Advances in Science and Technology Vol. 172

Abstract: This paper presents a two-dimensional numerical model of blast-wave propagation in a gaseous medium based on the compressible Euler equations and an ideal-gas equation of state. The governing conservation laws are discretised with a triangular finite-element formulation and stabilised using a local Lax–Friedrichs (Rusanov) numerical flux; time integration employs an explicit Euler scheme. The implementation generates an n × n mesh over a square domain, assembles the semi-discrete system, and advances the solution to capture the spatio-temporal evolution of pressure, density, and energy. Simulations reproduce the salient physics of explosions in air: rapid energy release at the epicentre, formation and outward propagation of a supersonic shock, a positive overpressure phase followed by rarefaction, and compression/expansion trends consistent with gas dynamics. Quantitatively, the model yields large transient overpressures (up to ~400× atmospheric at early times in the reported case) and density jumps across the shock front. The approach offers a practical tool for analysing sensitivity to initial/boundary conditions and for exploring parameter effects relevant to underground safety and protective-structure design. Limitations and extensions are discussed, including the need to incorporate viscous effects, real-gas thermodynamics, and fluid–structure interaction for confined or complex geometries.

Abstract: Gas hydrates, crystalline water-methane structures, offer vast energy potential but require optimized degassing for methane extraction. This theoretical study evaluates key parameters – pressure, temperature, chemical inhibitors, and geological conditions – using literature data. Depressurization (10→2 MPa) boosts dissociation rates by 50% but risks sediment instability. Thermal stimulation (2°C→10°C) enhances yields, with marine sediments (60–80% efficiency) outperforming permafrost (40–60%). Chemical inhibitors (e.g., methanol, 10–20% concentration) improve yields but face environmental and cost hurdles; saline solutions offer safer alternatives (30–50% yields). High porosity (30–40%) and permeability (10⁻¹² m²) increase recovery by 25%, while clay-rich formations reduce efficiency by 15%. Kinetic and equilibrium models provide insights but lack real-world validation. The study highlights the need for experimental tests to refine models and assess environmental impacts. Tailored strategies balancing dissociation speed with geomechanical stability and ecological safeguards could enable sustainable extraction. This work advances foundational knowledge for industrial-scale methane recovery from hydrates, emphasizing the potential of integrated approaches to unlock this unconventional resource.

Abstract: The article examines the development features of the studied gas field and analyzes the efficiency of different hydraulic fracturing (HF) technologies. An integrated analysis of the field’s production history was carried out, covering the evaluation of applied HF methods, results of diagnostic injection tests, regression calculations, and characterization of fracture parameters. Historical production and reservoir pressure data were used to calibrate a material balance model in MBAL, ensuring consistency between observed and simulated results. HF operations using both crosslinked gel and slickwater were analyzed. Results of DFIT and mini-frac tests allowed the determination of key fracture parameters – length, height, conductivity (FCD), net pressure, and fluid efficiency. Based on the integrated dataset, a five-year forecast of field performance was developed. Wells treated with slickwater demonstrated higher and more stable flow rates compared with conventional crosslinked gel treatments, especially under lower reservoir pressures and timely well clean-up. The study emphasizes the importance of combining historical production analysis, fracture diagnostics, and regression methods with material balance modeling for reliable long-term productivity forecasting. The findings provide practical implications for optimizing HF parameters, selecting fluid systems, and planning reservoir development strategies aimed at maximizing gas recovery under depletion conditions.

Abstract: The development of offshore unconventional petroleum fields, including gas hydrates, shale, and coalbed methane, presents significant technological, environmental, and strategic challenges. While advances in drilling, completion, and enhanced recovery technologies have improved operational efficiency, structured project management tailored to these unconventional resources remains underexplored. This study analyzes the state-of-the-art approaches for offshore unconventional field development, emphasizing the integration of technical innovation, environmental management, and project governance. Key methodologies include adaptive/agile project management, multi-criteria decision analysis (MCDA), and risk management with contingency planning. These approaches enable iterative decision-making under high geological and operational uncertainty, optimize resource allocation, and ensure environmental safety. The study further examines the innovative use of existing gas transmission systems for CO₂ transport and methane production from marine hydrate deposits, highlighting the dual economic and environmental benefits. Results demonstrate that combining lifecycle-based project management with technology-specific strategies and sustainability-oriented planning enhances project resilience and efficiency. The proposed integrated framework provides a structured methodology for managing offshore unconventional petroleum projects, addressing uncertainties, minimizing risks, and aligning with national energy security goals. This research contributes to both theoretical and practical knowledge by bridging gaps between technological innovation and strategic project management in complex offshore environments.

Abstract: In this study, we compared the closed mines of the Donetsk basin of Ukraine and the Ruhr coal mining area of Germany by the conditions of mine water heat recovery. The set of criteria includes maximum thermal capacity, heat pump COP, the relation of energy gained to energy spent, potential profit of operation, and CO₂ emission reduction. The complex indicator of efficiency that comprises all these parameters was used to rank eight mine drainage stations in Ukraine and the same number in Germany. Based on the calculations for potential open-loop and closed-loop systems, we revealed statistically significant correlations between expected energy efficiency, the water temperature, and the flooding interval length for 27 mines in Ukraine and 28 mines in Germany. The average expected thermal capacity of closed-loop systems at the current water level in the mines of the two basins is similar, against the background of higher heterogeneity of geothermal conditions in Donbas and greater depths and higher temperatures in Ruhr area mines. The similarity of mining conditions and estimated energy efficiency indicators of geothermal systems for two basins is in favor of the feasibility and efficiency of such systems in Ukrainian mining sites.

