Izvestiya Tomskogo Politekhnicheskogo Universiteta Inziniring Georesursov

EXPERIMENTAL STUDIES OF OPERATION OF A PNEUMATIC SPRING PRESSURE COMPENSATOR WITH QUASI-ZERO STIFFNESS

2019-04-30T08:46:00+00:00

The relevance of the research is caused by vibration negative effect on the elements in the installation of the electric centrifugal pump. The presence of vibration increases the number of premature failures. One of the reasons for the vibrational effects on the electric centrifugal pump unit is the pressure drop at the pump discharge, and the frequencies of such fluctuations are small. The main aim of the research is to develop a laboratory installation simulating oscillatory processes occurring on the discharge line of an electric centrifugal submersible pump in a well. Objects: a model of a pneumatic spring pressure compensator with quasi-zero stiffness, structurally representing a pneumatic spring, inside of which there is a package of five sequentially installed disc springs. Methods: numerical solutions of differential equations; theory of oscillations, mathematical analysis, mathematical statistics, methods of mathematical modeling. Results. To confirm the theoretical results obtained by calculation the authors have developed the laboratory facility, which allows studying the system with quasi-zero stiffness. This is is a set of pneumatic spring having a force characteristic with a working area of positive stiffness and a package of sequentially connected disc springs having a force characteristic with a working area of negative stiffness. The parameters of the disk springs were experimentally selected in such a way as to obtain a power characteristic with a region of quasi-zero stiffness at a given pressure in the cylinder sub-piston cavity. To ensure the necessary stability of the system to small changes with the help of the analysis of power characteristics, an optimum number of disk springs is obtained. The authors investigated the power characteristic of a pneumatic compensator with quasi-zero stiffness on the discharge line of an electric centrifugal submersible pump. The result of the research on the laboratory installation was the coincidence with the given error of the oscillation amplitude measurements and theoretically predicted results, which allowed proving the correctness of theoretical conclusions.

GEOCHEMICAL TYPES OF WATERS OF LEAD-ZINC DEPOSITS TAILINGS IN THE EASTERN TRANSBAIKALIA

2019-04-30T08:45:25+00:00

The relevance of the topic is caused by the need to solve the problem of conserving the quality of water resources in the conditions of mining impact. The main aim of the research is to study chemical composition of technogenic-transformed waters in the areas of development of three lead-zinc deposits of Transbaikalia and their geochemical typification. Objects of the research are the waters of tailings of lead-zinc deposits Blagodatskoe, Akatuevskoe and Kadainskoe, located in the Eastern Transbaikalia. Methods. Concentrations of anions were measured by turbidimetric, potentiometric, colorimetric methods; cations and metals were determined by the atomic-adsorption method and inductively-coupled plasma mass spectrometry (ICP-MS). To determine the equilibrium composition of secondary mineral phases the authors have used the diagrams of the stability fields of aluminosilicate minerals, plotted by the method proposed by R.M.Garrels and C.L.Christ. The results. According to the ratio of the main ions, the considered waters belong to hydro-carbonate, sulfate-hydro-carbonate, hydro-carbonate-sulfate and sulfate magnesium-calcium and calcium-magnesium chemical types. Drainage waters of lead-zinc deposits are characterized by significant excess of heavy metal contents (As, Zn, Cd, Pb, Sb, Mn, Mo, U, La, Se) over the average composition of leaching zone waters, with a maximum for arsenic more than 800 times and zinc – 200 times. The character of location of water composition points on the stability diagrams of the aluminosilicate minerals indicates their saturation with respect to clay aluminosilicates and calcite, that allows referring them to two geochemical types: silica-calcium-magnesium and siliceous carbonate-calcium, taking into account the peculiarities of their chemical composition. The change of these two types is caused by the intensity of water exchange. Typification of anomalous hydrogeochemical fields in mining regions is aimed at improving the ecological and geochemical monitoring of natural waters and can be used in developing measures to prevent pollution and purify waters.

APPLICATION OF METHODS OF ELECTRICAL EXPLORATION WITH CONTROLLED SOURCES FOR DETECTING CAUSES OF SUB-PASS-LOCATION PROCESSES DEVELOPMENT

