Study and exploration of the pre-Jurassic oil and gas complex in Western Siberia is one of the aspects of hydrocarbon raw-material base development. The main scope of this study is to locate the source of Paleozoic hydrocarbons. The problem of modeling and assessing the role of Paleozoic Mesozoic hydrocarbon generation centers in the formation of «Paleozoic» oil deposits in the section of the Ostaninskoe oil and gas condensate field (Tomsk region) is solved. In the formation of the oil and gas content of the pre-Jurassic basement two reservoirs are involved: the weathering crust and the roof of the bed-rock Paleozoic. The first was formed during the period of 213–208 Ma, and the second is genetically determined by epigenetic processes in the weathering crust. Potential hydrocarbon sources for the weathering crust and bed-rock Paleozoic reservoirs are Domanic type rocks in the crystalline basement: Larinskaya S1lr, Mirnaya D1mr, Chuzikskaya D2cz, Chaginskaya D3cg Formations, as well as Tyumenskaya J1-2tm and Bazhenovskaya J3bg Formations in sedimentary cover.
To perform joint paleotemperature modeling of sedimentary basins of the «modern» Jurassic-Cretaceous and Paleozoic «paleobasins», the Ostaninskaya 438P well was selected, which is due to the presence of measured temperatures both in the Jurassic sections and in the pre-Jurassic formations, as well as fluid inflows from the pre-Jurassic horizons into the well. At the first step, the solution of the inverse problem of geothermics was obtained using reservoir temperatures and vitrinite reflectance measurements from the Mesozoic deposits: density of deep heat flow from the base of sedimentary section was determined, which is characterized by a quasi-constant value from the Jurassic to the present. The second step was to solve the inverse problem using vitrinite reflectance measurements from Paleozoic sediments. As a result, the heat flow value was obtained for the key moments of geodynamic history of the stratigraphic section, starting from the Silurian. By solving direct problems of geothermics with the given values of heat flow, the structural-tectonic and thermal history of four Paleozoic potential oil source formations (as well as Jurassic – Bazhenov and Tyumen Formations) has been retraced. The controversial aspects of the heat transfer model in the section of the Ostaninskoe field are considered.
It has been established that the Tyumen and Bazhenov oil sources (most likely Bazhenov) are syngenetic (in terms of generation, accumulation and preservation time) for the weathering crust and the Paleozoic reservoirs. The role of the Chaginskaya Formation as gas source is insignificant.

Two express methods are presented in this paper. The first method is a high-resolution gamma-spectroscopic method based on a germanium detector, the second method is an IR-spectroscopic method. The applied complex of methods allows to determine the sources of uranium and thorium, identify the rhythms of uranium accumulation associated with regional events; identify areas with a high content of uranium due to the influence of local sources (faults, hydrothermal, etc.); determine the amount of authigenous uranium in the composition of total uranium; determine thermal maturity of organic matter in shales without their preliminary demineralization. To identify levels of increased uranium intensity in the high-carbon strata, a set of indicators has been proposed, which includes both applied indicators in practice of geological work and new indicators.
New indicators have been tested on the collection of shale reference samples. For them, values were established that characterize the processes of uranium accumulation and uranium removal. On the example of Ukhta Region according to the proposed indicators, the sections from the VendianRiphean to Domanic inclusive were interpreted.
The performed work showed the possibility of comparing the calculated gamma-spectroscopic data with the data of other methods. This opens up a broader perspective for the use of express non-destructive gamma-spectroscopic method for detecting levels with a high content of uranium in the shale rocks, to which ore-bearing concentrations of a number of metals are also confined.

