Western Siberia has oil and gas potential that is very important for the development of the oil and gas industry in Russia. The north of Western Siberia has special significance for the industry, that's where the maximum aggregate deposit of hydrocarbon reserves is located in fields, such as Urengoy, Yamburgskoye and Medvezhye. Over the last decade, a tendency to reduce the efficiency of geological exploration has appeared, therefore, it is necessary to conduct a comprehensive analysis of the actual material and to select priority areas. The Lower Cretaceous complex of the Cretaceous oil and gas megalithic complex located in the north of Western Siberia is the most lucrative. The Neocomian clinoform Achimov deposits of this complex are the main object of study. Achimov deposits are trapped almost throughout the Nadym-Pur interfluve area and are having a complex structure. The formation of Achimov rocks mostly took place in the deep-water part of the paleosea that affected their heterogeneity. An analysis of the geological and field parameters of the Achimov deposits determined the maximum aggregate of hydrocarbon deposits in the eastern and northern parts of the study area, as well as zones of active rifting. Geological exploration should be carried out in such zones initially. 

A quantitative measure of well productivity is the productivity factor. Its value is determined by many factors, but especially by filtration-volume parameters of the zone immediately adjacent to the bottomhole.

Filtration-capacitive properties of these zones are formed mainly at the stage of penetration and development of productive object. The practice shows that the present set of technological measures, which characterize the completion cycle, largely determines the reduction of filtration characteristics of the reservoir in the near-wellbore area.

Often the consequences are so severe that even from highly permeable intervals it is not possible to obtain commercially viable flows of formation fluid.

Under conditions of annually growing volumes of drilling and oil and gas production, old technological methods and schemes are no longer satisfying production. Today there is an urgent need to find and develop new, highly effective methods of drilling, production, field development, allowing meeting the needs of the domestic economy in hydrocarbons.

The process of well completion plays an important role in this process. Promising in this area should be considered such a set of measures, which allows preventing or eliminating the negative impact of the cycle of well construction on the productive capacity of the reservoir to the greatest extent.

In this regard, the right choice of technical or technological solutions is largely conditioned by the availability of information about the degree of their influence on the change in reservoir properties.

The process of compaction of sediments determines the patterns of changes in the properties of rocks of oil and gas bearing sections, primarily their porosity. The porosity of rocks of different lithology varies depending on their depth. The study of the regularities of changes in the porosity of rocks is important for the identification of geological sections, for substantiating the intervals of the existence of reservoirs with intergranular porosity type, for forecasting the properties of support layers by section and for methodological support for the geological interpretation of the materials of geophysical studies of wells. The existing concept of gravitational compaction of sediments doesn't reflect a number of features of this process of rocks in real conditions. The article substantiates the conditions of precipitation formation corresponding to their transition to an initial relatively stable state. The features of precipitation formation in the initial marine and continental conditions, as well as the features of their formation in permafrost strata are substantiated.

The general patterns and features of the compaction curves of typical sandstones and clays are considered according to the data of reference wells drilled within the West Siberian oil and gas basin. 

Thermobaric conditions in oil and gas wells require the use of backfill materials with special physical and chemical properties. Cement composites are subject to the requirements of fluidity (to ensure uninterrupted delivery to the cementing site), timely formation of the necessary mechanical strength (to prevent the interaction between the cement glass and reservoir fluids), corrosion resistance, impermeability and durability. Therefore, the composition of the cement slurry should be selected based on the mining and geological characteristics of the well.

Wellbores wall are reinforced with protective pipes, which are attached to the well with cement or cement slurry. It is needed to protect wellbores wall from rock falls, gas, oil and water shows and to isolate productive formations. If this operation is carried out qualitatively, then the outer part of the casing string will be protected from the impact of the formation fluid. Otherwise, pipe corrosion may occur, which can lead to the destruction of the cement stone and, as a result, to accidents.

The article is devoted to the regularities of the propagation of self-induced hydraulic fracturing cracks in the process of injection of the displacement agent into the formation in order to maintain reservoir pressure. Technogenic and petrological factors have a significant impact on the processes of initiation, propagation and degradation of self-induced hydraulic fracturing cracks. In modern oil and gas field practice, we are just beginning to use geomechanical simulators for private calculations and have not yet used them in integrated calculations of field development options, nevertheless, the influence of geomechanical processes of the spread of man-made cracks makes a significant contribution to the field development indicators. The aim of the study is a complex of factors that prevent and contribute to the development of self-induced hydraulic fracturing cracks. The study uses the author's methodology for estimating the crack length of a selfinduced hydraulic fracturing depending on the downhole pressure in the injection well. The results of the work have developed a classification of factors influencing the development of self-induced hydraulic fracturing cracks, a quantitative analysis of the differences in the characteristics of the spread of man-made cracks for two deposits with different geomechanical and hydrodynamic properties. The work makes a significant contribution to the understanding of the laws of the development of man-made cracks and has broad prospects for development, allowing us to significantly improve the current 3D digital models and analytical filtration models, which will improve the production of field reserves and increase the value of the oil recovery factor. 

Field development at a late stage is characterized by high water-cut and considerable volumes of produced water that causes field pipeline congestion. An increase in the volume of produced water entails an increase in hydraulic resistance in pipeline sections, which may limit the effect of ongoing geological and technical actions to intensify oil production. As a result, the production rates decrease at neighboring wells, but at the same time, the hydraulic resistance in the sections of overloaded pipelines increases. In this regard, it makes sense to determine the boundary, which allows you to observe the balance between the increase in amount of geological and technical actions and the current field pipeline congestion. 

Global climate change and its impact on the environment is one of the main problems of the 21^st century. In the Arctic zone, where considerable oil and gas reserves are located, warming is 2-3 times faster than the world average. Against the backdrop of increased Arctic warming, thermal pollution has created permanent urban heat islands, where urban temperatures are  1-2 degrees Celsius higher than in surrounding areas. The aim of the article was a geoinformation assessment of climatic and anthropogenic characteristics in various zones of Tyumen (recreational zones (parks and reservoirs) and the zone of urban highways) in the summer of 2021. The Earth program was used in the studies, statistical processing of the results was carried out using the IBM SPSS Statistics 21 software.  It has been found that a circadian diurnal rhythm is observed both in recreational areas (parks and reservoirs) and in the area of urban highways (wind speed, temperature and relative humidity, concentration of CO, CO₂, SO₂, NO₂) in the summer of 2021. The revealed correlation relationships between climatic characteristics and anthropogenic pollutants and aerosols indicate that global climate change is associated with the deterioration of the ecological situation in the urban environment and doesn't depend on the landscape features of the city.