2019-04-30T08:44:51+00:00

The relevance of the work is caused by insufficiency of knowledge on the reasons of development of suffusion processes expressed as land surface failures menacing to infrastructure of industrial production in Caspian Depression. The aim of the research is to determine the near-surface and deep geoelectric structure of the site of manifestations of suffusion-subsidence formations to identify possible causes of their occurrence. Object of the research are suffusion-subsidence formations in the form of funnel-shaped earth surface dips with a depth of 1 to 6 m in an amount of 15 pieces located in three practically parallel zones. Methods The entire volume of field data is obtained by three different depth methods of geoelectrics: electrotomography, vertical electric sounding, non-stationary electromagnetic sounding. Processing, interpretation, visualization of data were carried out using interactive simulation and inversion software packages ERA, EMS, Zond, Res2D, ERTLab. The justification of the results is based on the analysis and comparison of the obtained geoelectric data with a priori geological data. Results. Based on the results of the work done, with depths of up to 400–500 m, sections and maps of electrical resistivity distribution at different depths, three-dimensional geoelectric models for both the near-surface and the deep part of the section were constructed. As a result of geological interpretation of the data, the zones were identified (according to the resistivity parameter) to which the existing funnels were confined, the direction of removal of the destroyed (washed out) rocks was determined. The authors identified the structures related to the zones of development of suffusion-subsidence processes, and stated possible reasons for their formation. Conclusions. The paper demonstrates high efficiency of the complex of electromagnetic methods used on the site with the destructive phenomena. It is concluded that the main mechanism for funnels formation is associated with leaching of limestone and salt «cement» from the N-Q sediments, with further unloading into deeper watered horizons. This complex can be recommended at the solution of similar tasks in other regions where there are zones of manifestation of suffusion processes, and also for monitoring their development.

METHOD OF VIBRO-JET HYDRODYNAMIC TECHNOLOGY TO RETAIN THE FLUIDITY OF HYDROCARBON FUELS AND PETROLEUM PRODUCTS AT LOW TEMPERATURES

2019-04-30T08:44:18+00:00

The relevance of the research is cased by the need to develop an energy-efficient way to maintain the fluidity of hydrocarbon fuels at low temperatures, at temperatures significantly lower the freezing point of the product. Under conditions of low temperatures of high latitudes of Siberia and Arctic, there are problems with the launch of power plants operating on hydrocarbon fuels and oils. Thermal and chemical methods used to preserve the fluidity of fuel, oil and coolant fluid do not provide a complete guarantee in operational preparation for operation of autonomous objects. Vibration technologies can significantly change the rheological properties of hydrocarbon fuels by creating high shear rates and hysteresis heating of petroleum products. The process of vibratory creation of high shear velocities in a continuous medium has energy costs ten times less than the thermal method for maintaining fuel flow. The low thermal conductivity of hydrocarbon fuel contributes to formation of solidified fuel near the inner walls of the tanks, which are the thermal insulation. Introducing a mechanical vibration power inside the tank, the fuel inside this system will be sufficiently liquid and ready for use on demand. The main aim of the research is to create a method for calculating heat-insulating effect of a frozen petroleum product, to determine the amount of energy required to maintain the fuel in a liquid state at different ambient temperatures. Methods: mathematical calculation of the temperature difference in the system «tank wall – layer of solidified fuel» and experimental studies of changes of rheological properties of petroleum products under the influence of a submerged vibrating confuser system.

Results. The authors have proposed the engineering method for calculating frozen fuel thickness on the inner walls of the tank at negative ambient temperatures and the amount of mechanical energy required to maintain fuel fluidity.

INVESTIGATION OF OPERATION OF A LOW VOLTAGE SHOCK GENERATOR IN AN ELECTROHYDRAULIC DEVICE FOR SEISMIC EXPLORATION AT SMALL DEPTH

2019-04-30T08:43:42+00:00

The relevance of the study is caused by the need to develop new sources of powerful current pulses for operation in an electrohydraulic device with moving electrodes that can be used to excite seismic waves in non-explosive seismic surveys. The aim of the research is to carry out computational and experimental studies of operation of a low-voltage shock generator on an arc in water, initiated by moving electrodes in the mode of single pulses and in production of a series of pressure pulses. Optimization of the parameters of the shock generator and the electrohydraulic radiator, in order to obtain the maximum pressure pulse. Objects: low-voltage shock generator, made in the dimensions of the crane asynchronous motor MTН-612, connected to an electrohydraulic source with moving electrodes. Methods: matching parameters of a shock generator and an arc discharge by the method of experiment planning using a mathematical model. Results. The authors have carried out the laboratory studies of operation of a low-voltage shock generator on an arc in water initiated by moving electrodes in the regime of single pulses and in the generation of a series of pulses. Using the method of experiment planning, the authors obtained the mathematical model of the shock generator operation on an arc in water, initiated by moving electrodes in the regime of single pulses; the regression equations are obtained for output parameters of the arc discharge. Optimization of the parameters of the shock generator and the electrohydraulic source was carried out, which allows obtaining the maximum pressure pulse for seismic exploration at shallow depth. The obtained amplitude-frequency spectrum of the pressure pulse showed that the main energy of the pressure pulse lies in the low-frequency range from 0 to 180 Hz, which provides a high seismic efficiency for seismic exploration at shallow depth.

