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)
\(\mathrm{Cb}\): Circulation Rate (gpm)
Wm: Mud Weight (ppg)
Cpa: Circulating Pressure 1 (psi)
\(\mathrm{Cpb}\): Circulating Pressure \(2(\mathrm{psi})\)
\(P_{\max }\): Max surface pressure (psi)
\(\mathrm{d}\): Dia of the nozzle chosen (in.)
\(\mathrm{n}\): No. of nozzles (unit)
Output(s)
A: Nozzle Area (in. \({ }^{2}\) )
Pba: Bit Nozzle Pressure Loss 1 (psi)
Pbb: Bit Nozzle Pressure Loss 2 (psi)
\(P_{c a}\): Total Pressure Loss for pump pressure 1 except bit nozzle (psi)
\(P_{c b}\): Total Pressure Loss for pump pressure 2 except bit nozzle (psi)
M: Slope of Line (unitless)
\(P_{\text {iopt }}\): Optimum Pressure for Impact Force (psi)
\(P_{\text {hopt }}\): 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)
\(Q_{\text {iopt }}\): Optimum flowrate for impact force (gpm)
\(Q_{\text {hopt }}\): Optimum flowrate for hydraulic horsepower (gpm)
\(A_{\text {in }}\): Area of nozzle for Impact force (in. \({ }^{2}\) )
\(A_{h n}\): Area of nozzle used for hydraulic horsepower (in. \({ }^{2}\) )
\(A_{n}\): Area of nozzle used (in. \({ }^{2}\) )
Formula(s)
Reference(s)
Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 166.