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Mud Hydraulics Optimization 95

Table 4.2 Mud Flow Rate-Related Parameter Values Given by HYDPRO

Pump Parasitic Bit
2000
Hydraulic Horsepower (HP) 1500

1000

500

0
0 200 400 600 800
Flow Rate (gpm)
Figure 4.3 Hydraulic horsepower versus flow rate profile in the circulating
system.

that the bit hydraulic horsepower will reach 50% of pump horsepower at
a mud flow rate of about 500 gpm.
The calculated jet impact force profile is presented in Figure 4.4,
which indicates that the impact force will be maximal at a mud flow rate
of about 570 gpm. The calculated equivalent circulating density profile is
illustrated in Figure 4.5. It shows that the ECD profile is between the
pore pressure gradient, 9.2 ppg, and the fracture pressure gradient,
10.65 ppg, if the mud flow rate is less than 560 gpm—that is, neither