SPECIAL METHODS FOR INTERPRETING THE SPEED VIBRATION SPECTRUM FOR DIAGNOSTIC OF GAS-PUMPING UNIT STATE

2019-04-30T08:43:08+00:00

The relevance of the research is caused by the need to develop additional methods for assessing the technical state of gas-pumping units of the main gas pipelines compressor stations. Emergency situations entail consequences of a global nature for the material base and the surrounding environment. The main direction of maintenance of trouble-free compressor stations operation is the maintenance of the technical state of gas-pumping units at the required level. The main aim of the research is to develop a method for assessing the technical state of gas-pumping units by interpreting the vibration spectrum of oscillations of the bearing housing of the low-pressure turbine of the unit with the formulation of the conclusion «there is a defect/there is no defect». The objects of research are GTK-10 gas-pumping units operated by PJSC Gazprom. Units of this type provide more than 8 GWt of installed capacity, which is more than 20% in the country's gas-pumping system. The database for the research is the data of the results of vibration units diagnostics for 4 years. Methods. To assess the technical state of gas-pumping units based on the interpretation of the vibro-survey spectrum, it is proposed to use the method of constructing a separating surface in a 340-dimensional phase space according to the characteristics of a training sample of vibrospectra. It is established that the reliability of the classification of the spectrum rises with increasing the training sample volume, formed a priori. The greatest effect can be achieved if there are separate strongly marked harmonics in the spectrum. Results.The authors have constructed a hyperplane to diagnose the technical condition of gas-pumping units of compressor stations of PJSC «Gazprom» by interpreting the spectra of vibration analysis. Taking into account the number of spectra excluded by the separating surface, the probability of erroneous classification of the working vibro-spectra of a gas-pumping unit is set in the range of 0,15–0,30.

RESEARCH OF PULVERIZED HALURGIC POTASSIUM CHLORIDE AGGLOMERATION

2019-04-30T08:42:35+00:00

The relevance. The industrial pulverized halurgic potassium chloride (KC1) is mixed with the finished conditioning product, which leads to its dustiness and caking, as well as losses during transportation. The enlargement of the pulverized KC1 will increase the quality of the main product, by eliminating the mixing stage of different components. The agglomeration by molding will make it possible to obtain a product of a size close to the concentrate. Investigation of agglomeration features with various binders will allow studying their influence on the efficiency of the process and the quality of the product obtained. The main aim of the research is to study the molding of pulverized halurgic potassium chloride and to establish agglomeration features of moistened fertilizer using various binders. Methods. To study the state of the agglomerates surface, electron-scanning microscopy was applied using the shooting modes BSE3D and SE with an increase to 1500X; to determine the elemental composition formed in molding and drying the fertilizer mixture, the X-ray spectral analysis was used; the quality of the resulting product was evaluated using a sieve analysis and the method of measuring the static strength of an IPG-1M instrument. The results. It was found that increasing the moisture content of the granulated mixture promotes an increase in the content of the commodity fraction to 84 % and a static strength up to 10 N/granule; the use of binders has a positive effect on the quality of the product (increasing the yield and strength of the agglomerates), and they can have fundamentally different features of molding the pulverized halurgic KC1, resulting in formation of agglomerates with significant structural differences, as confirmed using electron microscopy. The use of sodium metasilicate makes it possible to obtain agglomerates with a tight adherence of particles to each other, and the needle-shaped crystals of silicon oxide formed by the thermal decomposition of Na₂SiO₃·5H₂O increase the roughness of the KC1 particles, the number of crystallization centers, and strengthen the bonds in the granule. When molasses are used, the resulting agglomerates have KC1 particles with intimate contact, but the remainders of the binder are visible between them; on their surface there are accumulations of microparticles with a size of 10–30 μm of the initial pulverized raw materials in the form of «shell».

