Paleogeographic reconstruction of the West Siberian basin during the Jurassic is based on a variety of criteria used to evaluate the depositional environments (paleontological, sedimentological, geochemical, etc.). Extensive geochemical data on the hydrocarbon biomarkers in bitumen from organic matter are first used to constrain the depositional setting of this large region over a span of about 45 Myr. The study provides a detailed description of paleogeographic maps compiled for the main epochs of the Jurassic period with the reconstruction of paleorelief and differentiation of potential external and internal sources of terrigenous material. The paleogeographic reconstructions of the basin are considered with implications for the formation of regional seals and reservoir units. A special emphasis is given to interpretation of organic matter type and depositional setting of the major oil and gas source rocks. The study infers a paleogeographic control on the stratigraphic and areal distribution of hydrocarbon accumulations in the basin.

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The type sections of the Bazhenov Horizon and formations recognized within this horizon have been identified based on a comprehensive analysis of paleontological, lithological, geophysical (well-log and CDP seismic data), and geochemical data on the West Siberian Basin. The Bazhenov Horizon was traced throughout the entire West Siberian sedimentary basin. The criteria for the recognition of the top and base of this horizon within the stratigraphic equivalents of the Bazhenov Formation were suggested. The proposed facies-stratigraphic zonation of the Bazhenov Horizon reflects the spatial location of all formations identified within this horizon. As seen on the newly proposed thickness map, the Bazhenov Horizon reaches a thickness of 15–25 m within the Bazhenov and Tutleim Formations, 30–35 m within the Mulym’ya Formation, 30–45 m within the Danilov Formation, 40–65 m within the Mar’yanovka Formation, up to 100 m within the Golchikha Formation, > 350 m within the Yanovstan Formation, up to 35 m within the Bagan Formation, and 35–40 m within the Maksimkin Yar Formation. A marginal filter (according to A.P. Lisitzin) has been identified along the East Siberian land.

The results of study of hydrogeological conditions of oil and gas bearing deposit of the southern areas of Ob-Irtysh interfluves (southern regions of West Siberian basin) are presented. The hydrodynamic field is characterized by direct dependence and the presence of normal and increased pressure (formation anomalous pressure factor not exceed 1.13) is common in Apt-Alb-Cenomanian, Neokomian, Jurassic and pre-Jurassic complexes. The results of study of the reservoir properties and hydrodynamic conditions indicated that the elision water exchange play the dominant role in the modern hydrogeological structure formation. Two types of water drive system is established: elisional (lithostatical and termodehydrational) in the inner areas (southern part of Koltogor-Nyurolsky trench, Nyurolskaya megadepression, Verkhnevasyugansk anteclise and other structures) and infiltrational within the territory of Baraba-Pikhtovo monocline. Elisional system is replaced by the elisional-termodehydrational at the depth 2.0-2.2 km. Large piezo maximum zones (southern part of Koltogor-Nyurolsky trench and Nyurolskaya megadepression) become the inner regions of water pressure generation (the inner feed areas) with the maximal degree of hydrogeological closure of the interior. The region of piezo minima, tracing the structures of the Barabinsk-Pikhtovskaya megamonocline, relates to the external feed area. The hydrodynamic model of the southern areas of Ob-Irtysh interfluves is building for the first time and allow to predict the pressure change trends in the areas with poorly provided with the actual data.

This paper discusses the most important aspects of the development of the oil and gas industry in Russia. To replace declining oil production in Russia, we need to change the obsolete paradigm of the development of the domestic resource base. In the twenty-first century, the priority tasks in the search for oil deposits should be the Russian Arctic shelves and immature onshore provinces as well as unique unconventional oil accumulations (Bazhenov, Domanik, Khadum, Kuonamka Formations, etc.). In addition, special focus should be placed on the exploration of small and smallest oil and gas fields, which will be developed with the collaboration of small- and medium-sized oil businesses to ensure up to 20% of domestic oil production. The shift from extensive to intensive development of Russias oil and gas sector will require the prioritizing of technological tasks.

The article is devoted to the approach to geothermal zonality. The results of geothermal studies of oil and gas bearing deposits in the northern territory of Novosibirsk region and adjacent areas are presented. Geothermal zoning was carried out, and the major geothermal anomalies were determined. The features of the geothermal zonality of Mesozoic sediments in the region under investigation are first of all defined by the material composition of the Paleozoic basement, the structural arrangement, and the warming effect of ground water during its crossflows from deeper lying horizons. Formation temperatures get leveled within the boundaries of Aptian-Albian-Cenomanian sediments, and no anomalies are distinguished. The highest geothermal gradients sup to 3,6-4,6 °C/100 m and correspond to the edge zones of the development of intrusive formations of pre-Jurassic rocks. Lower gradients sup to 2,4-3,0 °C/100 m and characterize the regions, in which Paleozoic carbonate rocks occur.

Приводятся первые результаты комплексного изучения изотопного состава пластовых вод разрабатываемых нефтяных месторождений Новосибирской области. Установлено, что пластовые воды нефтяных залежей нейтральные (pH = 6,9-7,4), характеризуются Cl-Na составом с величиной общей минерализации от 21,7 до 71,1 г/дм 3 и содержанием кремния 13,0-22,4 мг/дм 3. Выявлена широкая вариация изотопных отношений δD (от-77,9 ‰ до-61,7 ‰) и δ 18 О (от-9,0 ‰ до-5,1 ‰) вод, которые расположены значительно ниже GMWL. Изотопные отношения δ 13 CDIC исследованных вод варьируют в диапазоне от-21,6 ‰ до-1,4 ‰ и позволяют разделить их на две группы. Первые формировались преимущественно в континентальных обстановках (δ 13 CDIC =-10,5-1,4 ‰). Для второй группы вод с более легкими изотопными отношениями (δ 13 CDIC =-21,6-11,8 ‰) наиболее вероятным источником изотопов углерода служило ОВ различного происхождения. Отношение Sr 87 /Sr 86 всех изученных проб находится значительно ниже современных морских вод и составляет у вод меловых отложений-0,70539-0,70707, юрских-0,70609-0,70763 и палеозойских-0,70613. За счет процессов смешения все воды разрабатываемых залежей схожи по изотопным отношениям δD-δ 18 О, δ 13 C-δ 18 О, 87 Rb/ 86 Srδ 18 О, 87 Sr/ 86 Sr-δ 18 О и 87 Sr 86 /Sr-87 Rb/ 86 Sr. Они находятся в одной области с водами апт-альб-сеноманского водоносного комплекса, которые изначально выступали в качестве агента заводнения и поступали в систему поддержания пластового давления.

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