Hydraulic Horsepower
Hydraulic horsepower is based on the theory that cuttings are best removed from beneath the bit by delivering the most power to the bottom of the hole.
The amount of pressure lost at the bit, or bit pressure drop, is essential in determining the hydraulic horsepower. Bit pressure drop is determined by:
where: MD = Mud Density (lb/gal)
Vn = Nozzle Velocity (ft/sec)
From the bit pressure loss, hydraulic horsepower can be calculated:
To optimize Bottom Hole Cleaning and Bit Hydraulic Horsepower, it is necessary to select a circulation rate and nozzle sizes which will cause 65% of the pump pressure to be expended forcing the fluid through the jet nozzles of the bit.
