Methods and systems for drilling boreholes in earth formations

A system for drilling into an earth formation, comprising:

• an earth-boring drill bit comprising fixed cutting elements configured to engage with and remove an underlying earth formation;
• a drill string configured to be connected to the earth-boring drill bit to transfer longitudinal and rotational loads to the earth-boring drill bit;
• a drawworks configured to suspend the earth-boring drill bit and the drill string and to apply weight to the earth-boring drill bit via the drill string to advance the earth-boring drill bit into the underlying earth formation;
• a first sensor operatively associated with the drill string, the first sensor configured to sense a rotational speed of the drill string;
• a second sensor operatively associated with the drill string, the second sensor configured to sense a rate of penetration of the drill string during advancement of the earth-boring drill bit;
• and
• a control unit operatively connected to the first and second sensors and to the drawworks, the control unit comprising a processing unit and non-transitory memory operatively connected to the processing unit, the processing unit programmed to:
• determine an instantaneous average depth of cut of the cutting elements of the earth-boring drill bit utilizing a sensed rotational speed of the drill string and a sensed speed of advancement of the drill string utilizing the following algorithm:
• DOC
• =
• ROP
• RPM
• ×
• Redundancy
• wherein DOC is the instantaneous average depth of cut, ROP is the sensed rate of penetration, RPM is the sensed rotational speed of the drill string, and Redundancy is a sum of diameters of the cutting elements of the earth-boring drill bit divided by a radius of the earth-boring drill bit;
• compare the instantaneous average depth of cut to a predetermined minimum depth of cut stored in the nontransitory memory;
• and
• cause the drawworks to increase weight on the earth-boring drill bit when the instantaneous average depth of cut is less than the predetermined minimum depth of cut.