We are drilling along at $6,000ft$ with a $\frac{97}{8}$ bit with a mud rate of $300gpm$ at a pump pressure of $2500$ psig. At $200gpm,$ the pressure is $900g.$ The pump is $900hp$ with an efficiency of $0\mathrm{.}92.$ Minimum flowrate $($cuttings$)$ is $160gpm.$ The maximum pump pressure allowed is $3200$ psig.

a$.$ If we want to maximize hydraulic impact force, what is the appropriate nozzle diameter and flow rate for the next run?

b$.$ What is the bit horsepower and impact force at these conditions?

c$.$ Say we were to come back later when we are at $8,000ft,$ would you expect the optimum nozzle diameter to be larger or smaller?