Синтезированы и исследованы бинарные системы глубоких эвтектических растворителей (ГЭР): “четырехатомный спирт – соль четвертичного аммониевого основания” (ГЭР1), “четырехатомный спирт – карбамид” (ГЭР2), “соль четвертичного аммониевого основания – карбамид” (ГЭР3), и тройная система “четырехатомный спирт – соль четвертичного аммониевого основания – карбамид” (ГЭР4). Эвтектические составы бинарных систем характеризуются существенно более низкими температурами застывания/плавления по сравнению с исходными компонентами. Самое низкое значение температуры среди бинарных смесей наблюдается для эвтектического состава ГЭР3. Тройная система ГЭР4обладает еще более низкой температурой плавления (–14 °С), что связано с образованием межмолекулярных донорно-акцепторных водородных связей внутри системы. На основе ГЭР4 был приготовлен водный раствор с концентрацией 26 мас. % и определен его водородный показатель в зависимости от температурных условий приготовления. При комнатной температуре pH трехкомпонентного ГЭР составляет 6.6–7.1, а после термостатирования в течение 6 ч при 150 °С увеличивается до 9.2 за счет гидролиза карбамида. Предполагается, что в дальнейшем при использовании ГЭР4в качестве основы щелочной нефтевытесняющей композиции непосредственно в пласте, под действием температуры закачиваемого теплоносителя образуется СО2 и аммиачная буферная система с максимальной буферной емкостью в интервале рН 9–10. Образовавшийся углекислый газ, растворяясь преимущественно в нефти, будет приводить к снижению ее вязкости, с одной стороны, а сформированная щелочная среда, являясь наиболее благоприятной для работы поверхностно-активных веществ за счет снижения межфазного натяжения и разжижения высоковязких слоев или пленок на границах “нефть – вода – порода”, с другой – обеспечат эффективное применение такой системы для нефтевытеснения. Кроме того, нефтевытесняющая композиция на основе ГЭР4 будет низкозастывающей, что открывает возможности ее транспортировки и применения в условиях северных регионов и Арктической зоны. The binary systems of deep eutectic solvents (DESs) have been synthesised and investigated: tetraxydroxy alcohol – a salt of a quaternary ammonium base (DES1), tetrahydroxy alcohol – carbamide (DES2), a salt of a quaternary ammonium base – carbamide (DES3), and the ternary system tetrahydroxy alcohol – a salt of a quaternary ammonium base – carbamide (DES4). Eutectic compositions of binary systems DES1, DES2and DES3are characterised by significantly lower pour/melting points than those of the initial components. The lowest pour point among the binary mixtures is that of eutectic composition DES3. The ternary system is characterised by an even lower pour point (-14 °C), which is associated with the formation of intermolecular donor-acceptor hydrogen bonds within the system. An aqueous solution of DES4with the concentration of 26 wt% was prepared, and its pH value was determined depending on temperature during preparation. At room temperature, pH of three-component DES is 6.6–7.1, but after thermostating for 6 h at 150 °C pH increases to 9.2 due to carbamide hydrolysis. It is assumed that further on, using DES4as the basis for an alkaline oil-displacing composition directly in the reservoir, under the influence of the temperature of injected heat carrier, CO2is formed, along with the ammonia buffer system with the maximal buffer capacity within the pH range 9–10. Resulting carbon dioxide, dissolving predominantly in oil, will cause a decrease in its viscosity, on the one hand, while the formed alkaline medium, being most favourable for surfactant performance due to a decrease in interfacial tension, liquefaction of high-viscosity layers or films at the oil-water-rock boundaries, on the other hand, will ensure efficient use of this system for oil displacement. In addition, the oil-displacing composition based on DES4will be low-solidifying, which opens the possibility of its transportation and use in the northern regions and the Arctic zone.

