Identification of the source rock potential and distribution area is the most important stage of the basin analysis and oil, and gas reserves assessment. Based on analysis of the large geochemical and geological data base of the Petroleum geology department of the Lomonosov Moscow State University and integration of different-scale information (pyrolysis results and regional palaeogeographic maps), generation potential, distribution area and maturity of the main source rock intervals of the Barents-Kara Sea shelf are reconstructed. These source rocks wide distribute on the Barents-Kara Sea shelf and are characterized by lateral variability of generation potential and type of organic matter depending on paleogeography. During regional transgressions in Late Devonian, Early Permian, Middle Triassic and Late Jurassic, deposited source rocks with marine organic matter and excellent generation potential. However in the regression periods, during the short-term transgressions, formed Lower Carboniferous, Upper Permian, Induan, Olenekian and Late Triassic source rocks with mixed and terrestrial organic matter and good potential.
Upper Devonian shales contain up to 20.6% (average – 3%) of marine organic matter, have an excellent potential and is predicted on the Eastern-Barents megabasin. Upper Devonian source rocks are in the oil window on the steps, platforms and monoclines, while are overmature in the basins. Lower Permian shale-carbonate source rock is enriched with marine organic matter (up to 4%, average – 1.4%) and has a good end excellent potential. Lower Permian source rocks distribute over the entire Barents shelf and also in the NorthKara basin (Akhmatov Fm). These rocks enter the gas window in the Barents Sea shelf, the oil window on the highs and platforms and are immature in the North-Kara basin. Middle Triassic shales contain up to 11.2% of organic matter, there is a significant lateral variability of the features: an excellent generation potential and marine organic matter on the western Barents Sea and poor potential and terrestrial organic matter in the eastern Barents Sea. Middle Triassic source rocks are in the oil window; in the depocenters it generates gas. Upper Jurassic black shales are enriched with marine and mixed organic matter (up to 27,9%, average – 7.3%) and have an excellent potential. On the most Barents-Kara Sea shelf, Upper Jurassic source rock are immature, but are in the oil window in the South-Kara basin and in the deepest parts of the Barents Sea shelf.

Russian shelf is one of the most important areas for hydrocarbon forecast and mineral resources development. The main features of the geological structure of the shelves of the Far Eastern seas are discussed in the paper. The most promising basins on the Okhotsk shelf are located around Sakhalin island where the majority of the hydrocarbon fields have been discovered. The Bering and the Japan shelf has not been sufficiently studied by now but nevertheless has high oil and gas potential.
The main focus is made on the geological and geophysical data, licensing, lithological and stratigraphic structure, seismic interpretation, oil and gas fields distribution. The structuraltectonic zoning of the entire Far Eastern region has been done in order to identify zones of deep troughs with thick sedimentary cover to predict the sources of hydrocarbon generation.

The article considers the elements of organic geochemistry in the regional aspect, which aims to separate quantitative prediction of oil and gas content of regions. The principles and results of balance calculations of generation and emission of liquid and gaseous hydrocarbons for different faciesgenetic types of organic matter and methods for calculating the scale of hydrocarbon emission are considered. Finally, a list of the main regularities of organic geochemistry is given.

Berezovsky depression, located on the northeast of the Pre-Patom foredeep, is a promising target for hydrocarbon prospecting, as evidenced by oil and gas shows established while drilling, the presence of structures and natural reservoirs. However, this area has not yet been adequately explored due to the low drilling density. Geochemical study of organic matter (OM) of the Riphean, Vendian and Lower Cambrian sediments showed that the main oil and gas source rock is represented by terrigenous-carbonate Vendian deposits. Rocks of the Seralakh Formation possess highest initial and residual potential, as well as interlayers of rocks with heightened content of algal OM in the Vendian and Lower Cambrian sections. The oxidation of OM during sedimentation and the presence of bottom algae could have a negative impact on the generation potential of these deposits, which led to a decrease in OM concentrations and deterioration of kerogen; most likely, these factors determine the smaller resources of the Berezovsky depression. Probably, the study of the Riphean complex deserves attention, because there are oil-source rocks highly enriched in OM in the Middle and Upper Riphean of the south-west of the Baikal-Patom fold zone, the transformation of which is corresponded to peak of «oil window» – «gas window».

