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Date submitted2024-04-22
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Date accepted2024-09-24
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Date published2024-11-12
On peculiarities of composition and properties of ancient hydrocarbon source rocks
Precambrian rocks are widespread within all continents of the Earth; that said, sedimentary associations of these deposits are of special interest in search for oil and gas fields. A wide range of paleontological, lithological and geochemical methods is utilized for conducting integrated geological-geochemical analysis and evaluating the initial hydrocarbon generating potential of organic matter of Precambrian source rocks. Investigated were peculiarities of depositional environments of the organic matter, specific features of its composition in sedimentary rocks and its generation characteristics. Own research efforts were performed in combination with generalization of other authors’ publications focused on Precambrian sequences enriched in organic matter – their occurrence, isotopic and biomarker characteristics and realization schemes of the hydrocarbon generation potential of Precambrian organic matter in the process of catagenesis. Geochemical peculiarities of initial organic matter are illustrated on various examples, type of the organic matter is determined together with the character of evolution of realization of its initial generation potential.
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Date submitted2023-05-21
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Date accepted2024-05-02
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Date published2024-08-26
Assessment of the influence of lithofacies conditions on the distribution of organic carbon in the Upper Devonian “Domanik” deposits of the Timan-Pechora Province
The study of high-carbon formations was instigated both by the decreasing raw material base of oil as a result of its extraction, and by the progress in development of low-permeability shale strata, primarily in the USA, Australia, and China. The most valuable formations occur in traditional hydrocarbon production areas – the West Siberian, Volga-Ural and Timan-Pechora, North Pre-Caucasian and Lena-Tunguska oil and gas provinces. Specific features of the Late Devonian-Early Carboniferous high-carbon formation occurring in the eastern marginal part of the East European Platform are: heterogeneous section due to intense progradation of the carbonate platform from west to east; succession of lithofacies environments that determined the unevenness of the primary accumulation and secondary distribution of organic matter (OM); possible migration or preservation in the source strata during the subsidence stages of the moving parts of bitumides, which determined the prospects for oil and gas potential. The distribution pattern of the present OM content was investigated depending on lithofacies conditions and lithological composition of rocks in the “Domanik type” Upper Devonian-Tournaisian deposits in the Timan-Pechora Province (TPP), its transformation degree to bring it to the initial content of organic carbon and further estimation of the share of stored “mobile oil” in oil and gas source formation. The study was based on the analysis of the data set on organic carbon content in core samples and natural exposures in the Ukhta Region in the Domanik-Tournaisian part of the section including more than 5,000 determinations presented in reports and publications of VNIGRI and VNIGNI and supplemented by pyrolytic and bituminological analyses associated with the results of microtomographic, macro- and lithological studies and descriptions of thin sections made at the Saint Petersburg Mining University. For each tectonic zone of the TPP within the investigated high-carbon intervals, the content of total volumes of organic carbon was determined. The data obtained allow estimating the residual mass of mobile bitumoids in a low-permeability matrix of the high-carbon formation.
