Generation Zone Research Articles

О ПОПЕРЕЧНОЙ ПЕТРОГЕОХИМИЧЕСКОЙ ЗОНАЛЬНОСТИ МЕЗОЗОЙСКИХ ВУЛКАНИТОВ В РУДНЫХ ПОЛЯХ ЗАБАЙКАЛЬСКОГО СЕГМЕНТА МОНГОЛО-ОХОТСКОГО СКЛАДЧАТОГО ПОЯСА

Актуальность работы обусловлена необходимостью изучения закономерностей формирования оруденения в Забайкальском сегменте Монголо-Охотского складчатого пояса. Цель работы состоит в установлении условий образования, выявлении наличия поперечной геохимической зональности в мезозойской вулканической дуге Забайкальского сегмента Монголо-Охотского складчатого пояса. Методы. Определение элементного состава пород производилось рентгенфлуоресцентным методом (ГИН СОРАН, г, Улан-Удэ). Концентрации редкоземельных элементов определялись методом сорбционно-атомноэмиссионного анализа с индуктивно-связанной плазмой (ГИН СОРАН, г, Улан-Удэ). Силикатный анализ проводился стандартным методом «мокрой химии» (ГИН СОРАН, г, Улан-Удэ). Результаты. Установлена поперечная геохимическая зональность мезозойских вулканитов Забайкальского сегмента Монголо-Охотского складчатого пояса, выраженная в увеличении концентраций от фронтальной части вулканической дуги Монголо-Охотского складчатого пояса к тыловым ее частям концентраций K, Rb, Sr, Zr, Sb, Ba, Th, U, Ce отношений K/Na, Th/U, Rb/Sr, ∑TR. Отмечена пространственная приуроченность золоторудных месторождений к фронтальной части мезозойской вулканической дуги, полиметаллических и оловополиметаллических месторождений – к тыловым ее частям. Вулканиты полиметаллических месторождений характеризуются более значительной степенью окисленности железа и меньшей степенью дифференциации магматических очагов. Окисленность железа (мера окислительных условий), соотнесенная к кремнекислотности пород в вулканитах золоторудных месторождений, варьирует от 0,19 до 0,90 (среднее значение – 0,53); в вулканитах полиметаллических месторождений – от 0,32 до 0,93 (среднее – 0,58). Такая закономерность типична для вулканитов островных дуг зон перехода континент–океан. Выявлено, что по мере удаления от фронтальной части вулканической дуги увеличиваются глубины генерации магм вулканитов Забайкальского сегмента Монголо-Охотского складчатого пояса. Такая закономерность характерна для Курило-Камчатской островной дуги. Это объясняется увеличением глубин зоны генерации магм по мере удаления от фронтальной части зоны субдукции. Глубины генерации магм вулканитов золоторудных месторождений, по данным Rb-Sr соотношений, составляют 15–20 км и более, полиметаллических и оловополиметаллических месторождений – 20–30 км и более.

A field investigation on the distribution characteristics of structure cracks in the Chengchao Iron Mine, China

In this study, a comprehensive assessment on the generation mechanism, distribution characteristics, and extension rules of structure cracks was conducted by in situ monitoring and field investigation in the Chengchao Iron Mine. Structure cracks are affected by many factors, e.g., surface deformation, structure strength, occurrence position, and machine vibration. They initially occur in a structure when the strength of the structure is not enough to resist the inner strain as surface deformation increases. In contrast, increases in width and length of structure crack exert stress release in the structure and thus decrease structure deformation surrounding the crack. A great ground crack may adversely aggravate structure cracking and release the stress of surrounding rock masses. In addition, micro cracks in rock masses provide favorable conditions for the generation and extension of cracks, resulting that cracks occur in shaft walls more easily and extend towards the deeper. The initial distribution of cracks is generally consistent with such micro cracks. Subsequently, cracks in deep rock masses will extend along the strike of the mined-out area as surface deformation increases. Sensibilities to cracking of structures are changed by their different strain resistances and become stronger from bolt-shotcrete shaft, bolt-shotcrete tunnel, and brick-concrete building to brick wall. Based on distribution characteristics of cracks and wave velocity in rock masses, the overlaying strata affected by underground mining can be divided into four zones: broken zone, broken transition zone, crack generation zone, and micro deformation zone.

