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Date submitted2024-10-29
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Date accepted2024-10-29
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Date published2024-11-12
Study of thermodynamic processes of the Earth from the position of the genesis of hydrocarbons at great depths
In the context of significant depletion of traditional proven oil reserves in the Russian Federation and the inevitability of searching for new directions of study and expansion of the raw material base of hydrocarbon raw materials in hard-to-reach regions and on the Arctic shelf, a scientific search is underway for accumulations in complex geological conditions and in manifestations that differ significantly from traditional ones, which include the processes of oil and gas formation and preservation of oil and gas in low-permeability “shale” strata and in heterogeneous reservoirs at great and super-great depths. Within the oil and gas provinces of the world, drilling of a number of deep and super-deep wells has revealed deposits at great depths, established connections between hydrocarbon deposits and “traces” of hydrocarbon migration left in the core of deep wells, which has made it possible to significantly re-evaluate theoretical ideas on the issue of oil and gas formation conditions and the search for technologies aimed at solving applied problems. Modern geochemical, chromatographic, bituminological, coal petrographic and pyrolytic methods of studying oil and bitumoids extracted from the host rocks of deep well cores give a hope for identifying correlations in the oil-source system, revealing processes that determine the possibility of hydrocarbon formation and accumulation, and defining predictive criteria for oil and gas potential at great depths.
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Date submitted2023-08-14
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Date accepted2023-12-27
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Date published2024-12-25
Modelling of compositional gradient for reservoir fluid in a gas condensate deposit with account for scattered liquid hydrocarbons
In oil and gas reservoirs with significant hydrocarbon columns the dependency of the initial hydrocarbon composition on depth – the compositional gradient – is an important factor in assessing the initial amounts of components in place, the position of the gas-oil contact, and variations of fluid properties throughout the reservoir volume. Known models of the compositional gradient are based on thermodynamic relations assuming a quasi-equilibrium state of a multi-component hydrodynamically connected hydrocarbon system in the gravity field, taking into account the influence of the natural geothermal gradient. The corresponding algorithms allow for calculation of changes in pressure and hydrocarbon fluid composition with depth, including determination of the gas-oil contact (GOC) position. Above and below the GOC, the fluid state is considered single-phase. Many oil-gas-condensate reservoirs typically have a small initial fraction of the liquid hydrocarbon phase (LHC) – scattered oil – within the gas-saturated part of the reservoir. To account for this phenomenon, a special modification of the thermodynamic model has been proposed, and an algorithm for calculating the compositional gradient in a gas condensate reservoir with the presence of LHC has been implemented. Simulation cases modelling the characteristic compositions and conditions of three real oil-gas-condensate fields are considered. The results of the calculations using the proposed algorithm show peculiarities of variations of the LHC content and its impact on the distribution of gas condensate mixture composition with depth. The presence of LHC leads to an increase in the level and possible change in the type of the fluid contact. The character of the LHC fraction dependency on depth can be different and is governed by the dissolution of light components in the saturated liquid phase. The composition of the LHC in the gas condensate part of the reservoir changes with depth differently than in the oil zone, where the liquid phase is undersaturated with light hydrocarbons. The results of the study are significant for assessing initial amounts of hydrocarbon components and potential efficiency of their recovery in gas condensate and oil-gas-condensate reservoirs with large hydrocarbon columns.
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Date submitted2023-02-10
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Date accepted2023-09-20
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Date published2024-04-25
Depth distribution of radiation defects in irradiated diamonds by confocal Raman spectroscopy
Five colored diamonds were investigated. According to the results of the study by FTIR, UV-Vis-NIR and Photoluminescence spectroscopy, they are natural type Ia diamonds. The depth distribution of the color intensity was carried out by measuring the intensity of the PL peak at 741 nm (GR1 center) upon excitation by a laser with a wavelength of 633 nm of Raman Confocal microscope. To minimise the perturbation due to geometrical effects, defect distribution profiles were normalised with respect to diamond Raman peak intensity (691 nm) point by point. For two diamonds, the intensity of the GR1 peak (741 nm) sharply decreased to a depth of 10 µm, and then became equal to the background level, which is typical for irradiation with alpha particles from natural sources like uranium. In other diamonds, the profiles vary slightly with depth, and the color intensity is close to uniform, which is for irradiation with accelerated electrons or neutrons. The source of radiation has not been determined. However, long duration radioactivity measurements of the diamonds suggested that neutrons were not used for colour centers production in the diamonds studied.
