Vol 246
- Vol 271
- Vol 270
- Vol 269
- Vol 268
- Vol 267
- Vol 266
- Vol 265
- Vol 264
- Vol 263
- Vol 262
- Vol 261
- Vol 260
- Vol 259
- Vol 258
- Vol 257
- Vol 256
- Vol 255
- Vol 254
- Vol 253
- Vol 252
- Vol 251
- Vol 250
- Vol 249
- Vol 248
- Vol 247
- Vol 246
- Vol 245
- Vol 244
- Vol 243
- Vol 242
- Vol 241
- Vol 240
- Vol 239
- Vol 238
- Vol 237
- Vol 236
- Vol 235
- Vol 234
- Vol 233
- Vol 232
- Vol 231
- Vol 230
- Vol 229
- Vol 228
- Vol 227
- Vol 226
- Vol 225
- Vol 224
- Vol 223
- Vol 222
- Vol 221
- Vol 220
- Vol 219
- Vol 218
- Vol 217
- Vol 216
- Vol 215
- Vol 214
- Vol 213
- Vol 212
- Vol 211
- Vol 210
- Vol 209
- Vol 208
- Vol 207
- Vol 206
- Vol 205
- Vol 204
- Vol 203
- Vol 202
- Vol 201
- Vol 200
- Vol 199
- Vol 198
- Vol 197
- Vol 196
- Vol 195
- Vol 194
- Vol 193
- Vol 191
- Vol 190
- Vol 192
- Vol 189
- Vol 188
- Vol 187
- Vol 185
- Vol 186
- Vol 184
- Vol 183
- Vol 182
- Vol 181
- Vol 180
- Vol 179
- Vol 178
- Vol 177
- Vol 176
- Vol 174
- Vol 175
- Vol 173
- Vol 172
- Vol 171
- Vol 170 No 2
- Vol 170 No 1
- Vol 169
- Vol 168
- Vol 167 No 2
- Vol 167 No 1
- Vol 166
- Vol 165
- Vol 164
- Vol 163
- Vol 162
- Vol 161
- Vol 160 No 2
- Vol 160 No 1
- Vol 159 No 2
- Vol 159 No 1
- Vol 158
- Vol 157
- Vol 156
- Vol 155 No 2
- Vol 154
- Vol 153
- Vol 155 No 1
- Vol 152
- Vol 151
- Vol 150 No 2
- Vol 150 No 1
- Vol 149
- Vol 147
- Vol 146
- Vol 148 No 2
- Vol 148 No 1
- Vol 145
- Vol 144
- Vol 143
- Vol 140
- Vol 142
- Vol 141
- Vol 139
- Vol 138
- Vol 137
- Vol 136
- Vol 135
- Vol 124
- Vol 130
- Vol 134
- Vol 133
- Vol 132
- Vol 131
- Vol 129
- Vol 128
- Vol 127
- Vol 125
- Vol 126
- Vol 123
- Vol 122
- Vol 121
- Vol 120
- Vol 118
- Vol 119
- Vol 116
- Vol 117
- Vol 115
- Vol 113
- Vol 114
- Vol 112
- Vol 111
- Vol 110
- Vol 107
- Vol 108
- Vol 109
- Vol 105
- Vol 106
- Vol 103
- Vol 104
- Vol 102
- Vol 99
- Vol 101
- Vol 100
- Vol 98
- Vol 97
- Vol 95
- Vol 93
- Vol 94
- Vol 91
- Vol 92
- Vol 85
- Vol 89
- Vol 87
- Vol 86
- Vol 88
- Vol 90
- Vol 83
- Vol 82
- Vol 80
- Vol 84
- Vol 81
- Vol 79
- Vol 78
- Vol 77
- Vol 76
- Vol 75
- Vol 73 No 2
- Vol 74 No 2
- Vol 72 No 2
- Vol 71 No 2
- Vol 70 No 2
- Vol 69 No 2
- Vol 70 No 1
- Vol 56 No 3
- Vol 55 No 3
- Vol 68 No 2
