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Date submitted2023-10-31
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Date accepted2024-11-07
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Date published2025-01-24
Specifics of magnetotelluric studies in Antarctica
One of the priority areas of scientific research in Antarctica is the study of its deep structure. Most of the continent is covered with a thick ice sheet, so the main geoscientific data are acquired using geophysical methods, among which magnetotelluric (MT) ones have the greatest penetration depth and insignificant environmental impact. The possibility of acquiring high-quality MT data in the conditions of the sixth continent has long been questioned. The work is aimed at studying the specifics of magnetotelluric survey in Antarctica. The following tasks were set: to summarize the world experience of studying Antarctica using MT sounding methods; to identify factors that negatively affect the high-quality data acquisition; to determine methods for minimizing the influence of these factors. The article analyses geophysical studies conducted by the magnetotelluric sounding method in the Antarctic region from 1964 to the present. The application of the method is complicated by the following: extremely low temperature affects the drop in the batteries capacity, freezing of the non-polarizing electrodes solution, and changes in the strength properties of materials. Electromagnetic noise occurs during strong winds; proximity to the magnetotelluric field source can violate the plane wave principle on which the method is based. The ice sheet covering most of Antarctica does not allow acquiring optimal values of the contact resistance of the electrode grounding; the extended coastline distorts the acquired data. Studies of the influence of factors complicating the MT sounding method in the coastal and central parts of Antarctica made it possible to formulate recommendations for preparing equipment and adapting the work procedure, modifying the processing flow and a set of measures to ensure safety, the implementation of which will both allow safe performance of geophysical investigations and high-quality data acquisition.
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Date submitted2023-04-06
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Date accepted2023-12-27
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Date published2024-04-25
Localization of sites for the development of geomechanical processes in underground workings based on the results of the transformation and classification analysis of seismic data
The paper considers an approach to localizing the intervals of development of geomechanical processes in underground structures based on the classification and transformation of seismic data. The proposed approach will make it possible to identify the intervals of fracturing, rock decompression, water inflow and other geomechanical processes when interpreting the results of seismic surveys. The technique provides for the formation of matrices of longitudinal (Vp), transverse (Vs) velocities and velocity ratios (Vs/Vp) along the research profile to perform sequential filtration. The filtration results serve as the basis for the formation of a bank of informative materials for further classification. Based on the domestic KOSKAD 3D software, four approaches have been implemented for a combined digital model of the Vp, Vs and Vs/Vp parameters. One of the key elements in the classification process is to combine grids to increase the probability of detecting intervals with heterogeneous identification features. The result of the application of this methodical approach is the construction of a comprehensive interpretative model, on which potential zones of geomechanical risks development are clearly manifested.
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Date submitted2022-05-26
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Date accepted2022-11-17
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Date published2022-12-29
Renovation method of restoring well productivity using wavefields
A stagewise theoretical substantiation of the renovation vibrowave method of influencing the near-wellbore zone of reservoir for restoring well productivity is presented. The area of treatment by the proposed method covers the reservoir with a heterogeneous permeability with fractures formed by fracking. In this method a decrease in concentration of colmatants occurs due to a change in direction of contaminants migration. Under the influence of pressure pulses, they move deep into the reservoir and disperse through the proppant pack. The results of mathematical modelling of the propagation of pressure wave and velocity wave and the calculations of particles entrainment in wave motion are presented.
