Petroleum and gas preparation

As a rule, the initial stage of petroleum extraction from oil wells occurs under the natural layer pressure practically without contamination with water. With time, however, the water layer gets produced together with the petroleum layer. About two-thirds of all petroleum is extracted in high humidity conditions. Water layers can differ considerably by their chemical and bacteriological contents. During the extraction of this mixture of petroleum with water layer, an emulsion is formed. Emulsions can be considered to be a physical mixture of two immiscible liquids, one of which is distributed in another phase as droplets of various sizes. The water present in petroleum results in an increase in the transportation price because of an increase in both volume and viscosity of the resulting liquid to be transported. 

The presence of corrosive mineral salts in solution in the water leads to fast deterioration of petroleum pumps and oil refining equipment. The presence of up to 0.1% of water in petroleum leads to intensive foam formation in the rectification tower of oil refineries. This results in an alteration of the technological scheme for oil processing. Besides, it also affects the condensation equipment. 

The light fractions of petroleum (gases from methane to butane) are valuable raw materials for the chemical industry from which products such as solvents, liquid motor fuel, alcohol, synthetic rubber, fertilizers, artificial fiber and other products of organic synthesis are made. Therefore, it is necessary to reduce the loss of light fractions during petroleum processing. Thus, all hydrocarbons derivable from petroleum need to be preserved for subsequent processing. 

Modem petrochemical complexes manufacture various high-quality oils and fuels as well as new types of chemical products. The quality of these products depends on the quality of the initial raw material, i.e. crude petroleum. In the past, the technological processing scheme of older oil refineries could be used to process crude petroleum with mineral salts contents of 100—500 mg/L. Petroleum with a lower salt content is required in modern refineries. Thus, frequently before 

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