Emulsions horizontal heater-treater

Treating Vessels. Horizontal heater treaters used in breaking produced oil-water emulsions use water jets and drains similar to those described for cone-bottom tanks to remove solids collected at the bottom... 

FIGURE 1.18. Schematic of horizontal heater-treater showing the oil, emulsion, and free water passing around the deflector hood to the spreader located slightly below the oil-water interface where the liquid is "water-washed" and the free water separated. 

Most horizontal heater-treaters built today do not use fire-tubes. Heat is added to the emulsion in a heat exchanger before the emulsion enters the treater. In these cases the inlet section of the treater can be fairly short because its main purpose is to degas the emulsion before it flows to the coalescing section. 

The primary separator may also be known as a heater/treater tank. Heater/treater tanks are usually vertical tanks but some are horizontal. In a vertical heater/treater, the produced fluids flow into the top of the heated tank where they fall to the bottom and are circulated through varies baffles or other features in tank. The gas generally separates from the mixture and is taken off the top of the tank. The water in oil emulsion is then mechanically mixed and some separation occurs. An oil take-off value is usually located in the upper half of the tank that allows any free oil to be drained off. A drain in the bottom of the tank also will allow any free water to be taken off as well. 

The emulsion that remains in the heater/treater is then sent to a secondary separator which may be referred to as a free water knock out. This type of separator may or may not be heated and is usually horizontal. 

Heaters are vessels used to raise the temperature of the liquid before it enters a gunbarrel, wash tank, or horizontal flow treater. They are used to treat crude oil emulsions. The two types of heaters commonly used in upstream operations are indirect fired heaters and direct fired heaters. Both types have a shell and a fire tube. Indirect heaters have a third element, which is the process flow coil. Heaters have standard accessories such as burners, regulators, relief valves, thermometers, temperature controllers, etc. 

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