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Geomechanics is a complex discipline that covers issues of geology, geophysics, petrophysics, mechanics, etc. Building a digital geomechanical model begins with audit input data. This stage lays the foundations for all subsequent work. For geomechanical modeling, the basis of the future project is a special logging complex, which must include DTP, DTS, RHOB, CALI, GR. In this paper, on the example of one of the deposits of the Krasnoleninsky arch, the solution to the problem of reconstructing the P-, S-waves slowness, as well as bulk density, is shown based on various approaches.

Considers issues of three-dimensional geological modeling of gas and oil fields in Neocomian clinoform deposits of the Western Siberia. The features of the geology of the studied deposits, which are important for the creation of lithological models, are analyzed. The essential difference of lithological modeling methods of shelf and Achimov deposits is shown. Examples of building the lithological models taking into account the revealed features of geological structure are given.

According to lithological and petrophysical data the core of the Bazhenov Formation, discovered in the central part of the Tundrin Basin, the structure of the section was characterized , productive oil intervals were identified, in which the collectors of pore and fissure-pore types are developed.

The composition of Bazhenov and Abalak Formation rocks of Western Siberia is presented. Correlations of macro- and micro-components concentration with the base mineral and organic matter content in rocks are showed. Investigations of trace elements allow determining sedimentation conditions: redox conditions, hydrogen sulfide contamination and the source of the sedimentary material. The results showed that the rocks of the Bazhenov Formation were formed at low flows of clastic material under reducing conditions and a periodic hydrogen sulphide mode.

The paper presents the results of coal petrographic and geochemical studies of the Tutleim Formation rocks organic matter in the area of the Em-Egovskaya summit. Five macerals were identified that compose the organic matter of the studied formation: "standard" bituminite, "atypical" bituminite, radiolarian organic matter, alginite and vitrinite, as well as bitumen and bitumen films, which are the products of the original organic matter transformation. The metamorphosis in macerals during catagenesis is described, and the order of their entry into the generation phase is established. It has been shown that alginite starts transforming first, then "standard" bituminite, "atypical" bituminite, and the last one is the radiolarian organic matter. The results obtained were confirmed by the laboratory modeling of the further organic matter transformation. New bitumens are formed with different fluorescent properties compared to the initial ones. The results obtained in combination with the study of changes in the composition of both macerals and bitumen can make it possible to assess the contribution of individual organic matter microcomponents to the process of petroleum hydrocarbons generation.

The experimental results on the synthetic oil production from Domanik Formation rocks under hydrothermal conditions are given. Oil fractions extracting potential of the rocks under hydrothermal was shown to be up to 60 mg/g or 6,0 wt.%. Inorganic additives (sodium carbonate or silica) incorporation does not influence on the oil recovery factor. Meanwhile the amount of recoverable oil products depends on the mineral composition of the rock. The dependence between the percentage of hydrocarbons emission and mineral composition of the rocks was determined. Clay minerals and silica increase the yield of synthetic oil, carbonates, conversely, inhibit the process.

The foraminiferal assemblages from the mud volcanic breccia of the Shugo mud volcano (Kerch-Taman volcanic region, Taman peninsula) was studied in order to clarify the stratigraphic section of this region. Mud volcanic breccia contain shells of Miocene foraminifera, numerous well preserved Middle Eocene (Lutetian), and Upper Cretaceous (Santonian, Campanian, and Maastrichtian) species. The poorer preservation of the Cretaceous shells may be associated with the composition of the accommodating rocks, probably represented by terrigenous and carbonate-terrigenous turbidites. Finding the remains of the Upper Cretaceous and Middle Eocene foraminifera in the mud volcanic breccia indicates the presence of strata of this age in the section.

The article provides the results of the hydrocarbon compounds (HCS) molecular composition in open and closed pores of the Bazhenov horizon source rocks studying. Extraction with solvents of different polarity allows to withdraw additional HCS from both open and closed pores of rock samples, and their composition systematically differs both in the distribution of normal alkanes and in the values of biomarker parameters characterizing the maturity and sedimentary conditions. HCS in open pores is more thermally maturated than HCS in closed pores, and in both cases, maturity can decrease in blocked pores, especially in those sealed with soluble in alcohol-benzene resins-asphaltenes. The values of parameters Pr/Ph and dia/(dia+reg)C27 are higher for bitumen in open pores, but the values of C29/C30 and H35S/H34S are much higher for bitumen in closed pores, and can vary in blocked pores with respect to the open ones. As a result, a improved model of HCS distribution in the pore space was proposed, which shows the presence of residual light HCS in open pores, as well as two types of blocked pores, in which HCS are sealed by different resins-asphaltenes in both open and closed pore spaces.

The Bazhenov Formation of Western Siberia is one of the most important and promising high-carbon formations. Its peculiarity is a huge area of distribution and high generation potential of its constituent deposits. Another feature of the formation is the predominance of silicides in its composition, among which the most interesting are radiolarites, which are often associated with hydrocarbon inflows. However, the mechanism of the forecast and the nature of their distribution still do not have an unambiguous solution. Based on a study of the composition and textural features of the structure of radiolarite layers in the clayey-siliceous rocks of the Bazhenov formation, a model of their formation based on the interaction of plankton (radiolarians) and currents is proposed.

Using the example of lower nutovsky thickness on Odoptu field discusses the possibility and efficacy of sequence-stratigraphic approach to integrated interpretation of seismic data and drilling materials. Sequence stratigraphic model, graph showing sea level changes and regional chronostratigraphic correlation chart with reference to the existing geochronological scale was developed for the formation of the sedimentary cover in the research area.

The paper presents a study of the structure and reservoir properties of rocks of the Bazhenov formation in the sections of three wells located in different structural zones of the Priobskoye field. It is shown that the porosity of the samples varies from 0.02% to 6.95%, the absolute gas permeability of the rocks reaches 1.364 mD. It is established that the collectors in the Bazhenov formation are confined to silicite-radiolarites (possessing porosity associated with the leaching of radiolarian shells) and kerogen-clay-siliceous rock and kerogen-clay silicite (porosity is associated with the release of space between the clay-siliceous matrix and kerogen by ripening organic matter). The following secondary processes influenced the formation of voids in these lithotypes: recrystallization of radiolarians and local warming up.

The analysis of Bazhenov high-carbon formation organic matter catagenesis zonal distribution in connection with its own reservoir's organic matter porosity made in this work. Realized research helped to articulate regional prospecting criteria for oil deposits in Bazhenov's formation unconventional reservoir with organic porosity.

The most prospective section intervals in the Bazhenov formation (Tutleimskoy) and Abalak formation are composed of interbedded siliceous and carbonate rocks. Based on the core analysis, genetic typing of carbonate rocks was performed to improve the quality of their prediction, the most promising of them for finding of oil-saturated reservoirs are identified.

А new anomalous section of the Bazhenov formation was described in the territory of the Urengoy oil and gas condensate field in the northern part of Western Siberia. Article 1 presents the results of the lithological description of the core, the division of the main rocks into lithotypes, the results of granulometric and palynological analyzes. It was revealed that gray-colored sandy-clay deposits and sandy vein-like bodies are younger than the host rocks of the Bazhenov Formation, represented by black kerogen-siliceous-clay rocks. On the basis of palynological studies, as well as the similarity of the mineral and granulometric compositions of the studied sandstones with the sandstones of the Achimov strata, it was assumed that the studied clastic rocks belong to the Achimov deposits, which were intruded into the deposits of the Bazhenov Formation.