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Date submitted2024-04-27
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Date accepted2024-11-07
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Date published2025-03-05
Comprehensive studies of the snow-firn layer in the area of the Russian Antarctic Vostok Station
The article presents the findings from research conducted at Vostok Station during the 69th Russian Antarctic expedition. The primary goal of the research is to perform a thorough investigation of the snow-firn layer using both direct (drilling and core analysis) and indirect (georadiolocation and seismic exploration) methods. As part of the research, fundamental tasks related to the study of the structure and dynamics of the upper part of the ice sheet were addressed, as well as applied tasks aimed at justifying the depth of explosive charge placement for seismic work with the goal of conducting a detailed study of Lake Vostok and selecting the point for drilling access to the lake. Data on the microstructure and physical properties of the snow-firn layer were collected. The findings will allow for future improvements to the firn densification model, which is required to understand the evolution of ice grains during the early stages of metamorphism. The study's findings aided in the understanding of the structural features of the ice sheet's surface layer, allowing for more precise determination of the structural and physical characteristics of the snow-firn layer and ice, potentially leading to a better understanding of climatic and geological processes in Antarctica.
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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 submitted2022-09-21
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Date accepted2024-06-03
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Date published2024-12-25
Analysis of the assessment of the prospects for the burial of CO2 in unexplored aquifer complexes on the example of a facility in the Perm Region
One of the most important problems of our time is the annual increase in greenhouse gas emissions into the atmosphere. It is possible to combat this phenomenon by reducing emissions or developing and applying technologies for capturing, storing, using and disposing of CO2. In this work, an assessment of the expediency and possibility of carbon dioxide burial in deep aquifers is considered, the study of which is carried out to a small extent and due to the lack of useful material in them. The parameters and results of CO2 injection into the aquifer of one of the oil fields of the Perm Region, the geological properties and characteristics of which are determined in this work, are studied. The criteria of applicability, methods of estimating the volume of the reservoir and laboratory studies to determine the properties of CO2 and the features of its interaction with the model of the reservoir fluid are considered. The injection object and reservoir volume were determined, PVT studies of the target gas were performed, and its solubility in reservoir water was determined. The duration of filling the full volume of the trap when capturing 400 thousand tons of CO2 per year from the target industrial facility is calculated to be 202 years. This conclusion signals the prospects for the burial of carbon dioxide in the underground deposits of an undeveloped aquifer complex in the Perm Region, which reflects the importance of studying such geological CO2 burial sites in order to achieve global carbon neutrality goals.
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Date submitted2023-06-21
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Date accepted2023-10-25
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Date published2024-08-26
Specific action of collector from phosphoric acid alkyl esters class in flotation of apatite-nepheline ores
Increasing amount of apatite-nepheline ores with complex mineral composition involved in processing, growing content of the associated minerals in ore which are similar in their floatability to apatite lead to the necessity of using highly selective collectors. Non-frothing flotation method gave a comparative assessment of floatability of pure minerals and demonstrated a high selectivity of the action of phosphoric acid esters in relation to apatite. The effect of four reagent modes differing in the number of selective synthetic collectors was studied using the example of flotation of an apatite-nepheline ore sample containing 17.27 % apatite and 40.18 % nepheline. Mineralogical analysis of crushed ore showed that it contained two apatite varieties – coarse-grained free and finer poikilitic as inclusions in rock-forming minerals. Free apatite opens and occurs as open grains even in coarse-grained (+0.16 mm) grades. Poikilitic apatite occurs as intergrowths with different minerals, mainly with nepheline and its alteration products (natrolite, spreustein, sodalite, etc.), and pyroxene. Optical microscopy demonstrated that a growing share of reagent from the phosphoric acid oxyethylated esters class in the composition of the collector mixture allows improving the quality of the produced apatite concentrates by reducing the number of apatite intergrowths with nepheline and pyroxenes in the concentrates. In the concentrate obtained in the most selective reagent mode, the intergrowths are characterized by a 50/50 and higher ratio in favour of apatite. Concentrates of lower quality comprised intergrowths with lower apatite content, to 20/80 or less.