ANALYSIS OF CARBON MATERIALS USED AS ANODES IN FLUORINE PRODUCTION

2019-04-30T08:42:01+00:00

The relevance. Electrolysis of hydrogen fluoride of potassium difluoride molten KF·nHF system is the only industrial method for obtaining fluorine. In this case, medium-temperature (95–105 °С) electrolyzers with an electrolyte of KF·2HF composition with a current strength of 5 to 40 kA are mainly used. The electrolyzer is a very complex device, but many problems associated with the corrosivity of fluorine, hydrogen fluoride and other fluoride environments have been already solved. At the same time, there is a technological challenge to increase the service life of anodes made of carbon plates. Carbon has various forms depending on the structure of the material: graphite, soot, coke, diamond and others. The most stable carbon form for electrolysis of medium flowing at 95±105 °C was coke, wherein the carbon has a disordered X-ray-amorphous structure, so these plates called coke. Coke plates are obtained mainly from petroleum pyrolysis low-sulfur coke of a certain fractional composition and coal tar pitch. Recently, coke plates have become of extremely poor quality. Some components of the plates were replaced by cheaper ones, for example, oil pitch was replaced by coal tar. The quality of the coke plates produced by Russian manufacturers must meet the requirements of Technical Specifications (TS) 48-12-34-95 «Coke burned plates». TS establish the following indicators and requirements for them: apparent density – not less than 1,64 kg/dm³; compressive strength – not less than 58,8 MPa; porosity – no more than 21 %; ash content is not more than 0,6 %; the specific electrical resistance is (25–40) μOm·m. In the analysis of fluorine production in Russia, it was noted that the life of many coke plates that meet the requirements specifications is not the maximum. This testifies that the indicators set by this specification are not enough to assess the quality of a coke plate. Therefore, research for development of new quality tests of coke plates is relevant. Due to this we carried out a comprehensive analysis of the quality of coke plates produced by foreign companies in order to test the possibility of using them in fluorine production in Russia. The main aim is to analyze physical-mechanical, chemical and physicochemical properties of coke plates made by foreign firms and their quality. Methods: differential thermal analysis, X-ray structural analysis, atomic emission spectroscopy, scanning electron microscopy, physical-mechanical and electrical methods of analysis. Results. The authors have determined density, porosity, ash content, specific resistance, compressive strength of coke-oven plates of foreign manufacturers, which basically meet the requirements of TS 48-12-34-95. However, they differ. The compressive strength of Chinese plates of the «HS» mark exceeds the requirements of TS by almost 1,8 times. The porosity and ash content of Japanese plates are much lower than the requirements of TS. The elemental analysis of plates by atomic-emission spectroscopy method was carried out and it was established that the chemical compositions of coke plates are close. The total content of impurities in the investigated coke plates does not exceed 0,5–0,6 wt. %, the content of the main harmful sulfur impurity in the samples being not more than 0,1–0,3 %. The size of pores and their distribution in the plates were determined by scanning electron microscopy. In general, French and Chinese samples are characterized by pores with dimension in the range of 2,9–117 μm. German samples are characterized by pore size which is less than 5,9 μm. Almost 70 % of pores of Japanese samples correspond to three intervals: 2,9–5,9; 2,0–2,3 and 0,9–2,0 μm. X-ray diffraction analyses show that materials of all manufacturers have similar diffraction patterns, except for the samples of Japanese «GS-R», which are characterized by the presence of a significant amount of carbon with a graphite structure, determined by the position of the reflexes. This is obviously due to the various conditions of crystal formation in production of these coke plates. According to the results of differential thermal analysis, the authors determined the characteristics of the main processes occurring during heating the coke plates in the air. The coke plates we classified as well according to thermal stability.

PROSPECTS FOR DEVELOPMENT OF TECHNOLOGY AND FACILITIES OF PILOT BORES HORIZONTAL DIRECTIONAL DRILLING FOR TRENCHLESS LAYING OF PIPELINES

2019-04-30T08:36:55+00:00

The relevance. In the process of horizontal directional drilling, it is often necessary to overcome solid inclusions or hard rocks, that requires the use of a rational way of their destruction by an impact. However, the existing percussion mechanisms of modern drill rigs form power impulses of irrational form, which do not take into account the properties of the rock to resist destruction. This form of power pulses and the short duration of their impact on the rock reduces the drilling deeper, forming a tensile deformation wave that destroys the drilling tool. Therefore, there was a need for scientific substantiation and development of a conceptually new technique to improve the technology of pilot bores horizontal directional drilling. The main aim of the research is scientific substantiation and development of a fundamentally new former of power impulses in the drill string, taking into account the behavior penetration resistance into the rock, and new design of thread joints of drill pipes, taking into account the wave nature of the power impulses propagation through them for pilot bores horizontal directional drilling. Object: facilities of horizontal directional drilling of pilot wells using the energy of power pulses propagating through the drill string. Methods: review and analysis of scientific and technical information; methods of theoretical and applied mechanics; strain measurement of the drill string during elastic deformation waves propagation via a bench simulating artificial bores; mathematic simulation of the power pulses forming system and the process of their propagation through thread joints of the drill string. Results. The paper introduces the overview of trenchless technology. The authors have identified the prospects for improving the technology of horizontal directional drilling of pilot bores as the initial stage of trenchless pipe laying technology and proposed the techniques to improve the horizontal directional drilling of pilot wells, providing a significant increase in penetration drilling rate.

