Introduction. The difficult geological, physical and technological conditions for the development of gas condensate fields in the Far North lead to the fact that they are prematurely flooded with formation waters. One of the factors influencing the process of flooding «Valanginian» wells is the quality of cementing. It was revealed that the main watering of wells occurs due to a violation of the tightness of the annulus. Based on the results of work to eliminate water inflows in the wells of the Beregovoy and Urengoy fields, a two- and three-composite technology was tested, which proved an increase in the success of VIR.
Materials and methods of research. The field practice of carrying out measures to eliminate water inflows (WLI) in wells has shown the effectiveness of the technology according to a two-three-component scheme. At the initial stage of LPW implementation, a water-repellent agent is used, which has selective filterability in the most permeable and watered reservoir intervals. Then, a water-blocking composition with high thermal stability based on alkali metal silicates (liquid glass) or compositions based on polyacrylamide, etc. is pumped. The requirements for reliable isolation of formation water breakthrough are imposed on compositions with different physical and chemical properties. At the final stage, the first two compositions are fixed with a composition with high adhesion to the rock (cement-based with various composition additives) to reinforce the waterproofing screen.
Results and Discussion. To eliminate water inflows in wells, despite the difference in the geological structure between the Urengoy and Beregovoye fields, the compositions used have fluidity (low viscosity) while maintaining its stability in the process of performing a full cycle of activities. The work experience has shown the prospects of the technology aimed at the success of LSP in the «Valanginian» wells. The gelation period is adjustable and the formulations are resistant to formation water dilution. The results of previous well workovers in 2015 by the Urengoy UIRS showed a low success rate of about 30%. The low efficiency is associated with insufficient injection pressure at the final stage of the insulating composition into the reservoir, etc. The implementation of LSP in the «Valanginian» wells according to the implemented technology using a multicomponent additive based on biopolymers has shown effectiveness. At the same time, the natural permeability of the reservoir is preserved. So in 2016, the success of VIR increased and amounted to 70%. The effect was obtained from the implementation of the same technology of VIR at well No. 252 of the Beregovoye field with the use of a complex additive.
Conclusion. Thus, based on the results of the liquidation of water inflows in wells draining the Valanginian gas condensate deposits of the Beregovoy and Urengoy fields, the improved two- and three-composite technology proved to be successful. Also, promising insulating compositions aimed at the effectiveness of LPV have been identified. The use of technology with a multi-component additive based on biopolymers has proven its effectiveness. Thus, in 2016, the success of VIR at the «Valanginian» wells of the Urengoyskoye field increased and amounted to 70%. This technology was used to perform a design and survey work at well No.252 of the Beregovoe field. As a result of the elimination of behind-thecasing flows from the underlying aquifer, a positive effect was obtained. This well is currently working in a gas gathering reservoir.

