Water, Sediment, and Salt Contents in Crude Oils

7 Water, Sediment, and Salt Contents in Crude Oils 

Crude oils contain, in very small quantities, water, sediments and mineral salts most of which are dissolved in the water, the remainder found as very fine crystals. 

These materials can damage equipment by means of corrosion, erosion, deposits, plugging, catalyst poisoning, etc. 

In the crude, water is found partly in solution and partly in the form of a more-or-less stable emulsion this stability is due to the presence of asphaltenes or certain surfactant agents such as mercaptans or naphthenic acids. 

The water content of crude oils is determined by a standardized method whose procedure is to cause the water to form an azeotrope with an aromatic (generally industrial xylene). Brought to ambient temperature, this azeotrope separates into two phases water and xylene. The volume of water is then measured and compared with the total volume of treated crude. 

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