Исследованы реологические (структурно-механические) свойства гелеобразующих композиций, гелей и криогелей на основе поливинилового спирта, а также разработанные в Институте химии нефти СО РАН композиции, перспективные с точки зрения борьбы с эндогенными пожарами, а также интенсификации метановыделения при поинтервальном гидроразрыве угольных пластов. В осцилляционном режиме на реометре с контролируемой деформацией получены амплитудные и кинетические зависимости модуля упругости (G¢), модуля потерь (G¢¢) и комплексной вязкости для составов, отличающихся соотношением компонентов при различных температурах. Показано, что гель начинает образовываться уже в момент смешивания компонентов, а у формирующейся структуры преобладают упругие свойства (G¢ > G¢¢). Определены значения точек гелеобразования. Установлено, что с повышением концентрации сшивателя возрастает прочность образующейся структуры, а время образования геля снижается. При понижении температуры прочность образующейся структуры также возрастает. В статическом режиме деформирования образца установлено, что после цикла замораживание-оттаивание гель дополнительно стабилизируется. Разработанный состав композиции обладает прочностными свойствами и хорошей адгезией к поверхности угля, его можно использовать для защиты от самовозгорания забоев угольных разрезов и в качестве защиты от угольной пыли на технологических дорогах. Исследовано изменение зависимости “деформация - сжатие” при постоянной нагрузке от времени для геля и криогеля. Установлено, что при постоянной нагрузке (7 кПа) деформация геля достигает 25 %, а криогеля - 15 %, т. е. после цикла замораживания-оттаивания упругие свойства композиции увеличиваются. В связи с этим проведение работ на объектах предпочтительно в осенне-весенний период. The rheological (structural-mechanical) properties of gel-forming compositions, gels and cryogels based on polyvinyl alcohol, as well as the compositions developed at the Institute of Petroleum Chemistry SB RAS, which are promising from the viewpoint of preventing endogenous fires and intensifying methane release during interval hydraulic fracturing of coal seams, have been studied. The amplitude and kinetic dependences of the elastic modulus ( G' ), loss modulus ( G'' ) and complex viscosity were obtained in the oscillatory mode using the rheometer with controlled deformation for the compositions differing from each other in the ratio of components at different temperatures. It has been shown that the gel starts to form already at the moment of component mixing, and the elastic properties of the forming structure predominate ( G' > G'' ). The values of gelation points were determined. It is found that with an increase in crosslinker concentration, the strength of the resulting structure increases, and the time of gel formation decreases. As the temperature decreases, the strength of the resulting structure also increases. In the static mode of sample deformation, it is established that the gel is further stabilised after the freeze-thaw cycle. The developed composition has strength properties and good adhesion to the surface of coal. It can be used to protect coal mine faces from spontaneous combustion and as a protection from coal dust on technological roads. The change of the deformation-compression dependence under constant load on time for gel and cryogel was studied. It has been established that under a constant stress of 7 kPa, gel deformation reaches 25 %, while cryogel deformation is 15 %, that is, the elastic properties of the composition increase after a freeze-thaw cycle. In this regard, it is preferable to carry out the work at sites in the autumn and spring time.

The results of laboratory tests of an acidic oil-displacing composition based on a deep eutectic solvent (DES) are presented. The dissolving ability of the composition in relation to a carbonate reservoir rock was determined, and corrosion activity toward St3 steel was studied. Filtration tests demonstrated the high oil-displacing efficiency of the composition due to the equalization of filtration flows, increased formation sweep, and high oil-displacing ability.

A composition characterised by adjustable physicochemical parameters within a broad range has been developed relying on the results of studies of the phase equilibria in the ternary system of deep eutectic solvents (DES) glycerol - carbamide - boric acid. The effect of this composition on oil recovery enhancement is studied, and results obtained in the laboratory studies of the effect of DES-based composition on the filtration characteristics of a heterogeneous formation in the carbonate reservoir of the Usinsk field are presented. The efficiency of the composition for oilfields at the early and late stages of development has been assessed by physical modelling. The treatment of a model of a heterogeneous reservoir with the composition is determined to cause a substantial increase in oil displacement coefficient at either low or high temperatures due to equalisation of filtration flows, an increase in reservoir coverage, and restoration of initial permeability. Investigation of the composition and properties of heavy high-viscosity oil before and after treatment with the composition shows that the application of DES-based acid composition does not affect the qualitative composition of oil. The use of the composition leads mainly to redistribution of the content of low- and high-molecular structures: predominantly light occluded hydrocarbons are displaced, while heavy oil components are adsorbed on the reservoir.

