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Date submitted2024-03-20
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Date accepted2024-11-07
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Date published2025-02-27
Analysis of the stress state of rocks transformation near a horizontal well during acid treatment based on numerical simulation
The article presents an overview of the assessment and modelling of the stress state of rocks in the near-wellbore zone of horizontal wells during acid stimulation of the formation for improving the efficiency of oil and gas field development. A numerical finite element model of near-wellbore zone of the reservoir drilled by a horizontal section was compiled using one of oil fields in the Perm Territory as an example. The distribution of physical and mechanical properties of the terrigenous reservoir near the well was determined considering transformation under the action of mud acid for different time periods of its injection. Multivariate numerical simulation was performed and the distribution of horizontal and vertical stresses in near-wellbore zone was determined with regard for different values of pressure drawdown and changes in stress-strain properties depending on the area of mud acid infiltration. It was found that a change in elastic modulus and Poisson's ratio under the influence of acid led to a decrease in stresses in near-wellbore zone. Analysis of the stress distribution field based on the Coulomb – Mohr criterion showed that the minimum safety factor of rock even after the effect of mud acid was 1.5; thus, under the considered conditions of horizontal well modelling, the reservoir rock remained stable, and no zones of rock destruction appeared.
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Date submitted2023-07-07
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Date accepted2023-12-27
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Date published2024-12-25
A new insight into recording the mineral composition of carbonate reservoirs at well killing: experimental studies
Well killing operation remains an important technological stage before well workover or servicing, during which filtrate penetrates the bottomhole area of the formation. The impact of process fluids and their filtrate on rock has a significant influence on permeability and porosity of carbonate reservoirs, which decrease due to fines migration. There are few known scientific studies of the interaction of killing fluid filtrate with carbonate rock and fines migration. In our experiments, an aqueous phase was used which is the basis for well killing in pure form, for the preparation of blocking agents and is used in reservoir pressure maintenance system. Core samples taken from the pay of the reservoir were used to simulate the well killing process with generation of reservoir thermobaric conditions. Killing fluid filtrate was kept for seven days, which characterizes the average workover time at flowing wells in the fields of the Perm Territory. Using micro-X-ray tomography and scanning electron microscope, images were obtained before and after the experiment, which allowed confirming a decrease in total number of voids due to fines migration and, as a consequence, a decreasing permeability of samples. Measurement of pH and fines concentration in the aqueous phase was performed before and after the experiment and pointed to mineral reactions occurring as a result of rock dissolution. The results of experiments made it possible to record a decrease in permeability of carbonate samples by an average of 50 % due to clogging of void space and migration of fines (clayey and non-clayey).
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Date submitted2023-03-14
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Date accepted2023-10-25
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Date published2024-04-25
Predictive assessment of ore dilution in mining thin steeply dipping deposits by a system of sublevel drifts
The purpose of research is the study of stress-strain state of marginal rock mass around the stope and predictive assessment of ore dilution with regard for changes in ore body thickness in mining thin ore deposits on the example of the Zholymbet mine. Study of the specific features of the stress-strain state development was accomplished applying the methodology based on numerical research methods taking into account the geological strength index (GSI) which allows considering the structural features of rocks, fracturing, lithology, water content and other strength indicators, due to which there is a correct transition from the rock sample strength to the rock mass strength. The results of numerical analysis of the stress-strain state of the marginal part of the rock mass using the finite element method after the Hoek – Brown strength criterion made it possible to assess the geomechanical state in the marginal mass provided there are changes in ore body thickness and to predict the volume of ore dilution. It was ascertained that when mining thin ore deposits, the predicted value of ore dilution is influenced by the ore body thickness and the GSI. The dependence of changes in ore dilution values on the GSI was recorded taking into account changes in ore body thickness from 1 to 3 m. Analysis of the research results showed that the predicted dimensions of rock failure zone around the stopes are quite large, due to which the indicators of the estimated ore dilution are not attained. There is a need to reduce the seismic impact of the blasting force on the marginal rock mass and update the blasting chart.
