Page 137 - Air and gas Drilling Field Guide 3rd Edition

128 CHAPTER 5 Compressors and Nitrogen Generators

5.6.4 Fuel Consumption
In order to plan air or gas drilling operations effectively, it is important to be able
to predict the fuel consumption by the prime movers of compressor system units.
The consumption of either liquid or gaseous fuels is initially calculated in pounds
of fuel used per horsepower-hour (lb/hp-hr, N/kW-hr). Fuel consumption is very
dependent upon the prime mover’s power ratio, or percent power utilization of
total power available.
Figure 5-16 gives the approximate fuel consumption for prime movers fueled
with gasoline, propane/butane, or diesel [3, 12]. Most stationary prime movers
can be field converted to operate on propane/butane or natural gas. Figure 5-17
gives the approximate fuel consumption for prime movers fueled by natural gas
[3, 12].
Figures 5-16 and 5-17 are approximate values covering most prime mover
designs. However, more accurate estimates for prime mover fuel consumptions
can be obtained from the manufacturer specifications.
Illustrative Example 5.3 Determine the diesel fuel consumption rate (in
gallons per hour) for the primary reciprocating piston compressor system and
conditions given in Illustrative Example 5.1 for (a) a surface location at sea level
and (b) a surface location elevation of 6000 ft (1829 m).

0.80

0.75 4.50
Gasoline
Fuel consumption (lb/hp-hr) 0.65 Propane/Butane 4.00 Fuel consumption (N/kW-hr)
0.70

0.60
3.50

0.55

0.50 Diesel 3.00

0.45
50 60 70 80 90 100
Percent load on prime mover

FIGURE 5-16. Fuel consumption for gasoline, propane/butane, and diesel [3, 12].