The results of rheological measurements of a low-temperature composition based on inorganic components developed at the Institute of Petroleum Chemistry SB RAS (GALKA®) are presented. The studies were carried out with a Haake Viscotester IQ rheometer using CC25 geometry (oscillation mode at a frequency of 1 Hz) at different temperatures. The amplitude test determined the range of strain and stress amplitude values corresponding to the range of linear viscoelasticity. For a given value of the deformation amplitude from the range of linear viscoelasticity, the dependences of the complex viscosity modulus (|η*|), the elastic modulus (storage modulus, G´), and the viscosity modulus (loss modulus, G´´) on time were recorded at a temperature of 38, 30, and 20 °С. The kinetics of the gel formation process was characterized, the maximum strength of the formed structure was estimated from the maximal elastic modulus, the time of its formation and the starting points of gelation were determined.

Zeolites of the structural type ZSM-5 were synthesized using a template, which was pentaerythritol (PER), carbamide (CA), or a deep eutectic solvent (DES) - a binary mixture of PER and CA. It is determined by IR spectroscopy and X-ray diffraction analysis that the nature of the templates used in the synthesis of zeolites affects the phase purity and the degree of crystallinity of the obtained samples. The textural and acidic properties of zeolites and Mo-containing catalysts prepared from them by dry mechanical mixing with nanoscale molybdenum powder have been studied. It is shown that the textural properties of zeolites depend on the template nature. The use of CA promoted obtaining the zeolite with maximal specific surface area and pore volume. The strength of the acid centres of unmodified samples, depending on the structure-forming additive, decreases in the series: DES > CA > PER, and the concentration of acid centres of both types, on the contrary, decreases for zeolites in the series: PER > CA > DES. The catalytic activity of synthesized zeolites has been studied in the processes of non-oxidative methane conversion and refining of the straight-run gasoline fraction of oil. The dependence of the activity and stability of samples on their physicochemical properties caused by the template nature is determined. It has been shown that zeolite synthesized using DES and the 4.0%Mo/ZSM-5 catalyst obtained on its basis exhibit higher activity and stability in the processes of non-oxidative methane conversion into aromatic hydrocarbons and in upgrading the straight-run gasoline fraction of oil, in comparison with zeolite-based catalysts obtained using PER or CA.

The paper presents the results of development and research of multifunctional acid oil dis-placing composition for application in the West Siberian viscous oil field with terrigenous reservoir type. On the basis of the results of physical modeling of oil displacement process the efficiency of multifunctional acid oil-displacing composition has been evaluated in relation to the conditions of viscous oil fields of Western Siberia, which are at early and late stages of development. The oil displacement process with the use of multifunctional acid oil displacing composition was carried out under conditions modeling the natural development mode at the temperature of 23 degrees & Scy;and at the temperature of 90 degrees & Scy;.The study of oil-displacing ability of multifunctional acid composition showed its high efficiency for oil production intensification and oil recovery enhancement of viscous oil fields of Western Siberia with terrigenous reservoirs. The composition provides increase inoil displacement coefficient from high-permeability and low-permeability models of highly heterogeneous reservoir due to high oil-washing properties, as well as equalization of injectivity profile, increase inreservoir coverage coefficient by physical and chemical influence (change of permeability ratio of layers in the reservoir model). As a result of analysis of the components of the composition in the samples taken at the outlet of the model of heterogeneous reservoir, the presence of a large amount of urea in them is shown, and the value of the hydrogen indicator pH during the experiment decreases from 7.2 to 2.4 pH units and then, after heating to 90 degrees & Scy;and subsequent exposure, as a result of partial hydrolysis of urea, which is part of the composition, shifts to the region of neutral values, reaching 6.2 pH units. The composition has low corrosive activity and good solubilizing ability in relation to terrigenous reservoir rock.

