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Date submitted2020-02-19
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Date accepted2020-04-17
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Date published2020-10-13
Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit
- Authors:
- Oleg I. Kazanin
- Valeriy V. Yaroshenko
The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.
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Date submitted2019-10-30
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Date accepted2020-02-03
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Date published2020-10-13
Concept of technology for determining the permeability and porosity properties of terrigenous reservoirs on a digital rock sample model
- Authors:
- Ivan P. Belozerov
- Marsel G. Gubaydullin
The aim of the article is to form the concept of technology for determining the permeability and porosity properties of terrigenous reservoirs using mathematical modeling methods on a digital rock sample model. Digital rock sample modeling is used to assess geological oil reserves. The article presents the concept of digital rock sample modeling technology, which allows carrying out qualitative investigations to determine the permeability and porosity characteristics of the formation, including modeling the pore space and filtration processes. The essence of the concept is that the simulation model of the microstructure for the digital model is formed on the basis of a large number of parameters obtained during lithological and petrographic investigations of thin sections, a study of the sludge and geophysical investigations of wells. The acquired model can be used as a basis for subsequent modeling of filtration processes. Conductivity of single channels of the formed model can be calculated using molecular dynamics methods, models of Boltzmann's lattice equations, and other mathematical models and methods. Based on the results of the study carried out, the application of stochastic packing methods for modeling the structure of the pore space in the digital rock sample model of terrigenous reservoirs is substantiated. In connection with the development of computer and nanotechnologies and their use in the oil and gas industry, solutions that allow obtaining adequate results of digital rock sample models are of high importance and relevance for the production sector. It is especially important to use digital rock sample models in the study of reservoir rocks of shelf fields in the western part of the Russian Arctic, oil shales, rocks represented by loose weakly cemented reservoirs, and others, which are complex for physical experiments.
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Date submitted2019-12-25
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Date accepted2020-06-30
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Date published2020-10-13
Accounting of geomechanical layer properties in multi-layer oil field development
Amid the ever-increasing urgency to develop oil fields with complex mining and geological conditions and low-efficiency reservoirs, in the process of structurally complex reservoir exploitation a number of problems arise, which are associated with the impact of layer fractures on filtration processes, significant heterogeneity of the structure, variability of stress-strain states of the rock mass, etc. Hence an important task in production engineering of such fields is a comprehensive accounting of their complex geology. In order to solve such problems, the authors suggest a methodological approach, which provides for a more reliable forecast of changes in reservoir pressure when constructing a geological and hydrodynamic model of a multi-layer field. Another relevant issue in the forecasting of performance parameters is accounting of rock compressibility and its impact on absolute permeability, which is the main factor defining the law of fluid filtration in the productive layer. The paper contains analysis of complex geology of a multi-layer formation at the Alpha field, results of compression test for 178 standard core samples, obtained dependencies between compressibility factor and porosity of each layer. By means of multiple regression, dependencies between permeability and a range of parameters (porosity, density, calcite and dolomite content, compressibility) were obtained, which allowed to take into account the impact of secondary processes on the formation of absolute permeability. At the final stage, efficiency of the proposed methodological approach for construction of a geological and hydrodynamic model of an oil field was assessed. An enhancement in the quality of well-by-well adaptation of main performance parameters, as well as an improvement in predictive ability of the adjusted model, was identified.
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Date submitted2019-12-20
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Date accepted2020-09-01
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Date published2020-10-13
Features of the underground storages construction in depleted oil and gas condensate fields
The paper considers the features of the underground storages (US) construction in depleted oil and gas condensate fields (DOGCFs). The requirements for the structure of the formation, corresponding to the parameters of the object for possible US creation are presented. The influence of geological, hydrogeological, mining and technical rock formation conditions on the reliability and tightness of underground storages, including underground gas storages, has been evaluated. The necessary conditions for the US design are analyzed at the example of the Ach-Su oil and gas condensate field, in the presence of a well-explored trap with acceptable parameters for the construction of an underground storage. An important aspect is the geological conditions that meet the criteria for selecting the object: the required structure, the absence of fracturing faults, high reservoir properties of the formation, a sufficient volume of the deposit for the storage. Geological conditions lay the basis for determining the individual characteristics of the US construction technology at each DOGCF. The refined results for the current gas-saturated pore volume and the rate of pressure drop in the formation are presented, which makes it possible to select improved technological indicators in the course of operation of the created US. In order to select the optimal option for the design and construction of the US, the results of economic and geological scenarios analysis were studied concurrently with the capabilities of the technological operation of the object and transport system, which can ensure the maximum daily production of the storage.