Epoxidation of Ethylene with Products of Thermal Gas-Phase Oxidation of n-Butane

Epoxidation of ethylene with the reactive products formed during thermal gas-phase oxidation of n-butane has been carried out under flow conditions with the separation of the zones of generation of radicals and their interaction with ethylene. Butane is oxidized in the first section of a two-section reactor, and ethylene is fed to the second section. It has been found that increasing the residence time of a butane–oxygen mixture in the first section of the reactor from 7 to 13 s increases the ethylene oxide accumulation rate. A further increase in the contact time leads to a decrease in the rate. Similarly, increasing the C4H10/O2 ratio in the range of 0.05–0.25 leads to an increase in the rate of accumulation of ethylene oxide. A further increase in this ratio decreases the rate of epoxidation. It has also been found that the temperature dependences of the ethylene oxide accumulation rate in both sections of the reactor pass through a maximum. The obtained data give evidence for the occurrence of the ethylene epoxidation reaction initiated by the n-butane oxidation products under the conditions when ethylene itself is slightly oxidized.

ASSESSMENT THE HYDROCARBON POTENTIALITY OF THE MIDDLE JURASSIC SARGELU FORMATION, NORTHERN IRAQ

The Middle Jurassic Sargelu Formation is evaluated for its hydrocarbon generation potential in three wells near Duhok Governorate, Northern Iraq using ten borehole cutting samples analyzed by Rock-Evil pyrolysis, gas chromatography coupled with gas chromatography-mass spectrometry (MSS) and stable isotope. The results showed that the total organic carbon and genetic potential of the formation ranges from 0.5 to 11.6 wt.% and 1.7 to 66.3 mg HC/g of rock, respectively indicating fair to excellent source rock petroleum potential, with hydrogen index values between 270 to 555 mg HC/g TOC. The results also show kerogen Types II and mixed II/III reflecting thermal maturity within the oil generation zone. The estimated ratios of Pr/Ph, Pr/n-C17 and Ph/n-C18 ­­­­­­ from the extracted bitumen reveal primary accumulations of marine organic matter under reducing conditions. The δ13CSat and δ13CAro for the extracted bitumen range from -29.5 to -27.5‰ and -28.4 to -27.2‰, respectively. The biomarkers results indicate a significant contribution of marine organic matters preserved under relatively anoxic conditions.

Wind Turbines Offshore Foundations and Connections to Grid

Most offshore wind farms built thus far are based on waters below 30 m deep, either using big diameter steel monopiles or a gravity base. Now, offshore windfarms are starting to be installed in deeper waters and the use of these structures—used for oil and gas like jackets and tripods—is becoming more competitive. Setting aside these calls for direct or fixed foundations, and thinking of water depths beyond 50 m, there is a completely new line of investigation focused on the usage of floating structures; TLP (tension leg platform), Spar (large deep craft cylindrical floating caisson), and semisubmersible are the most studied. We analyze these in detail at the end of this document. Nevertheless, it is foreseen that we must still wait sometime before these solutions, based on floating structures, can become truth from a commercial point of view, due to the higher cost, rather than direct or fixed foundations. In addition, it is more likely that some technical modifications in the wind turbines will have to be implemented to improve their function. Regarding wind farm connections to grid, it can be found from traditional designs such as radial, star or ring. On the other hand, for wind generator modeling, classifications can be established, modeling the wind turbine and modeling the wind farm. Finally, for the wind generator control, the main strategies are: passive stall, active stall, and pitch control; and when it is based on wind generation zone: fixed speed and variable speed. Lastly, the trend is to use strategies based on synchronous machines, as the permanent magnet synchronous generator (PMSG) and the wound rotor synchronous generator (WRSG).

Possible in-service damages of steam generators at VVER-1000 and VVER-1200 NPP units and their impact on long-term operation

Specific features of corrosion-mechanical damages of primary circuit header to steam generator vessel branch welds at VVER-1000 NPPs and their impact on safety and economic efficiency during long-term operation are analysed. Measures to avoid the damages for similar zones of VVER-1200 steam generators are discussed.

