DBPapers
DOI: 10.5593/sgem2017H/15/S06.027

GEOCHEMICAL CHARACTERISTICS OF THE ORGANIC MATTER OF THE ROCKS AND OILS OF THE ANSAGAN DEPOSIT OF THE CASPIAN BASIN

S.A. Sitnov, A.V. Vakhin, Y.V. Onishchenko, A.E. Chemodanov, R.R. Yermagambetov
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-26-3 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 15, 211-218 pp; DOI: 10.5593/sgem2017H/15/S06.027

ABSTRACT

The deposits of light oil and gas in the Devonian sediments of the "Ansagan" deposit are found. In the deposits of the Famenian stage of the upper Devonian, a gush of gas condensate was obtained. Samples of formation fluid are characterized by low density (0.78 g/cm3). The extracted oil refers to low-tar and paraffin (the content of paraffins is more than 2-3 %). The genetic relationship between oils and organic matter of rocks has been studied. To determine the group composition of bitumoids, the SARA method was used. The chemical structure of resins and asphaltenes has been established by IR-spectroscopy. Kerogen was separated by step-by-step dissolution of minerals with hydrochloric and hydrofluoric acids. According to elemental analysis, the type of kerogen is determined from the Van Crevelen diagram, based on the ratio of H/C and O/C. The ratio of isoprenoid alkanes (pristane and phytan) varies insignificantly and closely, both for oils and bitomoids. Dependence of maturity on depth of occurrence is established.

Keywords: organic matter, maturity, composition, Caspian basin