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Date submitted2022-06-27
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Date accepted2023-06-20
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Date published2023-12-25
Analysis of the problems of high-quality drinking water extraction from underground water intakes on Vysotsky Island in the Vyborg district of the Leningrad region
This article presents the results of drilling, experimental filtration work and laboratory studies aimed at assessing the resources and quality of groundwater in the licensed area of Vysotsky Island located in the Leningrad region, in the Gulf of Finland in accordance with the requirements of regulatory documents. Analysis of the results of hydrochemical studies and their comparison with data on water intakes in adjacent areas gives the right to conclude that it is possible to classify a hydrogeological unit as a different type of resource formation than those located in the surrounding areas. Groundwater in this area is confined to an unexplored deep fractured regional high-pressure zone. According to the received data, the explored water intake can be attributed to a unique groundwater deposit, which has an uncharacteristic composition of groundwater in the north of the Leningrad region, which may be due to the mixing of modern sediments and relict waters of the Baltic glacial lake. The stability of groundwater characteristics is confirmed by long-term monitoring.
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Date submitted2021-10-31
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Date accepted2023-03-02
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Date published2023-12-25
Improvement of technological schemes of mining of coal seams prone to spontaneous combustion and rock bumps
On the example of the Alardinskaya mine, the problem of underground mining of seams prone to spontaneous combustion and rock bumps in the conditions of the Kondomsky geological and economic region of the Kuznetsk coal basin is considered. The contradictions in the requirements of regulatory documents for the width of the inter-panel coal pillars in the mining of seams with longwalls in conditions of endogenous fire hazard and in the mining of seams that are dangerous due to geodynamical phenomena are discussed. These contradictions impede the safe mining of seams using traditionally used layouts with the danger of spontaneous combustion of coal and rock bumps. A mining-geomechanical model is presented, which is used for numerical three-dimensional simulation of the stress-strain state of a rock mass with various layouts for longwall panels using the finite element method. The results of the numerical analysis of the stress state of the rock mass immediately before the rock bump are presented, and the main factors that contributed to its occurrence during the mining of the seam are established. A dangerous degree of stress concentration in the coal seam near the leading diagonal entries is shown, especially in conditions of application of abutment pressure from the edge of panels’ gob. The analysis of the features of stress distribution in the inter-panel pillar at different widths is carried out. Recommendations for improving the layout for the development and mining of coal seams that are prone to spontaneous combustion and dangerous in terms of rock bumps in the conditions of Alardiskaya mine have been developed. The need for further studies of the influence of pillars for various purposes, formed during the mining of adjacent seams, on the stress-strain state of previously overmined and undermined seams is shown.
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Date submitted2022-08-01
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Date accepted2022-11-17
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Date published2023-02-27
Use of machine learning technology to model the distribution of lithotypes in the Permo-Carboniferous oil deposit of the Usinskoye field
- Authors:
- Denis V. Potekhin
- Sergei V. Galkin
Permo-Carboniferous oil deposit of the Usinskoye field is characterized by an extremely complex type of the void space with intense cross-sectional distribution of cavernous and fractured rock. In this study, for this production site, the process of 3D geological modeling has been implemented. At the first stage, it provided for automated identification of reservoir volumes by comparing the data of core and well logging surveys; at the second stage, identification of rock lithotypes according to Dunham classification is performed on the basis of comparison of thin sections examination and well logging data. A large array of factual information enables the use of machine learning technology on the basis of Levenberg – Marquardt neural network apparatus toward achievement of our research goals. The prediction algorithms of reservoir and rock lithotype identification using well logging methods obtained on the basis of the training samples are applied to the wells without core sampling. The implemented approach enabled complementing the 3D geological model with information about rock permeability and porosity, taking into account the structural features of the identified lithotypes. For the Permo-Carboniferous oil deposit of the Usinskoye field, the volumetric zoning of the distribution of different rock lithotypes has been established. Taking into account the lithotypes identified based on machine learning algorithms, density and openness of fractures were determined, and fracture permeability in the deposit volume was calculated. In general, during the implementation, the machine learning errors remained within 3-5 %, which suggests reliability of the obtained predictive solutions. The results of the research are incorporated in the existing 3D digital geological and process model of the deposit under study.
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Date submitted2022-03-17
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Date accepted2022-10-04
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Date published2022-11-10
Improving the reliability of 3D modelling of a landslide slope based on engineering geophysics data
Landslides are among the most dangerous geological processes, posing a threat to all engineering structures. In order to assess the stability of slopes, complex engineering surveys are used, the results of which are necessary to perform computations of the stability of soil masses and assess the risks of landslide development. The results of integ-rated geological and geophysical studies of a typical landslide slope in the North-Western Caucasus spurs, composed of clayey soils, are presented. The purpose of the work is to increase the reliability of assessing the stability of a landslide mass by constructing a 3D model of the slope, including its main structural elements, identified using modern methods of engineering geophysics. Accounting for geophysical data in the formation of the computed 3D model of the slope made it possible to identify important structural elements of the landslide, which significantly affected the correct computation of its stability.
