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EP-4444982-B1 - DAMPING DRILL STRING VIBRATIONS

EP4444982B1EP 4444982 B1EP4444982 B1EP 4444982B1EP-4444982-B1

Inventors

  • CAYEUX, ERIC

Dates

Publication Date
20260506
Application Date
20221205

Claims (11)

  1. A device (100) for damping vibrations of a rotary drill string in motion in a wellbore, the device comprising: brake means to counter the vibrations, by way of resisting the motion in dependence upon the speed of motion, wherein the brake means comprises at least one pair of brake parts (15, 65); an inner, tubular body (13) extending longitudinally between first and second ends (11, 12), the first end (11) being configured with a threaded section to screw connect the tubular body (13) to a first adjacent section of a drill string, and the second end (12) being configured with a threaded section to screw connect to a second adjacent section of the drill string, the tubular body (13) thus being configured to rotate with the drill string; an outer sleeve (60) supported on the inner, tubular body (13), the tubular body (13) being arranged rotatably within the outer sleeve (60); and at least one roller wheel (64) for supporting the sleeve (60) on a wall of the wellbore, the roller wheel (64) being configured to facilitate longitudinal movement of the device (100) along the wall and prevent rotational slipping of the outer sleeve (60) relative to the wall upon rotation of the drill string; wherein the inner, tubular body (13) is associated with the one brake part (15) of the pair, and the outer sleeve (60) is associated with the other brake part (65) of the pair, the one brake part (15) being movable relative to the other brake part (65) upon rotation of the tubular body (13) relative to the outer sleeve (60); characterized in that: the brake parts (15, 65) are operable, through the movement of the one brake part (15) relative to the other brake part (65) upon rotation of the tubular body relative to the outer sleeve (60) with the drill string, to produce a braking force in dependence upon the speed of rotation of the inner, tubular body (15) relative to the outer sleeve (60) for braking or resisting rotational vibrations; and either: the one brake part (15) comprising at least one magnet to produce a magnetic field, and the other brake part (65) comprising non-magnetic, conductive material to be subjected to the magnetic field, so that upon relative movement between the brake parts (15, 65) eddy currents are obtained in the non-magnetic, conductive material of the other part (65) for resisting the movement; or the other brake part (65) comprising at least one magnet to produce a magnetic field, and the one brake part (15) comprising non-magnetic, conductive material to be subjected to the magnetic field, so that upon relative movement between the brake parts (15, 65) eddy currents are obtained in the non-magnetic, conductive material of the one part (15) for resisting the movement.
  2. A device as claimed in claim 1, wherein either or both of the brake parts (15, 65) comprise a ring or sleeve or annular member.
  3. A device as claimed in claim 1 or claim 2, wherein the outer sleeve is supported on the inner tubular body on bearings for facilitating rotation of the inner tubular body with respect to the outer sleeve upon rotating the drill string in use.
  4. A device as claimed in any preceding claim, further comprising at least one other pair of brake parts (68, 75) for braking or resisting a longitudinal component of movement of the device (100) relative to the wellbore in use.
  5. A device as claimed in claim 4, wherein the other pair of brake parts (68, 75) for braking or resisting the longitudinal component and the pair of brake parts for braking or resisting the rotational component are operable to respond independently to longitudinal and rotational components of motion of the string with respect to the wellbore.
  6. A device as claimed in claim 4 or claim 5, wherein the pair of brake parts (68, 75) for braking or resisting the longitudinal component are disposed on the outer sleeve (60).
  7. A device as claimed in claim 6, wherein the at least one roller wheel (64) is coupled to at least one of the brake parts (68) of the other pair so that the movement of the wheel (64) on the wall of the wellbore in use longitudinally is communicated to produce movement between the brake parts (68, 75) of the other pair in dependence upon the movement of the string along the wellbore.
  8. A device as claimed in claim 7, wherein either or both brake parts (68, 75) of the other pair for braking or resisting the longitudinal movement along the wellbore comprises a ring, a body or a sleeve which is rotatable about an axis (7) and is coupled to the roller wheel (64) through a gear arrangement (80) for converting the rotational movement between the brake parts (68, 75) to longitudinal tracking of the roller wheel (64) along the wellbore or vice versa in dependence upon the longitudinal movement of the drill string with respect to the wall of the wellbore.
  9. A rotary drill string including at least one device (100) in accordance with any preceding claim disposed on a downhole section of the drill string.
  10. A rotary drill string as claimed in claim 9, including a plurality of devices (100) disposed on the drill string for damping vibrations at different downhole positions along the drill string, each being a device (100) in accordance with any of claims 1 to 8.
  11. A method of drilling a borehole using a drill string in accordance with claim 9 or claim 10.