The ancient Precambrian formations of Eastern Siberia include oil and gas source rock (SR) interlayers, but in most cases, they can’t be classified as high-carbon ones, because the actual organic carbon content in these strata is low and rarely exceeds 10%. This point effect the approach to the available geochemical data interpretation and the method of quality samples selection. The aim of the work was to determine methods for pyrolytic data verification and the oil and gas Lower Vendian SR quality assess, that based on the results of geochemical researches. It was identified, that before SR catagenetic transformation analyzation by the Tmax parameter and determining the OM type, samples with a low generation potential or with the migrated bitumen presence should be excluded from the consideration. The presence of secondary epigenetic bitumen also indicates the active HC fluids migration within the basin. After data verification, the SR properties were assessed. So lower Vendian SRs have OM with a satisfactory and high generation potential, second type and low maturity in most cases. The oil and gas window zones are located within large depressions and troughs. In addition, the local heating was noted in zones with a large number of faults, where the heating was conducted due to the intrusions introduction and the hydrothermal fluids action.

The paper considers palaeoincisions in the Turnean limestones of the Volga-Ural basin, made by alluvial-deluvial sediments of the Visean age and containing interlayers of coals. Processes occurring in these sediments (catagenic reduction of thickness of coal beds and coal-bearing mudstones, aggressive influence of products of defluidization of coal organic matter on the host rocks, etc.) strengthen the fluid dynamic heterogeneity of intracrustal deposits and contribute to emigration of hydrocarbons (HC). The main oil-and-gas-generating strata in the Carboniferous section include rocks of the Tournaisian stage and the Bobrikovsky horizon of the Viseian stage. Palaeoincisions, along with the area distribution of Viseian coals, can be considered as centers of fluid generation, including liquid and gas HC.

Riphean-Vendian Petroleum system of VolgaUral Basin (Northern part, Kama-Belsky aulakogen) main elements are described. Reservoirs and properties of them (porosity and permeability), source rocks are characterized geochemically by results of pyrolysis, extraction, gas chromatography. To understand the conditions of Volga-Ural Proterozoic petroleum system formation were analyzed lots of publications and collected huge dataset (regional geological data, seismic, well data, geochemical data and so on). Were made maps of Riphean-Vendian tectonics and location in North part of VolgaUral Basin. The main characteristics important for petroleum system formation and oil and gas prospects estimation were indicated.

The article deals with the lithology and geochemistry of organic matter of Upper Devonian-Lower Carboniferous deposits (Carbonate Devonian) of the eastern part of the South Tatar arch. Rocks of this age have a high generative potential due to increased concentrations of organic matter (OM) and its phytogenic and zoophytogenic composition. They refer to non-traditional sources of hydrocarbons. The generative potential depends on the facial environment and the transformation of OM. The highest potential have carbonate-siliceous and siliceous-carbonate rhythmites domannic horizon.

Unconventional oil and gas resource development and exploration is the one of the most prospective concept in petroleum geology. High carbon Khadum facies are investigated as unconventional resources in the Precaucas basin and contain gas, gas condensate and oil accumulations. Oligocene and Lower Miocene structure, prospectivity and fields distribution are the one of the most relevant subjects nowadays.
This study is focused on the main stages Late Eocene and Early Oligocene deposits formation and the paleogeography of the Khadum formation in the Precaucas oil and gas basin. The new prospective zones are developed in Khadum formation based on the complex analysis of seismic, paleogeography and lithofacies analysis.

Within the eastern part of the Fukang depression, the main productive series are confined to the Permian and Jurassic oil and gas complexes (OGC), in which the Middle Permian and Lower-Middle Jurassic oil and gas source rocks (OGSRs) are distinguished. The article discusses in detail the oil and gas source characteristics of the Middle Permian and Lower-Middle Jurassic rocks, the molecular composition of oils and bitumoids from the OGSRs, and also interprets the characteristics of the biomarkers in them from the standpoint of the sedimentary-migration theory of oil generation. An attempt is made to explain the reasons for the difference in the properties and composition of oils from different OGCs. It is shown that the composition of hydrocarbon fluids of deposits is determined not only by the geological and geochemical conditions of sedimentation of oil and gas source deposits, but also associated with migration processes and subsequent secondary changes in the accumulation. In terms of composition, three groups of oils were identified: Permian and Jurassic heavy oils with a light carbon isotopic composition and the presence of β-carotene and gammacerane, they underwent different degrees of biodegradation, which depended on the geological conditions of the deposits; Permian medium oils in density (0.84 and 0.87 g/cm3 ), the composition of biomarkers of which is very close to that of the first group, and Jurassic light oils with a high content of solid paraffins and a heavier carbon isotopic composition, almost do not contain β-carotene and gammacerane concentrations are low.

