The article presents the facts of possible gas field discovery in Petukhovo district of Kurgan region. In 1962, a structural prospecting well 4-G was drilled to a depth of 928 m in the area of Petukhovo state farm in Kurgan region. When drilling the well in the process of trial pumping from a depth of 900.85-923.4 m, a gas release occurred with a rapid release of combustible methane gas. The first signs of weak carbonation were observed from a depth of 227 m, gas indicators didn't exceed 7%.

Subsequent seismic surveys established a calm occurrence of sediments of Mesocainozoic age and revealed a weak dislocation of rocks of the Paleozoic complex. The study of the surface of the lower reference reflecting horizon, which is linked to the bottoms of Mesozoic sediments or the roof of the Paleozoic foundation, made it possible to identify three local positive structures: Medvedevskoe, in the area of Lake Medvezhye, measuring 4×13 km, contoured with an isohypse of -700 m, with an amplitude of 50 m; the west of the village of Kazantsevskoye, measuring 1×2.5 km, contoured with an isohypse of -650 m; the north of the village of Kazantsevskoye, measuring 2×3.5 km, contoured with an isohypse of -700 m, with an amplitude of 50 m. The selected structures at that time were recommended for testing oil and gas prospects by drilling. In case of positive results, it was recommended to continue areal seismic studies in order to delineate the selected uplifts the north of the village of Pashkovo and the northwest of the village of Grenadiers, followed by their verification by drilling.

The authors of the article carried out an expedition to Petukhovo district. As a result, they found liquidated wells in the north of Lake Domozhirovo (presumably, wells 4-G and 2-PR), the conditions of mouths of these wells were established. The authors give recommendations for conducting geological exploration in the territory of Petukhovo district.

For the Beregovoye field (West Siberia, Yamalo-Nenets Autonomous Okrug), a new subsurface geologic model for AT6-8 group of reservoirs in the Lower Cretaceous (Hauterivian-Aptian) interval within Ereyamskaya formation was built following the reprocessing and reinterpretation of 2D and 3D seismic data in 2020, drilling of new wells (new wells, which were drilled after 2016, account for about 10 % of the total well stock that penetrated the AT6-8 reservoirs), updating the structural framework, additional core studies, and revising the well test results. Well log correlation in the AT6-8 interval was based on the reservoirs formation in alluvial and tidal delta plain environments. Multidirectional source areas formed disconnected zones in the net reservoir interval, which controlled the oil and gas content of these reservoirs. Taking into account the results of the geochemical survey, a stage-by-stage approach to hydrocarbon accumulations (light oil and gas condensate) formation was proposed, which led to vertically and laterally varied phase compositions of the discoveries.

Studies of the hydrogeochemical features of groundwater in deep horizons of the West Siberian megabasin are important. They are closely related to applied and fundamental issues of oil and gas hydrogeology and allow studying the processes of formation, accumulation and migration of hydrocarbons.

The article deals with our analysis of the hydrogeochemical conditions of the Mesozoic hydrogeological basin within the Ravninnoe oil field. The ion-salt composition of groundwater in deep horizons in the territory is variable. Basically groundwater are of the calcium chloride type (according to V. A. Sulin's classification), but magnesium chloride and sodium bicarbonate types of water are locally distributed. The hydrogeological conditions of the field are manifested in the change in the chemical composition of groundwater and in the vertical hydrochemical zonality. The article describes the features of the regional distribution of reservoir temperatures and reservoir pressures of the Aptian-Albian-Cenomanian, Neocomian and Jurassic hydrogeological complexes. The study of the formation factors of the hydrogeochemical field of these deposits was carried out taking into account paleotectonic, paleogeomorphological and paleohydrogeological reconstructions of the conditions that influenced the accumulation of fluids. Faults are widespread in the deposits of the pre-Jurassic complex, as well as angular unconformities between rocks of different ages, which predetermined the migration of hydrocarbons and the formation of their deposits.

To date, the reserves of fields with oil rims are significant and belong to the category of hard-to-recover. Not only domestic companies, but also foreign companies, such as Shell, Repsol and Schlumberger, are interested in developing these fields. A particularly important stage in the development of fields with oil rims is the selection the well operation method. Mistakes in choosing the extraction method can lead to losses of the project's NPV and the impossibility of further development of the field. This article provides a comparative analysis of methods for evaluating the method of well operation, and identifies their key advantages and disadvantages. We also describe our own methodology for selecting a method for operating wells in oil-rim conditions. The technological and economic efficiency of the proposed method, tested at one of the field of company LUKOIL-Komi LLC with oil rim, is proved. The developed method is compared with other methods for evaluating production methods.

Every year, the relevance of developing oil rims, which were not previously involved in development due to the need to use expensive technologies, is growing. However, at present time the development of oil rims is determined by the depletion of light oil reserves. The massive gas cap and the high gas factor in oil rims don't allow to accurately determine the possibility of developing an oil rim in the depletion drive. The aim of the article is to develop a tool for evaluating the effectiveness of the development of boundary oil rims in the depletion drive. The key geological and physical factors that have the greatest impact on the efficiency of the development of oil rims were identified; analogous deposits were analyzed, on the basis of which geological and hydrodynamic models were built. We evaluated the role and influence of studied factors, such as permeability, angle of inclination of the oil rim, volume of the gas cap, thickness of the oil rim. A tool has been developed to assess the effectiveness of the development of boundary oil rims in the depletion drive and the use of the tool has been demonstrated.

The process of separating solid paraffins from heavy oil fractions is one of the most expensive and difficult to implement in oil refining. Dewaxing is usually carried out by the method of low-temperature crystallization of solid paraffins in the presence of a multiple excess of selective solvents. The search for other, simpler and inexpensive technologies for the isolation of solid paraffins is an urgent task. Some Russian scientists devoted their work to studying the possibility of dewaxing oil fractions in an electric field.

These article deals with the influence of the main parameters of solid paraffin hydrocarbons electrodeposition in an electric field on the qualitative parameters of the process. It has been established that the shape of the electric field and the degree of its inhomogeneity don't affect the target indicators. Increasing the electric field strength to a certain limit leads to a decrease in the required time to complete the electrodeposition process. Increasing the process temperature leads to the release of higher melting paraffins. The complete release of solid paraffins in an electric field depends on the field strength, process temperature, type and concentration of the introduced additive.

The article is devoted to the possibility of using the dielectric spectroscopy method for assessing the low-temperature properties of oil. For 25 samples of oil in the fields of Tyumen region the physical and chemical characteristics have been determined, in the temperature range dielectric permittivity ℇ and the tangent angle of dielectric losses tg δ were obtained. The dielectric relaxation of oil was established. The calculated values of dielectric relaxation parameters made it possible to interpret this process as a glass transition process. The glass transition temperature tС and the region of structural solidification ∆t of oil have been determined. The dependences of tС and ∆t of oil on its physico-chemical characteristics have been established and investigated by methods of correlation and regression analysis. The glass transition temperature tС and the temperature range of structural solidification ∆t have been proposed to estimate the lowtemperature properties of oil. In the future, on the basis of data obtained, recommendations for application of dielectric spectroscopy method for forecasting and operational control of some (individual) characteristics of oil in the processes of its production, collection, preparation and transportation can be developed.