In-depth additional studies were carried out to assess oil and gas potential of deep-lying Jurassic and pre-Jurassic deposits of the northern territories of Western Siberia. As in previous work, the geological and mathematical program “Vybor” was used. Based on the first constructed series of model maps with probabilistic values of informative geochemical and geological parameters, the most promising both local and regional objects were selected.
Increasing complexity of the traps structure with depth was noted. As a rule, from the Cretaceous deposits to the Jurassic and Paleozoic, the type of trap from the predominant anticline (in the Cretaceous) changes to a much more complex combined one, which requires special approaches (and new technologies) to identify and explore such objects. Studies based mainly on seismic data indicate rather high oil and gas content of both the Paleozoic and Triassic deposits, which have a platform occurence and large thicknesses, as well as crystalline basement formations. In this regard, unconventional combined traps of deep-lying deposits of the North of Western Siberia are of significant interest in terms of incremental oil and gas resources and reserves.

The main features of the geochemistry of individual aromatic compounds (phenanthrenes, dibenzothiophenes, monoand triaromatic steroids) in chloroform extracts (bitumoids) from the open (regular form and coarse-crushed (≥0.5 cm) samples) and closed (fine-crushed (0.25 mm) samples) pore space of the Bazhenov Formation have been determined. The differences in the aromatic compounds distribution of organic matter of the Bazhenov Formation in the North of the Khantey hemiantheclise (Surgut region, KhantyMansiysk Autonomous District, Western Siberia) are mainly related to its stage of thermal maturity which decreases in the south-west direction within the studying area. The most sensitive to maturity variations at the same catagenesis gradation are the parameters: CPI, Ts/Tm, 1/Ki ((n-C17 + n-C18)/(Pr + Ph)), MDR (4-MDBT/1- MDBT), DBTI ((2+3-MDBT)/DBT) and TASI (TAS I/(TAS I + TAS II)). Based on some indicators (PI, MPI, PP-1, MDR, DBTI etc.), it is possible to notice the decrease and equalization of its values in bitumoids from closed pores compared with those from open ones. It seems to be associated with the removal of the most transformed, light and migratory-capable part of bitumoids during their extraction from the open pore space of rocks.

The article considers the geochemical characteristics of the rocks of the Bazhenov and Nizhnetutleim formations in the southwestern part of the West Siberian oil and gas province, or rather in the territory of the Karabash search zone. The work was carried out on the basis of the core material study of the section of 29 wells within the Karabash zone by pyrolysis on the Rock-Eval 6. The regularities of the distribution of organic carbon concentrations (С_org, %) on the studied territory were obtained. With the help of data mapping, it was established that the maximum concentrations of organic matter are timed to the southern regions of the zone (the most submerged parts of the paleobasin). The assessment of the catagenesis degree (degree of maturity) of organic matter of the Bazhenov horizon in the study area was carried out. Level maturity of organic matter of rocks is specified in the parameter T_max Rock-Eval. Within the study area it’s increasing from South to North, from graduation PK3 (according to the scale of N.B. Vassoevich) (T_max < 430 0 С) in the area of wells Verkhnetyumskaya 34 to MK2 (T_max 440–445 0 С) in the area of Molodezhnaya and the Zapadno-Frolovskaya square. The resulting catagenetic zoning determined the boundaries of the generation kitchen for this territory. Generation scale for the Upper Jurassic source rocks was estimated, taking into account its lithofacial structure.

Despite the long history of geological exploration and scientific research in the Caspian region many issues of its oil and gas geological zoning remain controversial, including justification the boundaries of oil and gas provinces at the ancient and young platforms: PreCaspian, Ciscaucasia-Mangyshlak and North-Ustyurt. This paper discusses problems of the ancient and young platforms sedimentary cover’s oil and gas zoning using the example of Pre-Caspian region. It is proposed to carry out oil and gas geological zoning of these regions with taking into account the types of the Earth’s crust sections and sedimentary cover’s hydrocarbon systems types, as well as the types of the main oil and gas complexes’ structures. The type of the Earth’s crust section is crucial upon identification oil and gas provinces boundaries; the type of hydrocarbon systems is in the foreground when identifying sub provinces; and the boundaries of oil and gas regions are determined by the main types of oil and gas complexes’ sections and structures.
In the Pre-Caspian province three sub-provinces are identified and their oil and gas potential is characterized. The proposed boundaries of the province closely coincide with the distribution contours of the Kungur saliferous strata with considerable thickness (hundreds of meters). Due to the lack of a clear structural boundary between the Paleozoic hydrocarbon systems the Pre-Caspian and Volga-Ural oil and gas provinces are proposed to be considered as a single marginal-continental oil and gas mega-province. The obtained materials and conclusions can serve as a basis for basin modeling and hydrocarbon resources forecast’s refinement.