The work proposes a method for forming a composite cryotron material based on an aqueous solution of polyvinyl alcohol for application to the surface of a snow-ice sheet. Freezing an aqueous solution of polyvinyl alcohol at a negative temperature and subsequent thawing at a temperature above zero leads to the formation of elastic cryogels. The introduction of boric acid into a polymer solution leads to chemical cross-linking of kinetically individual macromolecules of polyvinyl alcohol into spatial networks that have elastic properties. The practical interest in using materials based on cryogels is due to environmental safety, high physicochemical and thermophysical properties, a simple method for their preparation and low cost. When studying the kinetics of gelation of multicomponent systems, it was observed that the formation of a gel at a temperature of 5 degrees C occurs after approximately 13 hours. It has been established that with increasing temperature control time of the gel at a temperature of 5 degrees C, the el astic modulus of samples obtained as a result of a chemical reaction increases by 2 times in approximately 120 h. It has been shown that after cryostructuring of multicomponent solutions, the elastic modulus increases 9 times. The presence of sand in a structured system significantly increases the elastic properties of the gel and cryogel. It should be noted that the thermal conductivity coefficient of cryogels is almost 2 times less than that of water, and the melting point is more than 60 degrees C. The results of practical experiments show that coating a snow-ice surface with cryogel reduces the rate of its melting and, therefore, compositions based on cryogels can be used to extend the life of safe operation of winter roads.

Within the framework of green chemistry principles, the concept of deep eutectic solvents (DES) was used to develop solid commercial forms of oil-displacing compositions. It has been shown that the eutectic composition on the phase diagram of the binary system ammonium salt - carbamide corresponds to DES as the basis of solid commercial forms of oil-displacing composition with the best physicochemical and technological characteristics. The optimal concentrations of solid commercial forms in the working solution of the composition were determined for the ternary DES system ammonium salt - carbamide - water. The results of laboratory studies and field tests of the working solution based on the solid commercial forms of the oil-displacing composition are presented.

The binary systems of deep eutectic solvents (DESs) have been synthesised and investigated: tetraxydroxy alcohol - a salt of a quaternary ammonium base (DES1), tetrahydroxy alcohol - carbamide (DES2), a salt of a quaternary ammonium base - carbamide (DES3), and the ternary system tetrahydroxy alcohol - a salt of a quaternary ammonium base - carbamide (DES4). Eutectic compositions of binary systems DES1, DES2 and DES3 are characterised by significantly lower pour/melting points than those of the initial components. The lowest pour point among the binary mixtures is that of eutectic composition DES3. The ternary system is characterised by an even lower melting point (-14 °C), which is associated with the formation of intermolecular donor-acceptor hydrogen bonds within the system. An aqueous solution of DES4 with the concentration of 26 wt% was prepared, and its pH value was determined depending on temperature during preparation. At room temperature, pH of three-component DES is 6.6-7.1, but after thermostating for 6 h at 150 °C pH increases to 9.2 due to carbamide hydrolysis. It is assumed that further on, using DES4 as the basis for an alkaline oil-displacing composition directly in the reservoir, under the influence of the temperature of injected heat carrier, CO2 is formed, along with the ammonia buffer system with the maximal buffer capacity within the pH range 9-10. Resulting carbon dioxide, dissolving predominantly in oil, will cause a decrease in its viscosity, on the one hand, while the formed alkaline medium, being most favourable for surfactant performance due to a decrease in interfacial tension, liquefaction of high-viscosity layers or films at the oil-water-rock boundaries, on the other hand, will ensure efficient use of this system for oil displacement. In addition, the oil-displacing composition based on DES4 will be low-solidifying, which opens the possibility of its transportation and use in the northern regions and the Arctic zone.

This paper describes the study of a method for controlling the physical and chemical properties of an oil reservoir in order to increase its oil recovery by injecting a GBA-F acid composition into the reservoir. An experimental testbed is developed to physically simulate the effect of the acid composition on the oil reservoir. Experiments are carried out using the flat model with a single injection of the reagent into the central wellbore. Experimental results confirm the effectiveness of the acid composition.