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Date submitted2020-05-13
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Date accepted2020-06-24
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Date published2020-10-13
Barriers to implementation of hydrogen initiatives in the context of global energy sustainable development
Modern trends in the global energy market linked to the Sustainable Development Goals often lead to the adoption of political decisions with little basis in fact. Stepping up the development of renewable energy sources is an economically questionable but necessary step in terms of its social and ecological effects. However, subsequent development of hydrogen infrastructure is, at the very least, a dangerous initiative. In connection with mentioned above, an attempt to examine hydrogen by conducting an integral assessment of its characteristics has been made in this article. As a result of the research conducted, the following conclusions concerning the potential of the widespread implementation of hydrogen in the power generation sector have been made: as a chemical element, it harms steel structures, which significantly impedes the selection of suitable materials; its physical and volume characteristics decrease the general efficiency of the energy system compared to similar hydrocarbon solutions; the hydrogen economy does not have the necessary foundation in terms of both physical infrastructure and market regulation mechanisms; the emergence of widely available hydrogen poses a danger for society due to its high combustibility. Following the results of the study, it was concluded that the existing pilot hydrogen projects are positive yet not scalable solutions for the power generation sector due to the lack of available technologies to construct large-scale and geographically distributed infrastructure and adequate international system of industry regulation. Thus, under current conditions, the risks of implementing such projects considerably exceed their potential ecological benefits.
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Date submitted2019-11-20
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Date accepted2020-01-20
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Date published2020-10-13
Effect of shear stress on the wall of technological pipelines at a gas condensate field on the intensity of carbon dioxide corrosion
The object of the study is a section of the gas and gas condensate collection system, consisting of an angle throttle installed on a xmas tree and a well piping located after the angle throttle. The aim of the study is to assess the impact of the flow velocity and wall shear stress (WSS) on the carbon dioxide corrosion rate in the area of interest and to come up with substantiated recommendations for the rational operation of the angle throttle in order to reduce the corrosion intensity. In the course of solving this problem, a technique was developed and subsequently applied to assess the influence of various factors on the rate of carbon dioxide corrosion. The technique is based on a sequence of different modeling methods: modeling the phase states of the extracted product, three-dimensional (solid) modeling of the investigated section, hydrodynamic flow modeling of the extracted product using the finite volume method, etc. The developed technique has broad possibilities for visualization of the obtained results, which allow identifying the sections most susceptible to the effects of carbon dioxide corrosion. The article shows that the average flow velocity and its local values are not the factors by which it is possible to predict the occurrence of carbon dioxide corrosion in the pipeline section after the angle throttle. The paper proves that WSS has prevailing effect on the corrosion intensity in the section after the angle choke. The zones of corrosion localization predicted according to the technique are compared with the real picture of corrosion propagation on the inner surface of the pipe, as a result of which recommendations for the rational operation of the angle throttle are formed.