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Date submitted2021-05-27
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Date accepted2022-09-06
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Date published2022-11-10
Application of resonance functions in estimating the parameters of interwell zones
It is shown that the use of force resonance leads to the effect of “shaking” the formation, followed by breaking up the film oil and involving it in the further filtration process. For the first time in oilfield geophysics, the concept of passive noise-metering method is justified for monitoring oil and gas deposit development by measuring the quality factor of the contours in the point areas of formation development channels in interwell zones. It is established that determining the depth of modulation for the reactive substitution parameter of the linear FDC chain is crucial not only for determining the parametric excitation in FDC attenuation systems, but also without attenuation in the metrological support for the analysis of petrophysical properties of rock samples from the wells. It is shown that based on the method of complex amplitudes (for formation pressure current, differential flow rates, impedance), different families of resonance curves can be plotted: displacement amplitudes (for differential flow rates on the piezocapacity of the studied formation section), velocities (amplitudes of formation pressure current) and accelerations (amplitudes of differential flow rates on the linear piezoinductivity of the FDC section). The use of predicted permeability and porosity properties of the reservoir with its continuous regulation leads to increased accuracy of isolation in each subsequent sub-cycle of new segment formation in the FDC trajectories, which contributes to a more complete development of productive hydrocarbon deposits and increases the reliability of prediction for development indicators.
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Date submitted2021-11-10
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Date accepted2022-05-25
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Date published2022-12-29
Predicting the permeability of the near-bottomhole zone during wave impact
The research reveals that during selection of a method to increase oil recovery it is necessary to take into account rheological features of fluid movement through the formation, effect of capillary forces and heterogeneity of reservoir properties of the productive formation in thickness and along the bedding. Low-frequency wave impact, which is used to increase production in oil fields, is considered. At low-frequency impact new fractures appear and existing fractures in rocks increase in size. The greatest increase in porosity and permeability of rocks occurs at an impact frequency up to 10 Hz. Dynamics of oscillation amplitude during wave's movement in saturated porous medium is studied in the paper: essential attenuation of amplitude occurs at distance up to 1 m from borehole axis. With increase of frequency from 1 to 10 Hz the intensity of amplitude's attenuation decreases. The technology was tested on a well in Perm region (Russia). The actual permeability value was 50 % higher than the predicted value. According to the results of hydrodynamic investigations processing, it was noted that the greatest increase of permeability took place near the wellbore, while away from the wellbore axis permeability remained almost unchanged. In order to refine the mathematical model for prediction of wave impact on rock permeability it is necessary to take into account interconnection of pore space structure, change of adhesion layer, as well as to study transfer of particles during vibration.
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Date submitted2021-07-13
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Date accepted2021-10-18
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Date published2021-12-16
Prediction of the stress state of the shotcreting support under repeated seismic load
- Authors:
- Maksim A. Karasev
- Roman O. Sotnikov
The article assesses the impact of repeated blasts on the stress-strain state of the shotcreting support, which negatively affects the bearing capacity of the support and can lead to the formation of local rock falls in places of significant degradation of the shotcreting strength. Despite the fact that a single seismic load usually does not have a significant impact on the technical condition of the shotcreting support, repeated dynamic loading can lead to the development of negative processes and affect the safety. The article considers unreinforced and dispersed-reinforced shotcreting concrete as a shotcreting support. Models of deformation of rock and shotcreting support have been studied. To describe the deformation model of a rock mass, an elastic–plastic model based on the Hook-Brown plasticity condition has been accepted, which accurately describes the elastic-plastic behavior of a fractured medium. When performing the prediction of the stress-strain state of the shotcreting support, a model of plastic deformation of concrete with the accumulation of Concrete Damage Plasticity (CDP) was adopted, which allows to comprehensively consider the process of concrete deformation both under conditions of uniaxial compression and stress, and with minor edging draft. At the first calculation stage, a forecast of the seismic waves propagation in the immediate vicinity of the explosive initiation site was made. At the second stage, forecasts of the seismic waves propagation to the mine working and the stress-strain state of the support were made. On the basis of the performed studies, a methodology for assessing the impact of repeated blasts on the stress-strain state of the shotcreting support of the mine working is proposed.