Abstract: Ukraine's resource potential in providing critical sectors of the economy with raw materials of mineral aluminium for energy transition and decarbonization is determined. The current state of the global aluminium mining industry and the change in demand, cost dynamics over the past 14 years are established. The main reasons that lead to the rise and fall of the cost of aluminium raw materials on the world market are given. The main minerals that are potential sources of aluminium raw materials, according to the criterion of economic feasibility, are determined. The mining and geological conditions of the occurrence of explored bauxite deposits in Ukraine, which are potentially attractive for further open-pit development, are considered. The main areas of aluminium application in critical sectors of the economy are given, which meet the climate and energy goals of the EU by 2040 and lead to an increase in demand for it by 30%. Estimated aluminium reserves are established in four promising areas for mining activities: Vysokopilske, Mazurivske, Bihanske, and Berehivske. The determined aluminium content in alunite ores of Ukrainian deposits allows us to assert that they contain promising reserves of raw materials, which can be a resource base for strengthening global technological chains.

Abstract: A comprehensive analysis of the results of theoretical generalisations, field surveys and laboratory experiments was carried out to assess the environmental risks from overburden dumps. Changes in the qualitative parameters of the edaphotope of adjacent territories, in particular agricultural land, were established through the study of granulometric composition, organic carbon content, mineral forms of nitrogen, acidity of water extract, etc. The samples show that the soils at the foot of the dump are characterised as low-humus, the soils in the adjacent field are also low-humus, while the soils on the side of the field far from the man-made object are medium-humus. This indicates degradation processes in chernozems caused by wind accumulation of erosion products from the surface of the dumps. Further accumulation of dust deposits in combination with anthropogenic load from motor vehicles can cause alkalisation of agricultural soils and reduce the bioavailability of trace elements for cultivated plants. The analysis of the dynamics of chemical indicators for 2022 and 2024 showed the need to integrate dust load parameters into environmental impact assessment procedures, taking into account its long-term effects. It is recommended to design protective forest belts or other measures to reduce the man-made dust pressure from overburden dumps.

Abstract: The article substantiates the designation of Waste from Uncontrolled Destruction (WUD) as a distinct category of anthropogenic waste generated by war, terrorist attacks, natural disasters, and major technological incidents. The objective is to demonstrate the necessity of such recognition and to propose a classification model with methods for assessing WUD volumes, morphology, and risk. Methods include a review of international and national regulatory frameworks, comparative analysis with construction and demolition (C&D) waste, synthesis of international case evidence, and development of an operational WUD-A…E classification accompanied by a matrix of hazards, safety barriers, and management routes (from upfront safety assurance to sorting, decontamination, recycling, and specialized disposal). Results indicate that WUD differs materially from C&D in mixed morphology, elevated hazard, and reduced recyclability, which precludes the direct application of standard C&D approaches without prior risk reduction and robust quality control. For Ukraine, priorities are outlined: formal recognition of WUD in national waste lists, deployment of mobile and stationary debris-processing capacity, implementation of GIS-based monitoring, workforce training, and international coordination. The formal institutionalization of WUD and tailored standards are prerequisites for safe, timely, and resource-efficient post-crisis recovery.

Abstract: The article is devoted to the study of a comprehensive approach to the development of secondary resources in coal-mining regions as a key factor in ensuring sustainable development and energy security. The theoretical foundations and practical aspects of the use of coal industry waste, including rock dumps, mine water and mine methane, are considered. The article considers modern technologies for processing coal industry waste, which consist in forming a more balanced approach to the use of natural resources and creating preconditions for a gradual transition to more environmentally friendly technologies in the energy sector. A conceptual model of sustainable development of coal-mining regions based on the principles of the circular economy is proposed, which is based on five key principles that can form a comprehensive system for managing secondary resources in coal-mining regions. This will make it possible to increase the overall efficiency of the system by 35-50% compared to the isolated application of individual production processes, create economic models for coal-mining regions that are resistant to external shocks, form unique competitive advantages in the global market, and ensure long-term social, economic and environmental stability in the region.

Abstract: This study presents a hybrid CFD-ML model for liquid filtration systems, overcoming limitations of traditional approaches. The model accurately predicts pressure drop (2.3% RMSE) and filtration rates, outperforming standard CFD (8.7%) and Darcy models (12.4%). By integrating the Kozeny-Carman equation with an ML-enhanced k-ϵ turbulence model, it achieves 65% faster computations (12 vs. 34 minutes). Validations using nanofiber membranes show high accuracy (3.1–4.8% error, R² = 0.95–0.97). Applications in water treatment and oil refining yield 12% energy savings in reverse osmosis and 15% efficiency gains in oil-water separation at optimal porosity (0.80) and velocity (0.08 m/s). Sensitivity analyses reveal porosity and velocity as critical parameters, with a 10% porosity increase reducing pressure drop by 8 kPa. While the model advances filtration technology by capturing turbulence and adapting to diverse materials, it neglects fouling dynamics and assumes Newtonian behavior. Future work should address multiphase flows, dynamic fouling, and alternative characterization methods to broaden industrial use in sustainable processes like water purification and biotechnology. The framework offers actionable insights for designing efficient, cost-effective filtration systems with real-time control potential.