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Date submitted2024-09-09
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Date accepted2024-11-05
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Date published2024-11-12
Acoustic emission criteria for analyzing the process of rock destruction and evaluating the formation of fractured reservoirs at great depths
In order to study the mechanism of destruction of rocks of various genesis and the formation of fractured reservoirs at great depths, laboratory studies of rock samples in the loading conditions of comprehensive pressure with registration of acoustic emission (AE) and parameters of the process of changing the strength and deformation properties of samples were carried out. The spatial distributions of the hypocenters of AE events for each sample were investigated. By the nature of the distributions, the fracture geometry is described, then visually compared with the position of the formed macrofractures in the samples as a result of the tests. The time trends of the amplitude distribution b, set by the Guttenberg – Richter law, were calculated, which were compared with the loading curves and trends of the calculated AE activity. Based on the analysis of the AE process for three types of rocks – igneous (urtites), metamorphic (apatite-nepheline ores), and sedimentary (limestones) – parameterization of acoustic emission was carried out to determine the features of the deformation process and related dilatancy. As a result, three types of destruction of samples were identified, their geometry and changes in strength and seismic criteria were established.
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Date submitted2022-04-07
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Date accepted2023-04-21
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Date published2023-08-28
Development of a new assessment system for the applicability of digital projects in the oil and gas sector
Digital transformation is one of the global trends that has covered most sectors of the economy and industry. For oil and gas companies, the introduction of digital technologies has become not just a trend, but one of the factors for ensuring competitiveness and maintaining a stable position in the market in a rapidly changing macro environment. At the same time, despite the positive effects achieved, digital transformation is a complex process from the point of view of implementation and is associated with high technological, financial, and economic risks. The work aims to develop and test a new system for evaluating the applicability of digital projects in the oil and gas sector. The research methodology includes the application of the Gartner curve, methods of expert assessments, and tools for assessing the economic efficiency of investment projects. The developed assessment system is based on a comprehensive accounting of four components: the level of digital maturity of the company; compliance of the implemented technology with the goals and objectives of the organization; the level of reliability of the implemented technology; the level of innovation of the implemented project. Particular attention is paid to the practical testing of the proposed methodology based on the evaluation of a digital project implemented by a Russian oil and gas company.
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Date submitted2021-03-05
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Date accepted2021-10-18
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Date published2021-12-16
Physical and mathematical model of rock destruction by a milling machine cutter
As a result of the analysis of the work on rock destruction by cutters of milling of machines, it was found that the existing developments do not allow us to proceed to the derivation of calculation d dependencies for determining fracture resistance, or can be used only in preliminary calculations of the known by design parameters of milling machines. To eliminate these disadvantages, a combined physical and mathematical model of the process of interaction of a single milling cutter with a spherical tip with the rock has been developed. Consideration of the physical picture of the action of forces and stresses acting from the cutter with spherical tips on the separating rock element in the limiting condition allowed to describe analytically the components of total resistance, which are the mathematical part of the physical and mathematical model of rock destruction by cutters. Analytical dependences for determining the tangential and normal components of fracture resistance of rocks of medium hardness have been obtained. The adequacy of the physical and mathematical model to the physical process of destruction of rocks of different hardness by cutters on a universal stand was tested both in the field and in the laboratory conditions. Technical evaluation of the results of experimental studies confirms the reliability of the developed physical and mathematical model.