Dipole reorientation and local density of optical states influence the emission of light-emitting electrochemical cells.

Herein, we analyze the temporal evolution of the electroluminescence of light-emitting electrochemical cells (LECs), a thin-film light-emitting device, in order to maximize the luminous power radiated by these devices. A careful analysis of the spectral and angular distribution of the emission of LECs fabricated under the same experimental conditions allows describing the dynamics of the spatial region from which LECs emit, i.e. the generation zone, as bias is applied. This effect is mediated by dipole reorientation within such an emissive region and its optical environment, since its spatial drift yields a different interplay between the intrinsic emission of the emitters and the local density of optical states of the system. Our results demonstrate that engineering the optical environment in thin-film light-emitting devices is key to maximize their brightness.

Influence of Mild Bottom Slopes on the Overtopping Flow over Mound Breakwaters under Depth-Limited Breaking Wave Conditions

The crest elevation of mound breakwaters is usually designed considering a tolerable mean wave overtopping discharge. However, pedestrian safety, characterized by the overtopping layer thickness (OLT) and the overtopping flow velocity (OFV), is becoming more relevant due to the reduction of the crest freeboards of coastal structures. Studies in the literature focusing on OLT and OFV do not consider the bottom slope effect, even if it has a remarkable impact on mound breakwater design under depth-limited breaking wave conditions. Therefore, this research focuses on the influence of the bottom slope on OLT and OFV exceeded by 2% of incoming waves, hc,2% and uc,2%. A total of 235 2D physical tests were conducted on conventional mound breakwaters with a single-layer Cubipod® and double-layer rock and cube armors with 2% and 4% bottom slopes. Neural networks were used to determine the optimum point to estimate wave characteristics for hc,2% and uc,2% calculation; that point was located at a distance from the model toe of three times the water depth at the toe (hs) of the structure. The influence of the bottom slope is studied using trained neural networks with fixed wave conditions in the wave generation zone; hc,2% slightly decreases and uc,2% increases as the gradient of the bottom slope increases.

Effects of ultrasound-assisted freezing on the water migration of dough and the structural characteristics of gluten components

The effects of ultrasound-assisted freezing on the freezing time and water migration of dough, and the structural characteristics of gluten components were investigated. The effects of ultrasound-assisted freezing in the whole immersion freezing process (UWF) on the freezing time were better than those of ultrasound-assisted freezing in the maximum ice crystal generation zone. The shortest freezing time was obtained at 80 W/L, and was 577 s shorter than that with traditional immersion freezing. The UWF treatment at 80 W/L significantly (p < 0.05) affected the absorption enthalpy, freezable water content and water migration of frozen dough. In UWF compared with traditional immersion freezing, the SH content of gluten, glutenin and gliadin was significantly (p < 0.05) higher, by 12.06%, 27.55% and 21.65%, respectively. The surface hydrophobicity of gluten, glutenin and gliadin in UWF treated samples significantly (p < 0.05) decreased, by 19.67%, 13.21% and 9.17%, respectively. The secondary structure of gluten components was also significantly changed by UWF. The network of gluten, the chain structure of glutenin and the gliadin particles were all changed by UWF treatment. These findings indicated that UWF is an effective method to improve the moisture distribution in dough and reduce the damage to protein molecular structure caused by freezing.

ELECTRON PROBE MICROANALYSIS OF CARBONACEOUS ROCKS

The problems that often arise during the X-ray analysis of light elements are caused by the physics of the X-ray spectrum process and the mathematical algorithms (correction systems) used to calculate the concentration of elements. Therefore, the solution to these problems is determined by the hardware implementation of the analysis methods and its functionality. The most difficult situations arise in the qualitative and quantitative analysis of rocks that contain carbon in their composition. This is due to the fact that in the zone of generation of the X-ray signal, the polymerization of residual oil vapors and the appearance of a carbon film on the surface of the sample under study occurs. Therefore, with the standard method of studying a sample of unknown composition using an energy dispersive spectrometer, the peak of carbon is usually excluded from the scheme for calculating the concentrations of elements, which is unacceptable for carbon-containing samples. Using the example of the study of calcium and strontium carbonates, we have developed a method for measuring elemental chemical composition using the INCA Energy+ X-ray analysis system, which includes energy dispersive and wave dispersive spectrometers. The X-ray spectrum analysis system was applied in the study of carbon-containing unstable samples under the electron probe – unique remnants of paleoflora in the impact-melted rocks of the impact crater Elgygytgyn.Ref

