Bit Nozzle Selection Optimized Hydraulics

These series of formulas will determine the correct jet sizes when optimizing for jet impact or hydraulic horsepower and optimum flow rate for two or three nozzles.

1. Nozzle area, sq in.:

   
   

2. Bit nozzle pressure loss, psi (Pb):

   
   

3. Total pressure losses except bit nozzle pressure loss, psi (Pc):

   
   

4. Determine slope of line mml:

   
   

5. Optimum pressure losses (Popt)

   1. For impact force:

      
      

   2. For hydraulic horsepower:

      
      

1. For optimum flow rate (Qopt):

   1. For impact force:

      
      

   2. For hydraulic horsepower:

      
      

1. To determine pressure at the bit (Pb):

   
   

2. To determine nozzle area, sq in.:

   
   

3. To determine nozzles, 32nd in. for three nozzles:

   
   

4. To determine nozzles, 32nd in. for two nozzles:

   
   

• Example: Optimize bit hydraulics on a well with the following:

  • Select the proper jet sizes for impact force and hydraulic horsepower for two jets and three jets:

    • DATA: Mud weight = 13.0 ppg

    • Jet sizes = 17-17-17

    • Maximum surface pressure = 3000 psi

    • Pump pressure 1 = 3000 psi

    • Pump rate 1 = 420 gpm

    • Pump pressure 2 = 1300 psi

    • Pump rate 2 = 275 gpm

1. Nozzle area, sq in.:

   • 

   • Nozzle area, sq in. = 0.664979

1. Bit nozzle pressure loss, psi (Pb):

   • 

   • Pb ₁ = 478 psi

   • 

   • Pb ₂ = 205 psi

1. Total pressure losses except bit nozzle pressure loss (Pc), psi:

   • Pc ₁ = 3000 psi ? 478 psi

   • Pc ₁ = 2522 psi

   • Pc ₂ = 1300...