- Vol 69 No 1
- Vol 68 No 1
- Vol 67 No 1
- Vol 52 No 3
- Vol 67 No 2
- Vol 66 No 2
- Vol 64 No 2
- Vol 64 No 1
- Vol 54 No 3
- Vol 65 No 2
- Vol 66 No 1
- Vol 65 No 1
- Vol 53 No 3
- Vol 63 No 1
- Vol 61 No 1
- Vol 62 No 1
- Vol 63 No 2
- Vol 62 No 2
- Vol 61 No 2
- Vol 59 No 2
- Vol 60 No 2
- Vol 51 No 3
- Vol 60 No 1
- Vol 49 No 3
- Vol 50 No 3
- Vol 59 No 1
- Vol 57 No 2
- Vol 58 No 2
- Vol 58 No 1
- Vol 56 No 2
- Vol 57 No 1
- Vol 55 No 2
- Vol 48 No 3
- Vol 56 No 1
- Vol 47 No 3
- Vol 55 No 1
- Vol 54 No 2
- Vol 53 No 2
- Vol 54 No 1
- Vol 52 No 2
- Vol 46 No 3
- Vol 53 No 1
- Vol 52 No 1
- Vol 51 No 2
- Vol 51 No 1
- Vol 50 No 2
- Vol 49 No 2
- Vol 48 No 2
- Vol 50 No 1
- Vol 49 No 1
- Vol 45 No 3
- Vol 47 No 2
- Vol 44 No 3
- Vol 43 No 3
- Vol 42 No 3
- Vol 48 No 1
- Vol 46 No 2
- Vol 45 No 2
- Vol 46 No 1
- Vol 47 No 1
- Vol 44 No 2
- Vol 43 No 2
- Vol 41 No 3
- Vol 42 No 2
- Vol 39 No 3
- Vol 37 No 3
- Vol 45 No 1
- Vol 41 No 2
- Vol 39 No 2
- Vol 44 No 1
- Vol 38 No 2
- Vol 37 No 2
- Vol 38 No 3
- Vol 43 No 1
- Vol 42 No 1
- Vol 41 No 1
- Vol 40
- Vol 39 No 1
- Vol 36 No 2
- Vol 35 No 2
- Vol 38 No 1
- Vol 35 No 3
- Vol 34 No 2
- Vol 34 No 3
- Vol 33 No 2
- Vol 36 No 1
- Vol 37 No 1
- Vol 36 No 3
- Vol 35 No 1
- Vol 34 No 1
- Vol 32 No 3
- Vol 33 No 3
- Vol 32 No 2
- Vol 33 No 1
- Vol 31
- Vol 30 No 3
- Vol 30 No 2
- Vol 30 No 1
- Vol 32 No 1
- Vol 29 No 3
- Vol 29 No 1
- Vol 29 No 2
- Vol 28
- Vol 27 No 1
- Vol 27 No 2
- Vol 26 No 2
- Vol 26 No 1
- Vol 25 No 2
- Vol 25 No 1
- Vol 23
- Vol 24
- Vol 15 No 16
- Vol 22
- Vol 20
- Vol 17 No 18
- Vol 21
- Vol 19
- Vol 13 No 3
- Vol 14
- Vol 13 No 2
- Vol 12 No 3
- Vol 12 No 2
- Vol 13 No 1
- Vol 12 No 1
- Vol 11 No 3
- Vol 11 No 2
- Vol 10 No 3
- Vol 10 No 2
- Vol 11 No 1
- Vol 9 No 2
- Vol 10 No 1
- Vol 9 No 1
- Vol 8
- Vol 7 No 3
- Vol 7 No 2
- Vol 7 No 1
- Vol 6 No 2
- Vol 6 No 1
- Vol 5 No 4-5
- Vol 5 No 2-3
- Vol 5 No 1
- Vol 4 No 5
- Vol 4 No 4
- Vol 4 No 3
- Vol 4 No 2
- Vol 3
- Vol 4 No 1
- Vol 2 No 5
- Vol 2 No 4
- Vol 2 No 3
- Vol 2 No 1
- Vol 2 No 2
- Vol 1 No 5
- Vol 1 No 4
- Vol 1 No 3
- Vol 1 No 2
- Vol 1 No 1
-
Date submitted2020-05-08
-
Date accepted2020-06-12
-
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.