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Date submitted2021-01-25
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Date accepted2021-02-22
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Date published2021-04-26
Conducting industrial explosions near gas pipelines
The problem to ensure the safety of objects which are in the area of blasting operations, ensuring the destruction of hard rocks, remains relevant. The article presents the results of a large-scale experiment to determine the safe conditions for conducting drilling and blasting operations near the active gas pipeline. The simplest and most reliable way to ensure the safety of the protected object from seismic impact is to reduce the intensity of the seismic wave, which is achieved by changing the parameters of drilling and blasting operations. This requires research to determine the impact of blasting operations on the parameters of seismic waves and the development of methods for measuring these parameters. The paper presents a detailed analysis of the seismic blast wave impact on the displacement of the ground and the model gas pipeline. The features of seismic monitoring during blasting operations near the active gas pipeline are shown. The seismic coefficients and attenuation coefficient of seismic waves are determined. It is proved that the readings of the seismic receivers on the surface and in the depth of the massive differ by two or more times.
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Date submitted2020-06-15
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Date accepted2020-06-15
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Date published2020-06-30
Non-destructive testing of multilayer medium by the method of velocity of elastic waves hodograph
- Authors:
- Aleksandr I. Potapov
- Artem V. Kondratev
The method of velocity of elastic waves hodograph, aimed at non-destructive testing of structurally heterogeneous composite materials and products based on them, as well as multilayer products and constructions, is considered. The theoretical basis for determining the propagation velocity of elastic waves in a multilayer medium by the hodograph method is given. Based on the studies, recommendations are given for determining the propagation velocity of elastic waves in each individual layer of a multilayer medium, which allows non-destructive testing of the physicomechanical characteristics of each layer of a multilayer medium. It is shown that in addition to simple multiple reflections in a homogeneous medium, in a multilayer medium with parallel interfaces consisting of two or more layers, complex types of multiple reflected waves and mixed waves (reflected-refracted and refracted-reflected) can arise. The main task of applying the low-frequency ultrasonic method is to determine the acoustic parameters of the propagation of elastic waves (velocities, amplitudes, spectra). The main methods for determining the elastic wave velocities are considered, based on the hodograph equation of the indicated reflected waves in a multilayer medium.
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Date submitted2019-05-07
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Date accepted2019-07-25
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Date published2019-10-23
Intensification of Bacterial-Chemical Leaching of Nickel, Copper and Cobalt from Sulfide Ores Using Microwave Radiation
- Authors:
- A. V. Kioresku
Currently, Russia and other countries display a steady tendency to decrease the amount of high grade and free- milling ore reserves. In this regard, the attention is being paid to the technology of bacterial-chemical leaching (BCL), which, unlike traditional pyrometallurgical enrichment methods, is well applicable for processing low-grade mineral raw materials. However, this technology has a significant drawback, which is the inability of microorganisms to create sufficiently aggressive conditions for the effective destruction of mineral complexes, which negatively affects the duration of the processes. The article presents the results of an experiment, the purpose of which was to study the multiple short-term effects of microwave radiation on the efficiency of extraction of nickel, copper, and cobalt in the process of bacterial-chemical leaching of sulfide ore. A microwave oven with a power of 900 W and a radiation frequency of 2.45 GHz was used as a source of microwave radiation. Irradiation was carried out every day throughout the experiment. The exposure time was 5 and 10 s; the flux density was 0.7 W/cm 2 . It was found that for all the studied microwave irradiation modes, a significant increase in the efficiency of biomass accumulation and the oxidizing ability of the medium was observed in comparison with the control that was not exposed to microwave radiation. Irradiation for 5 s twice a day increased the reduction of nickel by 16 %, cobalt by 15 % and copper by 6 %. The results of the study allow us to assess the prospects for the application of new biotechnology methods in the industrial practice of ore processing with an improvement in qualityindicators.
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Date submitted2018-11-18
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Date accepted2019-01-17
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Date published2019-04-23
Calculation of elastoviscoplastic displacement of well walls in transversal and isotropic rocks
- Authors:
- A. G. Gubaidullin
- A. I. Moguchev
The relevance of the work is justified by the need to improve the technical and economic indicators of well construction based on forecasting and preventing drilling tools sticking due to the narrowing of an open well bore in the intervals of transversely isotropic rocks. A mathematical model of elastic-viscous-plastic displacement of the walls of inclined and horizontal wells has been developed during the narrowing of the open borehole due to rock creep in the intervals of transversely isotropic rocks. In the program developed based on this mathematical model, the calculation of the elastic-viscous-plastic displacement of the walls of an obliquely directed and horizontal well in the reservoir of argillite from the Western Siberia deposit was carried out. As a result of the calculation, it was established that after opening the rock with bits, the cross-section of the open borehole due to the rock creep eventually takes the form of an ellipse, the small axis of which is in the plane of the upper wall of the well and decreases with time.