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Date submitted2022-10-24
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Date accepted2023-03-03
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Date published2023-04-25
Use of clay-containing waste as pozzolanic additives
Growing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiological safety of population. The article presents a possibility of recycling one type of such waste (clay-containing concentration tailings of apatite-nepheline and sylvinite ores, coal beneficiation tailings) by using them after preliminary thermochemical treatment as pozzolanic additives to cements and concretes, including concrete mixtures used for soil stabilization, development of territories, reclamation of mine workings, as a component of the insulating layer of landfills for the disposal of municipal solid waste. An analysis of the phase changes of kaolinite, one of the main minerals that make up clay-containing waste, in the temperature range of 200-1,000 °С showed that a change in its mineral form during heat treatment is the main factor in changing its pozzolanic activity. The effect of heat treatment of clay minerals at temperature of 700-800 °C on their pozzolanic activity, estimated by the ability to absorb calcium hydroxide (0.7 g Ca(OH) 2 per 1 g of modified kaolinite), is considered. It is shown that the addition of heat-treated samples (20 % by weight) improves the quality of cement increasing its activity by 15 %, in comparison with the use of unmodified clay minerals. It was proved experimentally that partial replacement of Portland cement with thermally modified kaolinite increases the strength of consolidating stowing mixture by up to 15 %. This approach to processing of ores containing layered silicates, which provides for thermochemical modification of run-of-mine ore, intensifies the processes of tailings thickening and filtering.
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Date submitted2022-03-22
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Date accepted2022-11-17
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Date published2023-02-27
Development of composition and study of sorbent properties based on saponite
The development of a comprehensive approach to preventing the pollution of natural objects is necessary due to the high requirements of environmental legislation for the discharge of industrial wastewater. Adsorbents are used in various industries to extract heavy metals from wastewater. In this study the possibility of using saponite clay as a raw material for the production of sorbent for the extraction of copper ions Cu 2+ from industrial wastewater is considered, a recipe and technology of sorbent production are developed, and its chemical composition is established. It has been established that the optimum temperature for heat treatment of the sorbent and corresponds to 550 ºC, since at this temperature saponite extrudates acquire strength (strength 34.1 kg/mm 2 ) and textural properties (specific surface area of pellets 22.803 m 2 /g), allowing them to be used as sorbents. The kinetics of molecular adsorption was studied using model solutions of copper (II) sulfate. The extraction efficiency of copper (II) ions from the model solutions is 93 %. Extraction efficiency of copper (II) ions from copper plating wastewater reaches 94 %. SEM results confirm the presence of metal on the sorbent surface.
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Date submitted2021-12-16
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Date accepted2022-04-07
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Date published2022-07-13
The Upper Kotlin clays of the Saint Petersburg region as a foundation and medium for unique facilities: an engineering-geological and geotechnical analysis
- Authors:
- Regina E. Dashko
- Georgiy A. Lokhmatikov
The article reviews the issues concerned with correctness of the engineering-geological and hydrogeological assessment of the Upper Kotlin clays, which serve as the foundation or host medium for facilities of various applications. It is claimed that the Upper Kotlin clays should be regarded as a fissured-block medium and, consequently, their assessment as an absolutely impermeablestratum should be totally excluded. Presence of a high-pressure Vendian aquifer in the lower part of the geological profile of the Vendian sediments causes inflow of these saline waters through the fissured clay strata, which promotes upheaval of tunnels as well as corrosion of their lining. The nature of the corrosion processes is defined not only by the chemical composition and physical and chemical features of these waters, but also by the biochemical factor, i.e. the availability of a rich microbial community. For the first time ever, the effect of saline water inflow into the Vendian complex on negative transformation of the clay blocks was studied. Experimental results revealed a decrease in the clay shear resistance caused by transformation of the structural bonds and microbial activity with the clay’s physical state being unchanged. Typification of the Upper Kotlin clay section has been performed for the region of Saint Petersburg in terms of the complexity of surface and underground building conditions. Fissuring of the bedclays, the possibility of confined groundwater inflow through the fissured strata and the consequent reduction of the block strength as well as the active corrosion of underground load-bearing structures must be taken into account in designing unique and typical surface and underground facilities and have to be incorporated into the normative documents.
