Given:

Oil gravity = 30°API, 0.875 S.G.

Oil flow rate = 5,000 bpd

Inlet oil temperature = 80°F

Water S.G. = 1.04

Inlet BS&W =10%

Outlet BS&W =1%

Solution:

1. **Settling Equation.** Investigate treating at 80°F, 100°F, 120°F.

2. **Retention Time Equation.** Plot computations of d and Leff with retention times less than 20 minutes.

The shaded area of Figure 6-13 represents combinations of d and Leff with t_{r} less than 20 minutes.

3. **Heat Required**

Substituting treating temperature values of 80°F, 100°F, and 120°F and substituting initial oil temperature value of 80°F will yield values of heat required of 0, 0.86, and 1.72 MMBtu/h.

4. **Selection.** Choose any combination of d and Leff that is not in the shaded area. Read corresponding treating temperature.

Example solutions are:

An economical solution would be a 72-inch-diameter treater with a 20-foot coalescing section and a 0.86-MMBtu/h firetube capacity. Given the nature of empirical design procedures, crude could possibly be treated at 80°F. The additional firetube capacity will allow a temperature of 100°F if required by field conditions.