Work string controller
AssigneeHalliburton Energy Services, Inc.
InventorJustin Borgstadt
Life of this patent
Estimating the term…
Abstract
Well bore servicing equipment is provided. The well bore servicing equipment comprises a first manipulator to grip a well bore work string, to raise the work string, and to lower the work string. The well bore servicing equipment further comprises a controller to receive a work string trajectory input and to automatically control the first manipulator to raise and lower the work string substantially in conformance with the work string trajectory input.
Claims20
A pressure observer, comprising:
- a first proportional-integral (PI) controller portion operable to determine a first pressure error and to generate a first corrective signal based on the first pressure error;
- a first feed-forward portion operable to determine a first flow rate based on a first velocity and a first gain;
- a first integrator operable to integrate the sum of the first corrective signal and the first flow rate;
- and
- a second gain operable to amplify an output of the first integrator by a first model gain and to produce a first pressure estimate.
A control system for controlling movement of a work string in a well bore, comprising:
- a controller comprising a processor, a memory, and a pressure observer component, the pressure observer component comprising
- a first proportional-integral (PI) controller portion operable to determine a first pressure error and to generate a first corrective signal based on the first pressure error;
- a first feed-forward portion operable to determine a first flow rate based on a velocity of a first hydraulic actuator and a first gain;
- a first integrator operable to integrate the sum of the first corrective signal and the first flow rate;
- and
- a second gain operable to amplify an output of the first integrator by a first model gain and to produce a first pressure estimate,
- wherein the controller commands the first hydraulic actuator to move the work string based at least in part on the first pressure estimate.
A method of servicing a wellbore with a work string, comprising:
- receiving a work string trajectory input from a user interface, wherein the work string trajectory comprises at least a first work string target position and a first work string target velocity;
- determining a first pressure error and generating a first corrective signal based on the first pressure error;
- determining a first flow rate based on a velocity of a first hydraulic actuator and a first gain;
- integrating the sum of the first corrective signal and the first flow rate to determine a first integrated value;
- determining a first pressure estimate based on amplifying the first integrated value by a first model gain;
- determining a first hydraulic actuator control command based on the first pressure estimate and the work string trajectory input moving the workstring within the wellbore responsive to the first hydraulic actuator control command.
Dependencies are inferred from the claim text.