摘要 |
A method of operating a drill string includes receiving signals indicative of rotation of a bottom hole assembly (BHA) of the drill string; receiving signals indicative of the torque experience by the BHA; determining from the received signals an average slipping torque and a maximum sticking torque; determining a friction ratio based on the maximum sticking torque and the average slipping torque; and generating an indication that the friction ratio exceeds a limit. |