency components or bands. In step 610, the one or more signals converted within step 604 and or step 608 are transmitted to an actuator 68 (FIG. 2). In step 612, based on the one or more signals from step 604 and or step 608, the actuator 68 exerts a counteracting moment to the pipe string 18 to counteract the oscillations generated from contact between the drill bit 20 and formation 14.
The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results, such as including a steering unit 25 with the drill string 16 (FIG. 3). In examples, controllers 28, 64 include an information handling system (IHS), which stores recorded data as well as processing the data into a readable format, and includes a processor, memory accessible by the processor, nonvolatile storage area accessible by the processor, and logics for performing each of the steps described herein. Controllers 28, 64 optionally includes memory 67, examples of which include non-transitory computer-readable storage medium having stored thereon, one or more of executable code, operating instructions, control information, data and database records. Examples of executable code include a set of instructions that causes processor/controller, to perform operations, such as receiving signals, generating and sending signals, where the signals include commands for operation of components (including those disclosed herein), and performing mathematical computations. In alternatives, memory is separate from controllers 28, 64 and connected for communication or integral with processor/controller and includes one or more of a computer diskette, magnetic tape, conventional hard disk drive, electronic read-only memory, optical storage device, any appropriate data storage device having a non-transitory computer readable storage medium stored thereon, and a server. Communication between controllers 28, 64 and/or surface S is optionally through communication means 30, examples of which include hardwired, wireless, fiberoptic, telemetry techniques described above, and the like. In examples, historical data is stored in processor/controller, and/or processor/controller, and/or other digital storage media (not shown). In another embodiment, a magnetorheological fluid is disposed between the sleeve and the drill string, and superimposing a magnetic field onto the magnetorheological fluid generates a torque t in the drill string to create damping. These and other similar modifications will readily suggest themselves to those skilled in the art and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.
Patent Application
20250075568
