Choke control tuned by flow coefficient for controlled pressure drilling
AssigneeWeatherford Technology Holdings, LLC
InventorsJose D. Brana, Jeffrey W. Niazy
Life of this patent
Estimating the term…
Abstract
A computerized control is used in controlling a choke when drilling a wellbore with a drilling system. The computerized control obtains a measured value of a parameter in the drilling system and controls the parameter in the drilling system using the choke. The computerized control obtains indications of an error between a set point of the parameter and the measured value of the parameter in the drilling system, a flow coefficient character of the choke, and a current position of the choke. Based on these indications, the computerized control then determines a position adjustment for the choke and adjusting the parameter in the drilling system by applying the position adjustment to the choke.
Claims27
A method, implemented by a computerized control, of drilling a wellbore with a drilling system having a choke, the method comprising:
- obtaining, with the computerized control, a measured value of a parameter in the drilling system;
- controlling, with the computerized control, the parameter in the drilling system using the choke;
- obtaining, with the computerized control, indications of an error between a set point of the parameter and the measured value of the parameter in the drilling system, a flow coefficient character of the choke, and a current position of the choke;
- determining, with the computerized control, a position adjustment for the choke based on the indications of the error, the flow coefficient character, and the current position comprising scaling a value of the error by a gain corrected for the flow coefficient character of the choke and applying the scaled value of the error to the current position;
- and
- adjusting, with the computerized control, the parameter in the drilling system using the choke by applying the position adjustment to the choke.
A method, implemented by a computerized control, of drilling a wellbore with a drilling system having a choke, the method comprising:
- drilling a wellbore with the drilling system by controlling, with the computerized control, a parameter in the drilling system using the choke;
- measuring a value of the parameter using at least one measurement device in the drilling system;
- calculating, with the computerized control, an error value between a set point of the parameter and the measured value of the parameter;
- interpolating, with the computerized control, a correction factor based on a flow coefficient character of the choke and a current position of the choke;
- determining, with the computerized control, a position adjustment for the choke by applying the correction factor to a gain and scaling the error value by the corrected gain;
- determining, with the computerized control, a new relative position for the choke by applying the position adjustment for the choke to the current position of the choke;
- and
- adjusting, with the computerized control, the parameter in the drilling system using the choke by applying the new relative position to the choke.
A computerized control of a choke used in a drilling system for drilling a wellbore, the control comprising:
- storage storing a flow coefficient character of the choke in relation to positions of the choke;
- and
- a programmable control device operatively coupled to the storage and to the choke, the programmable control device configured to:
- obtain a measured value of a parameter in the drilling system;
- control the parameter in the drilling system using the choke;
- obtain indications of an error between a set point of the parameter and the measured value of the parameter in the drilling system, the flow coefficient character of the choke, and a current position of the choke;
- scale a value of the error by a gain corrected for the flow coefficient character of the choke and apply the scaled value of the error to the current position to determine a position adjustment for the choke based on the indications of the error, the flow coefficient character of the choke, and the current position of the choke;
- and
- apply the position adjustment to the choke to adjust the parameter in the drilling system;
- and
- the position of the choke is adjusted by the programmable control device.
Dependencies are inferred from the claim text.