Introduction. Experimental development modeling is performed to predict condensate losses in the reservoir under initial reservoir conditions and during field operation. The assessment of gas condensate characteristics in laboratory conditions was carried out on samples of production from the wells of the Beregovoe field. The studies were carried out by stepwise extraction from the PVT-cell of the gas phase while maintaining the equilibrium conditions of the reservoir system. Under the initial thermobaric conditions, the pressure of the onset and maximum condensation of the studied hydrocarbon mixture was determined. At the final stage of the experiment, with the complete depletion of reservoir energy (standard conditions), the total hydrocarbon losses were calculated for the conditions of the Beregovoye oil and gas condensate field and the condensate recovery factor.
Materials and methods of research. Separation gas and saturated condensate samples were used as reservoir gas condensate system models. A series of experiments was carried out using recombined samples according to gas-condensate ratio (cm3/m3). Separation samples were taken during field studies of the wells of the Beregovoe field. The experiments were carried out by the method of contact and differential condensation (at a constant temperature) on a highpressure PVT installation. Modeling data made it possible to build diagrams in the coordinates “pressure - reservoir condensate loss” and determine the loss of hydrocarbons for the entire period of field development.
Results and Discussion. Experimental studies of the production of gas condensate wells of the Beregovoye field have shown that under various temperature and pressure conditions, the samples of the studied fluid differ in composition and its properties. The results of the study of formation gas samples (one of which was taken from the well R-77, during the joint testing of the PK191 and PK192 formations showed that the pressure of the start of condensation of the gas condensate mixture varies greatly (from 16.62 to 25.25 MPa). The reason for the possible discrepancy is due to the conditions For well R-77, the sample from well R-77 was in a two-phase state, which is possible due to the non-heightness of the container or the unreliable determination of the field condensate-gas factor (CGR). pressure.In the study of this gas condensate mixture and the construction of isotherms in the area of maximum condensation pressure, the process of both condensation and evaporation was observed. The resulting isotherms are the basis of the diagram in the coordinates “pressure — formation condensate loss”, on which the critical transition point is fixed.Also based on the simulation properties of hydrocarbon mixtures and shows the features of the transition of the gas condensate system from the gas state to the liquid state. Additionally, to calculate the CFC, the density of the condensate remaining after the studies in the PVT cell was determined. According to the measurement results, the density of the condensate taken from the well R-46 was 0.7913 g/cm3, and the density of the condensate from the well R-77 was lower and equal to 0.7792 g/cm3. The calculated coefficients of condensate recovery from the subsoil according to these samples were 0.76 and 0.72, respectively.
Conclusion. Thus, based on the results of studies of well production samples with different thermobaric conditions, composition and properties of the formation fluid of the Beregovoe field, the pressure of the onset and maximum condensation was determined. As a result, based on the obtained information about the composition of the separator samples, a recombined mixture was created, which was used for experimental modeling of the phase processes of the reservoir system. According to the results of the experiment by the method of contact condensation, it was found that the pressure of the beginning of condensation is consistent with the initial reservoir pressure. The factors influencing the change in the condensategas factor under separation conditions are determined. The obtained data are successfully used to adapt PVT-models, as well as other models used to calculate the field separation system during field development.

Introduction. Currently, most of the developed oil deposits are classified as complex fields. The specificity and main difficulties in the development of such deposits are determined by the conditions of occurrence in the productive horizon, which differ sharply in the formation anisotropy, as well as the presence of underlying formation water. The issue of operating wells of complex geometry is especially acute. As a model, a mathematical model developed by the authors is proposed, which makes it possible to describe the inflow to a production well of complex geometry. The results obtained when applying the author’s model and comparing the data with the known formulas for the inflow to a horizontal well showed good convergence. The proposed single-phase inflow model makes it possible to predict the potential flow rate of an undulating well during the development of the Srednebotuobinskoye field.
Materials and methods of research. The paper considers a mathematical model developed by the authors, which makes it possible to describe the inflow to a production well of complex geometry. The results obtained when applying the author’s model and comparing the data with the known formulas for the inflow to a horizontal well showed good convergence. The dependence of well productivity with a wavy trajectory on the anisotropy and the number of sinusoid cycles is shown. The area of application of wells with an undulating trajectory and the application of the proposed single-phase filtration model for predicting the productivity of a undulating well that has penetrated the oil rim of the Botuobinsky horizon with a gas cap and bottom water are determined.
Results and Discussion. The joint solution of the equation for the distribution of reservoir pressure and pressure in the wellbore makes it possible to obtain a system of equations, the solution of which is the flow rates of the well segments. A horizontal well can be considered as a special form of undulating well as the undulation index is zero. The paper proposes a numerical-analytical model for predicting and evaluating the productivity of undulating wells. The results obtained when applying the author’s model and comparing the data with the known formulas for the inflow to a horizontal well showed good convergence. The dependence of well productivity with a wavy trajectory on the anisotropy and the number of sinusoid cycles is shown. A numerical-analytical model is also proposed for predicting and evaluating the productivity of undulating wells.

