Modelling of deep wells thermal modes

Purpose. Investigation of various heat-exchange conditions influence of the tower liquid on the deep wells thermal conditions. Methods. Methods of heat-exchange processes mathematical modeling are used. On the basis of the developed scheme for calculation, the thermal condition in a vertical well with a concentric arrangement of the drill-string was investigated. It was assumed that the walls of the well are properly insulated, and there is no flow or loss of fluid. The temperature distribution in the Newtonian (water) and non-Newtonian (clay mud) liquid along the borehole was simulated taking into account changes in the temperature regime of rocks with depth. To verify the calculation method and determine the reliability of the results, a comparative analysis of the calculated and experimental data to determine the temperature of the drilling liquid in the well was performed. Findings. A mathematical model for the study of temperature fields along the well depth was proposed and verified. A steady-state temperature distribution along the borehole is obtained for various types (Newtonian or non-Newtonian) tower liquid, with a linear law of change in rocks temperature with depth. It has been established that the temperature of the liquid flow at the face of hole and at the exit to the surface depends on the type of liquid used and the flow regime. It has been established that due to thermal insulation of drill pipe columns, heat-exchange between the downward and upward flow is reduced, which leads to a decrease in the temperature of the downward flow at the face of hole, providing a more favorable temperature at the face, which contributes to better destruction of the rock and cooling the tool during drilling. Originality. The nature of temperature distribution and changes along the borehole under the steady-state mode of heat-exchange in a turbulent and structural flow regime for both Newtonian and non-Newtonian circulating liquid are revealed. Practical implications. The proposed mathematical model and obtained results can be used to conduct estimates of the thermal conditions of wells and the development of recommendations for controlling the intensity of heat-exchange processes in the well, in accordance with the requirements of a specific technology.Мета. Дослідження впливу різних умов теплообміну циркулюючої рідини на тепловий режим глибоких свердловин. Методика. Використано методи математичного моделювання процесів теплообміну. На основі розробленої схеми до розрахунку досліджувався тепловий режим у вертикальній свердловині з концентричним розташуванням бурильної колони. Передбачалося, що стінки свердловини належним чином ізольовані, приплив і втрати рідини відсутні. Моделювався розподіл температур у потоках ньютонівської (води) та неньютонівської (глинистого розчину) рідин уздовж стовбура свердловини з урахуванням зміни температурного режиму гірських порід з глибиною. Для верифікації методики розрахунку і визначення достовірності результатів був виконаний порівняльний аналіз розрахункових та експериментальних даних з визначення температури промивної рідини у свердловині. Результати. Запропонована і верифіційована математична модель для дослідження температурних полів з глибиною свердловини. Отримано стаціонарний розподіл температур уздовж стовбура свердловини для різних типів (ньютонівських або неньютонівських) циркулюючих рідин при лінійному законі зміни температури гірських порід з глибиною. Виявлено, що температура потоку рідини на вибої свердловини і на виході на денну поверхню залежить від типу використовуваної рідини і режиму течії. Встановлено, що за рахунок термоізоляції колони бурильних труб знижується теплообмін між низхідним і висхідним потоками, що призводить до зниження температури низхідного потоку на вибої свердловини, забезпечуючи більш сприятливий температурний режим на вибої, який сприяє кращому руйнування породи та охолодженню інструменту при бурінні. Наукова новизна. Виявлено характер розподілу та зміни температури вздовж стовбура свердловин при стаціонарному режимі теплообміну в турбулентному і структурному режимах течії як для ньютонівських, так і неньютонівських циркулюючих рідин. Практична значимість. Запропонована математична модель і отримані результати можуть використовуватися для проведення оціночних розрахунків теплових режимів свердловин та розробки рекомендацій з управління інтенсивністю теплообмінних процесів у свердловині відповідно до вимог конкретної технології.Цель. Исследование влияния различных условий теплообмена циркулирующей жидкости на тепловой режим глубоких скважин. Методика. Использованы методы математического моделирования процессов теплообмена. На основе разработанной схемы к расчету исследовался тепловой режим в вертикальной скважине с концентрическим расположением бурильной колоны. Предполагалось, что стенки скважины надлежащим образом изолированы, приток и потери жидкости отсутствуют. Моделировалось распределение температур в потоках ньютоновской (воды) и неньютоновской (глинистого раствора) жидкостей вдоль ствола скважины с учетом изменения температурного режима горных пород с глубиной. Для верификации методики расчета и определения достоверности результатов был выполнен сравнительный анализ расчетных и экспериментальных данных по определению температуры промывочной жидкости в скважине. Результаты. Предложена и верифицирована математическая модель для исследования температурных полей по глубине скважины. Получено стационарное распределение температур вдоль ствола скважины для различных типов (ньютоновских или неньютоновских) циркулирующих жидкостей при линейном законе изменения температуры горных пород с глубиной. Выявлено, что температура потока жидкости на забое скважины и на выходе на дневную поверхность зависит от типа используемой жидкости и режима течения. Установлено, что за счет термоизоляции колоны бурильных труб снижается теплообмен между нисходящим и восходящим потоками, что приводит к снижению температуры нисходящего потока на забое скважины, обеспечивая более благоприятный температурный режим на забое, который способствует лучшему разрушению породы и охлаждению инструмента при бурении. Научная новизна. Выявлен характер распределения и изменения температуры вдоль ствола скважин при стационарном режиме теплообмена в турбулентном и структурном режимах течения как для ньютоновских, так и неньютоновских циркулирующих жидкостей. Практическая значимость. Предложенная математическая модель и полученные результаты могут использоваться для проведения оценочных расчетов тепловых режимов скважин и разработки рекомендаций по управлению интенсивностью теплообменных процессов в скважине в соответствии с требованиями конкретной технологии.The authors thank the Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine (Dnipro, Ukraine) for providing technical and informational support in this work

