Page 88 - Formulas and Calculations for Petroleum Engineering

Drilling engineering formulas and calculations Chapter 2 81

Output(s)

P b : Bit Nozzle Pressure Loss (psi)

Formula(s)

MW
2
P ¼ Q
b 2
ð
10858 N Þ
a
Reference: Lapeyrouse, N. J., 2002, Formulas and Calculations for Drilling, Production and Workover, Second Edition,
Gulf Professional Publishing, Page: 165.

2.19 Bit nozzle selection—Optimized hydraulics for two and three jets

Input(s)
N a : Jet Size for nozzle 1 (in.)
N b : Jet Size for nozzle 2 (in.)
N c : Jet Size for nozzle 3 (in.)
Ca: Circulation Rate (gpm)
Cb: Circulation Rate (gpm)
Wm: Mud Weight (ppg)
Cpa: Circulating Pressure 1 (psi)
Cpb: Circulating Pressure 2 (psi)
P max : Max surface pressure (psi)
d: Dia of the nozzle chosen (in.)
n: No. of nozzles (unit)

Output(s)
2
A: Nozzle Area (in. )
Pba: Bit Nozzle Pressure Loss 1 (psi)
Pbb: Bit Nozzle Pressure Loss 2 (psi)
P ca : Total Pressure Loss for pump pressure 1 except bit nozzle (psi)
P cb : Total Pressure Loss for pump pressure 2 except bit nozzle (psi)
M: Slope of Line (unitless)
P iopt : Optimum Pressure for Impact Force (psi)
P hopt : Optimum Pressure for hydraulic Horsepower (psi)
Pilb: Pressure loss at the bit due to impact force (psi)
Phlb: Pressure loss at the bit due to hydraulic horsepower (psi)
Q iopt : Optimum flowrate for impact force (gpm)
Q hopt : Optimum flowrate for hydraulic horsepower (gpm)
2
A in : Area of nozzle for Impact force (in. )
2
A hn : Area of nozzle used for hydraulic horsepower (in. )
2
A n : Area of nozzle used (in. )