pdf № 273, September

DOI: 10.19110/2221-1381-2017-9-3-11

The biomarkers composition of bitumen isolated from the Vorkuta region coals (the Vorgashorskaya, Komsomolskaya and Oktyabrskaya mines) was studied by gas-chromatography-mass spectrometry. The values of Paq and Pwax coefficients indicate a pronounced contribution of aquatic vegetation to the composition of the initial organic mass of the coals, while the distribution of C27—C29 sterane hydrocarbons is characterized by the dominance of C29 sterane. The coals of the Vorkuta region were heterogeneous in composition of the aromatic fraction of bitumen. The predominance of the retene is characteristic for the coals of Vorgashor, as for coal of Komsomolskaya and Oktyabrskaya, this hydrocarbon does not stand out against the background of other aromatic compounds. For the three coal samples ashless extracts were obtained with N-methylpyrrolidone. The resulting hypercoal was studied by solid state13C NMR. Significant differences in the chemical structure of the initial coal, hypercoal and residue are not recorded.

Keywords: Vorkuta region, hypercoal, biomarkers, solid state 13C NMR.

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DOI: 10.19110/2221-1381-2017-9-12-22

The results of lithological-mineralogical and geochemical studies of the Middle-Upper Ordovician clay-carbonate rocks with chamosite ooids in facies different sections of the Bol’shaya Kos’yu Formation in the Ilych River basin of the Northern Urals are presented. In the siderite-chamosite ooids we identified nanococci and nanotubular bacteriomorphic and mineralized microbial films. The latter showed great similarity with the glycocalyx  a by-product of modern bacteria. The main minerals in ooids are represented by three species of chamosite, carbonates of a calcite-siderite number, phosphates, sulfates, oxides, sulfides, including framboidal pyrite. Isotopic composition of carbon and oxygen in rocks (d¹³С = 0.6—0.9 ‰, d¹⁸О = 21.7—22.6 ‰) and ooids (d¹³С = –2.86...–0.16 ‰, d¹⁸O = 20.57—22.31 ‰) reflects a supply of fresh river water in a sedimentation basin. Isotopic composition of carbon in the organic matter of rocks (–28.72 ‰) reflects a significant influence in the formation of precipitation of biogenic carbon. Formation of the Middle-Upper Ordovician siderite-chamosite ooids originated in subequatorial coastal-sea basin with a gas-fluid seeps and activity of sulfate-reducing bacteria.

Keywords: bacteriomorphic structures, authigenic minerals, chamosite ooids, d¹³С, d¹⁸О, euxinic environments, Middle-Upper Ordovician, Northern Urals.

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DOI: 10.19110/2221-1381-2017-9-23-29

The scheme of the fault tectonics of the Pechora-Kolva aulakogen was constructed on the basis of the interpretation of seismic data, an updated scheme of the fault tectonics of the Pechora-Kolvich aulakogen was constructed; kinematics, morphology and occurrence of deep tectonic deformation in the radon field were studied. The results of the research show that the faults are characterized by a complex internal structure, variability of kinematics at different sites, both in the longitudinal and transverse directions. The faults of the western side of the aulakogen and the Upper Pechora depression clearly occur in the radon field by high values of the volume radon activity.

Keywords:aulakogen, faults, kinematics, morphology, radon survey.

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 DOI: 10.19110/2221-1381-2017-9-30-33 

Two samples of sandstones were studied by means of X-ray tomography, which had been previously studied by acoustopolariscopic method with determination of spatial position of the elastic symmetry elements and type of elastic symmetry of rocks. Comparison of the obtained results showed the spatial coincidence of previously studied elements of elastic symmetry with the system organization of irregularities (texture, porosity, microfractures), easily visualized on X-ray tomograms. 

Keywords: X-ray tomography, acoustopolariscopy, elastic anisotropy of rocks, elastic symmetry.

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 DOI: 10.19110/2221-1381-2017-9-34-39

The gas industry plays an important role in the economy of the Komi Republic. This year marks 50 years of leading enterprise of the gas industry of the Republic — «Gazprom transgaz Ukhta». Along with this, the current state of raw material base of natural gas is characterized by its extreme depletion. The increase in gas production can be achieved by commissioning of new deposits and increasing the growth of proven reserves. The objects of prospecting there, which can give the corresponding effect, within proven oil and gas areas are not available. Significant increase in reserves and stabilization of production volumes of natural gas is only possible by the input of new gas-bearing areas in drilling and more efficient use of dissolved gas.

Keywords: raw materials base, gas presence, condensate, reserves, gas pipeline.

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