Hydraulic winch control
AssigneeSchlumberger Technology Corporation
InventorFanping Bu
Life of this patent
Estimating the term…
Abstract
A method for controlling a hydraulic winch includes acquiring measurements from sensors coupled to the hydraulic winch. A first control function is computed based on the measurements. The first control function sets pressure across a variable displacement motor that produces motion of the tool string following a desired motion trajectory. A second control function is computed. The second control function sets displacement of a variable displacement pump that causes the pressure across the variable displacement motor to track the first control function. A pump command is selected based on the second control function. The pump command is transmitted to the variable displacement pump. The tool string moves responsive to the pump command.
Claims20
A method for controlling a hydraulic winch to move a tool string within a wellbore, the method comprising:
- receiving, at a controller, measurements from sensors associated with a variable displacement pump of the hydraulic winch;
- estimating, by the controller, based on the received measurements:
- an effective drum radius of a drum of the hydraulic winch, wherein the effective drum radius includes a cable at least partially wound around the drum;
- and
- an effective mass of the drum, wherein the effective mass accounts for a portion of the cable that is at least partially wound around the drum;
- determining, by the controller, a desired movement profile for the tool string, wherein the desired movement profile includes at least a desired tool depth as a function of time;
- generating, by the controller, a control command based on the estimated effective drum radius, the estimated effective mass of the drum, and the desired movement profile;
- and
- providing the control command to the variable displacement pump, wherein the variable displacement pump carries out the control command to cause the drum of the hydraulic winch to raise or lower the tool string according to the desired movement profile.
A hydraulic winch for moving a tool string within a wellbore, comprising:
- a drum for winding or unwinding a cable attached to the tool string;
- a variable displacement motor configured to drive the drum;
- a variable displacement pump configured to drive the variable displacement motor;
- and
- a controller configured to provide control commands to the variable displacement pump, wherein the controller is further configured to perform stages comprising:
- receiving measurements from sensors associated with the variable displacement pump;
- estimating based on the received measurements:
- an effective drum radius of the drum, wherein the effective drum radius includes a cable at least partially wound around the drum;
- and
- an effective mass of the drum, wherein the effective mass accounts for a portion of the cable that is at least partially wound around the drum;
- determining a desired movement profile for the tool string, wherein the desired movement profile includes at least a desired tool depth as a function of time;
- generating a control command based on the estimated effective drum radius, the estimated effective mass of the drum, and the desired movement profile;
- and
- providing the control command to the variable displacement pump, wherein the variable displacement pump carries out the control command to cause the drum of the hydraulic winch to raise or lower the tool string according to the desired movement profile.
A controller for controlling a hydraulic winch to move a tool string within a wellbore, wherein the controller carries out instructions stored in a non-transitory, computer-readable medium to perform stages comprising:
- receiving measurements from sensors associated with a variable displacement pump of the hydraulic winch;
- estimating based on the received measurements:
- an effective drum radius of a drum of the hydraulic winch, wherein the effective drum radius includes a cable at least partially wound around the drum;
- and
- an effective mass of the drum, wherein the effective mass accounts for a portion of the cable that is at least partially wound around the drum;
- determining a desired movement profile for the tool string, wherein the desired movement profile includes at least a desired tool depth as a function of time;
- generating a control command based on the estimated effective drum radius, the estimated effective mass of the drum, and the desired movement profile;
- and
- providing the control command to the variable displacement pump, wherein the variable displacement pump carries out the control command to cause the drum of the hydraulic winch to raise or lower the tool string according to the desired movement profile.
Dependencies are inferred from the claim text.