The effect of catagenetic maturity on the formation of reservoirs with organic porosity in the Bazhenov formation and peculiarities of their extension

Калмыков, А. Г.; Karpov, Y.A.; Topchiy, M. S.; Fomina, Maria M.; Manuilova, E. A.; Tretyakova, Inna O.; Sheremeteva, Ekaterina V.; Пронина, Н. В.; Шишков, В. А.; Balushkina, N. S.; Фадеева, Н. П.; Stoupakova, A.V.

doi:10.18599/grs.2019.2.159-171

Cited by 12 publications

(2 citation statements)

References 16 publications

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“…Total organic carbon concentration varies from 1 to 25-30 wt.% (mean 8-9 wt.%) and the initial hydrogen index (HI 0 ) values range between 650 and 715 mg HC/g TOC [38][39][40]. The organic matter is type II kerogen with maturity varying along the region from immature (protocatagenesis stage PC3) in the Nyurolskaya Depression to the end of the oil window (mesocatagenesis stage MC3) in the Salym Arch [39,41,42]. Catagenesis stages are named according to [43], tectonic zoning is suggested by [44].…”

Section: Geological Settingmentioning

confidence: 99%

Alginite-Rich Layers in the Bazhenov Deposits of Western Siberia

et al. 2021

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In this study, we identified the luminescent layers containing a significant amount of alginite in the Upper Jurassic–Lower Cretaceous Bazhenov Formation named “the alginite-rich layers”. Lithological and geochemical methods were used to determine distinctive features of these layers and to evaluate their impact on the total petroleum generation potential of the Bazhenov Formation. We have shown that the composition of the alginite-rich layers differs significantly from the organic-rich siliceous Bazhenov rocks. Rock-Eval pyrolysis, bulk kinetics of thermal decomposition, elemental analysis, and the composition of pyrolysis products indicate type I kerogen to be the predominant component of the organic matter (OM). Isotope composition of carbon, nitrogen, and sulfur was used to provide insights into their origin and formation pathways. The luminescent alginite-rich layers proved to be good regional stratigraphic markers of the Bazhenov Formation due to widespread distribution over the central part of Western Siberia. They can also be applied for maturity evaluation of the deposits from immature to middle of the oil window, since the luminescence of the layers changes the color and intensity during maturation.

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Section: Geological Settingmentioning

confidence: 99%

Alginite-Rich Layers in the Bazhenov Deposits of Western Siberia

et al. 2021

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“…The increase in U/TOC ratio with increase in maturity (decrease in Kgoc ex ) can be explained by decrease in TOC during catagenesis. Increase in PI values with maturation is a result of additional porosity formation during the kerogen transformation into mobile hydrocarbons [45,46].…”

Section: Relationship Of Uranium Content Total Organic Carbon Mineral...mentioning

confidence: 99%

Uranium in Source Rocks: Role of Redox Conditions and Correlation with Productivity in the Example of the Bazhenov Formation

et al. 2022

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The paper reports comprehensive analysis of different factors affecting uranium content in oil source rocks and the relationship between uranium content and productivity of source rocks. The analysis of data for 13 wells of the Bazhenov Formation (Western Siberia, Russia) was carried out. The uranium content of the rocks was measured by gamma-ray spectrometry on core samples. In order to analyze factors affecting uranium accumulation in source rocks, we studied content and characteristics of organic matter (Rock-Eval pyrolysis), and also mineral, element, and isotope composition of rocks. We have shown that redox conditions at the sedimentation stage have the most pronounced impact on the uranium accumulation in the rocks of the Bazhenov Formation. It was also shown that productive intervals, containing increased amounts of mobile hydrocarbons, are characterized by low (<20 ppm) concentration of uranium. However, the intervals, containing phosphorite minerals may show better reservoir properties and oil saturation at higher concentration of uranium. The analysis of correlations and relationships between uranium content and Rock-Eval pyrolysis indexes (oil saturation index and productivity index) enabled formulation of criteria for selection of oil-saturated intervals using the spectral gamma and pulsed neutron spectroscopy log data.

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