Method, system, and medium for controlling rate of penetration of a drill bit

A system for controlling a rate of penetration of a drill bit, the system comprising:

• (a) a processor;
• (b) a non-transitory computer readable medium communicatively coupled to the processor and having stored thereon computer program code that is executable by the processor, wherein the computer program code when executed by the processor causes the processor to:
• (i) evaluate a control loop, for each of multiple drilling parameters, wherein each drilling parameter is associated with a corresponding drilling parameter setpoint, by:
• (1) obtaining a drilling parameter measurement by using a drilling parameter sensor;
• (2) determining an error measurement that represents a difference between the drilling parameter setpoint associated with the drilling parameter and the obtained drilling parameter measurement;
• and
• (3) determining, from the error measurement, an output signal proportional to the rate of penetration of the drill bit;
• (ii) after evaluating each of the control loops, select, from among the multiple evaluated control loops, the determined output signal of only one of the control loops;
• and
• (iii) use the output signal that is selected to control the rate of penetration of the drill bit.

A system for controlling a rate of penetration of a drill bit, the system comprising:

• (a) drilling parameter sensors;
• and
• (b) an automatic driller communicatively coupled to each of the drilling parameter sensors to determine drilling parameter measurements from sensor readings, wherein the automatic driller is configured to:
• (i) evaluating a control loop, for each of multiple drilling parameters corresponding to the drilling parameter measurements, wherein each drilling parameter is associated with a corresponding drilling parameter setpoint, by:
• (1) reading a drilling parameter measurement;
• (2) determining an error measurement that represents a difference between the drilling parameter setpoint associated with the drilling parameter and the read drilling parameter measurement;
• and
• (3) determining, from the error measurement, an output signal proportional to the rate of penetration of the drill bit;
• (ii) after evaluating each of the control loops, select, from among the multiple evaluated control loops, the determined output signal of only one of the control loops;
• and
• (iii) use the output signal that is selected to control the rate of penetration of the drill bit.

A non-transitory computer readable medium having stored thereon computer program code that is executable by a processor, and which when executed by the processor causes the processor to perform a method for controlling a rate of penetration of a drill bit, the method comprising:

• (a) evaluating a control loop, for each of multiple drilling parameters, wherein each drilling parameter is associated with a corresponding drilling parameter setpoint, by:
• (i) reading a drilling parameter measurement by using a drilling parameter sensor;
• (ii) determining an error measurement that represents a difference between the drilling parameter setpoint associated with the drilling parameter and the read drilling parameter measurement;
• and
• (iii) determining, from the error measurement, an output signal proportional to the rate of penetration of the drill bit;
• (b) (after evaluating each of the control loops, selecting, from among the multiple evaluated control loops, the determined output signal of only one of the control loops;
• and
• (c) using the output signal that is selected to control the rate of penetration of the drill bit.