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Date submitted2022-01-31
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Date accepted2022-09-06
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Date published2022-11-10
Filtration studies on cores and sand packed tubes from the Urengoy field for determining the efficiency of simultaneous water and gas injection on formation when extracting condensate from low-pressure reservoirs and oil from oil rims
- Authors:
- Nikolay A. Drozdov
Oil rims as well as gas condensate reservoirs of Russia's largest Urengoy field are developed by depletion drive without formation pressure maintenance, which has led to serious complications in production of oil, gas and condensate. In addition, field development by depletion drive results in low values of oil and condensate recovery. These problems are also relevant for other oil and gas condensate fields. One of the possible solutions is simultaneous water and gas injection. Rational values of gas content in the mixture for affecting gas condensate fields and oil rims of oil and gas condensate fields should be selected using the data of filtration studies on core models. The article presents the results of filtration experiments on displacement of condensate and oil by water, gas and water-gas mixtures when simulating the conditions of the Urengoy field. Simultaneous water and gas injection showed good results in the experiments on displacement of condensate, residual gas and oil. It has been ascertained that water-gas mixtures with low gas content (10-20 %) have a better oil-displacement ability (9.5-13.5 % higher) than water. An experiment using a composite linear reservoir model from cemented core material, as regards the main characteristics of oil displacement, gave the same results as filtration experiments with sand packed tubes and demonstrated a high efficiency of simultaneous water and gas injection as a method of increasing oil recovery at oil and gas condensate fields.
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Date submitted2021-09-17
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Date accepted2022-04-07
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Date published2022-12-29
Technique for calculating technological parameters of non-Newtonian liquids injection into oil well during workover
Technique for automated calculation of technological parameters for non-Newtonian liquids injection into a well during workover is presented. At the first stage the algorithm processes initial flow or viscosity curve in order to determine rheological parameters and coefficients included in equations of rheological models of non-Newtonian fluids. At the second stage, based on data from the previous stage, the program calculates well design and pump operation modes, permissible values of liquid flow rate and viscosity, to prevent possible hydraulic fracturing. Based on the results of calculations and dependencies, a decision is made on the necessity of changing the technological parameters of non-Newtonian liquid injection and/or its composition (components content, chemical base) in order to prevent the violation of the technological operation, such as unintentional formation of fractures due to hydraulic fracturing. Fracturing can lead to catastrophic absorptions and, consequently, to increased consumption of technological liquids pumped into the well during workover. Furthermore, there is an increased risk of uncontrolled gas breakthrough through highly conductive channels.
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Date submitted2021-09-22
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Date accepted2022-03-24
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Date published2022-04-29
Predicting dynamic formation pressure using artificial intelligence methods
Determining formation pressure in the well extraction zones is a key task in monitoring the development of hydrocarbon fields. Direct measurements of formation pressure require prolonged well shutdowns, resulting in underproduction and the possibility of technical problems with the subsequent start-up of wells. The impossibility of simultaneous shutdown of all wells of the pool makes it difficult to assess the real energy state of the deposit. This article presents research aimed at developing an indirect method for determining the formation pressure without shutting down the wells for investigation, which enables to determine its value at any time. As a mathematical basis, two artificial intelligence methods are used – multidimensional regression analysis and a neural network. The technique based on the construction of multiple regression equations shows sufficient performance, but high sensitivity to the input data. This technique enables to study the process of formation pressure establishment during different periods of deposit development. Its application is expedient in case of regular actual determinations of indicators used as input data. The technique based on the artificial neural network enables to reliably determine formation pressure even with a minimal set of input data and is implemented as a specially designed software product. The relevant task of continuing the research is to evaluate promising prognostic features of artificial intelligence methods for assessing the energy state of deposits in hydrocarbon extraction zones.