This paper presents the results of exploratory research in the field of synthesis of zeolite type ZSM-5 using deep eutectic solvents (DES) as structure-forming additives. The synthesis of zeolites was carried out by hydrothermal synthesis. As a source of silicon and aluminum, the sodium salt of silicic acid and the aqueous salt (nonahydrate) of aluminum nitrate were used. Binary and triple DES systems were used as structure-forming additives necessary for the initiation of the growth of zeolite crystals: "choline chloride - urea", "pentaerythritol - urea", "pentaerythritol - choline chloride", "urea - choline chloride - pentaerythritol" and "pentaerythritol - urea -boric acid". The study of synthesized materials by IR spectroscopy and X-ray phase analysis showed the success of obtaining zeolites in the presence of all structure-forming additives, with the exception of synthesis with the binary system "pentaerythritol -choline chloride" as a structure-forming additive. Structural parameters were determined for successfully synthesized zeolite samples: the specific surface area, distribution and pore size of the channels. It was found that the synthesis of zeolite in the presence of various DES leads to the formation of more mesoporous zeolites, having a smaller pore size, compared with the previously synthesized comparison zeolite. The study of the morphological features of the surface of zeolites synthesized using different DES showed a significant difference in the nature and shape of elementary zeolite particles. The use of more complex triple DES systems as structure-forming additives leads to the formation of a larger set of different forms of zeolite particles having the same elemental composition. The study of the acid characteristics of the synthesized samples and their comparison with the characteristics of the previously obtained and used zeolite allows us to put forward an assumption about the potential ability of zeolites to exhibit catalytic activity in the composition of catalysts for the processing of hydrocarbons.

Two methods for the transition of aqueous solutions of polyvinyl alcohol (PVA) from the liquid state of aggregation to the solid state are considered. Freezing an aqueous solution of PVA at a negative temperature and subsequent thawing at a positive temperature result in the formation of rubber-like cryogels. Another way is chemical crosslinking of kinetically individual PVA macromolecules to spatial networks having elastic properties. Sodium tetraborate was used to structure aqueous PVA solutions. The rheological properties of a two-component aqueous solution of polyvinyl alcohol were studied. The study shows that the polymer solution exhibits the properties characteristic of non-Newtonian liquids. The kinetics of gelation of the products of chemical structuring of aqueous PVA solutions with an aqueous sodium tetraborate solution was studied. It is shown that viscosity increases with time as a consequence of chemical interaction. The mechanical properties of carbon-containing composite materials obtained by various methods have been investigated. It has been determined that the most durable materials are those formed by the cryotropic method and those chemically structured after cryogenic treatments. The stress-strain and moisture-resistant properties of carbon materials enable their use as fuel briquettes with a minimum amount of a binder. They can also serve as high-energy fuels for domestic and industrial purposes. The chemical method of structuring a PVA solution can be used for dust control in coal mines.

In this paper, we analyzed the results of a series of laboratory experiments on oil displacement from a heterogeneous reservoir model, represented by parallel columns with oil-saturated core material with different permeability with a common inlet and a separate outlet. In the course of the experiment, the increase in the coefficient of oil displacement by water was estimated when injecting into the model batches of multifunctional oil-displacing and flow-diverting compositions of GBK and MIKA, developed at the IPC SB RAS. The multifunctional oil-displacing and flow diverting compositions MIKA and GBK considered in the article showed their effectiveness in the course of filtration experiments to displace oil from a heterogeneous reservoir model. The increase in the oil recovery factor in each experiment was observed both in the high-permeability and in the low-permeability column. The average increase in the oil recovery factor was 16.9%, with maximum values up to 29.9% for the model as a whole, and up to 49 % for a separate column. To analyze the results of the experiment, parameters were determined that characterize the heterogeneity of the model and flow, and show the change in flows due to their redistribution after the injection of the composition. The dependence of the increase in the oil displacement efficiency on the selected parameters made it possible to evaluate the contribution to the overall result of various mechanisms for increasing oil recovery - the actual oil displacement due to the oil-displacing properties of the composition, and the redistribution of flows in a heterogeneous model due to the viscosity of the composition. According to the analysis of the results of the experiment, the ratio of the increase in the oil recovery factor from oil displacement and redistribution is defined as 70:30. Oil-displacing properties play a more significant role, but the contribution from the redistribution of flows is significant, and it is the greater, the higher the heterogeneity. The results obtained can be used in the selection of objects for the commercial use of compositions - individual wells, sections, reservoirs and oilfields, and for predicting the technical and economic effect.