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Date submitted2021-02-24
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Date accepted2022-04-06
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Date published2022-07-13
Study of the kinetics of the process of producing pellets from red mud in a hydrogen flow
The reduction kinetics of serial phase transitions of iron oxides during reduction to a metallized state with different modes of technical hydrogen supply has been studied and substantiated. The results of the pellets formation when 3-5 % molasses is added to the red mud as a binding reagent are presented. The dependences of the reduction rate of iron oxides on the hydrogen flow rate are obtained. Based on the results of the experiments, a kinetic model was constructed, and with the help of X-ray phase and spectral analysis, it was proved that the agglomerates formed after heat treatment received high strength due to the adhesion of reduced iron particles with red mud particles. The use of a new type of charge materials in melting units will reduce the amount of emissions and dust fractions, as well as increase the metal yield.
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Date submitted2021-03-05
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Date accepted2021-04-28
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Date published2021-09-20
Rational design justification of the tunnel boring shield executive body for the conditions of the mines of Saint Petersburg Metrostroy
The article discusses the features of running tunnels in difficult mining and geological conditions of the Saint Petersburg Metrostroy using modern tunnel boring shields of Herrenknecht company with hybrid executive bodies equipped with a incisors and rock cutters. The work of a hybrid executive body is analyzed when driving along a heterogeneous bottomhole massif consisting of Cambrian clay with limestone interlayers. Theoretical and experimental studies of vibroactive cones, a graphical representation of the dependence of the depth of their penetration on the axial force and axial force together with the applied shock load (the dependences of the penetration depth are interpreted as a linear dependence) have been carried out. An increase in the intensity of destruction of a heterogeneous bottomhole massif consisting of Cambrian clay and limestone interlayers using vibroactive rock-cutting tools (spiked roller) was theoretically and experimentally confirmed, while the growth of the penetration rate is determined depending on the number of their parameters. The design is considered, the principle of operation and the method of power calculation of a rotary executive body equipped with vibroactive cutters are described, on the basis of which a nomogram of the dependence of the torque and performance of the tunnel boring shield on the feed rate of the executive body to the bottom is built.
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Date submitted2020-06-19
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Date accepted2020-10-06
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Date published2020-11-24
Practice of using the magnetic treatment devices to intensify the processes of primary oil treating
During the primary treatment of oil, gas and water, complications arise associated with the presence of hard water-oil emulsions, which cause an increase in fluid pressure in the gathering systems, pipeline damage, as well as difficulties in gas separation and preliminary water discharge at the preliminary discharge unit (PRU). Additional problems arise during transportation of highly paraffinic oils associated with the crystallization of paraffin in the flow path of the oilfield equipment and on the inner surface of pipes, leading to a drop in the productivity of pipelines. Article discusses the technology of magnetic-reagent treatment of water-oil media, which allows intensifying the processes of primary oil treatment at the facilities of its production. Bench and pilot tests have shown the ability of the magnetic field to accelerate oil demulsification processes, increasing the percentage of separated water during subsequent settling, and to reduce asphalt-resin-paraffin deposits (ARPD) on the inner surface of oil and gas field equipment. Mechanism of the magnetic field effect on water-oil media is described. Effect of treatment on the integrity of the armour shells of oil-water emulsions was studied. Various modes of magnetic treatment have been investigated with evaluation of its effectiveness. It is shown that the best effect is achieved with the combined use of reagents and a magnetic field. Synergistic effect is observed, which consists in increasing their effectiveness. This made it possible to conclude that this method can be applied to reduce the consumption of reagents used in oil production while maintaining the treatment efficiency.
