I.D. Timoshina, L.S. Borisova, A.N. Fomin
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Paleozoic, kerogen, asphaltenes, biomarker hydrocarbons, type and catagenesis of organic matter, hydrocarbon migration, North Tunguska oil and gas region
The organic matter (OM) of the coal-bearing terrigenous strata of the Tunguska Group (C2-P) and the Khanar Formation (C2-3) as well as the Devonian carbonate rocks of the North Tunguska oil and gas region (OGR) has a complex geologic history due to strong heating by traps. This explains the reduced values of genetic biomarker parameters, such as n - C 27/ n - C 17 ( n -alkanes), C29/C27 (steranes), and hopanes/tricyclanes, in a number of terrestrial bitumens and the possible change in tricyclane index ITC as a result of the accumulation/dispersion of migrating low-molecular compounds. The sterane maturity coefficient in most samples has undergone thermal inversion and is unfit for determining the grade of catagenesis. Devonian samples probably contain marine OM (low δ13C; high HI in the insoluble residue and kerogen; in the Pr/ n - C 17-Ph/ n - C 18 diagram of kerogen, the H/Cat values lie at the boundary or in the field of type II kerogen; also, low n - C 27/ n - C 17 and C29/C27 values are typical), although the isotope and pyrolytic characteristics of the kerogen of the Manturovka Formation (D1) are distorted, probably because of high-grade catagenesis. The coal-bearing strata contain terrestrial OM (with a low HI of kerogen; in the Khanar Formation, it is additionally characterized by high n - C 27/ n - C 17, C29/C27 steranes, and hopanes/tricyclanes ratios). The genetic characteristics of the saturated fractions of bitumens ( n - C 27/ n - C 17, C29/C27 steranes, and hopanes/tricyclanes) in several upper Paleozoic samples are significantly distorted because of the catagenetic redistribution of compounds, with a predominance of low-molecular ones. According to the elemental composition of kerogen, a half of the samples of the Khanar Formation and the Tunguska Group can be assigned to type III kerogen, and the other half, to type IV kerogen. Because of trap intrusions, the catagenesis grade of Carboniferous-Permian OM generally increases upsection from MC2 to apocatagenesis (which is evidenced by the changes in R oVt, MPI-1 of the aromatic fraction of bitumen, and H/Cat of kerogens and asphaltenes).
E.A. Kostyreva, I.S. Sotnich
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Bitumens, hydrocarbon biomarkers, Anabar-Khatanga oil- and gas-bearing area, organic geochemistry
This study is concerned with detailed geochemical investigations of organic matter in Carboniferous-Permian source rock from the Anabar-Khatanga oil- and gas-bearing area, using a representative (both by area and by section) collection of core material. The study has first shown that the organic matter of Permian deposits is polygenous throughout the section and is at different levels of thermal maturation (stages MC11-AC). It has exhausted its generative potential in most part of the section. The deposits contain paraautochthonous and allochthonous bitumens (chloroform source rock extracts) in addition to autochthonous (syngenetic) ones, which indicates intense migration processes. There are also bitumens with traces of biodegradation in Early Permian deposits from the Yuzhno-Tigyanskaya and Nordvikskaya wells.
M.I. Epov1, N.N. Mikhailov2,3,4, V.N. Sokotuschenko2, O.M. Ermilov2,5 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Gubkin Russian State University of Oil and Gas, Moscow, Russia 3Institute of Oil and Gas Problems, Russian Academy of Sciences, Moscow, Russia 4M.V. Lomonosov Moscow State University, Moscow, Russia 5OOO Gazprom Dobycha Nadym, Nadym, Russia
Keywords: Hard-to-recover reserves, low permeability reservoirs, nonlinear filtration, well flowrate, drawdown, skin factor, formation damage, indicator curves, hysteresis, power-law filtration
We comprehensively analyzed the influence of nonlinear reservoir processes on well flowrate vs. drawdown for low permeability reservoirs with hard-to-recover (HTR) hydrocarbon reserves. New nonlinear relationships between the flowrate of low permeability reservoirs and reservoir drawdown (indicator curves) were identified. The nonlinearity of the indicator curves is due to the combined effects of nonlinear filtration, technogenic reservoir change, and the dependence of formation damage parameters on drawdown. The applied approach allowed us to find out qualitatively new regularities in the relationship between flowrate and drawdown in low permeability reservoirs. A well productivity analysis revealed hysteresis in the indicator curves and a shift in critical drawdown values when considering both formation damage and filtration nonlinearity. It has been found that the combined effects of nonlinear filtration and damage effects lead to an additional flowrate decline of 25-40%, as compared to separately considering each of these effects. The obtained results are of practical importance for optimizing the development of low permeability reservoirs with HTR reserves and for predicting their productivity.