Предложены составы для формирования трехкомпонентных упругих криогелей на основе водных растворов поливинилового спирта (ПВС) и картофельного крахмала. Показано, что вязкость водных растворов зависит как от вида полимера, так и от суммарного содержания полимеров в системе. Модуль упругости трехкомпонентных криогелей зависит от концентрации в них крахмала и повышается от 5 до 15 кПа при добавлении 1-5 мас. % последнего. При введении в матрицу двух- и трехкомпонентных криогелей дисперсного материала (почвы), вследствие высокой адгезии полимера к наполнителю, получили наполненные криогели, модуль упругости которых в 16 раз больше, чем у криогелей без наполнителя. Введение 5 мас. % картофельного крахмала в состав криогеля ПВС увеличило время его полного высыхания на воздухе на одни сутки, а при хранении в воде - повысило его деструкцию на 5 % за неделю. Поведение двухкомпонентных криогелей при их хранении в воде резко различалось: криогель ПВС не менял массу, потеря массы для криогеля картофельного крахмала составила 11 % за неделю. В почвенном тесте под действием аборигенной почвенной микрофлоры показано снижение массы трехкомпонентных криогелей на 75-89 % за счет потери влаги и деструкции. Потеря массы двухкомпонентного криогеля на основе ПВС составила порядка 60 %. Тестирование почв на фитотоксичность после деструкции трехкомпонентных криогелей выявило снижение всхожести белой горчицы (Sinapis alba L.) на 2-10 % относительно контрольного опыта, в зависимости от содержания крахмала, а контрольного двухкомпонентного криогеля ПВС - на 18 %. Криоструктурирование верхнего почвенного слоя криогелем ПВС привело к повышению сухой надземной массы растений на 3.2 % по сравнению с контролем, криогелем картофельного крахмала - на 7.1 %, криогелем на основе ПВС и картофельного крахмала - на 9.4 %. Compositions for the formation of three-component elastic cryogels based on the aqueous solutions of polyvinyl alcohol (PVA) and potato starch are proposed. It is shown that the viscosity of aqueous solutions depends both on the kind of polymer and on the total content of polymers in the system. The elasticity modulus of three-component cryogels depends on the concentration of starch in them and increases from 5 to 15 kPa with the addition of starch in the amount of 1-5 wt%. By introducing a dispersed material (soil) into the matrix of two-and three-component cryogels, due to the high adhesion of the polymer to the filler, the filled cryogels were obtained, with the elasticity modulus 16 times higher than that of cryogels without the filler. The introduction of potato starch in the amount of 5 wt% into PVA cryogel caused an increase in the time of its complete drying by 24 h, and an increase in its destruction during exposure in water by 5% within a week. Two-component cryogels exhibited sharply different types of behaviour during storage in water: PVA cryogel did not lose its mass, while mass loss by the cryogel of potato starch was 11% within a week. A decrease in the mass of three-component cryogels by 75-89% due to the loss of moisture and destruction was demonstrated in the soil test under the action of aboriginal soil microflora. The mass loss by the two-component cryogel based on PVA was 60%. Soil testing for phytotoxicity after the destruction of three-component cryogels revealed a decrease in the germination capacity of white mustard ( Sinapis alba L.) by 2-10% with respect to the reference experiment, depending on starch content, while for the reference two-component PVA cryogel the corresponding decrease was by 18%. Cryostructuring of the upper soil layer by PVA cryogel caused an increase in the dry above-ground mass of plants by 3.2% in comparison with the reference, while the cryogel with potato starch caused an increase by 7.1%, and cryogel based on PVA and potato starch gave 9.4%.

The manufacturing of new biodegradable polymeric materials based on synthetic polyvinyl alcohol and vegetable starches is proposed. Rubber-like viscoelastic cryogels were prepared after a cycle of freezing-thawing of three-component solutions containing polyvinyl alcohol, starch and water. Particular interest in the use of cryogels is due to their elastic properties, environmental safety, and a simple way to prepare them. When studying the elastic properties of cryogels, an increase in the elasticity modulus of three-component cryogels against two-component cryogels was observed. The introduction of a filler (soil) into the matrix of the formed cryogel resulted in an additional increase in the elastic modulus from 5 kPa to 280 kPa. It has been found out that when three-component cryogels are stored in water, their mass decreases due to the washing out of starch biodegradation products from the multicomponent cryogel. Partial decomposition of the resulted polymeric materials by the natural soil microflora was as follows: for 14 days, the dry residual weight of the polymer in the soil was 19,6-59% of the initial one for cryogels with corn starch. For cryogels with potato starch, it decreased with increasing starch content to 12.5-57% of the initial weight. The role of soil microflora in the destruction of cryogels is confirmed by an increase in the count of first amylolytic and then ammonifying groups of microorganisms, which is accompanied by a change in a soil pH. After contact with the soil, the following changes in materials were visually observed: thinning of the layer, appearance of pores, and a decrease in mechanical strength. The appearance of cryogel degradation products in the soil reduced the germination of white mustard seeds by 2-12% as compared with the control. Cryostructuring of the soil (fixation of the upper soil layer) with two-component (PVA/water or potato starch/water) and three-component (PVA/starch/water) cryogels increased phytoproductivity: the dry weight of top of the same mustard was higher by 3.2-9.4% as compared with the control.

