VolgoUralNIPIgaz (Russia)

Introduction. Increasing interest of the scientific community to the natural hydrogen growths due its potential role as a substitute for traditional hydrocarbon energy sources. The initial migration of hydrogen occurs in the aqueous solution. Hydrogen transportation with subsequent accumulation is possible only in the underground aquifers. The heterogenization of the aqueous solution is determined by both P-T conditions and its saturation with gases and background salt composition. In our opinion, the model of the functioning of the hydrogen system deserves careful attention and is extremely relevant. The problem facing us is the interaction of hydrogen flows with existing deposits of predominantly methane composition. Understanding the mechanisms and dynamics of these processes requires the analysis of a complex multi-phase physicochemical system, which can be implemented by the computer physicochemical modeling of the hydrogen and methane behavior in modern software packages. The purpose of the study: to determine behavior features of the hydrogen and methane in the natural solutions of different salinities, namely, to establish the saturation points of hydrogen and methane solutions at different temperatures and pressures using numerical physicochemical modeling. Research methodology. GEM-Selektor (GEMS) is a software package created by a group led by D. Kulik, the software package is distributed by the Paul Scherrer Institute. The computational algorithms are based on the principle of Gibbs energy minimization (GEM), and allow interactive thermodynamic modeling of heterogeneous aqueous geochemical systems. Includes a built-in thermodynamic database in both thermochemical and reaction formats. To model the studied system, we used the MINES thermodynamic database, which was created and maintained by Professor Alexander Gysi from the Bureau of Geology and Mineral Resources, New Mexico, USA. Results. The modeled system was a solution (of different salinities: 0 and 10 wt. % NaCl eq.), equilibrated with a sandstone of the specified composition. It was duplicated at different temperatures from 10 °C to 240 °C and a pressure of 1751 bar with a step of 10 °C and 50 bar. The simulation conditions included: a temperature interval from 10 to 240 °C, and pressure parameters from 1 to 1751 bar. The results of the study include the gas saturation of electrolyte solutions of variable salinity (0 and 10 wt. % NaCl equiv.), which are demonstrated using mole fraction diagrams multiplied by 100%, depending on temperature and pressure. The saturation results of the different salinities solutions with hydrogen and methane are compared for a model with hydrostatic pressure and a geothermal gradient of 25 °C/km. Conclusions. The solubility of hydrogen and methane in aqueous sodium chloride solutions varies with temperature and pressure and increases with increasing temperature and pressure. During the dissolution of gases, pressure plays a greater role than temperature. A mixture of hydrogen and methane equilibrated with the formation solution will contain more hydrogen than methane at pressures above 200 bar, and more methane than hydrogen at pressures below 200 bar. At great depths and under high pressure hydrogen dissolves better in aqueous solutions than methane, and in near-surface conditions hydrogen dissolution is reduced.

The purpose of this study is to evaluate the effectiveness of the inhibited Neftyanaya Emulsiya Hlorno-Kalievogo Termostabilizirovannogo - inhibited drilling solution - (NEHKT) drilling solution when drilling unstable rocks in red-colour sediments in a certain range of occurrence at a particular well. The study includes preparation of the solution, laboratory tests to determine the optimal components and their proportions, and conducting controlled experiments during which the solution was used in practice. During these tests, the inhibited NEHKT drilling fluid was used in real drilling conditions to evaluate its effectiveness. Conducting controlled experiments allowed evaluating of its ability to prevent complications during the drilling process and the success of the descent and cementing of the production column. The effectiveness of the inhibited NEHKT drilling solution was confirmed under conditions of drilling unstable rocks in red-coloured sediments in the range of 2000-2600 m at well No. 810 of the Nebitdag area. Drilling was also successfully conducted without complications when using the solution, which confirms its ability to ensure the stability of the drilling process and prevent possible problems associated with unstable rocks. The ability of the inhibited NEHKT solution to maintain its structural and mechanical properties in conditions of high mineralisation, penetrate the interplane space of clays, preventing their hydration and swelling, and bind all the water in the solution into persistent hydrates, which contributes to the stability and safety of the drilling process, is identified. Thus, the results of this study indicate the prospects and effectiveness of the inhibited NEHKT drilling solution in the context of ensuring a safe and stable drilling process for unstable rocks in red-coloured sediments.

Heat tolerance is an important trait in cowpea, a crop that constitutes the primary protein source for a large portion of the human population in sub-Saharan Africa. Cowpea grows across this region, with cultivated, landrace, semi-wild, and wild cowpeas germplasm growing across diverse climatic conditions. This study used environmental association (envGWAS) and allele frequency outlier approaches in a panel of 580 gene bank accessions to identify genomic regions associated with heat and limited precipitation. Because allele frequency outliers are detected independent of potential selection factors driving differentiation, we used a ranking-based approach to identify the climate variables most associated with variants among outliers. Precipitation-related variables dominated the signals we identified for envGWAS and allele frequency outliers. We found variants on all eleven chromosomes putatively associated with the adaptation of cowpea to higher-temperature environments. The considerable overlap between variants associated with low precipitation and high temperature suggests that these traits may be inextricably linked in cowpea. The Sahel region is the source of many accessions with derived variants associated with high temperature, suggesting the potential for accessions from this region to contribute to heat tolerance alleles for cowpea improvement.