This thematic issue of the journal Chemistry for Sustainable Development is dedicated to the 55th anniversary of the Institute of Petroleum Chemistry of the Siberian Branch of the Russian Academy of Sciences (IPC SB RAS), which was celebrated in 2025. The Foreword describes the history of the creation and formation of IPC SB RAS and presents the main scientific activities of the Institute.
L. M. VELICHKINA1, L. N. VOSMERIKOVA1, V. G. BONDALETOV2, A. V. VOSMERIKOV1 1Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia 2National Research Tomsk Polytechnic University, Tomsk, Russia
Keywords: zeolite, template, hexamethylenediamine, polyaniline, catalyst, gasoline
A method of hydrothermal synthesis of pentasyl type zeolites (MFI or ZSM-5) with the silicate modulus of 40 is proposed, which consists in adding, along with hexamethylenediamine as a structure-forming agent (template), the second structure former - polyaniline, to alkaline alumosilicon gel. Polyaniline used in the work was also synthesised according to the authors’ method. It has been determined using IR spectroscopy and X-ray diffraction analysis that the synthesised zeolites belong to the pentasyl family, and their degree of crystallinity is close to 100 %. The acid characteristics of the obtained zeolite samples were studied by temperature-programmed desorption of ammonia, and a decrease in the strength and concentration of weak acidic centres in comparison with zeolite synthesised without the use of polyaniline was shown. On the contrary, the number of high-temperature acidic centres of zeolites obtained using polyaniline has somewhat increased. A correlation between the acidic properties of zeolites and the concentration of polyaniline added to the reaction mixture during synthesis has been established. The catalytic activity of the obtained zeolite catalysts was determined during the refining of the straight-run gasoline fraction of oil. An increase in the aromatising activity of the catalysts and the octane numbers of the resulting gasolines has been shown when using zeolites synthesised using two templates - hexamethylenediamine and polyaniline. The optimal temperature range for refining straight-run gasoline has been determined, which makes it possible to obtain high-octane gasoline, meeting the modern requirements for automotive gasoline in terms of hydrocarbon composition and octane number, on all the studied zeolite catalysts. The fractional composition of the gasoline produced (except for the final boiling point) corresponds to the summer grade of gasoline.
A. N. WERNER, I. V. PROZOROVA
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: diesel fuel, pour point, depressant compositions, plasma-chemical oxidation products, fuel additives
The potential for improving the low-temperature properties of summer diesel fuels using polymer additives is investigated. Polyalkyl methacrylate, sodium sulphonate, and atactic polypropylene with varying degrees of oxidation - low, medium, and high - were used as depressants. All polymers were used as toluene solutions with the polymer/toluene ratio ranging from 1 : 3 to 1 : 30 (by mass) and were introduced into the fuel at a concentration of 0.03-0.07 wt%. It has been found that the effectiveness of the compositions significantly depends on the degree of polymer dilution. The optimal polymer/toluene ratio has been determined to be within (1 : 6)-(1 : 10), providing pour point reduction to (-30)-(-33) °C, compared to the original fuel samples. It is demonstrated that the highest depressant activity is exhibited by the compositions based on highly oxidised atactic polypropylene. The maximum result was achieved by combining the products of plasma-chemical oxidation of benzene and toluene with polymers, which allowed reducing the pour point of fuel samples to -36.5 °C. The effectiveness of the additives also depended on the hydrocarbon composition of the fuel, showing better results in the samples with an increased content of low-molecular-weight n-alkanes C16-C17.
