Search

The use of tracer methods for studying oil wells makes it possible to determine the efficiency of oil field development. However, the reliability of the results of such studies largely depends on both the correctly selected indicators and the methods of interpretation. The currently developed theory of multiphase filtration and numerical analysis methods make it possible to use appropriate models to interpret the results of using various types of indicators. Of particular interest are mathematical models of processes occurring in oil-saturated rocks when using separable tracers.

The Arctic Zone of Russia (AZR), due to its significant potential, for the implementation of which infrastructure projects and strategic plans are envisaged, is of great importance for the country. Particular attention is paid to the transport and related infrastructure development. The implementation of such projects requires the creation and implementation of modern integrated solutions based on new technical and technological solutions. The development of new territories is accompanied by problems such as urbanization and the disruption of ecosystems, which will have a particularly negative impact on the Arctic zone. The situation is complicated by the fact that the work must be carried out in difficult conditions, which are associated with a large number of risks, including environmental ones. Currently, many types of businesses are characterized by a transition to the implementation of the concepts of green and blue economy, as well as ESG principles when building strategic development plans that include risk reduction. Achieving this goal is possible through an environmental risk management system. To create a suchlike system, it is necessary to identify the most significant risk characteristics of each type of activity, taking into account their negative impact on the environment, after which it will be possible to plan measures to either prevent risks or minimize their consequences. Taking into account the above, we plan to develop the concept of an environmental risk management system (ERMS) as part of the region's development strategy implementation. To reach this purpose, identifying the main groups of environmental risks depending on the danger source based on the scientific article review results, systematizing concepts aimed at improving the environmental situation under different types of anthropogenic impacts on the environment, developing an algorithm for implementing an environmental risk management system depending on the risk type, and proposing a concept for building an environmental risk management system are needed. The scientific novelty of the work lies in the fact that the main directions of negative anthropogenic impact on the environment are systematized, and possible ways to reduce environmental risks are outlined. The practical significance of the work lies in the fact that when implementing such a system, it will be possible to manage not only risks of a certain category, but also monitor the situation as a whole, identifying the consequences for related areas. [ABSTRACT FROM AUTHOR]

Transport and storage of liquid hydrogen (LH2) is currently the most attractive option for scaling up the hydrogen supply infrastructure. Hazards and associated risks for compressed gaseous hydrogen applications are relatively well investigated, yet there is less understanding of the hazards and associated risks for cryogenic hydrogen, including LH2. Validated models and tools are needed for hydrogen safety engineering of LH2 systems and infrastructure. This paper presents an overview of models developed and validated at HySAFER Centre of Ulster University, including within the PRESLHY project. These include models for assessment of hazard distances for incident scenarios. Experimental data have been used to validate the contemporary CFD models and build new correlations or reduced models. The analysed phenomena and relevant models are generally separated into three main pillars to assess consequences of incidents involving hydrogen: release and dispersion, ignition, and combustion. The developed and presented models are interconnected and can be used synergistically to provide a unified approach to the assessment of consequences of selected incident scenarios with LH2 starting from an initiating event. The models and tools aim to inform and underpin relevant Regulations Codes and Standards and assist stakeholders in performing hydrogen safety engineering. [ABSTRACT FROM AUTHOR]

This paper overviews some findings of the HyTunnel-CS project (www.hytunnel.net) on inherently safer use of hydrogen-powered vehicles in underground traffic infrastructure. The focus is on mitigation and prevention of hazards from blast wave and fireball following hydrogen tank rupture in a fire. It is demonstrated that hydrogen tank rupture in a fire is unacceptable and must be excluded. The criticism of the fire test protocol of GTR#13 is presented. It is underlined that hydrogen storage systems protected by thermally activated pressure relieve device (TPRD) do not exclude risk of tank rupture in a localised fire. The safety strategy for underground parking of hydrogen cars is described. The concept of explosion free in a fire self-venting (TPRD-less) tank is explained. The hydrogen safety engineering tools and QRA methodology developed in HyTunnel-CS are used for assessment of risk for incident scenarios of an onboard hydrogen storage tank rupture in Dublin tunnel fire. The risk is assessed in terms of fatalities per car per year, and cost per event. It is concluded that the fire-resistance rating (FRR) of the hydrogen storage tank should exceed 91 min to reduce the risk of a hydrogen-powered car in a tunnel fire to the acceptable level of 10-5 fatalities/vehicle/year. The ultimate safety solution to eliminate hazards and associated risks of hydrogen vehicles use in confined spaces is the application of the breakthrough safety technology of explosion free in a fire self-venting (TPRD-less) tank that was experimentally validated. [ABSTRACT FROM AUTHOR]