The heat flow, thermal history of the oil source Lower Jurassic Togurskaya suite and oil-and-gas potential of the Paleozoic of the Koltogor mezodepression(southern segment of the Koltogor-Urengoy paleorift)

Input of the pre-Jurassic («Paleozoic») oil is important to the reproduction of the in-situ resources base of Western Siberian oil and gas extraction. Prospecting and forecasting studies of the pre-Jurassic reservoirs in the territory of the Koltogor mezodepression and structures of its surrounding — in the north-western part of Tomsk Region, in the zone of the southern segment of the Koltogor-Urengoy Permian-Triassic paleorift are of interest. The pre-Jurassic oil and gas complex(oil and gas bearing horizon of the contact zone— OGBHCZ and, actually, the Inner Paleozoic) is assigned along with the Cretaceous (the Neocomian), Upper Jurassic, Middle Jurassic and Lower Jurassic oil and gas complexes in the study area. It is accepted that the Upper Jurassic Bazhenov suite is the oil source formation for the Middle Jurassic, Upper Jurassic and Cretaceous oil and gas complexes, as well as Togurskaya suite — for the Lower Jurassic and pre-Jurassic deposits. Researches are carried out in the context of the methodology of the sedimentary and migrational theory of naftidogenesis. Spatiotemporal localization of the generation foci of Togurskaya oil is performed with the original method of paleotemperature modeling. The heat flow in sections of 82 deep wells is calculated at the first stage of modeling. At the following stages the oil source suite geotemperatures are directly figured up in key moments of geological time. The integral express-assessment of realization of generation potential of the suite is performed on the base of calculated data about time of the oil source suite residence in the main oil generation zone and its geotemperatures. Vewing to the concept about predominantly vertical migration of hydrocarbons the forecasting is carried out in the outline of the oil source suite distribution. Schemes of distribution of Togurskaya oil accumulation density are built and zoning of deposits is performed taking into account the thickness and quality of potential reservoirs of the pre-Jurassic deposits. Oil geological zoning of the pre-Jurassic complex and ranking areas according to the degree of prospect abilities were accomplished. The most forward-looking zone for prospecting in the weathering crust reservoir is the area, which comprises the eastern part of the Cheremshanskaya mezzo saddle and its articulation with the northern side of the Koltogor mezodepression and the western slope of the Srednevasyuganskiy megaswell (in the order of 3500 km 2 ). The most optimistic forecast for the Inner Paleozoic reservoir is made for the same areas as for the weathering crust, less optimistic — for the Severo-Chkalovskiy incised valley and its articulation with the Murasovskiyhigh and Trassovoe dome-shaped uplift (in the order of 5700 km 2 ).Consistency of the forecast with established direct evidence of oil saturation amounts to 70 %. Detailed map of the heat flow density in the study area showed that the trench of the Koltogor-Urengoy graben-rift does not have significant manifestation in enhanced values of the heat flow. The article demonstrates methodological approaches and complex technology of zonal forecasting of oil and gas potential of the pre-Jurassic basement of Western Siberia, which are working out by Tomsk research school of Geothermy.

Geothermal conditions of hydrocarbon prospects of Meso-Cenozoic formations in South Caspian Basin