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Date submitted2021-03-31
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Date accepted2021-09-29
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Date published2021-10-21
Methodology of modeling nonlinear geomechanical processes in blocky and layered rock masses on models made of equivalent materials
- Authors:
- Boris Yu. Zuev
The research purpose is to develop a methodology that increases the reliability of reproduction and research on models made of equivalent materials of complex nonlinear processes of deformation and destruction of structured rock masses under the influence of underground mining operations to provide a more accurate prediction of the occurrence of dangerous phenomena and assessment of their consequences. New approaches to similarity criterion based on the fundamental laws of thermodynamics; new types of equivalent materials that meet these criteria; systems for the formation of various initial and boundary conditions regulated by specially developed computer programs; new technical means for more reliable determination of stresses in models; new methods for solving inverse geomechanical problems in the absence of the necessary initial field data have been developed. Using the developed methodology, a number of complex nonlinear problems have been solved related to estimates of the oscillatory nature of changes in the bearing pressure during dynamic roof collapse processes; ranges of changes in the frequency of processes during deformation and destruction of rock mass elements, ranges of changes in their accelerations; parameters of shifts with a violation of the continuity of the rock mass under the influence of mining: secant cracks, delaminations, gaping voids, accounting for which is necessary to assess the danger of the formation of continuous water supply canals in the water-protection layer.
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Date submitted2020-05-08
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Date accepted2020-06-12
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Date published2020-12-29
Gas-dynamic roof fall during the potash deposits development
In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.
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Date submitted2019-06-27
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Date accepted2019-09-07
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Date published2019-12-24
Optimization of geometrical parameters of the hydro-cyclone inertial Venturi separator
- Authors:
- V. N. Makarov
- A. V. Ugolnikov
- N. V. Makarov
The usage of nanosized particles as modifying agents opens new possibilities in the creation of materials with unique properties. The effective qualitative improvement of Russia's GDP structure is based on the recycling of technogenic mineral formations (TMF) and the production of high-tech products. Numerous studies have shown that the efficiency of this process is limited by high requirements to the fractional composition, median size, and dispersion of TMF particles, as well as imperfection of equipment and technology and their classification. The strict classification requirements must be taken into account, when developing separation methods for the dispersion of the median sizes of TMF microparticles under the conditions of the probabilistic distribution of the physical and mechanical parameters of the feed. The studies covered in the article are based on the provision on a significantly greater influence of inertial forces on the trajectory of a hydrodynamically unsteady motion of the dispersed «a microparticle – a drop of liquid» system during the hydro-cyclone separation with respect to the aerodynamic forces of their movement in a fluidized bed. The paper shows that within the range of kinetic energy of the translational motion of liquid droplets, which overcomes the aerodynamic barrier of coagulation of hydrophobic TMF particles, the minimum diameter of absorbed microparticles during hydro-cyclone coagulation depends only on the magnitude of the angular velocity of rotation of the liquid droplets. We obtained the equations for the Euler and Reynolds criteria, their average values, and the relaxation time of liquid droplets with integrated micro and nanoparticles of TMF, depending on their median size during hydro-cyclone separation. The developed mathematical model of inertial hydro-cyclone separation of finely dispersed TMF allows determining the optimal geometric parameters and energy characteristics of the Venturi separator, its aerator, and the position of the receiving tanks. The experimental results confirmed the possibility of classifying finely dispersed wastes of mining and metallurgical production in the range of median sizes (0.5-5)∙10 –6 m by fractions with a dispersion of not more than 20 %.
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Date submitted2019-03-17
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Date accepted2019-05-21
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Date published2019-08-23
Impact of External Factors on National Energy Security
- Authors:
- V. L. Ulanov
- E. Yu. Ulanova
The article examines both external and internal threats to national energy security, formulates the tasks of increasing energy security, discloses modern challenges, as well as measures to level them. In recent years, Russian economy has felt the growing influence of external threats and risks: unfair competition in world markets, high politicization of energy issues, and attempts to prevent Russia from monetizing national energy reserves. Influence of the use of renewable energy sources on national energy security, growth of liquefied natural gas production, stricter environmental requirements, changes in the demand for petroleum products, and introduction of anti-Russian sanctions are analyzed. The influence of internal risks is no less significant: quality of hydrocarbon reserves in the Russian Federation is declining, effectiveness of geological exploration is insufficient, and the share of hard-to-recover reserves is increasing. Energy security assessments are recommended taking into account modern challenges and on the basis of parameters such as ratio of the annual increase in the balance values of primary fuel and energy resources to the volume of their production, share of natural gas in the balance structure of primary fuel and energy resources, implementation of investment programs by fuel and energy sectors, change in the specific energy intensity of GDP, prices and etc.