IMPROVING THE TECHNOLOGY FOR PROCESSING SUNGULITE-VERMICULITE CONGLOMERATES

2019-04-30T08:38:03+00:00

Relevance. The improved energy and resource-saving technology, implemented in new technological complexes with preliminary «cold» re-preparation, allows returning valuable raw material resources to industrial circulation and obtaining vermiculite and sugulite concentrates from mining waste accumulated in the Kovdor flogopit-vermiculite deposit. Therefore, this work is devoted to the issues of improving the processing of sungulite-vermiculite conglomerates. The aim of the research is to analyze the possibility of improving the technology for producing thermally activated sungulite and expanded vermiculite from mining wastes of the Kovdor phlogopite-vermiculite deposit and increasing its energy efficiency. The object of the research is the technological equipment for processing sungulite-vermiculite conglomerates, which implements energy- and resource-saving technology for producing activated sungulite and vermiculite concentrate. The methods are based on the experimental data and analysis of aerodynamic separation of vermiculite and sungulite from olivine-pyroxene rock and increase of allotment of sungulite in sungulite concentrate. The results prove the aim of the research is achieved. On their basis, it is possible to develop the improved technology for vermiculite producing, including expanded and magnesia-silicate reagent (thermoactivated sungulite) from mining industrial wastes with energy savings of up to 182 kJ/kg, which reduces energy consumption of their processing by 28 % compared to the previous technology. Besides, additional technological operations make it possible to obtain 350 kg of raw vermiculite, 68 kg of pure magnesia-silicate reagent with grain sizes of 2,4...3.5 mm and 158 kg of sungulite concentrate in a thermo-activated form with grains of 1,3...2,4 mm at almost 86 percent concentration. In general, we can conclude that the continuation of work in the field of development and improvement of technologies for processing sungulite-vermiculite conglomerates is promising.

DETERMINATION OF VITALITY PARAMETERS OF PROTECTED CRITICAL ENGINEERING STRUCTURES UNDER SHOCK-WAVE LOADING

2019-04-30T08:37:29+00:00

The relevance of work is related to the trend of emergencies at oil and gas industry enterprises. In this relation, it is necessary to design reinforced concrete structures, which can be affected by intensive short-term dynamic loads of emergency shock-wave type. Taking into account the reaction of expansion during design allows revealing the hidden reserves of load-bearing capacity in bent ferro-concrete structures, as well as reducing cracking, due to the increase in rigidity. The effective way to reduce the magnitude of the dynamic impact is the use of yielding supports in the form of collapsible inserts of the annular section. Thus, the joint application of yielding supports and consideration of the spacer reaction make it possible to prevent damage, complete or partial destruction of structures. In addition, damage to the building structures of critical buildings and structures of the oil and gas complex leads to a halt in technological process, which in some cases is not only economically unprofitable, but also unacceptable, and can lead to significant material damage and loss of life. The aim of the work is to develop a methodology and algorithm for constructing energy diagram, perform a numerical assessment of using compliant supports for survivability of protected building structures under intensive loading Methods: experimental studies: reaction of input force, reaction of output force, acceleration, displacement by tensometry methods, numerical integration by Simpson method. Results. The authors have developed the technique and algorithm for constructing the averaged energy diagram and carried out the numerical assessment of using malleable supports for survivability of protected building structures of oil and gas facilities under short-term dynamic loading.

MATHEMATICAL MODELING OF HEAT TRANSFER BY OPERATION OF GEOTHERMAL HEAT PUMPS

2019-04-30T08:38:36+00:00

The relevance. The use of heat pumps to provide heat instead of traditional systems, which get energy from the burning of different fossil fuel kinds, has a number of environmental and economic benefits. Heat pumps can use air, ground, and water as an energy source. They can be used for various applications: hot water supply, air conditioning, heating and cooling water for different uses, air drying/dehumidification, vapor production, evaporation, and distillation. By the use of natural water surface (lakes, ponds, reservoirs) as a low-potential heat source for heat pump, ice can be formed on the evaporator pipe surface. It is important to study the heat exchange characteristics between the water and the evaporator pipe undergoing ice formation on its surface. The main aim of the research is mathematical modeling for non-stationary convective heat exchange between the water and the heat pump evaporator pipes under the conditions of ice formation on their surface. The object of the research is the heat pump evaporator heat exchanger which is surrounded by water. The methods of the research are numerical solutions for convective heat transfer problem under the conditions of the water phase change by the use of the finite element method in COMSOL environment. Results. The authors have established the unsteady convective heat transfer laws near the water source heat pump evaporator pipes with the temperature under water freezing point. In calculations of the heat flux and ice thickness growth rate on the surface of heat pump evaporator pipe, the natural convection in water effect must not be ignored. The authors obtained the dependence of Nusselt number on the natural convection heat exchange characteristics undergoing a phase change (Rayleigh, Fourier and Stefan numbers). It is revealed that the drop rate in water temperature around the pipe increases with the decrease of its depth from the surface of the water source for water temperatures values higher than 277 K. For water temperatures lower than 277 K, the heat flux is maximum around the pipe, which is located deeper.

