Astrakhan field of the natural-gas condensate

ASTRAKHAN FIELD of the natural-gas condensate (RU: Астраханское месторождение газоконденсатное) is situated within the Astrakhan province of the RSFSR, at the distance of 60 kilometres from the Astrakhan city to the north-east, it belongs to the Caspian oil-gas-bearing province.

It has been discovered in the 1976. It is confined to the vault of the same name with the size (at the depth of 4200 metres contour line) of 100x45 kilometres, with amplitude of more than 350 metres. The industrial gas-bearing capacity has been identified within the subsalt carbonatic depositions of the Middle Carboniferous. At the plane of the gas-water contact (the depth is 4073 metres) the size of the reservoir is 100x40 kilometres, the thickness of the gas-bearing layer is 220 metres. The collectors are the limestones without the visible signs of dolomitization and sulfatization; there have not been determined the macro-crackedness and cavernousness, there are characteristic the low filtering-containing characteristics: the porosity is 8-11%, the permeability is 0.4-1 millidarcies. The initial reservoir (layer) pressure is 6.3 megapascals. The composition of the gas is (%): CH4 is 50-55, H2S is 22-24, CO2 is 20-22, N2 is up to 3. The content of the gas condensate is from 240 to 560 cubic centimetres per cubic metre. There is formed on the base of the field the powerful industrial complex for the extraction and processing of the gas and condensate, for the production of sulfur.