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Date submitted2019-11-04
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Date accepted2020-01-12
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Date published2020-10-13
PDC cutter pressure on plastic-brittle rock in the process of its destruction
- Authors:
- Oleg B. Trushkin
- Hamzja I. Akchurin
Presently, there are no methods for calculating the parameters of the drilling practices with rock-cutting tools equipped with polycrystalline diamond composite (PDC cutters). To create such a method requires the studying their work. The article presents the results of bench studies of the PDC cutters in the process of a rock sample breakdown when reproducing the actual layout of the cutters on the working surface of the bit. An important parameter of PDC cutters operation, which is necessary for the bit load analysis, is the pressure of the cutters on the rock during its breakdown. The total pressure of a cutter on the rock can be broken into two mutually perpendicular components: the forcing pressure and the cutting pressure. It is proposed to evaluate the PDC cutters loading at breakage of rocks of different hardness using relative values of forcing and cutting pressures, which are calculated relative to the yield strength of the rock by the die. It is established that the variability of the average relative pressures of forcing and cutting is significantly influenced by drifting per bit turnover and the radius of the cutter on the bit. The dependences of the maximum relative pressures of PDC cutters at the plastic-brittle rock breakdown on the drifting per bit turnover and the radius of the cutter location on the bit are obtained. It has been established that when drifting up to 0.4 mm per turn, the main mechanism of breakdown is cutting, and with the increase of the breakdown depth, the process of forcing becomes decisive.
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Date submitted2019-11-28
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Date accepted2020-05-08
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Date published2020-10-13
Development of the drilling mud composition for directional wellbore drilling considering rheological parameters of the fluid
Article presents investigations on the development of a drilling mud composition for directional wells in an oil field located in the Republic of Tatarstan (Russia). Various rheological models of fluid flow and their applicability for drilling muds are analyzed. Laboratory experiments to measure the main rheological parameters of a solution, such as plastic viscosity, dynamic shear stress, as well as indicators of non-linearity and consistency are presented. On the basis of laboratory investigations, it was concluded that high molecular weight polymer reagents (for example, xanthan gum) can give tangible pseudoplastic properties to the washing fluid, and their combination with a linear high molecular weight polymer (for example, polyacrylamide) reduces the value of dynamic shear stress. Thus, when selecting polymer reagents for treating drilling muds at directional drilling, it is necessary to take into account their structure, molecular weight and properties. Combination of different types of reagents in the composition of the drilling mud can lead to a synergistic effect and increase the efficiency of the drilling process as a whole.
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Date submitted2020-04-15
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Date accepted2020-05-13
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Date published2020-10-13
Processing of platinum group metal ores in Russia and South Africa: current state and prospects
- Authors:
- Tatyana N. Aleksandrova
- Cyril О’Connor
The presented study is devoted to a comparative review of the mineral raw material base of platinum group metals (PGMs) and technologies of their processing in South Africa and Russia, the largest PGM producers. Mineralogical and geochemical classification and industrial value of iron-platinum and platinum-bearing deposits are presented in this work. The paper also reviews types of PGM ore body occurrences, ore processing methods (with a special focus on flotation processes), as well as difficulties encountered by enterprises at the processing stage, as they increase recovery of the valuable components. Data on mineralogical features of PGM deposits, including the distribution of elements in the ores, are provided. The main lines of research on mineralogical features and processing of raw materials of various genesis are identified and validated. Sulfide deposits are found to be of the highest industrial value in both countries. Such unconventional PGM sources, as black shale, dunites, chromite, low-sulfide, chromium and titanomagnetite ores, anthropogenic raw materials, etc. are considered. The main lines of research that would bring into processing non-conventional metal sources are substantiated. Analysis of new processing and metallurgical methods of PGM recovery from non-conventional and industrial raw materials is conducted; the review of existing processing technologies for platinum-bearing raw materials is carried out. Technologies that utilize modern equipment for ultrafine grinding are considered, as well as existing reagents for flotation recovery; evaluation of their selectivity in relation to platinum minerals is presented. Basing on the analysis of main technological processes of PGM ore treatment, the most efficient schemes are identified, i.e.,gravity and flotation treatment with subsequent metallurgical processing.