Control of mosaic disease using microbial biostimulants: insights from mathematical modelling

A major challenge to successful crop production comes from viral diseases of plants that cause significant crop losses, threatening global food security and the livelihoods of countries that rely on those crops for their staple foods or source of income. One example of such diseases is a mosaic disease of plants, which is caused by begomoviruses and is spread to plants by whitefly. In order to mitigate negative impact of mosaic disease, several different strategies have been employed over the years, including roguing/replanting of plants, as well as using pesticides, which have recently been shown to be potentially dangerous to the environment and humans. In this paper we derive and analyse a mathematical model for control of mosaic disease using natural microbial biostimulants that, besides improving plant growth, protect plants against infection through a mechanism of RNA interference. By analysing the stability of the system’s steady states, we will show how properties of biostimulants affect disease dynamics, and in particular, how they determine whether the mosaic disease is eradicated or is rather maintained at some steady level. We will also present the results of numerical simulations that illustrate the behaviour of the model in different dynamical regimes, and discuss biological implications of theoretical results for the practical purpose of control of mosaic disease

Psychological and Pedagogical Aspects of the Development of Integrative Readiness of Future Specialists for Professional Activity

The need to develop an integrative readiness of future specialists is a relevant scientific problem. The reasons for this could be based on the fact that that the specialists-to-be were expected to be involved in the fierce competition for vacancies and areas of activity, have modern information and communication tools, i.e. have an integrative readiness for professional activity. Institutions do not, however, have a single integration (interdisciplinary) framework for training, do not provide a comprehensive educational information, technical tools, strategies and technologies of education, reasoned psychological and pedagogical conditions. According to the author, the integrative readiness of future specialists for professional activity is a system-personality formation that reflects the unity of theoretical and managerial training and practical ability of students to comprehensively apply regulatory, socio-economic, psychological and pedagogical methods and technologies for solving different problems. This readiness reflects the unity of the motivational inclination of future specialists to professional activity and knowledge of practical technologies for solving a wide range of professional problems in personal and business interactions. The research methodology is based on the concept of key competence, which provides systematization, classification of significant problems, development of a matrix of significant problems, and determination of overall strategy, management technology of professional training development process. Students and teachers can use research materials can be used by in educational and practical activities; developers of content, organizational forms and methods of professional training to improve the practical component of curricula and standards of their development

Comparison of ratioing and RCNA methods in the detection of flooded areas using Sentinel 2 Imagery (case study: Tulun, Russia)

Climate change and natural disasters caused by hydrological, meteorological, and climatic phenomena have a significant impact on cities. Russia, a continental country with a vast territory of complex geographic–ecological environments and highly variable climatic conditions, is subject to substantial and frequent natural disasters. On 29 June 2019, an extreme precipitation event occurred in the city of Tulun in the Irkutsk oblast, Russian Federation, which caused flooding due to the increase in the water level of the Iya River that passes through the city, leaving many infrastructures destroyed and thousands of people affected. This study aims to determine the flooded areas in the city of Tulun based on two change detection methods: Radiometric Rotation Controlled by No-change Axis (RCNA) and Ratioing, using Sentinel 2 images obtained before the event (19 June 2019) and during the flood peak (29 June 2019). The results obtained by the two methodologies were compared through cross-classification, and a 98% similarity was found in the classification of the areas. The study was validated based on photointerpretation of Google Earth images. The methodology presented proved to be useful for the automatic precession of flooded areas in a straightforward, but rigorous, manner. This allows stakeholders to efficiently manage areas that are buffeted by flooding episodes.LA/P/0069/2020info:eu-repo/semantics/publishedVersio