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Date submitted2019-04-30
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Date accepted2019-07-16
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Date published2019-10-23
Salt Rock Deformation under Bulk Multiple-Stage Loading
- Authors:
- I. L. Pankov
- I. A. Morozov
The paper presents experimental justification of the possibility to use bulk multiple-stage loading to study the process of salt rock deformation in the laboratory conditions. Results of comparative tests between bulk multiple- stage and single-stage loading of salt rock samples are demonstrated. The paper contains results of research on the rate of lateral pressure and its impact on strength limit and residual strength limit of sylvinite, estimated using single- stage and multiple-stage methods. Research results demonstrate how the rate of lateral pressure impacts dilatancy boundary of salt rocks. Analysis of how the loading method influences certificate parameters of Mohr-Coulomb strength of sylvinite has been carried out. The dynamics of elastic modulus in the process of salt rock deformation is analyzed depending on the rate of lateralpressure. It is demonstrated how the method of multiple-stage loading adequately reflects the processes of salt rock de- formation and decomposition, and facilitates not only lowering impact of sample’s inner structure heterogeneities on the experimental results, but also significant reduction in the required amount of rock material.
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Date submitted2019-04-27
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Date accepted2019-07-10
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Date published2019-10-23
Estimation of Rock Mass Strength in Open-Pit Mining
The paper presents results of an experimental study on strength characteristics of the rock mass as applied to the assessment of open-pit slope stability. Formulas have been obtained that describe a correlation between ultimate and residual strength of rock samples and residual shear strength along the weakening surface. A new method has been developed to calculate residual interface strength of the rock mass basing on data from the examination of small-scale monolith samples with opposing spherical indentors. A method has been proposed to estimate strength characteristics (structural weakening coefficients and internal friction angles) of the fractured near-slope rock mass. The method relies on test data from shattering small-scale monolith samples with spherical indentors, taking into ac- count contact conditions along the weakening surface, and can be applied in the field conditions. It is acceptable to use irregular-shaped samples in thetests.
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Date submitted2019-05-26
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Date accepted2019-07-23
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Date published2019-10-23
Ensuring Stability of Undermining Inclined Drainage Holes During Intensive Development of Multiple Gas-Bearing Coal Layers
At high rates of production face advance, requirements towards reliable operation of undermining drainage holes get raised. The issue of maintaining high intensity of gaseous seams development under naturally increasing gas content, mining depth and capacity of production equipment poses a problem. The greatest threat comes from the loss of hole stability in the bearing pressure affected zone (in front of the face) and in the intensive shift area of overhanging rock corbels (behind the face). Intensification of air leaks due to deformation of borehole channel leads to impoverishment of removed methane-air mixture and an increasing risk to disturb safe aerogas regime in the mining area. The paper describes a mechanism of how coal-face operations affect the state of underground holes and formation of overhanging rock corbels. A typification of basic kinds of borehole deformations is presented. Authors point out critical disadvantages of the most widely-used technological schemes of gaseous seams development under high load on the production face, which hinder normal operation of a gas drainage system. As a result of research, a dependency of shot hole number, as well as the distance between shot hole axes and the borehole, on the stress state of the borehole outline has been defined more precisely. Basing on that, a formula to calculate drilling parameters of the discharge hole system has been suggested. Implementation of these measures will allow to increase the efficiency of underground gas drainage and to maintain growing intensity of gaseous coal seam development.