-
Date submitted2020-05-25
-
Date accepted2020-06-11
-
Date published2020-12-29
Technological aspects of cased wells construction with cyclical-flow transportation of rock
- Authors:
- Andrei S. Kondratenko
A high-performance technology for constructing cased wells is proposed. Essence of the technology is the advance insertion of the casing pipe into the sedimentary rock mass and the cyclical-flow transportation of the soil rock portions using the compressed air pressure supplied to the open bottomhole end of the pipe through a separate line. Results of mathematical modeling for the process of impact insertion of a hollow pipe into a soil mass in horizontal and vertical settings are considered. Modeling of the technology is implemented by the finite element method in the ANSYS Mechanical software. Parameters of the pipe insertion in the sedimentary rock mass are determined - value of the cleaning step and the impact energy required to insert the pipe at a given depth. Calculations were performed for pipes with a diameter from 325 to 730 mm. Insertion coefficient is introduced, which characterizes the resistance of rocks to destruction during the dynamic penetration of the casing pipe in one impact blow of the pneumatic hammer. An overview of the prospects for the application of the proposed technology in geological exploration, when conducting horizontal wells of a small cross-section using a trenchless method of construction and borehole methods of mining, is presented. A variant of using the technology for determining the strength properties of rocks is proposed. Some features of the technology application at industrial facilities of the construction and mining industry are considered: for trenchless laying of underground utilities and for installing starting conductors when constructing degassing wells from the surface in coal deposits. Results of a technical and economic assessment of the proposed technology efficiency when installing starting conductors in sedimentary rocks at mining allotments of coal mines are presented.
-
Date submitted2020-05-16
-
Date accepted2020-07-30
-
Date published2020-12-29
Results of the study of kinetic parameters of spontaneous combustion of coal dust
The article is devoted to the study of the problem of spontaneous combustion of energy grades of coal not only during storage, but also during transportation. As the main samples for the study, the energy grades of SS and Zh coals were selected. The main task of the scientific research was to study the rate of cooling and heating of coal depending on their thermophysical parameters and environmental parameters. To solve this problem, the authors used both the author's installations designed to study the thermophysical parameters of the spontaneous combustion process (the Ya.S.Kiselev method), and the NETZSCH STA 449 F3 Jupiter synchronous thermal analysis device, the NETZSCH Proteus Termal Analysis software package. On the basis of a complex study of the spontaneous combustion process, the authors of the article obtained the kinetic characteristics of the spontaneous heating process (activation energy and pre-exponential multiplier). Nomograms of the permissible size of coal density of different types and shapes of accumulation depending on the ambient temperature are presented, practical recommendations for the prevention (avoidance) of spontaneous combustion of coal fuel are given.
-
Date submitted2020-05-26
-
Date accepted2020-09-23
-
Date published2020-12-29
Automated ventilation control in mines. Challenges, state of the art, areas for improvement
The article is divided into three main parts. The first part provides an overview of the existing literature on theoretical methods for calculating the optimal air distribution in mines according to the criteria of energy efficiency and providing all sections of mines with the required amount of air. It is shown that by the current moment there are many different formulations of the problem of searching the optimal air distribution, many different approaches and methods for optimizing air distribution have been developed. The case of a single (main) fan is most fully investigated, while for many fans a number of issues still remain unresolved. The second part is devoted to the review of existing methods and examples of the automated mine ventilation control systems implementation in Russia and abroad. Two of the most well-known concepts for the development of such systems are automated ventilation control systems (AVCS) in Russia and the CIS countries and Ventilation on demand (VOD) abroad. The main strategies of ventilation management in the framework of the AVCS and VOD concepts are described and also the key differences between them are shown. One of the key differences between AVCS and VOD today is the automatic determination of the operation parameters of fan units and ventilation doors using the optimal control algorithm, which is an integral part of the AVCS. The third part of the article describes the optimal control algorithm developed by the team of the Mining Institute of the Ural Branch of the Russian Academy of Sciences with the participation of the authors of the article. In this algorithm, the search for optimal air distribution is carried out by the system in a fully automated mode in real time using algorithms programmed into the microcontrollers of fans and ventilation doors. Minimization of energy consumption is achieved due to the most efficient selection of the fan speed and the rate of ventilation doors opening and also due to the air distribution shift control and the partial air recirculation systems introduction. It is noted that currently the available literature poorly covers the issue related to emergency operation modes ventilation systems of mines and also with the adaptation of automated control systems to different mining methods. According to the authors, further development of automated ventilation control systems should be carried out, in particular, in these two areas.