Temperature data of oil and gas fields and prospecting sites in the South Caspian Basin (SCB) are summarized. From the array of measured temperatures and stratigraphy data from 190 offshore and onshore fields as function of depth, 3D interpolated maps of temperature fields and stratigraphic units of the area are constructed. Available data covers the stratigraphic interval from Neogene to Upper Cretaceous and include Pliocene productive formations and anticipated source rocks intervals (Oligocene and Upper Cretaceous suites). Geothermal modes (temperature-depth curves) for specific fields and for the region as a whole can be approximated by generalized parabolic type functions with fitted coefficients according to actual field data. The thermal mode of the South Caspian Basin is compared with similar major hydrocarbon fields worldwide. Specific features of the geological history and deposition, in particular, fast subsidence and avalanche sedimentation (sedimentation rate 1―2 km per MA) resulted in SCB being one of the coldest basin among giant hydrocarbon basins worldwide. This allows anticipating the availability of a hydrocarbon generation zone at depths up to 15―20 km, that is essentially below the sedimentary formations of the Pliocene Productive Suite and underlying Oligocene Maykop Suite, which nowadays are the most searched exploration targets. In particular, the results in conjunction with other research data from geochemistry, stratigraphy and tectonics, as well as backstripping simulations, allow us to expect large HC bearing structures in Mesozoic formations, including potential deposits at ultra big depths up to 12 km.

Mixgenetic concept of of oil and gas fields formation in basement and sedimentary cover on the shelf of South Vietnam

According to the geodynamic model of oil and gas formation, the most favorable conditions for the oil and gas fields are formed in the mobile zones of the earth’s crust, especially in areas of active continental margins, characterized by high seismicity, the presence of deep faults, the development of subduction and riftogenic processes. Therefore, it is logical that most of the world’s oil and gas deposits are concentrated in rifts or in the vicinity of paleo- and modern subduction zones. The study of the unique oil deposits in the granite basement of the White Tiger field, using data from other fields in the world, allows concluding that the formation of oil deposits in the basement can occur not only due to the resources of adjacent oil and gas deposits. Taking into account modern geodynamic ideas, in the context of the Earth’s internal geospheres, at least three oil generation zones can be distinguished: mantle-asthenospheric abiogenic synthesis; subduction-dissipative biomineral synthesis; stratospheric-biogenic synthesis. Obviously, all these three zones, as a single open system for the generation of hydrocarbons, will be interconnected only in conditions of deep faults, active continental margins and other parts of the Earth’s crust. This suggests that there are deep generation zones, which are currently fueling the developed fields.

Heat Transfer Search Algorithm for Combined Heat and Power Economic Dispatch

This paper suggests heat transfer search (HTS) algorithm for solving complicated combined heat and power economic dispatch (CHPED) problem. The valve point effect, prohibited operating zones of conventional thermal generators and transmission loss are taken into consideration. The main objective of the CHPED problem is to minimize the total fuel cost for producing electricity and heat supplying to a load demand. HTS is a novel meta-heuristic optimization algorithm that is based on the law of thermodynamics and heat transfer. The efficiency of the suggested HTS algorithm has been confirmed on four test systems. Test results of the suggested HTS algorithm have been compared with those achieved by other evolutionary algorithms. It has been observed from the comparison that the suggested HTS algorithm has the ability to offer superior solution.

Структура разнообразия по вегетативной и генеративной структуре кроны кедра сибирского на плантации с разреженной посадкой

