Geology, geography and global energy

Scientific and Technical Journal

Hydrogeochemical zonality and typification of underground waters of subsalt water-bearing complexes

2017. №3, pp. 101-106

Soloveva Alevtina V. - Senior Lecturer, Astrakhan State University, 1 Shaumyan sq., Astrakhan, 414000, Russian Federation, aleksandra_sh@list.ru

Role of underground waters and their zonality in general in formation, preservation or destruction of deposits of hydrocarbons is considerable. According to most of researchers, underground waters - an important factor in a chain "generation-migration-congestion-detection of hydrocarbons". For this reason system approach when studying underground waters and their components taking into account time factor is necessary. According to spatial change of the chemical composition of underground waters within water-bearing complexes on the horizons and a vertical distinguish horizontal and vertical hydrogeochemical zonality. According to the nature of water exchange with surface water researchers allocate three zones: free water exchange (top), the slowed-down water exchange (average) and very slowed down water exchange (lower). Hydrochemical zonality consists in natural change of genetic types of waters from sulfate-sodium through gidrokarbonatno-sodium and hloridno-magnesium to hloridno-calcium from areas of an external power supply to the central, the most lowered parts of pools. The mineralization of waters also gradually raises, from fresh to saltish, salty and to brines. Vulgar zonality in a section is reflected change of types of waters and their mineralizations with a depth; structure of dissolved it is also caused by change on the area and a section of nitric gases on metano-nitrogen and nitrogen-metane, growth of gas saturation and elasticity of the dissolved gases. According to hydrodynamic zonality there are zones: hydrostatic pressure where there is a horizontal movement of free gravitational waters from the fields of modern infiltration and creation of pressures to the fields of unloading; and zones of geostatic reservoir pressure where push-up the prochnosvyazannykh of waters, with the slowed-down movement of underground waters within this zone begins. Between hydrogeochemical, hydrodynamic, gas-hydrogeochemical zonalities there is close connection.

Key words: зональность, типизация, подсолевые водоносные комплексы, гидростатистическое давление, zonality, typification, subsalt water-bearing complexes, hydrostatistical pressure

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