Adjustable gas spring tuned mass damper
Vibration in a drill string is damped with a damping system coupled to the drill string. The damping system includes a chamber, a gas and piston in the chamber, and a mass connected to the piston. The gas defines a spring having a spring coefficient that is dependent on a volume or temperature of the chamber. The damping system is tunable in real-time by varying the volume or temperature of the chamber. In alternatives with multiple chambers interconnected to one another via ports, chamber volume at the existing pressure can be varied by selective actuation of valves between the chambers or the pressure of the gas can be varied by compressing or expanding a connected bellows or by heating or cooling the temperature of the gas. The damping system can selectively damp both radial and torsional vibrations.
1 . A method of drilling a wellbore into a subterranean formation, the method comprising:
rotating a drill string in the wellbore;
damping vibrations of the drill string with a damping system in the drill string, the damping system comprising a gas spring having a spring coefficient; and
adjusting, while the drill string and the damping system is in the wellbore, the spring coefficient in response to one or more drilling parameters.
2 . The method of claim 1 , wherein the gas spring comprises gas in a first chamber having a first volume and wherein the spring coefficient is adjusted in response to a monitored vibration parameter by changing the first volume of the first chamber to a particular volume in real-time.
3 . The method of claim 1 , wherein the drill string comprises an actuator configured to adjust the spring coefficient while the drill string is in the wellbore.
4 . The method of claim 1 , wherein the gas spring comprises a first chamber having a first volume and a second chamber having a second volume, and wherein the method further comprises adjusting the spring coefficient by controlling a valve between the first chamber and the second chamber.
5 . The method of claim 1 , wherein the gas spring further comprises a dashpot, the dashpot configured to damp the vibrations of the drill string.
6 . The method of claim 1 , further comprising monitoring the drill string vibrations in real-time, wherein the gas spring comprises gas in a chamber and wherein the spring coefficient is adjusted in response to the monitored vibrations by changing a volume of the chamber to a particular volume.
7 . The method of claim 6 , further comprising measuring a vibration parameter related to the vibrations of the drill string, wherein the one or more drilling parameters comprise the vibration parameter.
8 . The method of claim 7 , wherein the vibration parameter is one of a frequency of the vibrations and an amplitude of the vibrations.
9 . The method of claim 7 , wherein the vibration parameter is a frequency of the vibrations and wherein the volume of the chamber is changed so that a resonant frequency of the gas spring is substantially similar to the frequency of the vibrations.
10 . The method of claim 1 , wherein the drill string further comprises a controller operatively connected to the gas spring, further comprising harvesting energy from the vibrations of the drill string to power the controller to adjust the spring coefficient in response to the one or more drilling parameters.
11 . A drilling system for drilling a wellbore into a subterranean formation, the drilling system comprising:
a drill string configured to rotate within the wellbore; and
a damping system in the drill string for damping vibrations of the drill string, the damping system comprising,
a mass configured to move relative to the drill string in response to the vibrations;
a gas spring connected to the mass and the drill string, the gas spring having a spring coefficient that is adjustable in response to one or more drilling parameters while the drill string and the damping system are in the wellbore.
12 . The drilling system of claim 11 , wherein the gas spring comprises a first chamber having a first volume and wherein the spring coefficient is adjusted by adjustment of the first volume so that a resonant frequency of the gas spring is substantially similar to a frequency of vibration of the drill string.
13 . The drilling system of claim 12 , wherein the damping system comprises an actuator configured to adjust the first volume while the drill string is in the wellbore.
14 . The drilling system of claim 11 , wherein the gas spring comprises:
a first chamber having a first volume; and
a second chamber having a second volume; and
a valve configured to control communication between the first chamber and the second chamber, wherein the spring coefficient is adjusted by operating the valve.
15 . The drilling system of claim 11 , wherein the damping system further comprises a controller operatively connected to the gas spring and configured to adjust the spring coefficient in response to the one or more drilling parameters.
16 . The drilling system of claim 15 , wherein the controller is powered by energy that is harvested from the vibrations of the drill string.
17 . The drilling system of claim 11 , further comprising a piston having a first side in communication with the gas and a second side coupled with the mass.
18 . The drilling system of claim 11 , further comprising a vibration parameter measurement device in the drill string configured to measure a vibration parameter related to the vibrations of the drill string, wherein the one or more drilling parameters comprise the vibration parameter, the vibration parameter comprises a value selected from the group consisting of a frequency of the vibrations and an amplitude of the vibrations.
19 . The drilling system of claim 11 , wherein the mass is configured to move relative to the drill string in response to the vibrations in a direction that is transverse to the longitudinal axis of the drill string.
20 . The drilling system of claim 11 , wherein the gas spring comprises a gas and a controller configured to control a temperature of the gas.