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Date submitted2016-09-06
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Date accepted2016-11-15
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Date published2017-02-22
Modelling of fiberglass pipe destruction process
The article deals with important current issue of oil and gas industry of using tubes made of high-strength composite corrosion resistant materials. In order to improve operational safety of industrial pipes it is feasible to use composite fiberglass tubes. More than half of the accidents at oil and gas sites happen at oil gathering systems due to high corrosiveness of pumped fluid. To reduce number of accidents and improve environmental protection we need to solve the issue of industrial pipes durability. This problem could be solved by using composite materials from fiberglass, which have required physical and mechanical properties for oil pipes. The durability and strength can be monitored by a fiberglass winding method, number of layers in composite material and high corrosion-resistance properties of fiberglass. Usage of high-strength composite materials in oil production is economically feasible; fiberglass pipes production is cheaper than steel pipes. Fiberglass has small volume weight, which simplifies pipe transportation and installation. In order to identify the efficiency of using high-strength composite materials at oil production sites we conducted a research of their physical-mechanical properties and modelled fiber pipe destruction process.
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Date submitted2015-10-19
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Date accepted2015-12-27
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Date published2016-08-22
Key directions in processing carbonaceous rocks
- Authors:
- T. N. Aleksandrova
Mathematical statistics techniques and the data from laboratory mineral and technological studies of samples were used to identify the most common natural and technological associations of microelements in carbonaceous rocks which could be of industrial value if extracted in the form of commercial products. The discovered structures of spheroidal and ring ferrocarbonaceous clusters are respective formations of the class of metal fullerens with expressed magnetic properties. Such clusters may serve as construction blocks for new magnetic structures since each of them is a separate magnetic domain. Extracting such structures and their practical use opens the way to future technologies. It is expected to employ such results in the future in the course of designing new techniques and technologies for benefication of carbonaceous raw materials while developing comprehensively solid mineral resources in the mining industry regions of Russia.
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Date submitted2009-10-25
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Date accepted2009-12-19
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Date published2010-09-22
Principal technologies for prevention of natural dangers at coal mines
- Authors:
- Jozef Dubinsky
Modern mining of mineral resources to be the industry accepted by the society must meet the criteria for sustainable development. Work safety is its important element, which is a particular sphere in underground coal mines in the view of natural hazards occurring numerously, including the catastrophic failures. Among them are gas hazard, fires and rock burst hazard. The selected methodological solutions in terms of their recognition and technologies applicable for the actively combat of these threats, which are featured by high efficiency, have been pointed out.
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Date submitted2009-10-06
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Date accepted2009-12-24
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Date published2010-09-22
Geologo-geomechanical developments of structures of deep vertical shafts at coal mines in Donbass
- Authors:
- V. V. Levit
- S. V. Borshchevskii
The lithologo-geomechanical trend of conditions for strengthening the vertical shafts of collieries which coordinates and unites the lithologo-geomechanical and mining factors into a system has been developed.
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Date submitted2009-07-06
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Date accepted2009-09-01
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Date published2010-04-22
Evaluation and prediction of zones of inelastic deformations around mine workings
- Authors:
- V. D. Baryshnikov
- L. N. Gakhova
Using the in situ observation results and the Coulon – Mohr criterion, the authors have obtained the criteria for the determination of probable failure zones in rock masses. An example is given of prediction of stress state of advanced ore extraction of the kimberlite pipe with using the ascending method of mining.
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Date submitted2009-07-20
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Date accepted2009-09-24
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Date published2010-04-22
Methods for presetting of artificial yielding to anthracite pillars
- Authors:
- S. G. Stradanchenko
- N. V. Titov
- Yu. V. Turuk
The article contains the results of in situ investigation of influence of yielding pillars on the stability of protected workings with different modes of preset yielding. Graphs of roof movements in the workings protected with yielding pillars, are given.
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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.