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Date submitted2018-11-03
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Date accepted2019-01-21
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Date published2019-04-23
Estimation of critical depth of deposits by rock bump hazard condition
- Authors:
- V. N. Tyupin
During the development of minerals by the underground method, dynamic manifestations of rock pressure occur at a certain depth, which significantly reduces the safety of mining operations. Regulatory documents prescribe at the exploration and design stages to establish the critical depth for classifying a deposit as liable to rock bumps. Currently, there are a number, mainly instrumental, methods for determining the liability of rock mass to rock bumps and methods based on the determination of physical and technical properties and the stress-strain state of rock massifs. The paper proposes a theoretical method for determining the critical depth for classifying a deposit as liable to rock bumps. A formula for determining the critical depth of the rock bump hazard condition is obtained. A mathematical analysis of the influence of the physical and technical parameters of the formula on the critical depth is carried out. Its physical and mathematical validity is substantiated. The numerical calculations of the critical depth for 17 developed fields were carried out using a simplified formula. It also provides a comparison of calculated and actual critical depth values. It is established that the variation of the actual and calculated critical depth is due to the lack of actual data on the value of the friction coefficient and parameters of fracturing of the rock mass in the simplified formula. A simplified calculation formula can be used to estimate the critical depth of a field at the survey and design stages. More accurate results can be obtained if there are actual data on fracture parameters, friction coefficients and stress concentration near the working areas.
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Date submitted2017-09-20
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Date accepted2017-10-29
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Date published2018-02-22
Substantiation of strength of the filling mass by taking a blast effect into account for the room-and-pillar methods
- Authors:
- E. T. Voronov
- V. N. Tyupin
The development of the uranium ore bodies at the ore mines of PJSC «Priargunsky Industrial Mining and Chemical Union» (PJSC «PIMCU») by room-and-pillar method as high as a pillar between the levels (60 m) without fill, as a rule, leads to the fall of the adjoining rock, to the strong contamination of the ore and to the high yield of the oversize pieces of the barren rock. A longstanding industrial and theoretical research shows that the sizes of the self-sustaining rock escarpments at the ore mines of PJSC «PIMCU» in the solid mass of trachydacites, conglomerates, sandstones, felsites are equal to 20-40 m. Moreover, the sizes of the self-sustaining rock escarpments depend to a great extent on the intensity of fracturing of the adjoining rocks. The stable size of the escarpment does not exceed 5-10 m for the rocks with the size of a jointing up to 0.05 m. Consequently, timely performance of the filling operations of the worked-out space of the chamber is important. However, the question then arises: which characteristic strength should the filling mass have? The calculations of the characteristics of the filling mass in compliance with the reference guide «Shaft filling operations» show underestimated values of the characteristic compressive strength of the fill (1.4 MPa) for the room-and-pillar method, which leads to the increase of the ore contamination by the fill and provokes the additional costs for refilling of the volumes of the rock fall. On the basis of the Russian experience of using of the consolidated fill for the development of the ore bodies of 15 m thickness by chamber method the strength of the fill is taken as 3-5 MPa under the resultant value of the static stresses without taking into account the character of the dynamic loading stresses induced by the sequence blasthole ring initiating in a chamber. Overestimating the characteristic strength of the filling mass results in the high consumption of the cementing materials. On the basis of the theoretical research the authors suggested the theoretical dependence of calculation of the characteristic strength of the filling material with respect to compressive stresses of the fill induced by the blasting operations. The process of designing of the filling mass with the zones of diverse strength for the room-and-pillar extraction with the consolidated rock fill is proven to be economically reasonable. The bottom zone of the solid mass should have high strength (3-4 MPa), and the strength of the upper zone should be up to 2-2.5 MPa.
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Date submitted2016-09-16
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Date accepted2016-11-12
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Date published2017-02-22
Possibilities of seismic exploration for crystalline basement study
- Authors:
- A. N. Telegin
Possibilities of seismic methods of reflected and refracted waves have been examined for the purposes of detailed study on crystalline basement structure. Investigation of depth and structure of the basement plays an important role in the exploration of various deposits. Sedimentary cover is usually associated with oil and gas reserves. Ore deposits are formed in the basement rocks, basement splits and structure of its surface have a genetic relation not only to ore minerals, but also to oil resources. Reflection seismology is one of the main seismic methods of investigating structural geometry of the sedimentation mass, forecasting its material composition and possible hydrocarbon reserves. However, its possibilities for investigating crystalline basement are limited. Basing on many years’ experience of reflection seismology and physical modeling it has been identified that actual roughness of basement surface limits the obtainable amount of waves reflected from it. Possibilities of reflection seismology for basement structure study are mostly related to investigation of discontinuous faults as diffraction objects using diffracted waves. Method of refracted waves combined with modern procedures and material processing aimed at getting dynamic seismic sections holds much significance for the basement study, especially in the process of surface mapping and, to a lesser extent, in investigating discontinuous faults.
