A recommended bit program is being prepared for a new well, using bit performance records from nearby wells. Drilling records for three bits are shown below for a thick shale section encountered at 12,000 ft. Determine which bit gives the lowest drilling cost if the hourly operating cost of the rig is $1,000/hr and the trip time is 10 hours. The connection time is in- cluded in the rotating time shown below. Interval Drilled Rotating Time (hours) Bit Cost Bit ($) (ft) A 700 106 62 4,000 8,000 B 415 912 153 Answer: Bit B ($183.13/ft).