Hydrocyclone separators, sometimes called enhanced gravity separators, use centrifugal force to remove oil droplets from oily water. As shown in Figure 7-16, static hydrocyclone separator consist of the following four sections: a cylindrical swirl chamber, a concentric reducing section, a fine tapered section, and a cylindrical tail section. Oily water enters the cylindrical swirl chamber […]
Read More…Category: Produced Water Treating System
Deck Drainage
Federal regulations and most authorities having jurisdiction require that “free oil” be removed from deck drainage prior to disposal. It is extremely difficult to predict an oil drop size distribution for rainwater or washdown water that is collected in an open drain system, and regulations do not define what size droplet is meant by “free […]
Read More…Soluble Oil
In every system substances that show up as “oil” in the laboratory test procedure will be dissolved in the water. This is especially true where samples are acidized for “stabilization” prior to extraction with a solvent. This soluble oil cannot be removed by the systems discussed in this chapter. The soluble oil concentration should be […]
Read More…Produced Water
The first step in choosing a water treating system is to characterize the influent water streams. It is necessary to know both the oil concentration in this stream and the particle size distribution associated with this concentration. This is best determined from field samples and laboratory data. Various attempts have been made to develop design […]
Read More…Drain System
A drain system that is connected directly to pressure vessels is called a “pressure” or “closed” drain system. A drain system that collects liquids that spill on the ground is an “atmospheric,” “gravity,” or “open” drain. The liquid in a closed drain system must be assumed to contain dissolved gases that flash in the drain […]
Read More…Skim Pile
The skim pile is a type of disposal pile. As shown in Figure 7-18, flow through the multiple series of baffle plates creates zones of no flow that reduce the distance a given oil droplet must rise to be separated from the main flow. Once in this zone, there is plenty of time for coalescence […]
Read More…Disposal Piles
Disposal piles are large diameter (24- to 48-inch) open-ended pipes attached to the platform and extending below the surface of the water. Their main uses are to (1) concentrate all platform discharges into one location, (2) provide a conduit protected from wave action so that discharges can be placed deep enough to prevent sheens from […]
Read More…Sizing Dispersed Gas Units
It can be shown mathematically that an efficient design must have a high gas induction rate, a small diameter induced gas bubble, and relatively large mixing zone. The design of the nozzle or rotor, and of the internal baffles, is thus critical to the unit’s efficiency. As measured in actual field tests, these units operate […]
Read More…Dispersed Gas Units
In dispersed gas units gas bubbles are dispersed in the total stream either by the use of an inductor device or by a vortex set up by mechanical rotors. Figure 7-14 shows a schematic cross section of a unit that employs a hydraulic eductor. Clean water from the effluent is pumped to a recirculation header […]
Read More…Dissolved Gas Units
Dissolved gas designs take a portion of the treated water effluent and saturate the water with natural gas in a contactor. The higher the pressure the more gas can be dissolved in the water. Most units are designed for a 20 to 40 psig contact pressure. Normally, 20% to 50% of the treated water is […]
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