1. vb. [Production Facilities]
To remove water from a substance. The substance may be crude oil, natural gas or natural gas liquids (NGL). Fluid dehydration is needed to prevent corrosion and free-water accumulation in the low points of a pipeline. In the case of gas, it is especially important to avoid hydrate formation and also to meet pipeline requirements. Typical maximum allowable water vapor content is 7 pounds of water per million standard cubic feet. In colder climates, this threshold value could be 3 to 5 pounds per million standard cubic feet. Water vapor can also affect the sweetening and refining processes of a natural gas. Dehydration of crude oil is normally achieved using emulsion breakers, while gas dehydration is accomplished using various liquid desiccants such as glycols (ethylene, diethylene, triethylene and tetraethylene) or solid desiccants such as silica gel or calcium chloride [CaCl2].