V. V. KOZLOV, L. K. ALTUNINA, M. R. SHOLIDODOV
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: oil-displacing composition, enhanced oil recovery, terrigenous reservoir, heavy high-viscosity oil, intensification of development, filtration characteristics, oil displacement coefficient
The results of laboratory studies on the effectiveness of GBK-F acid composition for enhancing oil recovery from terrigenous reservoirs are presented. Experiments on reservoir models with oil of various viscosities (Vostochno-Messoyakhskoye and Olenye fields) confirmed the ability of the composition to increase the displacement coefficient by 20-26 % at both low (22-23 °C) and high (90 °C) temperatures. It has been determined that the use of the composition significantly equalises filtration flows in heterogeneous systems. It has been shown experimentally that the composition effectively eliminates water blocking in low-permeability intervals, increasing the phase permeability for oil from 0.013 to 0.357 mm2. It has been concluded that the mechanism of action of GBK-F is based on a complex chemical and rheological effect that improves the filtration characteristics of the reservoir. The obtained results allow us to recommend the use of GBK-F to intensity production and increase the coverage of heterogeneous terrigenous reservoirs.
P. V. PANTILOV, E. B. KRIVTSOV
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: oil shale, cracking, kerogen, thiophene, benzothiophene, dibenzothiophene
Extensive analysis of the composition (material and fractional composition, sulphur distribution over components and fractions, content of thiophene derivatives, etc.) of liquid products formed in thermal cracking of high-sulphur oil shale from the Kashpir deposit has been carried out, the effect of temperature and process duration on these parameters has been demonstrated. It has been found that the yield of liquid products at cracking temperatures of 425 and 450 °C increases with an increase in the time of thermal treatment from 40 to 100 minutes, reaching 26.40 and 23.62 wt%, respectively, due to an increase in the kerogen destruction depth. A further increase in process temperature to 475 °C intensifies secondary reactions, leading to a decrease in the yield of liquid products and the distillate fractions within them. The distribution of sulphur over distillate fractions was studied, and the predominance of benzothiophene and dibenzothiophene homologues in the diesel fraction was established. It has been shown that at cracking temperatures of 425-450 °C, an increase in process duration causes sulphur redistribution from the diesel to gasoline fraction against the background of an increasing proportion of thiophene homologues, which indicates the predominance of dealkylation and fragmentation of complex heterocyclic structures. At 475 °C, dibenzothiophene and its homologues accumulate in the residual fraction (>360 °C). The obtained data will improve the understanding of the patterns of thermal transformation of sulphur-containing structural fragments in the organic matter of high-sulphur oil shales during cracking.
T. O. PEREMITINA, I. G. YASHCHENKO
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: remote sensing, monitoring, oil pollution, vegetation index
The article presents the results of long-term monitoring of ecosystem recovery following an accidental oil spill at the Krapivinskoye field (Tomsk Region) using remote sensing methods. The normalized difference vegetation index (NDVI), calculated from MODIS spectroradiometer data for the period 2020-2025, was used as an integral indicator of vegetation condition. A detailed analysis of the seasonal and interannual dynamics of the index was carried out, identifying seven phenological intervals within the growing season. It was found that the average annual NDVI value decreased by 2.41 % over the six-year observation period, indicating the long-term oil pollution impact. Despite some periods of improvement in the indicators, the ecosystem did not reach its original productivity level by 2025. The effectiveness of the satellite monitoring methodology for the operational assessment of vegetation condition and the efficiency of reclamation measures on disturbed lands is demonstrated.
I. V. RUSSKIKH, E. B. STRELNIKOVA, O.V. SEREBRENNIKOVA
Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: organic compounds, herbaceous plants, background and post-pyrogenic areas, Khakassia
The composition of biomolecules of herbaceous plants, some of which possess biological activity, has been studied and identified by chromatography - mass spectrometry in post-pyrogenic and background areas of the steppe zone of Khakassia. Insignificant differences were noted in the composition of acyclic compounds - n-alkanes, n-aldehydes, n-alkanols and long-chain n-alkanones. More significant changes are observed in the composition of steroids, though the pyrogenic effect on their composition in certain species of herbs varies and leads, along with different changes in the total content (from a decrease in the majority of plants to an increase in iris), to the redistribution of the proportion of individual representatives. Less stable to the action of fire were steroids with an unsaturated (double) bond in position 24 of the molecule, the content of which in the composition of all the studied herbs in post-pyrogenic areas is lower than in the background.