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Date submitted2019-03-25
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Date accepted2019-05-14
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Date published2019-08-23
Increase in Intake Capacity by Dynamic Operation of Injection Wells
- Authors:
- E. V. Belonogov
- A. Yu. Korovin
- A. A. Yakovlev
The method of pumping water to compensate for fluid withdrawals from an oil formation in order to maintain formation pressure has long established itself as an effective technology and is widely used at oil and gas fields. At the same time, field operator is often faced with the problem of reduction in the intake capacity of injection wells, which may be caused by various complications arising in the near-wellbore area due to a violation of water treatment technology or other factors. This problem is typical for reservoirs with low permeability values, which leads to a decrease in the performance indicators of the formation pressure maintenance system. In order to counter contamination of the bottomhole zone of the well, as a rule, injection of specialized acid compositions for the purpose of cleaning is used. To increase the effectiveness of this procedure, the authors of the article propose to discharge the injection well at the maximum permissible speeds. This event will allow primary cleaning of the bottomhole zone of the formation from moving particles clogging the pore space, and reduce formation pressure in the vicinity of the injection well, which will subsequently improve the intake capacity of the well during treatment with acid compositions. The decrease in formation pressure in the bottomhole zone of the well also has a positive effect on the radius of acid penetration into the formation. The proposed approach has been successfully tested on a number of injection wells at one of «Gazprom Neft» enterprises. The results of pilot operations showed an increase in the quality of cleaning the bottomhole zone of the formation and an increase in the intake capacity of injection wells with subsequent preservation of intake dynamics.
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Date submitted2018-12-28
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Date accepted2019-03-24
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Date published2019-06-25
Modern physicochemical equilibrium description in Na2O–Al2O3–H2O system and its analogues
Equilibrium and non-equilibrium states of systems Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O are crucial for establishing key technological parameters in alumina production and their optimization. Due to a noticeable discrepancy between experimental results and thermodynamic calculations based on materials of individual researchers the necessity of systematization and statistical processing of equilibrium data in these systems to create a reliable base of their physicochemical state, analysis and mathematical modeling of phase equilibria is substantiated. The tendency to a decrease of the hydration degree of solid sodium aluminates with increasing temperature and the transition of systems from the steady state of gibbsite to equilibrium with boehmite is revealed. The paper contains approximating functions that provide high-precision description of equilibrium isotherms in technologically significant area of Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O concentrations. Approximating function can be simplified by dividing the isotherm into two sections with the intervals of alkaline content 0-0.25 and 0.25-0.4 mole/100 g of solution. The differences in solubility isotherms for Na 2 O–Al 2 O 3 –H 2 O and K 2 O–Al 2 O 3 –H 2 O systems provide are associated with changes in the ionic composition solutions that depends on concentration and temperature, as well as differences connecting with alkali cation hydration, which is crucially important for thermodynamic modeling of equilibria under consideration.
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Date submitted2018-11-09
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Date accepted2019-01-08
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Date published2019-04-23
Effect of chalk thermal treatment mode on its strength
- Authors:
- V. A. Lipin
- D. A. Trufanov
Natural chalk is characterized by a fine-grained structure. The processing of chalk in conditions traditional for calcium carbonate baking is accompanied by its almost destruction and the formation of a huge amount of dust. The paper presents strength characteristics of chalk and chalky stone baking obtained with different temperature-time conditions of heating the raw material to a temperature of 450-600 °C. The uniaxial compression method was used to determine the strength depending on variable factors. Based on the experimental data, a model was constructed that determines the dependence of chalk strength on time and heating temperature. In the temperature range of 450-600 °C, the strength of chalk stone increases with increasing temperature and decreases with the increasing heating rate. In the process of isothermal heating, several factors will immediately affect the strength of a chalky stone: the formation and growth of calcite crystals, the evaporation of water, and the agglomeration of calcite grains. With an increase in the heating temperature from 450 to 600 °C, the average size of the crystals significantly increases and crystals with an estimated size of more than 4 microns are detected. An increase in the size of crystals is associated with an increase in their growth rate. The agglomeration of grains occurs at a temperature of 600 °C.