Studies of the diversity of economically valuable traits in forest tree species are of great interest not only for forest selection and practical silviculture, but also important as a general biological problem. Among the objects of attention of breeders, a special place is occupied by cone-bearing species such as Siberian stone pine. Its cultivation through the forest tree plantations for wood and for cone-bearing will allow in the future to reduce the damage for natural ecosystems significantly. The purpose of this work was to analyze the structure of diversity in growth and generative development of the Siberian stone pine crown on a specially created plantation, where a low level of natural selection makes it possible to more efficiently select for early reproduction, growth and seed productivity. This plantation is located in the south of the area (Western Siberia, south of Tomsk region). It was created from stone pine seeds of the local population, that were sown in 1977 as forest crops with standard density (0,75 х 3 м). At the age of 10, they were planted out at a distance of 8 x 8 m. The vegetative and generative development of 89 trees aged 40 years was analyzed. We used a retrospective method that allows reconstructing of the tree organogenesis and growth on the scars on the bark of the shoots. The start of sexual reproduction has been reconstructed; a comparative characteristic of the vegetative and generative development of the tree crown has been carried out. The results show that, in general, the initial idea of the dependence of the efficiency of selection on the conditions in which the trees were formed is confirmed. In the natural dense stands, many of the leader trees in cone-bearing, which we found in our study, could fall behind due to slow growth and did not live to reproductive age. On the plantation where sparse tree planting was applied, they survived and became the leaders in cone-bearing. Early start of reproduction, even under conditions of sparse tree planting, is positively correlated with the growth rate in the pre-generative period of ontogenesis (r = + 0.65). The level of variations in the generative development of trees was much higher than in the vegetative one. The abundance of male shoots in the crown and the relative length of the male generative zone of crown were determined primarily by the height of the trees. On the contrary, the active growth of the tree in height did not have a noticeable influence on the development of the female shoots and the female generative zone of crown. Contrasting differences in the traits of male and female crown development with growth traits are very interesting result, in our opinion. Tall trees with a narrow crown are most promising for pollen productivity breeding, since they have a longer male generative zone and because of this they have more male shoots in the crown. Trees with a broad crown are promising for seed production breeding. Although seed productivity is not in all cases a direct function of the size of the crown, but depends on the specific genotype of the tree. This is confirmed by the fact that in each group (high, medium and low trees) there are individuals of high-cone-bearing and low-cone-bearing, which is promising for seed production breeding in groups of different growth levels. Using the calculated relative traits «1 m2 of the area of the horizontal projection of the crown onto the ground surface» made it possible to select the best trees for seed production (combining the minimum size of the crown with the number of cones per unit area of the crown) and growth (combining greater height and narrow crown).For citation: Velisevich S.N., Popov A.V. Pattern of diversity in the vegetative and generative crown structure of the siberian stone pine on a seed orchard with sparse tree planting. Lesnoy Zhurnal [Forestry Journal], 2019, no. 5, pp. 35–47. DOI: 10.17238/issn0536-1036.2019.5.35Funding: This work is supported by the Russian Science Foundation under grant no. 18-16-00058. The article is published within the framework of implementation of the scientific journals development program in 2019, based on proceedings of XIX International conference of the young scholars “Forests of Euro-Asia – The Southern Ural” (August 25-30, 2019. Chelyabinsk).

Trace elements of naftides of oil- and gas-bearing basin

The parameters of the concentration distribution of trace elements in the oil fields of oil and gas basins of the world, their physic-chemical properties, as well as the geological and geochemical features of oil formation in these basins were studied. It is shown that the ontogenesis of hydrocarbons associated with deep tectonic transformations (geodynamic factor) controls not only the placement of naphtides in the sedimentary cover, but also the diversity of their metallogenic specialization. The classification of oils of various ontogenesis zones is given in accordance to the degree of their enrichment of mineral elements and their belonging to the vanadium or nickel metallogenic type. The oil, characterized by primary rich concentrations of trace elements of the main zone of oil formation, and oil with initially low concentrations of trace elements in the zones of early generation are presented. The processes of transformation of the composition of oils in the areas of hypergenesis lead to their enrichment, whereas the oil of the catagenesis zone is depleted in trace elements.

Trace Elements in Naphthides in Oil and Gas Basins

The distribution of trace elements, physical and chemical properties of the oil, and geological and geochemical features of oil formation in world oil and gas basins were studied. It was shown that hydrocarbon ontogenesis associated with deep tectonic transformations (geodynamic factor) controls not just the distribution of naphthides in the sedimentary cover, but also the diversity of their metallogenic specialization. The classification of oils from various ontogenesis zones is given in accordance with their enrichment in trace elements and with the metallogenic (vanadium or nickel) type. Oil characterized by large primary concentrations of trace elements of the main zone of oil formation and oil with low initial concentrations of trace elements in the zones of early generation are presented. Transformation of the oil composition in the areas of hypergenesis leads to their enrichment, whereas the oil of the catagenesis zone is depleted in trace elements.

Observation of Laser-Induced Spark in the Density Jump in a Gas-Jet Target

In the design of powerful laser-plasma sources of extreme ultraviolet radiation with a gas jet as the target, the problem of degradation of gas nozzles is topical. Degradation is observed due to insufficient distance from the generation zone of the laser-induced spark to the nozzle exit. The comprehensive solution to this problem is proposed by forming the laser-induced spark in the density jumps that are generated upon deceleration of the supersonic gas jet. In such a density jump, the laser-induced spark is obtained and measurements of emission radiation intensity are performed.

