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Vadim L. Ilchenko
Vadim L. Ilchenko
Ph.D.
Senior Researcher
Geological Institute of the KSC RAS
Senior Researcher, Ph.D.
Geological Institute of the KSC RAS
Apatity
Russia

Co-authors

Articles

Article
Geology
  • Date submitted
    2024-10-24
  • Date accepted
    2025-07-02
  • Online publication date
    2025-11-14

Physical properties of Paleozoic-Mesozoic deposits from wells in the South Barents Basin

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The Arctic shelf zone is an important research target due to its significant hydrocarbon potential. A study of the physical properties (density, elasticity, elastic anisotropy index, specific acoustic impedance, and porosity) was conducted for core samples from six wells in the South Barents Basin: Admiralteyskaya-1, Krestovaya-1, Ludlovskaya-1, Shtokmanskaya-1, Arkticheskaya-1, and Severo-Kildinskaya-82. The sample collection consists of sandstones, siltstones, and limestones. Core analysis revealed that rocks from non-productive wells (Arkticheskaya-1, Admiralteyskaya-1, and Krestovaya-1), located in the central part of the South Barents Basin and within the Admiralty High, differ in their physical and petrographic properties from rocks in gas and gas-condensate wells (Shtokmanskaya-1, Severo-Kildinskaya-82, and Ludlovskaya-1), located near the boundaries of the South Barents Basin. Core samples from productive wells (Shtokmanskaya-1, Severo-Kildinskaya-82, Ludlovskaya-1) exhibit lower average P-wave velocities, lower specific acoustic impedance, and higher open porosity and/or elastic anisotropy index compared to non-productive wells (Arkticheskaya-1, Admiralteyskaya-1, Krestovaya-1). This combination of petrophysical parameters provides the reservoir properties of rocks prospective for hydrocarbons. The petrographic variation of the reservoir properties of the studied rocks from productive to non-productive wells is associated with a decrease in grain size and a transition from pore-filling cement to thin-film and basal cement. The sandstones from the Shtokmanskaya well have a larger grain size (0.1-0.5 mm), whereas the sandstones from the Arkticheskaya-1 and Krestovaya-1 wells are finer-grained (0.1-0.2 mm). The Shtokmanskaya-1 well is characterized by pore-filling cement, the Arkticheskaya-1 ‒ by thin-film cement, and the Krestovaya-1 ‒ by cement of the basal type. The established physical properties of sedimentary rocks, suitable for the development of productive strata, will allow for the screening out of empty areas at the preliminary stage of analyzing geophysical materials during the search for geological and tectonic structures prospective for hydrocarbon accumulations.

How to cite: Ilchenko V.L., Chikirev I.V. Physical properties of Paleozoic-Mesozoic deposits from wells in the South Barents Basin // Journal of Mining Institute. 2025.
Article
Geology
  • Date submitted
    2022-02-24
  • Date accepted
    2022-05-25

Litsa uranium ore occurrence (Arctic zone of the Fennoscandian Shield): new results of petrophysical and geochemical studies

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Mineralogical, petrophysical and geochemical studies have been carried out to determine the sequence and formation conditions of uranium mineralization within the Litsa ore occurrence (Kola Region). Mineralogical studies show the following formation sequence of ore minerals: uraninite – sulfides – uranophane, coffinite, pitchblende. Two stages of uranium mineralization are distinguished: Th-U (1.85-1.75 Ga) and U (400-300 Ma). The distribution of physical properties of rocks in the area is consistent with the presence of two temporal stages in the formation of mineralization with different distribution and form of uranium occurrence in rocks. The factors that reduce rock anisotropy are the processes of migmatization and hydrothermal ore mineralization, which heal pores and cracks. Fluid inclusions in quartz studied by microthermometry and Raman spectroscopy contain gas, gas-liquid and aqueous inclusions of different salinity (1.7-18.4 wt.% NaCl-eq.). According to homogenization temperatures of inclusions in liquid phase, the temperature of the Paleoproterozoic and Paleozoic stages of uranium mineralization at the Litsa ore occurrence is ~ 300 and 200 °С, respectively. Correlations of the spatial distribution of elastic anisotropy index with an elevated radioactive background allow using this petrophysical feature as one of the prognostic criteria for uranium and complex uranium mineralization when carrying out uranium predictive work.

How to cite: Il’chenko V.L., Afanasieva E.N., Kaulina T.V., Lyalina L.M., Nitkina E.A., Mokrushina O.D. Litsa uranium ore occurrence (Arctic zone of the Fennoscandian Shield): new results of petrophysical and geochemical studies // Journal of Mining Institute. 2022. Vol. 255. p. 393-404. DOI: 10.31897/PMI.2022.44