GEOCHEMISTRY OF URANIUM AND THORIUM IN BOTTOM SEDIMENTS OF SMALL ARTIFICIAL WATER RESERVOIRS AND LAKES IN THE SOUTH OF THE TOMSK REGION

2019-04-30T08:36:21+00:00

The relevance. Radioactive elements are effective markers of the bottom sediments of Tomsk region. The aim of the research is to study radiogeochemical features of the sediments of small water reservoirs in the south of Tomsk region. The object of the study is the bottom sediments of small reservoirs in the south of Tomsk region. Methods: detailed sampling of the sediments of small reservoirs, multi-element instrumental neutron activation analysis, and data processing and interpretation by applied statistics methods. Results. We carried out radio-geochemical study of the sediments of small water reservoirs in the south of Tomsk region. Mean contents of uranium and thorium in the sediments of small reservoirs in the south of the Tomsk region were estimated. The studies showed that the uranium and thorium contents depend on the type of sediments. The highest uranium content was found in the terrigenous type of the sediments, the lowest one was found in the peat. Two zones with high uranium content were found. The first zone is spatially coinsine with Kozhevnikovsky and Shegarsky districts of Tomsk region. Osinovo-Babarykinskaya anomalous zone of uranium accumulation in this region is clearly visible, which is well seen in the submeridional direction. Within Kozhevnikovo district, it can be associated with underground water discharge in the area of the Kolyvanskiy fault. In Shegarsky district, the high uranium contents spatially relate to granitoids of the late Paleozoic Foundation. The second zone of uranium accumulation extends along the southern frame of the West Siberian plate within the Kuznetsk-Alataussky block.

STUDY OF FILTRATION AND RHEOLOGICAL PROPERTIES OF POLYMER GEL TO IMPROVE OIL RECOVERY

2019-04-30T08:35:46+00:00

The relevance. Polymer flooding is widely used in practice in the development of oil fields. The high-concentration polymer solution has strong viscoelasticity, but with the increase in mass concentration of the polymer, the compatibility problem occurs between polymer molecules aggregate size and reservoir rock pore size during its practical application. Cr^{3 +} polymer gel based on intramolecular cross-linking has a smaller aggregate size and good compatibility with the reservoir, so it is relevant to study the effect of gel formation of Cr^{3 +} polymer gel and its influence factors. The main aim of the research is to study filtration and rheological properties of polyacrylamide-based aqueous gel with chromium acetate to enhance oil recovery. Methods: physical simulation of oil displacement and fluid filtration under reservoir conditions on a filtration unit, determination of viscosity of cross-linked polymer gel using the Brookfield DV-II viscometer, measuring the size of the molecular coil Dh in a Brookhaven BI-200SM light scattering system (Brookhaven Instruments Cop., USA), determination of viscoelasticity using the Harke10 rheometer. Results. Regulating the concentration of polymer, water solution salinity and the ratio of the polymer content and chromium (w(П/Cr³⁺)), one can obtain the Cr³⁺ polymer gel system based on intramolecular cross-linking with a smaller molecular aggregate and higher resistance confidence. After the reaction of intramolecular cross-linking of the polymer solution, on the one hand the viscoelasticity of the system is significantly improved and the oil displacement coefficient increased. On the other hand, the intramolecular crosslinking reaction reduces the flexibility of the polymer molecule aggregates, increases their rigidity, weaken their deformability in the process of passing through the pores, and enhance the retention ability in the high permeability layer. Cr^{3 +} polymer gel system not only has good injectability, it can also gradually reach a higher injection pressure, so it enlarges sweep volume effectively. In total, it is shown that the oil recovery coefficient of the polymer gel system is higher than the polymer solution.

IDENTIFICATION OF PARAMETERS OF VIBRATION ELECTROMAGNETIC ACTIVATOR MECHANICAL SYSTEM USING LIMITING NEAR-RESONANCE FREQUENCY