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Date submitted2018-07-12
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Date accepted2018-09-09
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Date published2018-12-21
Application of the theory of wavelets for compression and filtration of geoinformation
- Authors:
- A. S. Yarmolenko
- O. V. Skobenko
The purpose of the article is to develop a detailed and accessible technology for the application of wavelets in the processing of geo-information, the subject of research is wavelet-based filtering and compression of geo-information. The research methodology is based on the modern theory of wavelets in the light of linear algebra. Research methods involve study and generalization, abstraction, formalization, mathematical modeling using computer programs compiled by the authors. After the introduction and formulation of the problem, the basic positions of linear algebra are presented, on which the content of the article is based when constructing orthonormal bases in one- and two-dimensional cases. First, the application of the general theory to the decomposition of the vector of initial data in the Haar and Shannon bases is given. Further, on the basis of the Haar basis, orthonormal bases of wavelet transforms and filtering information are constructed. The procedure for creating wavelet filters by a sequence of convolutions, the use of MSA analysis for constructing an orthonormal basis of the wavelet transform is considered. Implemented the practical possibility of wavelet filtering based on specific programs for modeling geo-information data fields and images, data compression and filtering. The result of the work is the methods of constructing orthonormal bases by various methods of wavelet transform, based on which algorithms and corresponding computer programs for geoinformation compression are compiled using the example of terrain and photographic images. The efficiency of geoinformation compression and noise filtering using wavelets was investigated. A method has been developed for determining the value of a filter depending on the accuracy of the initial geo-information, illustrated by the example of calculating the filter value for compressing information about the heights of the terrain. The same technique is recommended for image filtering.
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Date submitted2018-05-22
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Date accepted2018-07-04
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Date published2018-10-24
Multivariance of a velocity model for structural plotting based on seismic and borehole data
- Authors:
- A. P. Sysoev
The paper discusses the peculiarities of structural modelling (forecast of the depths of the reflecting horizons) based on the seismic and drilling data system. Seismic data are represented by vertical time values and the stacking velocity of borehole data that are the depth marks of the reflecting horizons. Vertical time and the depth of the reflecting horizons are bound by the equation of average velocity but the average velocity is not determined in a seismic experiment, therefore an issue of choosing a velocity model of a complex natural object arises. The task of structural modelling is solved by the selection of formal expressions containing correlations between the parameters of the underlying model and kinematic parameters of the wave field. The optimal decision on model selection is determined by the minimum discrepancy between the predicted and actual values of the depth of the sample boreholes. A practical example shows possible variants of the interpretation model. An inverse kinematic problem on converting the vertical time of the reflected waves at the depth of horizons is solved in each production report on the results of seismic work and is probably the most common objective of seismic exploration. Considering the variety of research objects and the apparent obviousness of the solution, this topic is underrepresented in scientific literature.
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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 submitted2010-07-14
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Date accepted2010-09-29
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Date published2011-03-21
Basic requirements for shallow seismic field works technique by the reflected waves method for engineering-geological issues solving
- Authors:
- A. N. Telegin
- A. S. Yakovlev
The main requirements for the shallow seismic field works technique parameters for engineer-geological issues solving are represented. The optimum technique for the St.-Petersburg and its suburbs territory based on the results of experimental seismic studies, providing a detailed study of the upper part of the geological section, are proved.
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Date submitted2010-07-11
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Date accepted2010-09-14
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Date published2011-03-21
Application of seismic reflection method for engineering-geological issues solving in Saint Petersburg and Leningrad region
- Authors:
- A. S. Yakovlev
Several examples of seismic reflection method test surveys in St.-Petersburg and its suburbs are reviewed. The key point of research was the choice of an optimum field seismic works technique, processing and interpretation technique, providing the reliable solution of shallow depth investigation for the presented area.
