Bit Hydraulics Calculator
Calculate jet velocity, impact force, HSI, and optimize bit hydraulic performance
Input Parameters
Enter flow rate, mud weight, and nozzle configuration
Target Ranges
- Jet Velocity: 250-450 ft/s optimal
- HSI: 2.5-5.0 hp/in2 recommended
- Impact Force: Maximize for ROP
- Bit Pressure Drop: 50-65% of system
Hydraulics Results
Enter parameters and click Calculate
Nozzle Size Reference
| Size (32nds) | Diameter (in) | Area (in2) |
|---|---|---|
| 10 | 0.3125 | 0.0767 |
| 11 | 0.3438 | 0.0928 |
| 12 | 0.3750 | 0.1104 |
| 13 | 0.4063 | 0.1296 |
| 14 | 0.4375 | 0.1503 |
| 16 | 0.5000 | 0.1963 |
Formula Reference
Total Flow Area (TFA)
TFA (in2) = Sum of (PI/4 x d^2) for each nozzle
Where d = nozzle diameter (inches) = size/32
Jet Velocity
Vn = Q / (3.117 x TFA)
Where:
Vn = Jet velocity (ft/s)
Q = Flow rate (gpm)
TFA = Total flow area (in2)
Bit Pressure Drop
dP_bit = (MW x Q^2) / (10858 x TFA^2)
Where:
dP_bit = Pressure drop across bit (psi)
MW = Mud weight (ppg)
Q = Flow rate (gpm)
Impact Force
F_impact = (MW x Q x Vn) / 1930
Where F_impact = Impact force (lbf)
Hydraulic Horsepower at Bit
HHP_bit = (dP_bit x Q) / 1714
HSI = HHP_bit / Bit_Area (in2)