The use of hydrogen storage tanks at 100% of nominal working pressure (NWP) is expected only after refuelling. Driving between refuellings is characterised by the state of charge SoC <100%. There is experimental evidence that Type IV tanks tested in a fire at initial pressures below 1/3 NWP, leaked without rupture. This paper aims at understanding this phenomenon. The numerical research has demonstrated that the heat transfer from fire through the composite overwrap at storage pressures below NWP/3 is sufficient to melt the polymer liner. This melting initiates hydrogen microleaks through the composite before it loses the load-bearing ability. The fire-resistance rating (FRR) is defined as the time to rupture in a fire of a tank without or with blocked thermally activated pressure relief device. The dependence of a FRR on the SoC is demonstrated for the tanks with defined material properties and volumes in the range of 36–244 L. A composite wall thickness variation is shown to cause a safety issue by reducing the tank's FRR and is suggested to be addressed by tank manufacturers and OEMs. The effect of a tank's burst pressure ratio on the FRR is investigated. Thermal parameters of the composite wall, i.e., decomposition heat and temperatures, are shown in simulations of a tank failure in a fire to play an important role in its FRR. [ABSTRACT FROM AUTHOR]

This work focuses on the experimental and numerical investigation of maximum overpressure and pressure dynamics during ignited hydrogen releases in a storage enclosure, e.g., in marine vessel or rail carriage, with limited vent size area, i.e., the pressure peaking phenomenon (PPP) revealed theoretically at Ulster University in 2010. The CFD model previously validated against small scale experiments in a 1 m3 enclosure is employed here to simulate real-scale tests performed by the University of South-Eastern Norway (USN) in a chamber with a volume of 15 m3. The numerical study compares two approaches on how to model the ignited hydrogen release conditions for under-expanded jets: (1) notional nozzle concept model with inflow boundary condition, and (2) volumetric source model in the governing conservation equations. For the test with storage pressure of 11.78 MPa, both approaches reproduce the experimental pressure dynamics and the pressure peak with a maximum 3% deviation. However, the volumetric source approach reduces significantly the computational time by approximately 3 times (CFL = 0.75). The sensitivity analysis is performed to study the effect of CFL number, the size of the volumetric source and number of iterations per time step. An approach based on the use of a larger size volumetric source and uniform coarser grid with a mesh size of a vent of square size is demonstrated to reduce the duration of simulations by a factor of 7.5 compared to the approach with inflow boundary at the notional nozzle exit. The volumetric source model demonstrates good engineering accuracy in predicting experimental pressure peaks with deviation from −14% to +11% for various release and ventilation scenarios as well as different volumetric source sizes. After validation against experiments, the CFD model is employed to investigate the effect of cryogenic temperature in the storage on the overpressure dynamics in the enclosure. For a storage pressure equal to 11.78 MPa, it is found that a decrease of storage temperature from 277 K to 100 K causes a twice larger pressure peak in the enclosure due to the pressure peaking phenomenon. [ABSTRACT FROM AUTHOR]

The article presents a study of the environmental impact of dusting tailing dumps of rare-metal ore dressing in the Murmansk region of Russia. The purpose of the study was to establish patterns in the atmochemical halo migration of the dust pollution of loparite ore dressing tailings. The geotechnical characteristics and material composition of the tailings material have been investigated. Potentially dusty areas identified. Models of dispersion of inorganic dust under different meteorological scenarios are constructed: at low wind load, normal and unfavorable meteorological conditions. The modeling of the spread of pollutants in the area exposed to dust at the storage site was carried out in the program for modeling atmospheric pollution Ecolog-4.60. Calculation of the dispersion of inorganic dust containing 20–70% SiO2 showed that the atmochemical halo of tailings dust pollution spreads over tens of kilometers, and already at a wind speed of about 8 m/s, the concentration of suspended solids at the border of the enterprise sanitary protection zone exceeds the maximum one-time maximum permissible concentration is 3–3.3 times, and under unfavorable meteorological conditions—Dusting reaches the boundaries of the residential area (inhabited locality Revda), located in the north-west of the enterprise, and exceeds the MPCm.o. 1.5 times. [ABSTRACT FROM AUTHOR]