A different approach to the typing of the section of the Bazhenov Formation is presented – the identification of the reference section of the Bazhenov high-carbon formation (BHCF). Six packs were distinguished according to lithological and paleontological features, and their general characteristics were given. Also, indicators of the formation conditions are described, that allow to reconstruct the history and evolution of the basin, e. g. tuff and bone-bed horizons, alginate-rich layers, radiolarite layers, spicular limestones and limestones with a «con-in-con» texture, intensely pyritized layers, packs with an abundance of bivalves. Two types of sedimentation models are formed and described: island and intra-basin upland. On the basis of new data and identified features of the paleogeography of the Bazhenov Sea, a general model of the formation of BHCF deposits in the development zone of the Bazhenov and Tutleim formations is proposed.

The article presents the results of the Tutleim formation complex studies of core from 16 wells drilled on an area of 900 km2 near the Kamennaya crest of the Krasnoleninsky arch. The area is characterized by the variability of the structural plan, preserved from the time of deposits sedimentation, that might affect the structure of formation. Regionally traceable lithological units were used to describe different types of sections, which were firmly recorded on the core and on the logs. The article presents the results of the sections correlation, that shows the variability of the Tutleim formation through the area, identifies typical sections for the submerged, slope and crestal parts of the investigated field. The section may contain two reservoir intervals of different types: radiolarite and siliceousphosphate layers with average porosity values of 7% and 15%, respectively. The radiolarite layers form the main potential-productive intervals, that are found in all types of sections on one or two stratigraphic levels: in the crestal sections only in the third unit, in the slope and submerged sections – in the first, second and third units. The phosphorite layer in the fifth unit is a characteristic singularity only of the crestal sections. The obtained results allow predicting the distribution of the potential-productive intervals of the Tutleim formation and its stratigraphic analogues in different areas with higher accuracy.

A model of the activity of hydrothermal-metasomatic systems confined to certain structural elements is proposed in the present article. The model is based on the analysis of a large volume of traditional studies: measurements of porosity coefficients, permeability, pyrolytic measurements - together with specific measurements: isotopic composition of carbonate rocks, temperature of homogenization of gas-liquid inclusions, studies of the composition of rocks with a scanning electron microscope, a description of petrographic thin sections. The model allows to generalize the results of the impact of hydrothermal-metasomatic systems on the reservoir properties of the rocks of the BazhenovAbalak complex: constructive – leaching processes and increasing reservoir properties, and destructive – massive mineral formation that fills the pore space, up to the formation of secondary seals.

Nowadays, the term “organic petrology” is widely used for the microscopic study of the organic matter (OM) of rocks.
In the world, there are a large number of articles describing organic macerals in regions where shale oil and gas are produced. It is no coincidence that the new term “organic petrology” appeared instead of “coal petrography” since new macerals were found and described in the dispersed organic matter. So, along with alginites (previously the only term describing the oil-source sapropel-type OM), bituminite and bitumen appeared. Bituminite is heterogeneous, so it has varieties as “post-mature bituminite” and “atypical bituminite”. One of the typical components of the Bazhenov formation, along with described above, are the remains of soft radiolarians bodies. All of these organic macerals have a similar reflectance index with small differences.
Long-term studies of the OM rocks of the West Siberian basin have revealed indications of oil generation, which are easily established by standard microscopic studies.
These indications include a change in the colour of macerals, a different glow of oil-source components (all from the liptinite group), the appearance of bitumen films, the appearance of post-mature bituminite, the appearance of secondary porosity.