ПРОГНОЗ НЕФТЕГАЗОНОСНОСТИ ЮРСКИХ И ПАЛЕОЗОЙСКИХ ОТЛОЖЕНИЙ ЮЖНЫХ РАЙОНОВ ЗАПАДНО-СИБИРСКОГО БАССЕЙНА

Статья посвящена перспективам нефтегазоносности палеозойских и мезозойских комплексов в южных районах Западной Сибири. Для региона характерны сложнопостроенные неантиклинальные ловушки, связанные с полифациальным генезисом вмещающих толщ, особенностями тектонического и литологического строения. В связи с этим выявление перспективных земель для поисков залежей углеводородов невозможно без применения комплексного подхода, включающего геологические, литологические, тектонические и гидрогеологические исследования. Использование гидрогеологических критериев нефтегазоносности основано на ведущей роли подземных вод в процессах генерации, миграции и аккумуляции углеводородов. В процессе исследования установлены гидрогеохимические особенности подземных вод, выделены гидрогеохимические аномалии, тесно связанные с залежами углеводородов (I, B, Br, NH4 и др.). Охарактеризованы генетические типы подземных вод и степень их катагенетической преобразованности. Приведены основные результаты палеогидрогеохимических и палеогидродинамических реконструкций, выделены зоны нефтегазообразования и нефтегазонакопления, показаны возможные пути латеральной и вертикальной миграции флюидов. Изучены особенности геологического строения, выделены зоны развития улучшенных коллекторов. Совместное использование гидрогеологических и геологических показателей продуктивности недр позволило обосновать набор критериев нефтегазоносности, несколько различных для палеозойского, среднеюрского и верхнеюрского комплексов. С помощью предложенного комплекса критериев был осуществлен прогноз нефтегазоносности и оконтурены участки различных категорий перспективности (высокоперспективные, перспективные и земли с неясными перспективами, требующие дальнейшего изучения). Применение данного подхода будет способствовать локализации геологоразведочных работ и повысит эффективность геофизических методов при поиске новых залежей углеводородов в южных районах Западно-Сибирского бассейна.

Geochemical features of bitumen shows in the Lower-Middle Devonian deposits of the Northern-Western part of Kotelny Island (Novosibirsk Island Archipelago) v

The work presents the results of organic matter (OM) study of rocks, the composition, chemical structure of chloroform bitumen (CB), their fractions and the nature of the hydrocarbon biomarkers distribution in samples taken from outcrops. The obtained results confirmed the existing idea of ​​the domanicoid nature of OM and the high oil and gas potential of the studied deposits. According to our data, the aquagenic type of OM is indicated by a high content of Corg, a high yield of CB, a high content of oils in the composition of synbitumoids, and the predominance of relatively low molecular weight n-alkanes with a maximum at nС15-18. A sufficient maturity of bitumen can be judged by CPI coefficients close to unity and low absorption coefficients of oxygen-containing groups and bonds in the CB, thus deposits entered the main oil generation zone and generated liquid hydrocarbons that could migrate and form clusters. According to the data of Chromato Mass Spectrometry, it is shown that a feature of the composition of CB from the Lower Devonian sediments is the presence of high concentrations of dibenzothiophenes, in contrast to the Middle Devonian, which may be associated with the formation of the initial OM in an environment with higher hydrogen sulfide contamination of sediments. It has been suggested that naphthides generated by aquagenic OM of the Lower Devonian deposits can be enriched with dibenzothiophenes. The studied bitumen shows are mainly syngenetic in nature and have been influenced by hypergenic oxidation (judging by the nature of the IR spectra of resinous components) and contact metamorphism. According to the characteristics of the distribution of saturated hydrocarbons, it was shown that, in the Middle Devonian, bitumen occurrences along with chemical oxidation were affected to a different degree of bacterial oxidation processes, in contrast to the Lower Devonian bitumen shows. The results can be used to assess the generation potential of oil source strata and to forecast the prospects of oil and gas potential in the shelf of the eastern sector of the Russian part of the Arctic.