Page 132 - Petroleum and Gas Field Processing

It is advisable to have the oil bucket as deep as possible and to have either
the oil weir, or the water weir, or both to be adjustable to accommodate
any unexpected changes in flow rates and/or liquids properties. Such
problems are easily accommodated in the interface controller and weir
design of Fig. 1, as the interface controller could be easily adjusted. In
some cases, however, when the difference in density between the water and
oil, or the water and emulsion are small (e.g., in heavy oil operations), the
operation of the interface controller becomes unreliable and the bucket
design (Fig. 2) will be preferred.

4.3 VERTICAL THREE-PHASE SEPARATORS

As discussed in Chapter 3, the horizontal separators are normally
preferred over vertical separators due to the flow geometry that promotes
phase separation. However, in certain applications, the engineer may be
forced to select a vertical separator instead of a horizontal separator
despite the process-related advantages of the later. An example of such
applications is found in offshore operations, where the space limitations
on the production platform may necessitate the use of a vertical separator.
Figure 3 shows a schematic of a typical three-phase vertical
separator. The produced fluid stream enters the separator from the side

Figure 3 Schematic of a three-phase vertical separator.

Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved.