The article describes the study of the pre-Jurassic base rocks in the territory of the Kirilkinskaya area of Uvat district in the south of Tyumen region. It was demonstrated that in order to predict net reservoirs in the interwell space within the pre-Jurassic rock complex using 3D seismic CDP data, correct tie-in of the wave field with the material composition (net reservoir vs. non-reservoir) of the rocks is needed. Since the pre-Jurassic interval is usually only fragmentarily studied by the core (at the top and at the bottomhole), the article considers the option of using neural simulation technology based on well logging parameters to restore the material composition of the pre-Jurassic rocks. Since the approaches to the restoration of the material composition of rocks according to well logging data are based on a set of quantitative indicators of the curves for each type of rocks, the approach of dividing the preJurassic rocks into petrotypes is of great importance. In this study, the petrotypes were separated not only on the basis of the material composition of rocks, but the reservoir properties and logging-based properties were also taken into account. Logging-based material composition was estimated in several stages. At the first stage, petrotypes were separated from core data, which allowed to group all types of rocks described in the wells into six main petrotypes. Then, for each petrotype, based on the analysis of log-log cross-plots, a set of optimal logging parameters was identified. This allowed running a neural simulation based on Self-Organizing Maps and restoring the material composition of the pre-Jurassic complex for further net reservoir prediction from seismic data.

   The problem of groundwater protection in areas, where oil and gas production is taking place, is especially important today. The article focuses on the impact of groundwater extraction on the state of the filtration medium in small water bodies. Studies including hydrodynamic testing (cluster pumping) were being carrying out from 9 years at the same site. As a result of three exper-iments, experimental data were obtained, and then were interpreted in the framework of the Hantush model. The parameters of the aquifer are determined: coefficient of water conductivity and pressure conductivity factor, overflow factor, overflow coefficient. The article gives an analysis of changes in reservoir parameters. As a result, it was found that the long-term operation of ground-water in small water bodies also leads to an improvement in the state of the filtration medium, as well as in large deposits of fresh groundwater. It should be emphasized that in conditions of continuous extraction of groundwater the subsoil user should pay special attention to groundwater monitoring, namely, hydrodynamic studies, the results of which determine the hydrogeological parameters of the reservoir, and their changes indicate the state of the filtration medium.

   This article presents the results of drilling a 1-k core well in Zverinogolovskoye district of Kurgan region and the study of core material. A number of researchers have doubts about the fact that the reason of periodic appearance of an oil film on the Alabuga River was the migration of oil from the depths. Some people assumed that it could get to the river in a small amount by accident, for example, farmers spilled it during fieldwork. In 1959, 1-k and 2-k wells were drilled in order to check and study oil occurrences along the Alabuga River. Core wells 1-k and 2-k have traversed the cover deposits of the Meso-Cenozoic and have exposed the basement rocks represented by red flowers of presumably Permian-Triassic age. This made it possible to study the lithology and stratigraphy of the sediments, which were involved in the structure of the area. The angles of inclination of red-colored rocks measured by the core of the 1-k well give an idea of the degree of their disturbance. The facies-lithological features of these rocks, the absence of fauna and flora in them, and other signs indicate that the formation of red-colored deposits occurred under continental conditions. The signs of Permian-Triassic oil found in the 1-k well are of fundamental importance. These oil occurrences are also of interest in the fact that they were detected in the area, where oil was observed to the surface.

   In oilfield practice, the lithofacies criterion is very often decisive for the formation of deposits of liquid and gaseous hydrocarbons. The Absheron lithofacies type of sediments (Absheron facies), enriched in quartz material, composes the reservoirs of the horizons of all large oil and gas fields in the South Caspian Basin. The genesis of the Absheron facies is closely related to the genesis of the productive stratum, there is no consensus on both issues to date. It is indisputable that the productive stratum and the Absheron facies were formed in the conditions of a closed continental basin, which arose as a result of the orogenic restructuring of the areas surrounding the Caspian Sea, the bowing of its bottom and the subsequent Pontian regression of the sea. As a result of the restructuring of the hydrographic system in the south of the Russian Platform, many paleorivers, flowing along the newly formed land, began to flow and carry a huge amount of water and precipitation into the South Caspian Basin. Deposition of the productive stratum and Absheron facies began. The greatest role in the supply of quartz-enriched sandy material belonged to the Paleovolga, which, together with other paleorivers in the north of the South Caspian Basin, formed an extensive marginal delta, from which sediments were transported far to the south, west, and east.

   Miscibility largely determines the performance of gas injection. Miscible displacement allows achieving maximum effect. The minimum miscibility pressure (MMP) is a key parameter, which is determined when justifying a gas injection project. For the conditions of East Siberian reservoirs, the accuracy of correlation equations is 10-50 %, and A. M. Maklavani, H. M. Sebastian, and M. Dong equations demonstrate the most accurate values. The equation of state matched to the results of routine studies evaluates the MMP with an error of up to 30 %. Additional data from special studies (swell test) increased the estimating accuracy by up to 10 %. An express laboratory method for measuring the miscibility parameter (a method of vanishing interfacial tension) showed high accuracy of MMP estimate. The method also allows describing the process of changing the interfacial tension with increasing pressure or changing the gas composition, and complements the process of adjusting the equation of state when setting up a slim tube experiment.

   In the article, we consider movement of hydrophilic and hydrophobic liquids in a capillary. It is known that structure of flow of such fluids depends on set of conditions. The issue of correct choice of control parameters is of great importance for controlling the transition of the flow into different modes. The most important issue in the filtration problem is morphological stability of displacement front during filtration. It is generally assumed that it is sufficient to control the capillary number to change the flow regimes. The article shows that another parameter can be singled out, which is the disjoining pressure. If mechanisms of influence on wedging pressure can be found, then it is possible to control effectively flow by changing thickness of jet and to control the process of clustering (splitting of jet into droplets). In the article, it is shown that such mechanism can be interaction of hydrocarbon molecules with nanoparticles.

   It draws our attention to the processes of interaction between the well and the penetrated permeable formations during its construction, which are largely determined by geological and thermobaric conditions, types of fluid saturating the formation, used technologies and technical means. The article deals with the main problems of well construction intended for the high-viscosity oil production. Laboratory and experimental studies have been conducted to solve these issues, they will help to scientifically substantiate and implement new technologies and technical means to increase productivity and durability of wells intended for production of high-viscosity oil from productive formations with complex thermobaric conditions. In this work, the authors conducted a study of the formulations of flushing fluids to penetrate productive horizons with high-viscosity formation fluids. Based on the results of the laboratory tests, it was decided to use a fresh polycationic solution.

   It is necessary to know the value of the gas factor in order to perform technological calculations when designing systems for the rational use of associated petroleum gas. The value of the gas factor is determined by the results of a study of deep oil samples. As a rule, the well production of oil fields is waterlogged, and its value increases with time. Many researchers have proven the fact of the dissolution of hydrocarbon gases in reservoir water; for example, according to some results, up to one cubic meter of gas can be dissolved in one cubic meter of water. This fact has a significant impact on the technological modes of operation of well production preparation units, since in their design only the value of the gas factor of the produced oil is taken into account. It is necessary to develop a reliable method for calculating the limiting gas content of reservoir water and the amount of gas releasing during pressure reduction in order to correctly account for the volume of gas dissolving in produced water. The article presents the results of studies on the calculation of the gas factor of reservoir water using various methods; the obtained results are compared with laboratory data.

   To ensure efficient separation of oil production wells with a high content of associated petroleum gas, inlet separation units are used, consisting of an inlet separator, which ensures the separation of the main amount of free gas from liquid, an oil and gas separator, in which free gas is finally separated from the liquid, and a separator-drop catcher, designed to prevent entrainment of droplet liquid with gas. When a gas-water-oil mixture with a high water content enters the plant, an oil and gas water separator can be used instead of an oil and gas separator, which makes it possible to carry out a preliminary discharge of water simultaneously with degassing. The article considers the technology of separation and preliminary discharge of water for oils with high gas content and proposes a variant using heating of a partially degassed liquid. Empirical dependences of the minimum height of the liquid column above the oil and gas separator (gas and water separator) depending on the viscosity and density of the liquid are given. A technique for technological calculation of the mutual arrangement of apparatuses has been developed, the possibility of using heat exchangers as part of the installation has been shown.