Produced water treating systems

When hydrocarbons (crude oil, condensate, and natural gas) are produced, the wellstream typically contains water produced in association with these hydrocarbons. The produced water is usually brine, brackish, or salty in quality but in rare situations may be nearly fresh in quality. The water must be separated from the hydrocarbons and disposed of in a manner that does not violate established environmental regulations. Typically, the produced water is mechanically separated from the hydrocarbons by passing the wellstream through process equipment such as three-phase separators, heater-treaters, and/or a free-water knockout vessel. These mechanical separation devices do not achieve a full 100% separation of the hydrocarbons from the produced water. The produced water separated from the hydrocarbons in these mechanical separation devices will contain 0.1-10 vol.% of dispersed and dissolved hydrocarbons. Produced water treating facilities are used to further reduce the hydrocarbon content in the produced water prior to final disposal. 

---

Design a produced water treating system for data given ... 

Natural gas components are slightly soluble in water at moderate to high pressures and will be present in the produced water stream. The solubility of natural gas (primarily methane) is a function of pressure, temperature, and specific gravity of the water. It is interesting to note that natural gas components have an affinity for the dispersed oil droplets, and this principle is applied to the design of gas flotation equipment commonly used in produced water treating systems. 

FIGURE 3.4. Typical produced water treating system. 

---