Description

The present invention relates to drill strings, and in particular, it relates to a device for damping drill string vibrations of a rotary drill string. Drill stem vibrations during wellbore drilling operations are generally a significant problem and a source of drilling malfunctions. Vibrations can lead to failures of sensitive parts in the BHA like measurement while drilling tools, rotary steerable systems, positive displacement motors, but also to prematurely wear tool joints with the possible consequence of a pipe washout or even twist-offs. Repetitive shocks of the drill string with the formation rocks can destabilize the open hole leading to hole collapse. Also, unstable conditions at the bit deteriorate the rate of penetration and can lead to bit damage. Most current solutions that address drill string vibrations presuppose that the source of excitation is at the bit-rock interaction. Those existing solutions utilize one single vibration attenuation mechanism either inside the BHA like an anti-stall tool or at the top drive as with stick-slip mitigation systems that control the top-drive speed or torque to damp out torsional oscillations. However, drill string vibrations have many more sources of excitations such as mechanical friction between the drill string and the borehole in the axial and rotational directions, grinding of cuttings by the tool joints, the complex interactions between hydraulic generated forces and mechanical friction and centrifugal, Euler and Coriolis accelerations on the rotating pipes. All these additional sources of vibrations are distributed along the string. Some of those vibrations may propagate along the full length of drill string like torsional oscillations, while others may just concern a portion of the string such as during whirling conditions. The present inventor has found that typical single-location vibration damping solutions only deal with certain vibration scenarios. At least one aim of the invention is to obviate or at least mitigate one or more drawbacks of prior art. Example prior art includes U.S. Patent Application Publication Number US2020/0018377A1 and U.S. Patent Number US7306058B2. According to a first aspect of the invention, there is provided a device for damping vibrations of a rotary drill string in motion in a wellbore, the device comprising: brake means to counter the vibrations, by way of resisting the motion in dependence upon the speed of motion, wherein the brake means comprises at least one pair of brake parts; an inner, tubular body extending longitudinally between first and second ends, the first end being configured with a threaded section to screw connect the tubular body to a first adjacent section of a drill string, and the second end being configured with a threaded section to screw connect to a second adjacent section of the drill string, the tubular body thus being configured to rotate with the drill string; an outer sleeve supported on the inner, tubular body, the tubular body being arranged rotatably within the outer sleeve; and at least one roller wheel for supporting the sleeve on a wall of the wellbore, the roller wheel being configured to facilitate longitudinal movement of the device along the wall and prevent rotational slipping of the outer sleeve relative to the wall upon rotation of the drill string; wherein the inner, tubular body is associated with the one brake part of the pair, and the outer sleeve is associated with the other brake part of the pair, the one brake part being movable relative to the other brake part upon rotation of the tubular body relative to the outer sleeve; wherein the brake parts are operable, through the movement of the one brake part relative to the other brake part upon rotation of the tubular body relative to the outer sleeve with the drill string, to produce a braking force in dependence upon the speed of rotation of the inner, tubular body relative to the outer sleeve for braking or resisting rotational vibrations; and either: the one brake part comprising at least one magnet to produce a magnetic field, and the other brake part comprising non-magnetic, conductive material to be subjected to the magnetic field, so that upon relative movement between the brake parts eddy currents are obtained in the non-magnetic, conductive material of the other part for resisting the movement; or the other brake part comprising at least one magnet to produce a magnetic field, and the other brake part comprising non-magnetic, conductive material to be subjected to the magnetic field, so that upon relative movement between the brake parts eddy currents are obtained in the non-magnetic, conductive material of the one part for resisting the movement. The device may have any one or more further features as set out in any of the dependent claims 2 to 11 of the claims appended hereto, or anywhere else herein. In examples of this device, it can be appreciated that the inner tubular body is arranged within the outer