Crude Oil Treating System
Example Sizing a Vertical Treater
Given:
Oil gravity = 40°API, 0.875 S.G.
Oil flow rate = 2,000 bpd
Inlet oil temperature = 90°F
Water S.G. = 1.04
Inlet BS&W = 10%
Outlet BS&W =1%
Solution:
1. Settling Equation. Investigate treating at 90°F, 100°F, 120°F.
2. Retention Time. Plot computations of d and h with retention times less than 20 minutes.
d2 h = (20) (2,000)70.12 = 333,333
The shaded area [...]
6Oct2009 | admin | Comments Off | ContinuedExample Sizing a Horizontal Treater
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 [...]
6Oct2009 | admin | Comments Off | ContinuedTreaters Design Procedure
In specifying the size of a treater, it is necessary to determine the diameter (d), length or height of the coalescing section (Leff or h), and treating temperature or fire-tube rating. As we have seen, these variables are interdependent, and it is not possible to arrive at a unique solution for each. The design engineer [...]
15Sep2009 | admin | Comments Off | ContinuedTreaters Water Droplet Size
In order to develop a treater design procedure, the water droplet size to be used in the settling equation to achieve a given outlet water cut must be determined. As previously mentioned, it would be extremely rare to have laboratory data of the droplet size distribution for a given emulsion as it enters the coalescing [...]
15Sep2009 | admin | Comments Off | ContinuedTreater Retention Time Equations
The oil must be held at temperature for a specific period of time to enable de-emulsifying the water-in-oil emulsion. This information is best determined in the laboratory but, in the absence of such data, 20 to 30 minutes is a good starting point.
Depending on the specific properties of the stream to be treated, geometry required [...]
Treater Settling Equations
The specific gravity difference between the dispersed water droplets and the oil should result in the water “sinking” to the bottom of the treatment vessel.
Since the oil continuous phase is flowing vertically upward in both vertical and horizontal treaters previously described, the downward velocity of the water droplet must be sufficient to overcome the velocity [...]
Electrostatic Treaters
Some treaters use an electrode section. Figure 6-11 illustrates a typical design of a horizontal electrostatic treater. The flow path in an electrostatic treater is the same as a horizontal treater. The only difference is that an AC and/or DC electrostatic field is used to promote coalescence of the water droplets.
Procedures for designing electrostatic [...]