2019-04-30T08:41:25+00:00

The relevance of the research is caused by the fact that vibration electromagnetic activators are effective devices for mixing suspensions, emulsions, preparing drilling fluids, liquefying highly viscous petroleum products. Armature has special design is a hydraulic rectifier. When the armature vibrates at near-resonance frequencies, deeply submerged jets are created in the treated fluid medium, which ensure high efficiency of mixing fluid medium and decrease in viscosity of petroleum products for a long time at relatively low energy consumption of the vibration electromagnetic activator. The resonant frequency of the mechanical system depends on spring stiffness, mass of the armature-activator, added mass of the fluid oscillating with the armature and viscous friction coefficient that determines the removal of energy from the vibration mechanical system. When the rheological properties of the treated fluid change, both the parameters of the mechanical vibration system and the type of frequency response of the vibration electromagnetic activator change. The method of organizing monitoring of changes in the rheological properties of a treated fluid medium with the vibration electromagnetic activator based on direct measurements, for example using viscometers, is suitable only for laboratory conditions and is not suitable for industrial implementation. According to the authors a more promising approach is based on solving an inverse mathematical problem when analyzing the vibration electromagnetic activator frequency response in particular limiting near-resonance frequency, one can get reliable estimates of the parameters of the vibration electromagnetic activator vibration mechanical system. It is convenient to use these estimates for organizing indirect monitoring of changes in the rheological properties of the treated fluid during the vibration electromagnetic activator operation and for improving the structure of the vibration electromagnetic activator automatic control system. The main aim of the research is to design the parameters identification of the vibration electromagnetic activator mechanical system using limiting near-resonance frequency method and to determine the method’s limits of applicability in high damping vibration mechanical systems. Research methods: ordinary differential equations, Laplace transform, transmissibility, frequency response, algebraic equations. Results. The authors have obtained the analytical expressions relating the limiting near-resonance frequency to the parameters of a vibration mechanical system. Based on the latter the system of algebraic equations was obtained. The method’s limits of applicability in high damping vibration mechanical systems are shown.

SUCKER-ROD PUMPING UNIT BALANCE DIAGNOSTICS BY WATTMETER CARD

2019-04-30T08:40:17+00:00

The relevance of the research is conditioned by widespread use of unregulated sucker-rod pumping units, equipped only with mechanical adjustment tools. Application of that type of units results in considerable losses of both electricity and crude oil related to machine operating in non optimal regime. To solve this problem both new and already exploited sucker-rod pumping units are equipped with means of intelligent control and monitoring, which are included within control stations equipped with frequency converter and controller. Implementation of these tools on sucker-rod pumping units control station controller requires the development of appropriate algorithms to ensure autonomous, high performance, cost-effective and reliable function of plant during all life cycle. The main aim of the research is elaboration of the algorithms for determining pumpjack balance, optimal counterbalance position and polished rod dead centres passing moment. Objects of the research are the sucker-rod pumping unit in different operating modes and pumpjack balance, defined by the counterbalance position on the crank. Methods: mathematical analysis tool of differential equations and transfer functions, computer simulation, comparison and analysis of charts and diagrams. Results. The paper considers the existing ways of pumpjack balance detection and their shortcomings. It turns out that wattmetering is the most available and fail-safe sucker-rod pumping unit condition monitoring method which does not require installation of additional external sensors. The authors have developed the sucker-rod pumping unit computer model for investigating principles and load cycles of unit operation. Based on the data obtained by simulations the authors developed the algorithm of pumpjack balance detection, which can work as sucker-rod pumping unit intelligent control station software ensuring easy control, timely service and cost reduction.

EFFICIENCY OF ORE BLASTING IN SLOPING LOW-YIELD DEPOSITS

2019-04-30T08:39:09+00:00

The relevance of the study is explained by the fact that most of the base metal, noble metal and rare metal ores are extracted in difficult conditions, where the use of high-performance equipment is impossible. The alternative mining of that sort of ore bodies is chosen as a result of a compromise between extraction rating and quality of the produced ore. It is considered, that the longwall ore breaking in form of pit bank is the most effective one. Other options are considered as cost-intensive because of special drifting for ore breaking. The aim of the study is to prove, that the alternative options of ore production under the same conditions can compete with the main option upon performance and quality indicators, being much safer, excluding the presence of people in work in the mined-out area. The main method of the research is modeling of mining indexes in experimental blocks when conditions in a specific deposit are met. The obtained indicators are systematized and interpreted graphically. Results. The paper introduces the results of modeling the options of the heading system: the option of the bank ore breaking in the stopping zone is compared with the one of the ore breaking from the drilling room: sublevel drifts and risings. The authors have determined the quantitative indicators of alternative options. It is determined that the labour intensity of the drilling room sinking is compensated by the convenience of ore delivery and relative operating safety. It is proved that the options of the heading and room-and-pillar systems, using the drilling factor in the solid ore in special pits and ore breaking by the direct action of the explosion are economically sounder and safer. Conclusions. With little difference in the parameters of the compared options, the increasing labour intensity sinking of the special drilling rooms for ore breaking is compensated by cost saving in ore delivery when the ore bar is created using the direct action of the explosion.