-
Date submitted2020-07-22
-
Date accepted2020-11-12
-
Date published2020-12-29
Simulation of the electric drive of the shearer to assess the energy efficiency indicators of the power supply system
- Authors:
- Vyacheslav A. Voronin
- Fedor S. Nepsha
This paper considers the problem of electric drive of shearers simulation to assess the indicators of power supply system (PSS) energy efficiency in the context of the introduction of modern devices for controlling the flow of electricity and power. The block diagram of the shearer electric drive simulation model is presented. To take into account fluctuations in the level of consumption of active and reactive power, a model of the executive body of the shearer was used in the work, including a model of the moment of resistance on the auger when cutting. As a result, in the MATLAB Simulink environment, a simulation model of the electric drive of the UKD300 shearer was developed, suitable for assessing the energy efficiency of the electrical complex of mining areas and the feasibility of using modern devices for controlling the flow of electricity and power. As a result of the simulation, it was found that a significant irregularity in the graph of reactive power consumption, caused by repeated short-term operation, makes the use of capacitor units ineffective to compensate for reactive power.
-
Date submitted2020-06-02
-
Date accepted2020-12-15
-
Date published2020-12-29
Method for calculating dynamic loads and energy consumption of a sucker rod installation with an automatic balancing system
The efficiency of sucker rod pump installations, which have become widespread in mechanized lift practice, is largely determined by the balance of the drive. During the operation of sucker rod installations, the balance of loads acting on the rod string and the drive can change significantly due to changes in the dynamic fluid level, which leads to a decrease in balance and an increase in loads on the pumping equipment units. The increase and decrease in the dynamic level in accordance with the pumping and accumulation cycle occurs in wells operating in the periodic pumping mode. It is shown that during the operation of equipment in a periodic mode, fluctuations in the dynamic level and, accordingly, in the loads acting on the nodes occur. This leads to the need for dynamic adjustment of the balancing weights to ensure the balance of the pumping unit. A system for automatic balancing of the rod drive has been developed, including a balancing counterweight, an electric motor that moves the load along the balance beam, a propeller and a computing unit. To study the effectiveness of the proposed device, a complex mathematical model of the joint operation of the reservoir - well - sucker rod pump - rod string – pumping unit has been developed. It is shown that due to the dynamic adjustment of the balance counterweight position, the automatic balancing system makes it possible to significantly reduce the amplitude value of the torque on the crank shaft (in comparison with the traditional rod installation) and provide a more uniform load of the electric motor. Equalization of torque and motor load reduces the power consumption of the unit.