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Date submitted2009-10-14
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Date accepted2009-12-28
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Date published2010-09-22
Geodynamic model of hydrogen sulphide’s formation in natural gas and oil in the process of rocks impulsive compression under conditions оf earthquakes
- Authors:
- A. V. Petukhov
By experiments, conducted on the installation like Bridgeman’s anvil it was determined that under conditions of high pressure, displacement deformations and elastic wave’s effect of short duration, sulphates are reclaimed by hydrocarbons. As a result of this reaction sulphur and hydrogen sulphide are produced.
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Date submitted2009-09-17
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Date accepted2009-11-21
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Date published2010-06-25
The wave motions caused by oscillations of a flat wall
- Authors:
- S. I. Peregudin
- S. E. Kholodova
The research is devoted construction analytical, in particular, exact solution of a problem on movement of the electrically conducting ideal rotating liquid modeling wave movements in a liquid kernel of the Earth. Namely, the problem about radiation of waves in rotating incompressible electrically conducting liquid by the flat wall making, since the initial moment, harmonious fluctuations is considered. Such statement of a problem can serve as the first step to research of influence of heterogeneity of the liquid environment on generation and maintenance of a magnetic field of the Earth.
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Date submitted2009-09-06
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Date accepted2009-11-14
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Date published2010-06-25
The estimation of mass velocities in a layered roof and dividing pillars of the mining system in the time of influence of shock stress waves
- Authors:
- V. V. Karpenko
- G. A. Kolton
The mass velocity diagrams transformation in the layered border zone of the mining system in the time of tension explosion waves influence is considered. The explosion wave front is suggested to be parallel to the proximate handing roof environs discontinuity. Under the admitted assumption the mass velocity epures transformation is investigated in the layered roof stone of the mining system and in the dividing pillar.
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Date submitted2009-09-07
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Date accepted2009-11-17
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Date published2010-06-25
The transformation of zone of potentially dangerous accumulative wrecks in a layeked mining roof when combined effect of the rock pressure and shock stress waves
- Authors:
- V. V. Karpenko
The transformation of potentially dangerous zone of wrecks accumulation in the layeredroof of the mining system is considered, in the time of combined action of geostatic pressure and tension shok wave. The explosion wave front is suggested to be parallel to the proximate handing roof environs discontinuity. Under this condition in the article is considered the influence of levels of critical stress and the depth of opening location on the change of implicitly dangerous zone of faults accumulation in the layers of the root stone.
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Date submitted2009-09-19
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Date accepted2009-11-24
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Date published2010-06-25
Distribution of the wave of vertical polarization in the infinite plasma layer with the maximum of the electronic concentration
- Authors:
- A. V. Denisov
The problem of dispersion of a flat wave of vertical polarisation by a plasma layer with a maximum of electronic concentration and infinitesimal losses is considered. With use of the theorem of an average in the new way it is proved that the wave of vertical polarisation will not pass for a point with the maximum of electronic concentration if loss in layer to direct to zero.
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Date submitted2009-09-26
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Date accepted2009-11-14
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Date published2010-06-25
Automatic bulk solids moisture in stream control system
- Authors:
- S. S. Galushkin
- B. A. Vishniak
- V. N. Smirnov
Automatic moisture in fine-dyspersated stream control system based on microwave frequency method is presented. Minimizing means of interrupting factors peculiar to this method of measurement are produced and systematically proved.
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Date submitted2009-08-23
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Date accepted2009-10-17
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Date published2010-02-01
Mathematical description of microwave contact level controller for liquid agent
- Authors:
- N. V. Teterin
- O. M. Bolshunova
It is shown the problem of measurement of level in oil tanks. Considered the use of a method of the sway electromagnetic radiation for the control of level of section of environments in tanks, made its mathematical description, resulted the estimation of results of practical application.