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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 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 submitted2021-03-05
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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 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 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.
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Date submitted2009-08-17
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Date accepted2009-10-18
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Date published2010-02-01
Geotechnical engineering and hydrogeological specifics of estimate high-rise buildings construction and operation conditions (in terms of local zone on the right bank of Neva river)
- Authors:
- A. M. Zhukova
In the paper specificity of geotechnical engineering conditions in the local zone of the right river Neva bank are considered. The influence of underground topographies of Pre-Quaternary soils roof formed by paleovalleys on the specificity of engineering geological profile is analyzed. Influence of tectonic faults on physical and mechanical properties of Upper Kotlin clays (Upper Vendian) which it is planned to use as the basis for high-rise constructions is considered. Negative influence of Low Kotlin (Upper Vendian) pressure water-bearing horizon on clay properties in the construction foundation and structural materials is investigated.
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Date submitted2009-08-19
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Date accepted2009-10-02
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Date published2010-02-01
The estimation features of vulnerability and desintegration оf subway construction materials in Saint Petersburg
- Authors:
- P. V. Kotyukov
In this paper the features of subway construction materials degradation depending on engineering-geological, hydro-geological and geoecological conditions of Saint Petersburg underground space are considered. The basic types of subway construction placing and their destruction specificity depending on influence of water-bearing horizons hydrodynamic and hydro chemical conditions, natural and natural-technogenic gas bio-production and microbial activity are analyzed. The examples of the disintegrated materials and new growths (salt efflorescence, stalactites and others) chemical compound features depending on the content of ground waters basic components affecting on tunnels lining are resulted.
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Date submitted2008-10-12
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Date accepted2008-12-17
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Date published2009-12-11
Principles of development of geological engineering and geological criteria for safe burial of low radioactive wastes in lower cambrian blue clays in the Leningrad region
- Authors:
- R. E. Dashko
It is noticed that the chosen territory for nuclear-waste disposal in Lower Cambrian clay massif nearby Koporje of Leningrad region takes place in a tectonic zone. Lower Cambrian clays are considered as the block-fractured rock mass having a depth zone structure. The long radioactive irradiation of dark blue clays has led to transformation of their structure, physical-chemical and physical-mechanical properties, and also to activization of microbial activity. Nine criteria to the geoenvironmental and engineering geological characteristics allowing in a complex to estimate safety and reliability of a nuclear-waste disposal in clay formations on an example of dark blue clays are suggested.
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Date submitted2008-10-29
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Date accepted2008-12-11
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Date published2009-12-11
Experience in providing the stability of tunnel face and roof during its drivage in proterozoic clays
- Authors:
- V. A. Maslak
Methodology for assessment of state of advance support of face with fiberglass anchors and the working¢s roof – with tube anchors, is given. The results of in-situ experimental observations for efforts in anchors, displacements of excavation and growth of load on the advance supports in its roof are shown.
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Date submitted1951-08-26
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Date accepted1951-10-03
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Date published1952-04-24
Physical and mechanical properties of clays of the coal-bearing suite of the Lower Carboniferous of the Moscow Basin
- Authors:
- V. D. Lomtadze
In the Moscow Basin, clay deposits occupy a significant part of the section of the sandy-clayey coal-bearing suite of the Lower Carboniferous. This suite is almost continuously distributed throughout the basin (Fig. 1). Throughout its length, it is characterized by the inconsistency of the section in the vertical and horizontal directions. Along the southern wing of the basin, the coal beds are thicker, while to the north, along the western wing, the coal content of the suite gradually decreases, and already in the section of the Tikhvin region only black carbonaceous clays and occasionally thin coal interlayers are observed. At the same time, the saturation of the section with refractory clays is significantly reduced here, the place of which is occupied by bauxite deposits and red sandy clays. The variability of the section of the coal-bearing suite is explained by the coastal-marine and coastal-continental conditions of its accumulation. The change in the structure of the coal-bearing suite along the strike is the result of the facies replacement of coal by carbonaceous clays, and then carbonaceous clays by red sandy clays. A. E. Ulmer believes that the southern part of the western wing and the southern wing of the Moscow Basin are included in the facies zone of accumulation of continental and coastal-marine sediments, and the northern part of the western wing is included in the facies zone characterized by the predominance of continental erosion over accumulation.
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Date submitted1951-08-04
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Date accepted1951-10-18
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Date published1952-11-20
Determination of the temporary tensile strength of subcoal clays of the Moscow Basin
- Authors:
- A. I. Morozov
The conditions for developing heavily flooded brown coal deposits in the Moscow Basin, located in unstable rocks, are determined by the features of their geological and hydrogeological structure. For deep-lying deposits in the southern and western wings of the basin, the main feature is the presence of a subcoal aquifer with a water pressure of up to 90 m. These pressure waters are the cause of water breakthroughs from the soil of mine workings. At the same time, clay strata lying in the soil of mine workings and protecting them from water breakthroughs from the subcoal aquifer are of decisive importance for the safe conduct of preparatory and cleaning mining operations. The thickness of the subcoal clay layer and its strength determine the need and scale of drainage measures during deposit development. All other things being equal, the need to reduce the pressure of subcoal waters and the magnitude of this reduction will depend on the minimum strength of clays. Facts show that under the action of hydrostatic pressure, the soil of mines workings will experience tension when bending. Therefore, to correctly select the scheme and volume of drainage works, it is necessary to know the ultimate tensile strength of clays, their temporary resistance. The temporary tensile strength is usually the smallest compared to the temporary resistance to shear (shear) and compression. Thus, the value of the temporary tensile strength of clays is the main calculation parameter for deciding on the need to drain mine fields. Meanwhile, the tensile strength of clays has hardly been studied. In numerous articles devoted to the development and drainage of brown coal deposits in the Moscow Basin, this issue has hardly been covered.