-
Date submitted2020-06-16
-
Date accepted2020-11-09
-
Date published2020-12-29
Investigation of probabilistic models for forecasting the efficiency of proppant hydraulic fracturing technology
To solve the problems accompanying the development of forecasting methods, a probabilistic method of data analysis is proposed. Using a carbonate object as an example, the application of a probabilistic technique for predicting the effectiveness of proppant hydraulic fracturing (HF) technology is considered. Forecast of the increase in the oil production of wells was made using probabilistic analysis of geological and technological data in different periods of HF implementation. With the help of this method, the dimensional indicators were transferred into a single probabilistic space, which allowed performing a comparison and construct individual probabilistic models. An assessment of the influence degree for each indicator on the HF efficiency was carried out. Probabilistic analysis of indicators in different periods of HF implementation allowed identifying universal statistically significant dependencies. These dependencies do not change their parameters and can be used for forecasting in different periods of time. Criteria for the application of HF technology on a carbonate object have been determined. Using individual probabilistic models, integrated indicators were calculated, on the basis of which regression equations were constructed. Equations were used to predict the HF efficiency on forecast samples of wells. For each of the samples, correlation coefficients were calculated. Forecast results correlate well with the actual increase (values of the correlation coefficient r = 0.58-0.67 for the examined samples). Probabilistic method, unlike others, is simple and transparent. With its use and with careful selection of wells for the application of HF technology, the probability of obtaining high efficiency increases significantly.
-
Date submitted2020-05-13
-
Date accepted2020-11-12
-
Date published2020-12-29
Improving the efficiency of terrigenous oil-saturated reservoir development by the system of oriented selective slotted channels
A comparative assessment of variation in the flow rate of oil production wells was performed taking into account increasing of perforated area of the productive part of the rocks, as well as recover of reservoir rocks permeability due to their unloading by creating slotted channels with the method of oriented slotted hydro-sandblast perforation. Different orientation directions and slotting intervals were analyzed, taking into account water encroachment of individual interlayers and azimuth direction of the majority of remaining reserves in separate blocks of the examined formation. In order to estimate development efficiency of terrigenous oil-saturated porous-type reservoirs by means of oriented slotted hydro-sandblast perforation, calculations were performed on a full-scale geological and hydrodynamic model of an oil field in the Perm Region. The object of modeling was a Visean terrigenous productive forma tion. The modeling of implementing oriented slotted hydro-sandblast perforation was carried out on a 3D filtration model for fourteen marginal wells, located in the zone with excessive density of remaining recoverable reserves and he terogeneous reserve recovery along the section. An optimal layout of slotted channels along the depth of the productive part of the well section was developed. Selective formation of 24 slotted channels was carried out con sidering the intervals of increased oil saturation. Comparative analysis of estimated flow rate of the wells was per formed for cumulative perforation of the examined productive formation and the developed method of slotted perforation. As a result of modeling, an increase in the oil average flow rate of 2.25 t/day was obtained. With oriented slotted hydro-sandblast perforation, incremental cumulative production for two years of prediction calculations per one well reached 0.5 thousand t.
-
Date submitted2020-08-28
-
Date accepted2020-12-16
-
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.
-
Date submitted2020-06-12
-
Date accepted2020-06-15
-
Date published2020-12-29
Analysis of project organization specifics in small-scale LNG production
- Authors:
- Pavel S. Tcvetkov
- S. V. Fedoseev
Gas industry plays an important role in the global energy sector, and in the coming decades amountsof natural gas production will only increase. One of the fastest growing trends in gas industry is the production of liquefiednatural gas (LNG), which is associated with the necessity to organize flexible systems of gas supply to the regions,remote from gas extraction sites. Industrial structure of LNG production includes projects, belonging to several different groups depending to their scale, in particular, small-scale production (SSLNG), cumulative production capacityof which is approximately 10 % from the industry-wide one. Economic aspects of implementing such projects remainunderexplored, which does not allow to draw objective conclusions regarding the prospects of their implementationin particular regions.This paper contains a review of publications, devoted to SSLNG project studies, aimed at identifying specifics oftheir organization compared to projects of greater scale. The results demonstrate that the majority of internationalcompanies classify projects as SSLNG, if their annual production capacity is below 0.5 million tonnes per annum.Specific capital costs, as well as implementation timelines of such projects, are several times lower than those of projects with greater production capacity, which reduces their risks and minimizes barriers to market entry. Furthermore,SSLNG is the most decentralized subsector in gas industry, aiming to cover the market due to a growing numberof projects, not their specific production capacity. These specific features define significant prospects of SSLNGdevelopment in Russia, both in the context of energy supply to remote regions and diversification of export deliveries.