The results of rheokinetic measurements of changes in the fluidity of gel-forming compositions of various natures obtained by the methods of rotational and selection viscometry are presented. A technique for processing measurement results obtained by means of vibrational viscometry in measuring vessels of different sizes has been developed. Two directions of the interpretation of nonmonotonic rheokinetic dependences are considered.

To enhance oil recovery and intensify the development of fields with hard-to-recover reserves, including the deposits of high-viscosity oils, acid oil-displacing compositions with prolonged action have been developed on the principles of green chemistry using the method of deep eutectic solvents (DES). These compositions are based on surfactants and an adduct of inorganic acid, polyol and carbamide. As a result of experimental studies of acid base equilibria in three-component systems with donor-acceptor interactions "boric acid - carbamide - polyol (glycerol, pentaerythritol)", which are DES, the optimal compositions and concentration ranges of the components in acid compositions were determined. The results of laboratory studies and pilot tests of enhanced oil recovery technology with the use of acid compositions are presented. The compositions are compatible with mineralized formation waters, have a low freezing point ((-20)-(-50) & DEG;C) or a solid commodity form, low interfacial tension at the boundary with oil, are applicable in a wide temperature range (from 10 to 200 & DEG;C), provide effective oil displacement and prolonged impact on the formation. The acid GBA composition showed high efficiency under field conditions during pilot work in the experimental areas of the Permian-Carboniferous deposit of high -viscosity oil of the Usinsk oil field, developed under natural conditions and under thermal steam exposure, and was recommended for industrial use. The technology is environmentally friendly and technologically efficient. The industrial use of technologies for enhanced oil recovery and intensification of oil production is promising, which will make it possible to extend the profitable operation of fields at a late stage of development, to involve the fields with hard-to-recover oil reserves into development, in particular the deposits of high-viscosity oils, in a wide range of climatic conditions, including the northern regions and the Arctic.

Compositions for the formation of three-component elastic cryogels based on the aqueous solutions of polyvinyl alcohol (PVA) and potato starch are proposed. It is shown that the viscosity of aqueous solutions depends both on the kind of polymer and on the total content of polymers in the system. The elasticity modulus of three-component cryogels depends on the concentration of starch in them and increases from 5 to 15 kPa with the addition of starch in the amount of 1-5 wt. %. By introducing a dispersed material (soil) into the matrix of two-and three-component cryogels, due to the high adhesion of the polymer to the filler, the filled cryogels were obtained, with the elasticity modulus 16 times higher than that of cryogels without the filler. The introduction of potato starch in the amount of 5 wt. % into PVA cryogel caused an increase in the time of its complete drying by 24 h, and an increase in its destruction during exposure in water by 5% within a week. Two-component cryogels exhibited sharply different types of behaviour during storage in water: PVA cryogel did not lose its mass, while mass loss by the cryogel of potato starch was 11% within a week. A decrease in the mass of three-component cryogels by 75-89% due to the loss of moisture and destruction was demonstrated in the soil test under the action of aboriginal soil microflora. The mass loss by the two-component cryogel based on PVA was 60%. Soil testing for phytotoxicity after the destruction of three-component cryogels revealed a decrease in the germination capacity of white mustard (Sinapis alba L.) by 2-10% with respect to the reference experiment, depending on starch content, while for the reference two-component PVA cryogel the corresponding decrease was by 18%. Cryostructuring of the upper soil layer by PVA cryogel caused an increase in the dry above-ground mass of plants by 3.2% in comparison with the reference, while the cryogel with potato starch caused an increase by 7.1%, and cryogel based on PVA and potato starch gave 9.4%.