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Date submitted2018-08-29
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Date accepted2018-10-25
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Date published2019-02-22
The study of the effect of temperature on the ability of metals to accumulate energy during their plastic deformation
The subject of research is the surface layer of highly loaded parts, friction units of mining machines and equipment. The article presents a theoretical analysis of the factors that determine the ability of the material of the surface layer of parts to accumulate energy in the process of plastic deformation. It is suggested that the activation character of the accumulation of energy by metals. Based on the theory of diffusion, it was shown that the mobility of atoms, as well as the accumulated energy, are determined by the ratio of the test temperature to the melting temperature.
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Date submitted2018-06-28
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Date accepted2018-09-15
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Date published2018-12-21
Causes of fluid entry absence when developing wells of small deposits (on the example of Khadum-Batalpashinsky horizon)
- Authors:
- R. A. Gasumov
A promising direction for the development of the oil and gas industry is the drilling of small hydrocarbon fields, which constitute two thirds of Russia's total hydrocarbon reserves. When choosing an effective method of development and assessing the potential of small fields in Eastern Ciscaucasia, which are characterized by complex mining and geological conditions with abnormally high reservoir pressures and temperatures, it is necessary to determine the optimal amount of oil production taking into account the flow of edge water under elastic water drive. The article discusses the reasons for the lack of inflows of reservoir fluids in wells during their development, which are due to complex unconventional fractured clay reservoirs in the lower Maykop deposit and the presence of loose rocks in the section of the reservoir. The results of studies of the influence of technological and geological factors on the poroperm properties of the Khadum-Batalpashinsky reservoir are described, zones of rock softening are revealed, the intervals with bottom water and their influence on the well development process are specified. It has been established that the state of the hydrodynamic system of the field depends on the introduction of the bottom and edge waters of the sedimentation basin of the East Stavropol Depression. Oil deposits in the Khadum and Batalpashinskaya suites initially work in an elastic and then in an elastic-water drive mode. The main reasons for the lack of inflows of formation fluids into wells are the low reservoir properties of clay fractured reservoir rocks; clogging of the fracture capacity of reservoir rocks at the drilling in as a result of penetration of drilling mud and its filtrate deep into the reservoir; inflow of formation water from an overlying aquifer with abnormally high formation pressure; the closure of cracks in the clay reservoir due to a sharp decrease in pressure caused by the lowering of the slotted filter into the well; secondary dissection of productive layers by perforation during repression on the formation in a liquid medium with the presence of a solid phase and high density.
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Date submitted2017-09-17
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Date accepted2017-11-06
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Date published2018-02-22
Collaborative interpretation of the data obtained by resistivity and ground penetrating radar methods for assessing the permeability of sandy clay soils
- Authors:
- D. A. Lalomov
- V. V. Glazunov
A method for estimating the filtration factor of sandy clay soils is considered on the basis of a joint interpretation of the data of a set of methods of engineering electrical exploration, including electrical resistivity tomography and ground penetrating radar studies. The solution of this problem is based on the use of known empirical connections between the imaginary and real parts of the complex dielectric permittivity, specific electrical resistance, and Q factor. An example of the effective joint use of the ground penetrating radar and non-contact electrical resistivity tomography shows how to obtain qualitative and quantitative estimates of a changing filtration factor in a draining road layer. It is necessary to use precise engineering geological information in order to provide the required estimates. The proposed approach makes it possible to describe continuous profiles of a pavement and underlying layers by ground penetrating radar and electrical resistivity tomography, as well as to assess soil properties when conducting an electrical survey from the surface of asphalt concrete pavement. Recommendations for the implementation of the developed methods of complex engineering and geophysical research are given for solving issues of repair work design, supervision, and quality control of road construction.
