The following well conditions are given. Parameter Well depth, ft DP OD, in DP ID, in DP weight, lbm/ft DC (ODxID), in DC length, ft Casing (J-55) depth, ft Casing weight, lbm/ft Bit diameter, in Nozzles (three), in Power of duplex pump, hp Pump liner, in Rod size, in Stroke length, in Overall efficiency, % Surface piping, ft Mud density, ppg Minimum annular velocity, ft/min Rotational speed, rpm Dial reading, degrees Maximum surface pressure, psi Value 15000 5 4.33 19.5 8x3 600 4500 40.5 9.875 13/32 1500 Explanation Assume average hole size of 10 in. 6.5 2.5 18. 85 200 12 120 3 6 100 200 300 600 1.8 3 10 15 20 36 3500 Equivalent to drillpipe a) Compute the equivalent circulating density at depths of 4000 ft corresponding to an annular velocity opposite to drillpipe of 120 ft/min using the Power Law model. b) Compute the total nozzle area of the bit needed for maximum bit horsepower.