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Date submitted2021-03-16
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Date accepted2021-07-27
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Date published2021-10-21
Allocation of a deep-lying brine aquifer in the rocks of a chemogenic section based on the data of geophysical well logging and 2D seismic exploration
Advancement in the production of potassium fertilizers is an important strategic task of Russian agricultural industry. Given annually growing production rates, the reserves of discovered potassium-magnesium salt deposits are noticeably decreasing, which creates the need to ensure stable replenishment of the resource base through both the discovery of new deposits and the exploitation of deep-lying production horizons of the deposits that are already under development. In most cases, deposits of potassium-magnesium salts are developed by underground mining. The main problem for any salt deposit is water. Dry salt workings do not require any additional reinforcement and can easily withstand rock pressure, but with an inflow of water they begin to collapse intensively – hence, special attention is paid to mine waterproofing. Determination of spatial location, physical and mechanical properties of the aquifer and water-blocking stratum in the geological section represent an important stage in the exploration of a salt deposit. The results of these studies allow to validate an optimal system of deposit development that will minimize environmental and economic risks. On the territory of Russia, there is a deposit of potassium-magnesium salts with a unique geological structure – its production horizon lies at a considerable depth and is capped by a regional aquifer, which imposes significant limitations on the development process. To estimate parameters of the studied object, we analyzed the data from CDP seismic reflection survey and a suite of methods of radioactive and acoustic well logging, supplemented with high-frequency induction logging isoparametric sounding (VIKIZ) data. As a result of performed analysis, we identified location of the water-bearing stratum, estimated average thickness of the aquifers and possible water-blocking strata. Based on research results, we proposed methods for increasing operational reliability of the main shaft in the designed mine that will minimize the risks of water breakthrough into the mine shaft.
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Date submitted2020-09-09
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Date accepted2021-03-29
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Date published2021-09-20
Developing features of the near-bottomhole zones in productive formations at fields with high gas saturation of formation oil
The article studies the formation features of the bottomhole zones in productive formations during operation of production wells in the north of the Perm Territory. Their distinctive feature is the high gas saturation of formation oil. The most widely used parameter in Russian and world practice – the skin factor was used as a criterion characterizing the state of the bottomhole zone. Analysis of scientific publications has shown that one of the main problems of applying the skin factor to assess the state of bottomhole zones is the ambiguity of interpretations of its physical meaning and the impossibility of identifying the prevailing factors that form its value. The paper proposes an approach to identifying such factors in the conditions of the fields under consideration, based on multivariate correlation-regression analysis. Choice of this tool is due to the complexity of the processes occurring in the “formation – bottomhole zone – well” system. When describing complex multifactorial processes, the chosen method demonstrates a high degree of reliability. For a large number of wells in the region, significant material was collected and summarized, including the results of determining the skin factor (1102 values) during hydrodynamic investigations, as well as data on the values of various geological and technological indicators, which can probably be statistically related to the value of the skin factor. A series of multidimensional mathematical models has been built; the skin factor was used as a predicted parameter, and data on the values of geological and technological indicators were used as independent indicators. Analysis of the constructed models is a key stage of this study. Set of parameters included in the multidimensional models, sequence of their inclusion and contribution to the total value of the achieved determination coefficient as the main indicator for the performance of the constructed models were studied. It has been established that the main factor influencing the state of the bottomhole zone is oil degassing. Significant differences in the formation features of the skin factor in the terrigenous and carbonate sediments at the fields under consideration have been determined.
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Date submitted2020-08-28
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Date accepted2020-12-16
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Date published2020-12-29
Metrological support of equipment for geophysical research
The article discusses the problems associated with metrological support of equipment for geophysical research, issues of ensuring the uniformity of well measurements, the creation of Russian standards for calibrating well equipment when determining the porosity coefficients and oil, gas, water saturation, determining the parameters of defects during well cementing and technical condition of casing strings and the water-oil-gas flow. The problems of creating full-fledged methods for measuring the parameters of oil and gas fields with conventional and hard-to-recover reserves have been investigated. The key directions of development of the Russian metrological support of geophysical well measurements were determined. The tasks that need to be solved to create metrological support for geophysical well logging as an industry that meet international standards are indicated. The expediency of creating a Russian Geophysical Center for Metrology and Certification, the need to develop a new and update the existing regulatory framework, which will allow Russian geophysics to reach the level of world leaders in the field of geophysical research, are substantiated.