COMPUTING OF TEMPERATURE CORRELATIONS BETWEEN SOIL LAYERS IN RESEARCH WITH SHALLOW BOREHOLES

2019-04-30T08:40:50+00:00

The relevance of the research is caused by the need to study geological objects by direct geophysical measurements of their parameters and applications of the obtained data and the results of mathematical processing for solving environmental management problems. Effective solution of these problems is especially important when research the influence of meteorological parameters on the water-thermal regime of rocks in areas with deep seasonal freezing. The main aim of the research is to develop a geophysical complex to determine the spatial distribution of temperature in the ground, to research the dynamics of changes in this distribution over time, to compute correlation of freezing various soil horizons in the conditions of Siberia and the Far North. Objects of researches are the federal highway «Surgut–Salekhard» within the Yamal-Nenets Autonomous District and the road of territorial importance «Korotchaevo–Urengoy». Methods: methods of analyzing statistical data to research the relationship between the values of variables, including the study of the statistical relationship of two or more random variables (correlation analysis), functional analysis methods for the research of statistical data in the time-frequency range (wavelet transform). Results. It was shown that with an increase in soil depth the freezing pattern is more flat and with increasing distance between observation horizons the correlation between them decreases. In particular, in soil layers 1,9–2,1 m the values of the coefficients of temperature correlation practically do not change at all time scales of the sample. In the soil layers 0,9–1,2 m, 1,2–1,5 m, 1,5–1,8 m on the average time scales of the sample, there is an insignificant change in the coefficients of temperature correlation, and the maximum deviation of the correlation coefficients is observed at large sample time scales. In the soil layers 0,3–2,1 m, 0,3–1,8 m, 0,6–2,1 m on the average time scales of the sample, there is a significant deviation of the coefficients of temperature correlation, and the maximum deviation of the coefficients of temperature correlation is also observed at large scales of the sample. On the basis of the obtained temperature series, spectrograms of wavelet transforms for classical basic wavelets (Morlet wavelet, DOG wavelet, Paul wavelet) were obtained, which indirectly demonstrate the wavelike «promotion» of the cold front (phase) in the ground.

CALCULATION OF STABILITY OF SLOPES IN THE AREAS OF CONSTRUCTION OF SPORTS AND TOURIST COMPLEX «GORNY VOZDUKH» (MOUNTAIN BOLSHEVIK, YUZHNO-SAKHALINSK)

2019-04-30T08:39:43+00:00

The relevance of the researches is caused by the need of safety ensuring in functioning of STK «Gorny vozdukh» objects. On sloping parts of the STK there is a danger of landslide processes. The first stage of specialized monitoring was performed to assess the dynamics of development of landslide processes in places of mass accumulation of people in the STK functioning. The aim of the research is to study the dynamics of landslide processes and to assess the stability of slopes in places with a large number of holidaymakers and athletes for their safety. Objects: Northern, Southern and Western slopes of Bolshevik mountain; soil composing the upper part of the lithosphere to a depth of 10 meters; groundwater. Methods: relevant research in the cross stretch of the slope – route reconnaissance survey, excavation of test pits up to two meters deep (full passage deluvial sediments and the autopsy eluvial rocks), sampling of undisturbed structure with the interval of 0,2–0,3 m, geophysical investigation by ground penetrating radar scanning using a mobile GPR setup ОКО-2, laboratory testing of selected soil samples. Groundwater is not detected within the research process. Results. According to the research in November–December 2017 at three sites of STK «Gorny vozdukh» – the Northern, Southern and Western slopes – the authors have selected the representative sites on slopes, made specification of engineering-geological section of the listed slopes, in particular the position of the border «deluvium–eluvium», made the calculation of engineering-geological elements and the coefficients of stability of slopes within the studied plots according to the method of tangential forces for propped against the slope in the absence of groundwater.

INDICATORS OF NUCLEAR TECHNOGENESIS ON THE EXAMPLE OF THE TERRITORIES ADJACENT TO THE FORMER SEMIPALATINSK TEST SITE

2019-04-30T08:35:12+00:00

The relevance of the research is determined by the need to identify the indicator properties of chemical composition of the natural environment components, local and regional characteristics of their composition, taking into account natural and anthropogenic factors of influence in order to conduct environmental assessment and areas subdivision effected by nuclear technogenesis. Environmental zoning of the study areas was carried out only taking into account the dose loads of the population obtained as a result of the activities of the former Semipalatinsk test site. In this regard, it is necessary to study the natural geochemical specifics, which would allow a more accurate approach to the issue of environmental assessment of the studied areas, taking into account the complex impact of natural and man-made factors The main aim of the research is the complex study of the elemental composition of the environment components in the territory adjacent to the former Semipalatinsk Test Site Object of the research is the components of the environment (soil, salt deposits of drinking water, plant), food, biological objects. Methods. Complex of environmental components was sampled in residential courtyards. The main criterion in selection of the investigated residential yards was the fact that the respondents lived there for at least 10 years. After appropriate preparation, the samples of the selected components were studied on instrumental neutron activation analysis The paper introduces the results of a comprehensive study of elemental compositions of the environment components (soil, salt deposits of drinking water, biological objects, food products) that are in contact with them in the zone of influence of the former Semipalatinsk Test Site. Elements-indicators of the nuclear technogenesis effects were identified in the studied environment samples as a regional specificity of the chemical composition of the studied territory show in U and Zn accumulation.