National Oilwell Varco, L.p.

Christopher P Mullin

Ryan J Hanford

Francisco Ocegueda-Hernandez

Cole Wong

Benjamin Facker

A drilling system includes a drill string, a plurality of sensors, and a computing system. The drill string includes a downhole motor. The sensors are coupled to the drill string. The computing system is coupled to the sensors. The computing system is configured to compute, based on measurements provided by the sensors, a motor stall index, and to determine, by comparing the motor stall index to a motor stall threshold, whether the downhole motor has stalled. The computing system is also configured to, responsive to a determination that the downhole motor has stalled, adjust operation of the drill string to restart the downhole motor.

Downhole motor stall detection

Tagging bottom utilizing an automated control system and downhole tools may include determining, by a computer processor, that a drill bit has reached a predetermined distance from a bottom of a wellbore, in response to determining that the bit has reached the predetermined depth, transmitting a rate of penetration set point to reduce a lowering speed of the drill bit, directing the drill bit based on the rate of penetration, determining, by the computer processor, that the rate of penetration is stable, in response to the determining that the rate of penetration has stabilized, automatically taring a surface weight on the drill bit and a differential pressure, and in response to determining that the bit is within a predetermined off bottom range, monitoring for a true bottom based on one or more parameter triggers.

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Houston, TX, United States of America

Christopher P Mullin