Rare steppe plant communities in Ukraine: Status, threats and their minimization

Nowadays, the impact of anthropogenic activities on natural vegetation is constantly increasing, the level of threats is raised, and newer risk factors are emerging. Recent trends in the anthropogenic impact on plant communities are extremely pronounced, especially on those listed in the Green Book of Ukraine (GBU). Identifying such trends is required for the further development of strategic and tactical planning for the preservation and restoration of rare grass, shrub, and subshrub steppe, petrophyte and psammophyte plant communities of the steppe and forest-steppe zones of Ukraine. In addition to well-established threat factors that cause changes in the habitat of plant communities or mechanically affect plants, new specific threats occur. Today, the most important among them in Ukraine are as follows: climate change, military activity, growing population in the industrial cities, population poverty and government corruption, changes in forms of land ownership and the creation of a land market, lack of knowledge and effective policy, including lack of popular scientific information about the status of specific species and plant groupings, inadequate management of protected areas, uncoordinated environmental protection measures, ineffective sanctions, insufficient monitoring of the consumption of natural biological resources. The preservation of rare grass, shrubby and subshrubby communities in the steppe zone of Ukraine should be provided with proper support at the state level. There is a pressing need for a law of Ukraine “On the preservation of the steppes in Ukraine” and this will require mechanisms for its implementation. The issue of developing a strategy for the conservation and balanced use of steppe ecosystems in Ukraine, whose area is one of the largest in Europe, has long been raised. The main goal of the strategy is the actual preservation of steppe communities (most of which are currently rare) ensuring their restoration, minimizing degradation, and stopping biodiversity loss. In order to develop specific actions to eliminate threats or reduce their impact on rare plant groupings, it is required to investigate the causes of threats and assess their level and duration. This is required to preserve the landscape and biotic diversity in the steppe zone of Ukraine

Substantiation of thermomechanical technology parameters of absorbing levels isolation of the boreholes

The aim of the work is to improve the thermomechanical absorption insulation technology horizons of drilling wells by the established regularities of change and the substantiation of its regime parameters from the composition and physical-mechanical properties strengthen thermoplastic composite material and, on this basis, development a technological regulation containing recommendations on the manufacture of composites and organizations laying work, designing and isolation of the absorption zones of the washing liquid in the drilling rigs wells. The tasks set were solved by complex method research that contains analysis and synthesis of literary and patent sources, conducting analytical, experimental and industrial research. Experimental processing data was carried out using methods of mathematical statistics. Experimental research is carried out using the provisions of the theory of scientific experiment and theory random processes. The evaluation of the effectiveness of the results was carried out in production conditions

Disturbance indicator values for European plants

Motivation Indicator values are numerical values used to characterize the ecological niches of species and to estimate their occurrence along gradients. Indicator values on climatic and edaphic niches of plant species have received considerable attention in ecological research, whereas data on the optimal positioning of species along disturbance gradients are less developed. Here, we present a new data set of disturbance indicator values identifying optima along gradients of natural and anthropogenic disturbance for 6382 vascular plant species based on the analysis of 736,366 European vegetation plots and using expert-based characterization of disturbance regimes in 236 habitat types. The indicator values presented here are crucial for integrating disturbance niche optima into large-scale vegetation analyses and macroecological studies. Main types of variables contained We set up five main continuous indicator values for European vascular plants: disturbance severity, disturbance frequency, mowing frequency, grazing pressure and soil disturbance. The first two indicators are provided separately for the whole community and for the herb layer. We calculated the values as the average of expert-based estimates of disturbance values in all habitat types where a species occurs, weighted by the number of plots in which the species occurs within a given habitat type. Spatial location and grain Europe. Vegetation plots ranging in size from 1 to 1000 m(2). Time period and grain Vegetation plots mostly sampled between 1956 and 2013 (= 5th and 95th quantiles of the sampling year, respectively). Major taxa and level of measurement Species-level indicator values for vascular plants. Software format csv file

Ellenberg-type indicator values for European vascular plant species

Aims: Ellenberg-type indicator values are expert-based rankings of plant species according to their ecological optima on main environmental gradients. Here we extend the indicator-value system proposed by Heinz Ellenberg and co-authors for Central Europe by incorporating other systems of Ellenberg-type indicator values (i.e., those using scales compatible with Ellenberg values) developed for other European regions. Our aim is to create a harmonized data set of Ellenberg-type indicator values applicable at the European scale. Methods: We collected European data sets of indicator values for vascular plants and selected 13 data sets that used the nine-, ten- or twelve-degree scales defined by Ellenberg for light, temperature, moisture, reaction, nutrients and salinity. We compared these values with the original Ellenberg values and used those that showed consistent trends in regression slope and coefficient of determination. We calculated the average value for each combination of species and indicator values from these data sets. Based on species’ co-occurrences in European vegetation plots, we also calculated new values for species that were not assigned an indicator value. Results: We provide a new data set of Ellenberg-type indicator values for 8908 European vascular plant species (8168 for light, 7400 for temperature, 8030 for moisture, 7282 for reaction, 7193 for nutrients, and 7507 for salinity), of which 398 species have been newly assigned to at least one indicator value. Conclusions: The newly introduced indicator values are compatible with the original Ellenberg values. They can be used for large-scale studies of the European flora and vegetation or for gap-filling in regional data sets. The European indicator values and the original and taxonomically harmonized regional data sets of Ellenberg-type indicator values are available in the Supporting Information and the Zenodo repository