Page 12 - Treating Oilfield Emulsions

Segment III
Chapter 7

Treating with Heater-Treaters
Petroleum Extension-The University of Texas at Austin
A heater-treater (also called a flow treater or
emulsion treater) is a device that combines
all the various pieces of equipment used to treat
an emulsion in one vessel. Thus, a heater-treater
is the vessel in which the effects of chemicals,
heat, settling, and, often, electricity are applied to
an emulsion.

The Construction of Heater-Treaters
A heater-treater (fig. 32) is designed to include
in one unit any orall of the following elements: oil
and gas separator, free-water knockout, heater,
water wash, filter section, stabilizing section, heat
exchanger, and electrostatic field. A large num­
ber of modifications in the basic pattern of heater­
treatersareavailable. Any of its functions may be
emphasized, depending on the service for which
it is designed. For example, a heater-treater may
have greater free-water capacity or less heating
capacity, and it mayor may not have a hay sec­
tion- a section packed with excelsior, which acts
as a filter. In addition, each model may be avail­
able in a number of sizes to handle different vol­
umes of well fluids and may be available in a
vertical or a horizontal configuration. Some
treaters are designed for use in extremely cold
Figure 32. A vertical heater-treater
climates; others are designed especially to treat
foaming oil. Selecting the right treater for any
given set of conditions is a complex engineering was obtained with other types of treating equip­
decision that can be made only after a large ment and thus increase the selling price of the oil.
number of factors are known.
Vmica' Heater-Treaters
In vertical heater-treaters, the emulsion usually
Types of Heater-Treaters
passes through a heat exchanger, where it is
Treaters can be operated at abnospheric pres­ preheated by the warmer outgoing clean oil. Then
sure, but they often operate under low working the emulsion enters the vessel, splashes over a
pressure-from 5 to SO psi-<iepending on the pan, and falls downward through a downcomer
construction ofthe vessel and the type of controls tube. At the bottom, any free water in the emul­
used. It is often advantageous to use the treater as sion falls out, and the emulsion flows upward
a low-pressure, second-stage separator as well as through the water, which serves as a washing
a treating unit. Where flow-line pressures are medium. The water is heated by a fire tube pro­
low, it can be used as a primary separator, thus jecting into this compartment. After leaving the
eliminating the need for a regular separator. Use heated water wash, the emulsion rises into a
of the treater as a second-stage separator may settling space where water broken out of the
increase the API gravity of the oil over that which emulsion settles out and falls back into the water

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