The velocity characteristics of the Upper Proterozoic-Phanerozoic sedimentary cover of the AnabarOlenek region were studied, in particular, the bimodal character of the distribution interval P-wave velocities was established. Taking into account modern ideas about the chronostratigraphy of sediments encountered by the Charchykskaya-1, Burskaya-3410 and Khastakhskaya-930 deep boreholes, stratification of reflecting horizons was carried out and time sections from previous years were reinterpreted. From the perspective of seismic stratigraphic and seismic facies analysis, the Cambrian, Vendian, and Riphean intervals of the section were examined in detail. In the course of the analysis, adjustments to the stratigraphic breakdown of the Burskaya-3410 and Charchykskaya-1 boreholes are proposed. The study shows that the Lapar Formation, which underwent Prepermian erosion, increase in the thickness multiple in an eastward direction. The distribution areas of the Tuessal Formation, the Lower and Middle Cambrian clinoform complex, as well as the areas of the Upper Riphean Formations reaching the Prevendian erosion surface are contoured. An Intrariphean tectonic disagreement between the Kulady Formation and older deposits was established.

Barents Sea basin is the most explored and studied by the regional and petroleum geologists on the Russian Arctic shelf and has approved gas reserves. However, there are many questions in the petroleum exploration, one of them is the structural reconstruction. During its geological evolution, Barents Sea shelf was influenced by the Pre-Novaya Zemlya structural zone that uplifted several times in Mesozoic and Cenozoic. The main goal of the research is to clarify the periods of structural reconstructions of the Eastern Barents shelf and its influence on the petroleum systems of the Barents Sea shelf. A database of regional seismic profiles and offshore borehole data collected over the past decade on the Petroleum Geology Department of the Lomonosov Moscow State University allows to define main unconformities and seismic sequences, to reconstruct the periods of subsidence and uplifts in Mesozoic and Cenozoic. The structural reconstructions on the Eastern Barents Sea in the Triassic-Jurassic boundary led to intensive uplifts and formation of the huge inversion swells, which is expressed in erosional truncation and stratigraphic unconformity in the Upper Triassic and Lower Jurassic strata. In the Jurassic period, tectonic subsidence reigned on the shelf, when the uplifts including the highs of Novaya Zemlya were partially flooded and regional clay seal and source rocks – Upper Jurassic «black clays» – deposited on the shelf. The next contraction phase manifested itself as a second impulse of the growth of inversion swells in the Late Jurassic-Early Cretaceous. Cenozoic uplift of the Pre-Novaya Zemlya structural zone and the entire Barents Sea shelf led to significant erosion of the Mesozoic sediments, on the one hand, forming modern structural traps, and on the other, significantly destroying the Albian, once regional seal.

