Horizontal flow treaters

Horizontal flow treaters are not common. Figure 1.4 illustrates one design, which consists of a cylindrical treating tank incorporating internal baffles. The internal baffles establish a horizontal flow pattern in the cylindrical tank, which is more efficient for gravity separation than vertical flow and is less subject to short-circuiting. 

In addition to gravity separation, the emulsion must be collected and held in the treater for a certain retention time so that the emulsion will break. In horizontal flow treaters, the emulsion collects... 

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. 

Electrostatic treaters. Fig. 3 illustrates a typical horizontal elrrirostatir treater. The flow path in an electrostatic treater di- -am- - in a hi-i i/unt il hcan-r-trc.in-r. th- n il - difference is that an AC and/or DC electrostatic field is used to promote coalescence of water droplets. 

In a horizontal vessel, the cross-sectional area of the flow for the upward velocity of the oil is a function of the vessel diameter and the length of the coalescing section. For a vertical treater, the height of the coalescing section does not enter the equation. For larger diameter, vertical-flow treaters (i.e., such as gun barrels) a correction factor for short-circuiting effects must be included in the equation. 

For most multi-well flow streams, horizontal heater-treaters are normally required. Figure 1.16 shows a simplified schematic of a typical horizontal heater-treater. Design details vary from manufacturer to manufacturer, but the principles are the same. The horizontal heater-treater consists of three major sections front (heating and water-wash), oil surge chamber, and coalescing sections. 

FIGURE 1.17. Three-dimensional view of a horizontal heater-treater flow pattern. 

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. 

Some horizontal heater-treaters add an electrostatic grid in the coalescing section. Figure 1.25 illustrates a simplified schematic of a typical horizontal electrostatic treater. The flow path in an electrostatic heater-treater is basically the same as in a horizontal heater-treater, except that an electrostatic grid is included in the coalescing-settling section, which helps to promote coalescence of the water droplets. 

Fig. 2—Muftiweil installations normaRy employ horizontal treaters Flow enters from le t on d. iwing and is coml.K-ted tn a spm.vVr o liquid-filled coalescing section on ngnc...

Horizontal treaters. Multiwell installations normally require horizontal treaters. Fig 2 shows a typical design. Flow enters the front section of the tteatei where gas is flushed. Liq uid falls to the vicinity of the oil-water interface where it is water washed and freewater separated Oil and emulsion rise past the lire tubes and are. skimmed into the oil surge i Irani -her. "Fhe oil-water interface in the inlet section is controlled by an interface level controller that operates a dump valve for the freewater... 

Heavy-Oil Evaporation Dehydrator (HOE V-3). Figure B.5 illustrates the process flow schematics for the HOE unit. This horizontal vessel can serve as either an alternative to the DPET (should the oil-bitumen-rich stream exiting the FWKO contain less than 10% water) or as a secondary treater to the DPET. The HOE unit is designed to process an emulsion composed of oil-bitumen (70%), water (10%), and diluent (20%) at a combined rate of 460 L/h (70 barrels per day) for raw oil-bitumen of API gravity... 

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. 

---