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Date submitted2020-01-27
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Date accepted2020-05-22
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Date published2020-10-13
Sorption of rare earth coordination compounds
Rare earth elements (REEs) are valuable and strategically important in many high-technology areas, such as laser technology, pharmacy and metallurgy. The main methods of REE recovery are precipitation, extraction and sorption, in particular ion exchange using various sorbents, which allow to perform selective recovery and removal of associated components, as well as to separate rare earth metals with similar chemical properties. The paper examines recovery of ytterbium in the form of coordination compounds with Trilon B on weakly basic anion exchange resin D-403 from nitrate solutions. In order to estimate thermodynamic sorption parameters of ytterbium anionic complexes, ion exchange process was carried out from model solutions under constant ionic strength specified by NaNO 3 , optimal liquid to solid ratio, pH level, temperatures 298 and 343 K by variable concentrations method. Description of thermodynamic equilibrium was made using mass action law formulated for ion exchange equation and mathematically converted to linear form. Values of equilibrium constants, Gibbs free energy, enthalpy and entropy of the sorption process have been calculated. Basing on calculated values of Gibbs energy, a sorption series of complex REE ions with Trilon B was obtained over anion exchange resin D-403 from nitrate solutions at temperature 298 K. Sorption characteristics of anion exchange resin have been estimated: total capacity, limiting sorption of complex ions, total dynamic capacity and breakthrough dynamic capacity.
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Date submitted2019-10-15
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Date accepted2019-11-19
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Date published2020-10-13
Oilfield service companies as part of economy digitalization: assessment of the prospects for innovative development
- Authors:
- Svetlana V. Razmanova
- Olga V. Andrukhova
The digital transformation of the economy as the most important stage of scientific and technological progress and transition to a new technological structure is becoming one of the determining factors in the development and competitiveness of the domestic upstream sector. Prospects for innovative development of oilfield service companies are the key technological areas within the first project of the Hi-Tech Strategy of the German Government until 2020 – “Industry 4.0”. The purpose of this study is to assess the prospects for innovative development of the domestic oilfield service industry in the context of the digitalization of the oil and gas industry. The subject of the research is the process of the formation of key technological lines of “Industry 4.0” and their impact on the domestic oil and gas sector. The research is based on logical-theoretical and empirical analyses. The main factors that determine processes of digital transformation in the oil and gas industry are considered; the results of digitalization processes in the largest foreign and Russian industry companies of the upstream and oilfield services segments are presented. The information base is made up of data from oilfield service and oil and gas producing companies, presented on the official websites of companies in the public domain on the Internet. It has been proven that, unlike the world's leading companies in oilfield services segment, independent domestic oilfield service companies provide mainly traditional service technologies in a fairly narrow range. The limited scope of functioning and technological capabilities of Russian companies is explained by the lack of necessary investment in development and expansion of business, as well as interest on the part of the state and corporate sectors in the development and replication of domestic technologies and the formation of a full-fledged oilfield services market in Russia.
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Date submitted2020-04-24
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Date accepted2020-05-20
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Date published2020-10-13
Prospects and social effects of carbon dioxide sequestration and utilization projects
The issues of global warming and occurrence of the greenhouse effect are widely discussed on a global scale. Various methods of reducing greenhouse gas emissions are actively being investigated and tested, including technologies for sequestration of carbon dioxide, the implementation of which is carried out in the form of CC(U)S (carbon capture, utilization and storage) projects related to capture, disposal and, in some cases, use of CO 2 . In Russia, CC(U)S technologies are not yet used, but there is a significant potential for their development and distribution. CC(U)S technologies acquire a special role in the context of the development of the energy and industrial sectors of Russia, which are key sources of emissions, and the geological objects belonging to them are potential carbon storages. The purpose of this study is to conceptually analyze the CC(U)S technological cycle and typify such projects, assess the prospects for their implementation in Russia, and identify social effects from the implementation of CC(U)S projects. The main results of the study are presented in the form of a typology of CC(U)S projects, a strategic analysis of the prospects for introduction of such technologies in Russia, as well as development of approaches to assessing social effects with systematization and highlighting a set of indicators for their assessment, which can serve as a basis for re-estimation of the values of CC(U)S projects. The main research methods used were methods of decomposition, systematization and typology, as well as strategic analysis with a focus on relevant practical materials on the topic of the work. Directions for further research are related to the substantiation of the methodology for assessing social effects of CC(U)S projects, including for the conditions of Russia, based on the principles of balancing the interests of key participants.