STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Mud Pumps 645
APa = pressure loss in annulus in psi
AP,, = pressure drop through bit nozzles in psi
Table 4-42 shows the jet velocity. Table 443 shows the diameters and areas of
various nozzle sizes.
The required pump hydraulic horsepower (PHHP) can be calculated as
PHHP = HHPcirc + HHPbit (4-37)
where HHPci,, = total HHP loss due to pressure losses in the circulating system
HHPbit = hydraulic horsepower required at the bit
The general hydraulic horsepower is
Q LIP
HHP = -
1714
(4-38)
where Q = flow rate in gal/min
AP = pressure difference in psi
The minimum bit HHP is shown in Figure 4-104. The maximum useful bit
HHP is shown in Figure 4-105 and Figure 4-106 [18].
Useful Formulas
Theoretical output Q, (gal/min) for a double action duplex pump is
Q, = O.O13GNS( 0; - $) (4-39)
where N = strokes per minute
S = stroke length in in.
D, = liner diameter in m
d = piston rod diameter in in.
Theoretical output Q, (gal/min) for a single action triplex pump is
(2, = 0.0102 NS 0:
(4-40)
The volumetric efficiency q, for duplex pumps or triplex pumps is
q =a Q
" Q,
(441)
where Q, = actual volumetric flow rate in gal
Input engine power IHP (hp) required for a given pump theoretical output
Q, and pump working pressure PWP is
(text continued on page 650)