The article describes the geological structure of the Sokolovsk and Krasnokamensk massifs located in the central part of the Western subzone of the ChelyabinskAdamovka zone of the Southern Urals. They are of Lower Carboniferous age and break through the volcanogenicsedimentary deposits of the Krasnokamensk (D₃kr) and Bulatovo (S₁-D1bl) strata. It was found that these intrusions belong to the gabbro-syenite complex and are composed of gabbroids (phase I) and syenites, quartz monzonites, less often monzodiorites (phase II). The rocks of the second phase predominate (90–95%). Gabbros belong to the normal alkaline series of the sodium series and are close to tholeiitic mafic rocks, the formation of which is associated with riftogenic structures; syenites correspond to moderately alkaline series with K-Na type of alkalinity. It has been proved that in terms of their petrographic, petrochemical, geochemical, and metallogenic features (content of TiO₂ , K₂ O, Na₂ O, Rb, Sr, distribution of REE, the presence of skarn-magnetic mineralization), the rocks of the massifs under consideration undoubtedly belong to the gabbro-granite formation. Crystallization of the Sokolovsk and Krasnokamensk intrusions occurred at a temperature of 880–930 °С in the mesoabyssal zone at a depth of about 7–8 km (P = 2.2–2.4 kbar). At the postmagmatic stage, the transformation parameters of the initially igneous rocks were, respectively, T = 730–770 °C, P = 4.0–4.2 kbar. The fact that these massifs belong to the gabbro-granite formation makes it possible to include them, together with Bolshakovsk, Klyuchevsky, Kurtmaksky and Kambulatovo, into the Chelyabinsk-Adamovka segment of the South Ural Early Carboniferous rift system.

The study focuses on the comparison of the chemical and mineral composition of Lunar regolith probes from Luna-16, -20, -24 stations and their the seacontinent environments. Using microprobe JXA-8200 and JSM-5610LV (400 analyses, 50 images, 9 fragments of layer-by-layer core samples) 18 mineral phases and their 12 varieties were diagnosed. The most common are ironmagnesium and calcium-bearing varieties of silicates – anortite, clinopyroxenes and olivine. The typomorphic features of rock-forming minerals in two types of the lunar surface are discussed. The composition of chromespinelids is demonstrated on a triangular prism diagram.

A model problem of the permeability field identification for a three-dimensional reservoir opened by a large number of wells in the conditions of stationary singlephase fluid filtration is considered. The permeability field is determined in the process of solving the inverse coefficient problem by on known values of bottomhole pressure. The solving problem algorithm is constructed so that the proportionality coefficients of the layers permeability on wells obtained from the results of geophysical well survey are preserved. The influence of various types of errors on the identification results is studied.

A laboratory and numerical study of the mechanisms that affect the structure and physical properties of the borehole zone of a production well at various stages of development of a saline formation with textural wettability was conducted. It is shown that for the object of study is characterized by the formation of complex borehole vicinity of the structure and dynamic change of properties which define the specific geotechnical effects: desalinization; pinched adscititious water in the pore space; the decompression and the strain on the washed areas; precipitation of solid salt sediment at the moment of breaking through the highly mineralized front of the injected water. The synergetic effect of these effects leads to the formation of complex, including non-monotonic, permeability distribution profiles in the near-well zone.

Theoretical issues of joint underground storage of hydrogen with methane are poorly studied, and practical examples are rare. Therefore, it is extremely important to analyze the mutual influence of hydrogen-methane mixtures and the host geological environment. This article presents material that makes it possible to substantiate the most significant hydrochemical processes that affect the transformation of cap rocks. For this purpose, the results of our own experiments, as well as published data on the study of the influence of hydrochemical conditions on the diffusion loss of hydrogen, its interaction with rock-forming minerals, organic matter, and pore waters were used. A quantitative assessment of the decrease in the moisture saturation of clay-rocks samples and, as a consequence, the loss of the mass content of mineral and organic substances is given. It was found that the cyclic change of thermobaric effects leads to a change in the redox conditions in the system “rock ↔ pore water” and is accompanied by an increase in the reactivity of calcium, magnesium, sulfur, iron. The saturation indices of pore water with carbonate and sulfate calcium salts were calculated under the conditions of their precipitation, dissolution, and removal from solution. The interpretation of the experimental data made it possible to substantiate the most probable transformations in clayey cap rocks, which affect their screening capabilities. It is recommended to take into account, when designing and operating storage facilities for hydrogen-methane mixtures, the variety of accompanying hydrochemical and microbiological processes that affect the change in the filtration properties of cap rocks.