Introduction: The article examines the features of the formation of the microelement composition of soils of two landscapes of the semi-desert landscape province of the Stavropol Territory - Pravokum-Tersky and Kursk-Caspian. The importance of studying the microelement composition of soils of semi-desert landscapes lies in determining the general laws characteristic of soils of arid territories in fixing chemical elements. The low level of agricultural use of these soils determines the weak influence of anthropogenic activities on the transformation of their microelement composition.
Research materials and methods. The main methods of research were soil-geochemical, landscape-geochemical, geoecological. Field studies were carried out with the selection of soil samples, office work with the analysis of the content of trace elements (Cu, Zn, Pb, Cd) on an X-ray fluorescence spectrometer. An analysis of the available scientific publications on this topic was carried out, which made it possible to supplement the actual material received by the authors.
Research results and discussion. It was established that the peculiarities of the formation of the microelement composition of soils of semi-desert landscapes of the Stavropol Territory are largely related to the specific conditions of soil formation inherent in this territory. A nonwashing type of water regime, an arid climate, semi-desert wormwood-cereal vegetation, a high carbonate content of the soil profile create characteristic features of the chestnut type of soil formation. Lateral differentiation of the microelement composition of soils of semi-desert landscapes is weakly manifested due to the almost complete absence of differences in surface slope.
Conclusions. The microelement composition of soils of semi-desert landscapes of the Stavropol Territory is characterized by certain features associated with the manifestation of the main factors of soil formation. The fixation of trace elements in the soil profile is controlled by the processes of humus formation under sparse semi-desert vegetation, weakened vertical movement of soil formation products under conditions of non-washing water regime, high carbonation and, in some places, salinity of soil masses.

Introduction. The territory of the Caspian sandy hearth (43) occupies the eastern part of the Northwestern Caspian Sea, starting from the lower reaches of the Volga in the northeast to the lower reaches of the Terek in the south, the eastern boundary of the hearth is the coastline of the Caspian Sea. In landscape terms, the territory is a slightly hilly, almost flat plain inclined towards the sea.

Materials and methods of research. The work is based on the analysis of the results of long-term epizootological monitoring for the period 2010–2020, conducted in the Caspian sandy plague outbreak by specialists of the Kizlyar and Budyonnovsky anti-plague department of the Dagestan AntiPlague Station of Rospotrebnadzor.

Results. The ecosystems of the LEHR “Kizlyar Steppe” and “Nogai Steppe” differ both in the number of species of small mouse-like rodents and in their association with biotopes. The fauna of mouse-like rodents in the LEHR “Kizlyar Steppe” is eurytopic, the LEHR “Nogai Steppe” is represented by six species of which only two are eurytopic: the public vole and the house mouse. The fauna of mouse-like rodents is common in the landscape and climatic regions of the “Nogai and Mozdok steppe of the UK”, most species are eurytopian, although each species has its own favorite biotope, with a more pronounced confinement.

Conclusions. These calculations will optimize the work of epizootological examination of the territory of the Caspian sandy hearth.

Introduction. Global warming causes an increase in the frequency and intensity of dangerous weather events. Therefore, their forecast becomes relevant, which is in demand by the anti-hail services, as well as other sectors of the national economy. This is facilitated by the operational availability of the results of modeling the Earth’s atmosphere, in particular, the values of stratification according to the global model (GFS NCEP). In this article the possibility of hail predicting with a lead time of up to three days using discriminant analysis and estimating its size using a regression equation is considered. The success of the hail forecast is assessed by the criteria of forecast quality. The quality of the regression model according to the indicators characterizing the statistical significance and practical applicability of the regression equation meets the accepted criteria.
Materials and methods of research. The research materials were the output data of the global atmospheric model GFS NCEP with a lead time of up to three days. The forecast was carried out by discriminant functions. To assess the success of the hail forecast, a conjugacy table was compiled for the phenomena «hail» and «not hail», according to which the criteria for the quality of forecasts were calculated. To estimate the maximum size of the hail, a regression equation was compiled. The indicators characterizing the statistical significance and practical applicability of the equation were calculated.The observation data on the fallout of hail and its size were provided by paramilitary services for active impact on meteorological and other geophysical processes located within the radius of the representativeness of the actual data of aerological sounding at the «MineralnyeVody» station.
The results of the study and  their discussion. The results of the calculations showed that the hail forecast meets all the criteria for the quality of forecasts. The success rates of the forecast turned out to be good. Thus, the justifiability of the hail forecast was ≈70%.All the indicators characterizing the statistical significance and practical applicability of regression equations have shown that the proposed hail model can adequately estimate the maximum diameter of the hail.
Conclusion. Studies have shown that the proposed approach to hail forecasting and estimating its maximum size according to the global atmospheric model, with an increase in the lead time to three days, does not lead to a noticeable decrease in the quality of forecasts and the regression equation.

