Removal of stick-slip vibrations in a drilling assembly

Patent metadata

Field	Value
Publication number	US-10550683-B2
Application number	US-201314912087-A
Country	US
Kind code	B2
Filing date	Sep 17, 2013
Priority date	Sep 17, 2013
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

An example method for removal of stick-slip vibrations may comprise receiving a command directed to a controllable element of a drilling assembly. A smooth trajectory profile may be generated based, at least in part, on the command. A frictional torque value for a drill bit of the drilling assembly may be determined. The example method may further include generating a control signal based, at least in part, on the trajectory profile, the frictional torque value, and a model of the drilling assembly, and transmitting the control signal to the controllable element.

First claim

What is claimed is:

1. A method for removal of stick-slip vibrations of a drilling assembly, comprising:
receiving a command, at a control system of the drilling assembly, directed to a first controllable element of the drilling assembly, wherein the first controllable element comprises a drilling equipment of the drilling assembly and wherein the control system comprises a trajectory planning element, a drilling controller, an online system identification element and a system states observer, and wherein the system identification element comprises an online model and an online learning mechanism, and wherein the system states observer comprises a system model, and wherein the drilling controller comprises a feedforward model compensation element and a feedback controller element;
generating, by the trajectory planning element, a smooth trajectory profile based, at least in part, on the command, wherein the smooth trajectory profile is expressed as a smooth function, and wherein the smooth trajectory profile drives the first controllable element from a first operating point to a second operating point without saturating the first controllable element, wherein the trajectory planning element accesses one or more operation parameters corresponding to the first controllable element to which the command is directed;
receiving at the drilling controller the smooth trajectory profile, a first online system identification element output from the online system identification element and a first system states observer output from the system states observer, wherein the first online system identification output comprises an identified parametric value within the online model and wherein the first system states observer output comprises a system states estimation output from the system model, wherein the first system identification element output comprises a nonlinear friction torque on a drilling bit calculated by the first system identification element;
receiving at the online system identification element, the system states observer and the drilling controller one or more first measurements from one or more downhole sensors, wherein the one or more first measurements correspond to at least one of one or more drilling parameters and one or more downhole conditions;
generating, by the drilling controller, a first control signal based, at least in part, on the smooth trajectory profile, the first system identification element output and the first system states observer output;
transmitting, from the drilling controller, the first control signal to the first controllable element to change a drilling parameter of the drilling assembly, the online system identification element and the system states observer;
receiving at the online system identification element and the system states observer the first control signal, wherein a second online system identification element output and a second system states observer output are based, at least in part, on one or more second measurements from the one or more downhole sensors, the first control signal and one or more models of the drilling assembly; and
generating, by the drilling controller, a second control signal based, at least in part, on the second identification element output, the second system states observer output and a subsequently generated trajectory profile for a second controllable element.

2. The method of claim 1 , wherein the identified parametric value comprises a frictional torque value that is based, at least in part, on at least one of the one or more first measurements and an estimated downhole condition value for the online model of the one or more models.

3. The method claim 2 , further comprising determining the estimated downhole condition value for the online model based, at least in part, on the at least one of the one or more first measurements;
the first control signal; and
the frictional torque value.

4. The method of claim 3 , wherein determining the estimated downhole condition value for the online model comprises adaptively choosing one of a Kalman filter and a particle filter.

5. The method of claim 1 , wherein
the drilling assembly comprises
a drill string;
a top drive coupled to a proximal end of the drill string; and
the drill bit coupled to a distal end of the drill string; and

the first controllable element comprises the top drive.

6. The method of claim 5 , wherein generating the first control signal comprises receiving at a drilling controller
the smooth trajectory profile;
the frictional torque value;
an estimated downhole condition value for the online model; and
the one or more measurements.

7. The method of claim 6 , wherein the online model comprises a lumped mass model of the drilling assembly with masses corresponding to the top drive and the drill bit, and a torsional spring corresponding to the drill string.

8. The method of claim 7 , wherein generating the first control signal comprises determining a first motion profile for the drill bit to overcome frictional torque.

9. The method of claim 8 , wherein generating the first control signal further comprises;
determining a drill string twist value for the drill string that produces the first motion profile;
determining a second motion profile for the top drive that produces the drill string twist value; and
determining the control signal to the top drive that produces the second motion profile.

10. An apparatus for removal of stick-slip vibrations of a drilling assembly, comprising:
a processor;
a non-transitory memory device coupled to the processor, wherein the memory device contains a set of instructions that, when executed by the processor, cause the processor to:
receive a command, at a control system of the drilling assembly, directed to a first controllable element of the drilling assembly, wherein the first controllable element comprises a drilling equipment of the drilling assembly and wherein the control system comprises a trajectory planning element, a drilling controller, an online system identification element and a system states observer, and wherein the system identification element comprises an online model and an online learning mechanism, and wherein the system states observer comprises a system model, and wherein the drilling controller comprises a feedforward model compensation element and a feedback controller element;
generate, by the trajectory planning element, a smooth trajectory profile based, at least in part, on the command, wherein the smooth trajectory profile is expressed as a smooth function, and wherein the smooth trajectory profile drives the first controllable element from a first operating point to a second operating point without saturating the first controllable element, wherein the trajectory planning element accesses one or more operation parameters corresponding to the first controllable element to which the command is directed;
receive at the drilling controller the smooth trajectory profile, a first online system identification element output from the online system identification element and a first system states observer output from the system states observer, wherein the first online system identification output comprises an identified parametric value within the online model and wherein the first system states observer output comprises a system states estimation output from the system model, wherein the first system identification element output comprises a nonlinear friction torque on a drilling bit calculated by the first system identification element;
receive at the online system identification element, the system states observer and the drilling controller one or more first measurements from one or more downhol

Assignees

• Halliburton Energy Services Inc

Inventors

• Dykstra Jason D
• Bu Fanping
• Xue Yuzhen

Classifications

• G05D17/02

  characterised by the use of electric means · CPC title

• E21B19/06

  Elevators, i.e. rod- or tube-gripping devices · CPC title

• E21B44/00 Primary

  Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions · CPC title

• E21B44/04 Primary

  in response to the torque of the drive {; Measuring drilling torque (E21B44/06 takes precedence; measuring stresses in a well bore pipe E21B47/007)} · CPC title

• E21B21/08

  Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10) · CPC title