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Date submitted2016-09-04
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Date accepted2016-11-14
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Date published2017-02-22
Methodology of reducing rock bump hazard during room and rillar mining of North Ural deep bauxite deposits
- Authors:
- D. V. Sidorov
The article describes practical experience of using room and pillar mining (RAPM) under conditions of deep horizons and dynamic overburden pressure. It was identified that methods of rock pressure control efficient at high horizons do not meet safety requirements when working at existing depths, that is explained by changes in geodynamic processes during mining. With deeper depth, the geodynamic processes become more intensive and number of pillar and roof failures increase. When working at 800 m the breakage of mine structures became massive and unpredictable, which paused a question of development and implementation of tools for compliance assessment of used elements of RAPM and mining, geological, technical and geodynamic conditions of North Ural bauxite deposits and further development of guidelines for safe mining under conditions of deep horizons and dynamic rock pressure. It describes reasons of mine structure failures in workings depending on natural and man-caused factors, determines possible hazards and objects of geomechanic support. It also includes compliance assessment of tools used for calculations of RAPM structures, forecast and measures for rock tectonic bursts at mines of OAO “Sevuralboksitruda” (SUBR). It describes modernization and development of new geomechanic support of RAPM considering natural and technogenic hazards. The article presents results of experimental testing of new parameters of RAPM construction elements of SUBR mines. It has data on industrial implementation of developed regulatory and guideline documents at these mines for identification of valid parameters of RAPM elements at deep depths.
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Date submitted2014-09-01
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Date accepted2014-11-21
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Date published2015-06-26
Determenation of the bolting parameters under conditions of the zonal disintegration of rocks around underground workings
- Authors:
- M. A. Rozenbaum
- B. P. Badtiev
Recently the phenomenon of zonal disintegration of rocks had discovered at around underground workings at great depths. The main element of this fault concentric system that paralleled working profile. The paper presents the method and formula determination of the bolted mine workings developed on stress-deformed rock massif at great depths at zonal disintegration of rocks around un-derground workings.
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Date submitted2013-07-16
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Date accepted2013-09-21
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Date published2014-03-17
Gas emission control parameters determination for sublevel caving mining systems at the «Kiselevskaya» coal mine
- Authors:
- O. I. Kazanin
- A. A. Sidorenko
- V. V. Sementsov
The results of the aero- and gas-dynamics processes numerical researches for the sublevel caving mining system with mechanized roof support in conditions of «Kiselevskaya» coal mine are given in the article. It is shown, that reliable and effective panel ventilation is provided with the technological scheme with three entries at the each sublevel. The parameters of the technological scheme are determined.
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Date submitted2013-07-23
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Date accepted2013-09-11
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Date published2014-03-17
Use of coefficient of output at pit delimitation
- Authors:
- G. A. Kholodnyakov
- N. S. Vainonen
In work it is settled an invoice the final depth of a pit of the conditional complex occurrence presented by three minerals. It is shown that when developing complex occurrence it is more expedient to use coefficient of output, instead of overburden ratio.
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Date submitted2009-10-08
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Date accepted2009-12-10
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Date published2010-09-22
Control of dynamic rock pressure manifestations in mining the «Antey» deposit
The article considers the conditions and pattern of dynamic rock pressure manifestations in mining the «Antey» deposit of uranium ores. Data on geological, technological and geomechanical conditions of the deposit mining are given. The methods and means for rock pressure control are described as well as the results of their application at deep horizons of ore mine are given.
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Date submitted2009-07-12
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Date accepted2009-09-16
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Date published2010-04-22
Numerical assessment of stress-strain field in vicinity of large open pit mine taking into account geomechanical, geological and mining factors
The results of modeling of rock mass stress state in the vicinity of large open pit mine using finite-elements method are represented. The model allows to take into account the influence of large-scale fractures. The initiation of boundary conditions is based on the results of determination of stress parameters in situ. The locations of risk areas near the slope are defined.
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Date submitted2009-07-17
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Date accepted2009-09-18
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Date published2010-04-22
Transformation of the form and angular parameters of rock movement processes with depth at ore deposits
- Authors:
- A. G. Shadrin
- M. A. Shadrin
It was established the increase of movement angles with mining depth and the mechanism of forming the stable natural arching in underground mining of ore deposits. The conditions and parameters of forming the stable natural arching were determined, under which the zone of dangerous deformations localizes inside the ore mass and does not manifest itself on the earth surface. The nomogram for analytical determination of the rock movement angles was developed, and the table was drawn up of the natural arching conditions with due account of main mining-and-geological factors of ore deposit occurrence and its mining.
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Date submitted1908-06-28
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Date accepted1908-08-12
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Date published1908-12-01
Illustration of crystal structure with vector circles
- Authors:
- Ye. S. Fedorov
In the article “Precise imagery of space points on a plane”, the problem of such an image in three different elements is solved: vectorial and ordinary circles, and in parallel vectors. The practical application of images in parallel vectors of a system of mines is also given there. I will now show an essential application of the theory to the representation by vectorial circles of the spatial lattices of each structurally studied crystal.