The article presents the results of hydrocarbon compounds extracted from open pores and blocked by resinous-asphaltene compounds pores in the Tutleim formation rocks (a stratigraphic analogue of the Bazhenov formation) and the underlying Jurassic deposits on the territory of the Kamennaya crest of the Krasnoleninsky arch investigation. The aim of the work was both to study the possible migration of hydrocarbons along the section and area and to assess the variability of the bitumen composition in rocks relative to the structural plan of the area of interest, along the section, as well as unconventional reservoirs. It is shown that the structural features and the assumed additional heating of the rocks lead to variety in the hydrocarbons composition not only in open, but also in blocked pores, both through the area of Tutleim formation distribution and in different intervals of one well. It was established that in the sediments organic matter, which may slightly differ in nature within the formation, can accumulate, and this leads to some differences in the generation, accumulation and migration of hydrocarbon compounds processes. It is shown that the process of migration of hydrocarbons from the underlying sediments also affects the bitumen composition in the rocks of the Tutleim formation.

The aim of the work is to predict the filtration capacity of reservoirs based on core and well logs data at the stage of petrophysical study of rocks before the start of active development of the object.
All the results were obtained from the data of porometric characteristics of rocks on the example of the vikulovskaya series’s deposits of the Krasnoleninsky arch. The patterns of changes in pore sizes and their contribution to the total filtration depending on the lithophysical type of the rock were established on the core plug. A classification of rocks by pore radii is proposed, and a method for assessing the filtration capacity of reservoirs based on well logs data is developed, with the calculation of the share of each layer in the planned perforation interval.

Apparently, conceptual base of the sequence stratigraphy is one of the most acknowledged methodologies in the geological world at the present time for the sedimentary strata structure prediction. It is based on the complex analysis of the seismic, stratigraphic and sedimentary data on the depositional bodies where the structure and facies filling is regulated by the relative sea level changes. The Lower Cretaceous section of the Western Siberia in this regard is the unique object, as it is represented by the full range of the clastic depositional environments – from relatively deep-water to the continental, which are very sensitive to the conditions changes. Sequence-stratigraphic analysis results can be used to complete the pragmatic tasks in the petroleum geology as the analysis is based on the reconstruction of the sedimentogenesis processes in the past, and the understanding of that processes is the key to the generalized depositional model development. This model can be used to create the models, which can be applied to the unique local objects that occur in the Lower Cretaceous section.

Development of computer technologies allows not only to optimize the process of geological study of our planet, but also to create fundamentally new approaches in working with large arrays of geological data. This led to the transition of formalization of geological knowledge and information from the descriptive form to the technological one, i.e. aimed at the industrial application of unified approaches. The article explains the concept of “technology” as applied to the Earth sciences (“G&G-technology” – Geology & Geophysics Technology). The example of direct and reverse algorithm of hydrocarbon deposits study is given. Stages of new G&G-technologies creation and change of information content level at each stage of this process bring forward certain requirements when selecting geological objects for testing and verification of the obtained result. The practical example of set of criteria for verification of fracture zones mapping technology is considered and the importance of balance between theoretical, methodological and practical elements of mineral deposits study and modeling is described.

In current review, we consider the Russian and, mainly, international experience of the “digital core» technology, namely – the possibility of creating a numerical models of internal structure of the cores and multiphase flow at pore space scale. Moreover, our paper try to gives an answer on a key question for the industry: if digital core technology really allows effective to solve the problems of the oil and gas field, then why does it still not do this despite the abundance of scientific work in this area? In particular, the analysis presented in the review allows us to clarify the generally skeptical attitude to technology, as well as errors in R&D work that led to such an opinion within the oil and gas companies. In conclusion, we give a brief assessment of the development of technology in the near future.

The article discusses the fundamental possibilities of using the results of geochemical and hydrogeochemical studies of organic matter, oils and waters in oil and gas geology, including for objects at the stage of development. It is shown that complex geochemical studies of oils and waters make it possible to get more correct conclusions about the presence or absence of fluid-dynamic connectivity of different horizons. Studies of organic matter and oils allow (by basin modeling instrument) to understand the contribution of different source rocks to formation of oils of different reservoirs. Hydrogeochemical studies of associated waters and waters used in the reservoir pressure maintenance system in a complex of works not only actively complements the knowledge about the presence or absence of fluid-dynamic connections between reservoirs and production objects, but also make it possible to predict, for example, salt deposition on equipment and in the reservoirs, and therefore allow you to prevent the possibility of unwanted salt deposition. The conclusions are based on the results of comprehensive geological and geochemical studies carried out by the authors for one of the deposits of the Krasnoleninsky arch of Western Siberia, which is at the development stage, as well as on the previous experience of the authors.