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Date submitted2016-09-03
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Date accepted2016-11-24
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Date published2017-02-22
Research of compression strength of fissured rock mass
- Authors:
- A. G. Protosenya
- P. E. Verbilo
The article examines a method of forecasting strength properties and their scale effect in fissured rock mass using computational modelling with final elements method in ABAQUS software. It shows advantages of this approach for solving tasks of determining mechanical properties of fissured rock mass, main stages of creating computational geomechanic model of rock mass and conducting a numerical experiment. The article presents connections between deformation during loading of numerical model, inclination angle of main fracture system from uniaxial and biaxial compression strength value, size of the sample of fissured rock mass and biaxial compression strength value under conditions of apatite-nepheline rock deposit at Plateau Rasvumchorr OAO «Apatit» in Kirovsky region of Murmanskaya oblast. We have conducted computational modelling of rock mass blocks testing in discontinuities based on real experiment using non-linear shear strength criterion of Barton – Bandis and compared results of computational experiments with data from field studies and laboratory tests. The calculation results have a high-quality match to laboratory results when testing fissured rock mass samples.
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Date submitted2015-10-03
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Date accepted2015-12-10
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Date published2016-08-22
Directions and prospects of using low grade process fuel to produce alumina
- Authors:
- O. A. Dubovikov
- V. N. Brichkin
Power consumption across the globe is constantly increasing for a variety of reasons: growing population, industrialization and fast economic growth. The most widespread gaseous fuel – natural gas – has the low production cost. It is 2-3 times cheaper than liquid fuel production and 6-12 times cheaper than coal production. When natural gas is transported to distances from 1.5 to 2.5 thousand km by the pipeline, its cost with account of transportation is 1.5-2 times less than the cost of coal and the fuel storage facilities are not needed. Plants powered by natural gas have the higher efficiency as compared to the plants operating on other types of fuel. They are easier and cheaper to maintain and are relatively simple in automation, thus enhancing safety and improving the production process flow, do not require complicated fuel feeding or ash handling systems. Gas is combusted with a minimum amount of polluting emissions, which adds to better sanitary conditions and environment protection. But due to depletion of major energy resources many experts see the future of the global energy industry in opportunities associated with the use of solid energy carriers. From the environmental perspective solid fuel gasification is a preferred technology. The use of synthetic gas was first offered and then put to mass scale by English mechanical engineer William Murdoch. He discovered a possibility to use gas for illumination by destructive distillation of bituminous coal. After invention of the gas burner by Robert Bunsen, the illumination gas began to be used as a household fuel. The invention of an industrial gas generator by Siemens brothers made it possible to produce a cheaper generator gas which became a fuel for industrial furnaces. As the calorific value of generator gas produced through gasification is relatively low compared to natural gas, the Mining University studied possibilities to use different types of low grade process fuel at the Russian alumina refineries as an alternative to natural gas, access to which is restricted for some of the regions.
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Date submitted2015-07-14
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Date accepted2015-09-27
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Date published2016-02-24
Chemical and technological mechanisms of a alkaline aluminum silicates sintering and a hydrochemical sinter processing
- Authors:
- V. M. Sizyakov
Complex mineral raw material, as alkali aluminum silicates, is an interest for aluminum industry, chemical industry and for the production of constructional materials. They are well represented in the earth's crust, characterized by the complexity of material composition and variable content of the main components such as alumina, silica and alkalies. They often occur where due to the geological conditions there is no bauxite, for instance, in the United States, Canada, Venezuela, Mexico, Iran, Egypt, Portugal, Spain, Bulgaria and other countries. At the present time for the Russian economy the nephelines from this list are the most valuable and have the great concern for the raw materials balance of the national aluminum industry. Because of limited reserves the bauxites proportion of alumina produced from nephelines by sintering is 40 % and in time this proportion will increase due to the involvement in the production of new deposits of alkali aluminum silicates. Many of foreign companies have also shown interest to the complex processing of ores. The investigation of technology is based on the method of sintering ore with limestone. As a result, the after-sintering mixture consists of alkali metal aluminates and dicalcium silicate; after-sintering mixture is leached by circulating alkaline aluminate solution, alumina, soda and potash are thrown out from the solution. Dicalcium silicate (nepheline sludge) is processed to Portland. For the investigated after-sintering mixture the tendency shows the increasing of optimum sintering temperature with the lowering Al 2 O 3 content. With the increasing of silicate module (SiO 2 / Al 3 O 3 ) of the initial alkali aluminum silicates charges the temperature of after-sintering mixture formation increases. After-sintering mixtures that are on base of alkali aluminum silicates have different microstructure and the degree of crystallization in which b-С 2 S and sodium aluminate is improved with a decrease of the aluminate phase amount. Results of investigations show a very limited solubility of aluminate phase in dicalcium silicate, which theoretically justifies a sufficiently high level of useful components chemical extraction in the processing of different types of alkali aluminum silicates by sintering.