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Date submitted2023-02-28
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Date accepted2024-03-05
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Date published2024-04-25
Assessment of the contribution of Precambrian deposits in forming the petroleum potential of the eastern part of the Volga-Urals basin using results of modeling
- Authors:
- Dmitrii D. Kozhanov
- Mariya Bolshakova
Consideration is given to results of geochemical analysis of organic matter and oils of the Proterozoic (the RF-V complex) and the Paleozoic (the pay intervals D2, D3, C1-2) of the eastern part of the Volga-Urals petroleum basin. The obtained data is corroborated by results of 2D basin modeling along four regional profiles two of which are situated in the Kama and two in the Belaya parts of the Kama-Belaya aulacogen. An update is given to earlier data on degree of catagenetic alteration of oil/gas source rocks of the Riphean-Vendian play, maps of catagenesis are constructed. New evidence is provided concerning presence of Precambrian oils in the Paleozoic plays. The oils under investigation are mixed – those formed from generation products of the Precambrian (Riphean, Vendian) and Paleozoic (Devonian and Early Carboniferous) source rock intervals. The results of modeling have shown that the principal source rock intervals in the RF-V play of the Kama part of the Kama-Belaya aulacogen are deposits of the Kaltasy formation of the Lower Riphean and the Vereshchagino formation of the Upper Vendian, while in the Belaya part these are rocks of the Kaltasy, Kabakov, Olkhovo, Priyutovo, Shikhan and Leuza formations of the Riphean and the Staropetrovo formation of the Vendian. It is found that the interval of the main oil and gas window increases in the southeastward direction. In both depressions of the Kama-Belaya aulacogen, a single oil play is distinguished that functions within the stratigraphic interval from the Riphean to the Lower Carboniferous. As the principal petroleum source rock intervals within this play, Riphean-Vendian deposits are considered, reservoirs are confined to the Riphean carbonate complex, Upper Vendian and Middle Devonian clastic deposits, while the Upper Devonian – Tournaisian deposits serve as the upper seal.
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Date submitted2018-09-07
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Date accepted2018-11-08
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Date published2019-02-22
Assessment of refractory gold-bearing ores based on interpretation of thermal analysis data
- Authors:
- T. N. Aleksandrova
- G. Heide
- A. V. Afanasova
The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented. The obtained fragments for kerogen CH (m/z = 15), C 2 H (m/z = 29) and C 3 H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods. Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia.
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Date submitted2015-07-26
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Date accepted2015-09-12
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Date published2016-02-24
Technological aspects of extraction of precious and rare metals from carbonaceous rocks
- Authors:
- T. N. Aleksandrova
- E. G. Panova
The results of mineralogical, geochemical and technological research of black shale rocks are given. It is proved that black shales are now regarded as a new promising and innovative source of precious and rare-metal raw materials. It is pointed out that 3 wt. % of black shales samples is colloid-salt fraction (nanofraction) with a particle size less than 1000 nm and it can be extracted with water under specially chosen conditions. The use of water instead of chemically active reagents guarantees the absence of dissolved mineral matrix and clearly shows the colloidal salt component in samples. The results determine the direction of creating some new methods and technologies of carbonaceous feed dressing for integrated development of solid minerals in the mining and oil producing regions of Russia.
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Date submitted2014-07-14
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Date accepted2014-08-29
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Date published2014-12-22
The development of ideas for improving explosive destruction of rock masses – the basis of progress in mining
- Authors:
- S. D. Viktorov
- V. M. Zakalinskii
The article describes the main areas of research in the field of the explosive destruction of rocks used in mining. The results of studies carried out in recent years are presented. Information on possi-ble applications for breaking up rocks of various energy sources is provided. Ideas are given on the possibility of raising the efficiency of explosives for mining rock by increasing the scale of the ex-plosive destruction. Information about the widespread adoption of these methods at Russia’s biggest iron ore companies is presented. Recent results on the fracture processes at different levels of scale up to destruction to form particles of submicron size are shown. Studying the structural transforma-tions of rock mass at the micro and macro features of allocation and distribution of energy in the charges of various designs allowed us to control the action of a new explosion by breaking up rock masses and the complex structure of multicomponent fields.
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Date submitted2008-10-13
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Date accepted2008-12-28
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Date published2009-12-11
Ore-forming hydrothermal solutions and gas hydrate formation in the ocean
- Authors:
- S. M. Sudarikov
- S. S. Filatova
Geological and tectonic settings and thermobaric characteristics of hydrothermal activity are confronted with those of gas hydrate formation. Hydrocarbon concentrations and isotopic composition in hydrothermal fluids of mid-ocean ridges with different thickness of sediment cover and marginal oceanic basins are compared. The possible influence of rising thermal fluids on gas hydrate accumulations was analyzed and examples of hydrate formation linked with hydrothermal process are given.