Geology, geography and global energy

Scientific and Technical Journal

The geoecological and geochemical distribution of Astrakhan field’s gas and gas condensates

2013. №1, pp. 77-85

Khaled Gamal E. - Post-graduate student, Astrakhan State University, 20a Tatishchev st., Astrakhan, Russian Federation, 414056, geologi2007@yandex.ru

Almamedov Yalchin L. O. - Post-graduate student, Astrakhan State University, 20a Tatishchev st., Astrakhan, Russian Federation, 414056, geologi2007@yandex.ru

Serebryakova Valentina I. - Post-graduate student, Astrakhan State University, 20a Tatishchev st., Astrakhan, Russian Federation, 414056, geologi2007@yandex.ru

The article examines the geoecological and geochemical distribution of gas and gas condensates in Astrakhan Field, observing their respective characteristics. It adds that their concentration could be influenced by the location of wells (from a gas-water perspective), hydrocarbon deposits, and production temperature and pressure conditions, with these likely to affect the processing of raw materials into marketable products. At this stage, the critique seeks to clarify the distribution of hydrocarbon (gas and gas condensate) components in the overall field and in its productive reservoir’s vertical section. The latter, the paper notes, is promoting the selective extraction and processing of raw materials, subject to market conditions. Methane content, the review says, currently varies from 42 to 65 %, with the amount reportedly increasing from Astrakhan reservoir’s southwest toward its northeast (lower values are found in its southwestern and central sectors). Geological features of the gas and condensate components in Astrakhan Field could be divided into three geochemical composition types depending on their origin, composition and features: combustible hydrocarbon gases C1 to C4 and C5 + B; non-hydrocarbon gases, including chemically aggressive sulfide (H2S) and carbon dioxide (CO2); and neutral nitrogen and helium. The potential condensate content in the C5 + B supply changes from 130 g/m3 to 312 g/m3, with its concentration increasing from the southwest and northeast to the central section of the gas condensate field. The hydrogen sulfide content, by contrast, ranges from 34 % in the central part (and 16 % in eastern) and reaches a maximum of 60 % in gas-water contact. The blueprint speculates that similar patterns could be found in newer fields in the northern section of the Caspian Sea.

Key words: geochemistry,condensate,methane,hydrogen sulfide,Geo-ecology

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