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Date submitted2016-11-11
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Date accepted2017-01-21
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Date published2017-04-14
Conducting lithospheric heterogeneities as a criterion of predictive assessment for promising diamond areas (on the example of Siberian kimberlite province)
- Authors:
- E. V. Pospeeva
Results of magnetotelluric tests, carried out in Siberian kimberlite province, are examined from the viewpoint of structural control over location of kimberlite fields and bunches of kimberlite pipes. It is demonstrated that the key factors controlling occurrence of kimberlite magmatism are: deep systems of rift-driven fractures; areas of their intersection within high-ohmic blocks of Earth crust; conducting permeable areas, located at the intersections of deep faults. Various-rank objects of kimberlite magmatism are characterized by a certain combination of geoelectric heterogeneities, differing in resistance, lateral sizes and depth. The province is situated within the boundaries, limited by isolines 180-220 km of current asthenosphere; kimberlite areas – within the contours of high-resistance regional heterogeneities. Fields and bunches of kimberlite pipes are concentrated within boundaries of conducting subvertical zones. These factors can be used as criteria of predictive assessment for promising diamond areas of the ancient platforms.
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Date submitted2016-09-22
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Date accepted2016-11-14
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Date published2017-02-22
Technological problems and fundamental principles of methods of engineering-geocryological exploration during construction and exploitation of wells in permafrost rock mass
- Authors:
- Z. N. Cherkai
- E. B. Gridina
The article describes peculiarities and complicating factors when constructing wells in cryolithic zones. It also presents fundamental principles of methods of pilot parametric drilling for complex exploration of engineering-geocryological conditions of multiple-well gas production platforms. The article describes peculiarities of geophysical examinations within the complex of parametric drilling for clarification and correlation of log sheet, and identifying non-commercial gas reservoirs and interpermafrost head oil-filed water horizons in permafrost rock mass. We defined main ecological issues of parametric drilling and presented potential environment pollutants from well drilling in cryolithic zones. It concludes a list of factors, which should be considered during gas well drilling in northern zones for meeting the «safety – sustainability – low waste» criteria.
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Date submitted2009-07-27
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Date accepted2009-09-15
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Date published2010-04-22
Geomechanical problems in the forecast of stress-strain state of underground stations of the metro at a great depth
- Authors:
- P. A. Demenkov
- I. E. Dolgiy
- V. I. Ochkurov
Forecast of stress and strain state of deep underground metro stations is considered in this article. A complex approach to study of static work of the metro stations including the in situ testing at different stages of their construction and numerical modeling with finite element method is shown.
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Date submitted2008-11-01
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Date accepted2009-01-27
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Date published2009-12-11
The influence of the technological and organizational factors on the steady growth of the mining industry
- Authors:
- E. M. Pronin
- V. E. Vasiliev
The steady growth of the mining industry calls forth the character of its activities connected with the dependence of the work on the natural conditions which are practically unpredictable and constantly changeable. The two basic factors are chosen – the technology of the mining work and the organization of the industry, which have the decisive importance in the increasing of the basic indices of the activity of the enterprise. The possible technological and organizational solutions are offered as they permit to find possible directions in the lowering of the negative influence of the appearing problems.
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Date submitted2008-10-16
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Date accepted2008-12-24
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Date published2009-12-11
Procedures and techniques for operation of the new automatic core orientator
- Authors:
- Yu. T. Morozov
The most similar prototype models of foreign and domestic core orientators have been analyzed, and a model of a new automatic core orientator created by the author is presented. It provides continuous drawing of three lines on1,5 metercore surface section by diamond cutters in borehole drilling, secures accurate core orientation, decrease in time and general costs of this work.
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Date submitted2008-10-10
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Date accepted2008-12-23
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Date published2009-12-11
Modern methods of hydrogeological investigations in terms of prospecting of titanium-magnetic iron deposit «South-East Gremiakha»
The paper considers the contemporary level of hydrogeological investigations during prospecting of deposits. It is suggested to use numerical modeling, sensors, computer programs for pumping tests. These methods are illustrated by prospecting of the South-East Gremiakha deposit.
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Date submitted2008-10-02
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Date accepted2008-12-23
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Date published2009-12-11
Engineering-geocryological problems оf the «Amur» federal highway Chita – Khabarovsk
- Authors:
- V. G. Kondratiev
- S. V. Soboleva
The engineering-geocryological conditions of the 2165-km-long Chita-Khabarovsk «Amur» federal highway, which is one of the greatest recent constructions in Russia, are analized. The examples of the negative effect of the engineering-geocryological processes on the highway stability and reliability are presented. The concept of the system of engineering-geocryological monitoring of the «Amur» highway have been developed in order to maintain stability and reliability of the «Amur» highway during its exploration.