The study of the properties of clay minerals and the creation of innovative drilling fluids based on them are extremely important aspects for improving the processes of extraction of natural resources, reducing operating costs, and increasing the energy efficiency of industrial operations. The purpose of this study was to explore the possibilities of developing a composition of drilling fluids based on the investigation of the properties of clay minerals for drilling and maintenance of wells in the conditions of the Gubadag deposit located in Turkmenistan. Statistical methods, experiments, and analysis were used in the course of the work. The results of the study showed that clay from the Gubadag deposit is characterised by low hydrophilicity and weakened structural stability, which is manifested in limited hydration energy and high filtration permeability. This leads to low viscosity, rheological, and structural-mechanical parameters of natural solutions. It follows from this that Gubadag clay is classified as a low-quality material. The prepared solutions from the above samples on different types of water have volumes in the range of 2-3 m³. However, after treating sea water with caustic soda, sample No. 2 generates more than 4 m³ of solution, significantly different from other samples. This highlights the need for additional research to optimise drilling fluid formulae, since it is important to determine the effect of clay materials on the properties of solutions and develop more adapted formulae that consider the specifics of the material and the conditions of its use in drilling wells. The practical significance of the results obtained lies in a significant improvement in the efficiency of drilling and maintenance of wells in regions with difficult geological conditions, offering new methods for preparing drilling fluids.

Relevance. The greatest difficulties in emergencies of biological nature arise if health care is provided to significant contingents of persons engaged in work activities outside large settlements and united by common living, food and recreation conditions, for example, shift workers engaged in the implementation of large construction projects. Despite the pandemic of the new coronavirus infection (COVID-19), the construction of large industrial enterprises should continue, which makes the problem of medical support for shift workers extremely urgent. Intention. To analyze the experience of organizing and conducting anti-epidemic and medical evacuation measures during the medical support of personnel engaged in the construction of the Amur Gas Processing Plant (AGPP) in the conditions of the spread of the first wave of a new coronavirus infection (COVID-19). Methodology. The subject of the study was the medical support of shift workers employed in the construction of the AGPP. The total number of employees working on the construction site of the AGPP daily from March to September 2020 ranged from 30,390 to 39,120 people. Citizens of the Russian Federation as well as of foreign countries from near and far abroad worked on a shift basis. All employees lived in dormitories on the territory of temporary shift camps for construction workers, and ate in common canteens. Anti-epidemic and medical evacuation measures were developed and their effectiveness assessed using methods of historical analysis and comparison, systematic and logical analysis, expert assessments, statistical analysis. Results and Discussion. The results of a retrospective analysis of measures for medical support of workers employed in the construction of the AGPP are presented. Starting from 03/28/2020, the following anti-epidemic measures were implemented: disinfection of dormitories, canteens, transport and offices; the use of protective masks and gloves; daily measurement of body temperature; disposable tableware. Since 04/27/2020, there were restrictions on entry and exit from the AGPP; employees lived either in shift camps on the territory of the construction site, or in city dormitories with isolated perimeter (for engineering and technical personnel). After detecting the first case of COVID-19 infection, isolation of COVID-19 cases with contact tracing took place. From 29.05 to 06.06.2020, polymerase chain reaction (PCR) and immunofluorescence analysis were performed in 30,445 workers. As a result, a quarantine regime in shift camps was introduced, and medical prophylaxis was prescribed to their inhabitants in accordance with the Temporary Methodological Recommendations “Prevention, diagnosis and treatment of a new coronavirus infection (COVID-19)”, version 7.0 of 03.06.2020. During repeated mass testing from 12.06 to 19.06.2020, 95.9% of primary SARS-CoV-2-positive employees became negative after treatment with hydroxychloroquine and recombinant interferon-alpha, thus suggesting high effectiveness of anti-epidemic, therapeutic, and preventive measures. For treatment of COVID-19 cases, a hospital base was deployed, including three provisional hospitals, infectious disease department of the Svobodnenskaya Hospital and a temporary infectious disease hospital built in June-July 2020 directly on the site of the AGPP. The above facilities had all the necessary medical equipment and supplies. Due to the shortage of available beds in health facilities, on 14.06 and 19.06.2020 44 patients with COVID-19 of mild and moderate severity were evacuated by air to medical institutions of the Khabarovsk Territory and the Republic of Sakha (Yakutia). More than 150 healthcare workers, including doctors, nurses, paramedics and medical assistants were involved in anti-epidemic, therapeutic, and preventive measures at the AGPP. Conclusion. Thanks to the anti-epidemic and medical evacuation measures, the construction of the AGPP during the first wave of new coronavirus infection went on, and after the epidemic situation stabilization in August 2020, mass engagement of shift workers was resumed.

The purpose of this work is to assess the possibilities of using electromagnetic monitoring to study the development of a fracture system generated by hydraulic fracturing (HF) with a specified position of the controlled source. The option with the source (a vertical electric dipole) located in the interval of the oil-bearing formation and ground-based measurements was chosen as the most promising monitoring plan. We have built a geoelectric model equivalent to the system of hydraulic fractures, divided into 11 zones corresponding to HF stages. For the selected model, mathematical simulation was performed by solving the direct problem considering the impact of the steel casing, the presence of which reduced the effect. Despite this fact, no strong distortion of electromagnetic field anomaly was observed above the HF zone. Analysis of the simulation results at different HF stages showed that as new hydraulic fractures appeared and were filled with electrically conductive proppant, the total effect increased. The data on electric field anomaly demonstrated maximum deviation from the background level of more than 2 %. Provided that the studied formation is characterized by sufficient electrical conductivity, its magnetic field also becomes informative.

ФГБОУ ВО «Самарский