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Date submitted2014-11-07
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Date accepted2015-01-07
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Date published2015-10-26
The concept of reducing the risks of potash mines flooding caused by groundwater inrush into excavations
- Authors:
- V. P. Zubov
- A. D. Smychnik
Results of the analysis of factors influencing the probability of accidental groundwater inrush into mine workings of salt (potash, potassium and magnesium) mines are given in the article. The cases of the potash mine flooding that occurred in different countries with developed mining industry are given. It is shown that at the present technical and scientific level of solving this problem the unexpected groundwater inrush in potash mines usually results in the shutdown of the enterprise and negative ecological consequences. It is pointed out that the underground waters flow into the mines through water-conducting fractures of either natural or technogenic origin which location and influence on a mine was almost impossible to predict at the design stage under existing regulations. The concept of reducing the risks of potash mine flooding caused by underground waters in-rush is formulated. Administrative and technical measures which allow reducing the risks of potash mine flooding caused by groundwater inrush into the excavations are considered.
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Date submitted2010-07-28
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Date accepted2010-09-30
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Date published2011-03-21
Ingineering geological problems of high-rise construction with underground space development in Saint-Petersburg
- Authors:
- R. E. Dashko
- A. M. Zhukova
The history of high-rise construction is considered summarily. The main features of high-rise buildings and difficulties connected with theirs engineering and construction especially with underground space development and deep excavations in soft water saturated soils are characterized. Territorial construction guides «Residential and social high-rise buildings» prevail in Saint-Petersburg are analyzed in the context of recommendations for reliable basement choice. Brief description of Pre-Quanernary clays (Upper Vendian clays and Lower Cambrian clays) as basement for high-rise constructions are given. It is placed emphasis that the main feature of Pre-Quaternary clays is zone sequence of physical and mechanical properties and fissuring in depth. Physical and mechanical properties of Upper Vendian clays, Lower Cambrian clays and glacial clays are given. In addition, it is confirmed that glacial soils is not recommended to use as a basement for high-rise buildings.
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Date submitted2010-07-27
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Date accepted2010-09-09
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Date published2011-03-21
Utilization of enrichment waste of diamondiferous rock accounting peculiarities of M.V.Lomonosov deposit
- Authors:
- A. Yu. Oblitsov
In given article the questions of enrichment waste utilization of M.V.Lomonosov diamond deposit are considered taking in account some important peculiarities of this deposit and prospective of obtaining building materials on basis of enrichment waste products is stated.
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Date submitted2010-07-20
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Date accepted2010-09-01
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Date published2011-03-21
Experimental and theoretical studies and justification of geotechnology of stock pile formation from pelletized gold-bearing ores in order to enhance its filtration properties
- Authors:
- S. B. Tataurov
Optimal parameters of geotechnology of stock pile formation from pelletized gold-bearing ores were established basing on experimental and theoretical studies in order to enhance its filtration properties. In particular, exponential dependence was established of permeability coefficient on the stock pile height and the ultimate strength of the pelletized ore, its bulk weight and content of coarse particles +2 mmin combination with sandy-loamy and loamy fine grained soil. Without account of this data loss of gold within the stock pile can increase over 2 or 3 times. Basing on the results obtained application of the combined geothechnology of heap leaching of gold-bearing clayey materials of natural and man-made origin was justified.