Introduction. The task of developing the methodology optimal for studying unique processes and phenomena, especially in the light of the growing awareness of the globality of our planet and the integrity of processes – for example, biological and social – is formulated. Special importance and heuristic value of this kind of methodology is pointed out because of the special status of the categories of space and time, as the cognizing subject perceives the external reality only through space and time and in no other way (I. Kant).

Materials and research methods. The article substantiates the necessity of the use of integral or integral space-time methodology for the scientific analysis of unique phenomena (for example, biological phenomena). This methodology supplements the widely used differential methodology. It is stated that this task is currently of particular relevance. It is emphasized that integral methodology is doctrinally close to philosophy, scientific theory and intellectual tradition of holism.

The results of research and their discussion. The example of successful use of integral methodology in another disciplinary field by Hans Selye in discovering stress, or general adaptation syndrome, in the first half of the twentieth century is considered and analyzed. A conclusion is made about the possibility of fruitful application of this method in other problem areas, in interdisciplinary research and, in particular, in geospatial research when combined with the fundamentally integral concept of the Digital Earth and the Big Data method. The possibility of using the integral method in spatial studies for the reduction of Big Data without losing their heuristic value is considered. It is expedient to use the proposed method in the analysis of biomedical, ecological and social processes, particularly in the early stages of the pandemic COVID-19, the global dynamics of which was first recorded in world history with high accuracy.

Conclusions. The prospect of using the integral method in geospatial research is briefly summarized. It is pointed out that integral method can be successfully applied for testing of various hypotheses about the  nature of the COVID-19 pandemic by Popper's method.

Introduction. To study the history of the development of the ATD of the Stavropol Territory, an extensive series of ancient geographical maps created since the beginning of the development of the North Caucasus by Russia is of great scientific interest. Geoinformation technologies allow processing, spatial coordination of digitized old maps with optimal accuracy, creation of thematic layers necessary for spatial analysis and visualization of the results of work in the form of a series of maps displaying the ATD of the Stavropol region for different periods of development history.
Materials and research methods. As the main source of spatial data, old maps were used, selected according to 12 stages of the development of the Stavropol region ATD system over a 237-year period. For the processing and analysis of spatial data, the functionality of the GIS package Mapinfo Professional and the Vertical Mapper module were used. The construction of geoinformation models was carried out using the calculation of rasters obtained as a result of vector-raster transformations of the boundaries of ATD units. The mapping results are visualized using the capabilities of the Adobe Illustrator graphics editor.
Results of the study and their discussion. Modern methods of processing and analyzing spatial data have made it possible to carry out spatial coordination and mapping of the borders of the ATD displayed on ancient maps. Using computer graphics technologies, two series of maps of different scales have been created, which can be used for educational and scientific purposes to increase the perception of information about the history of the development of the administrative-territorial structure of the Stavropol Territory. Models are constructed for the duration of the territories being part of the Stavropol Territory and the stability of the boundaries of the Stavropol Territory.
Results. The system of administrative-territorial division of the Stavropol Territory has gone through a complex evolutionary path of development. The analysis of geoinformation models showed that 2/3 of the area of the region within the modern borders was formed by the territories that have been part of it for more than 2 centuries, and also that the modern borders of the Stavropol Territory, except for the border with the Karachai-Circassian Republic, have a historical maturity.