Dependencies of the viscoelastic and thermodynamic properties of high-viscosity oil from the oil-gathering reservoir of the N-Korenevskoye and Denisovskoye fields on the degree of water cut and temperature have been established. Under the conditions of shear deformations and at comparable temperatures, the nature of the processes of structure formation of oil at a low degree of water cut is due to phase transitions of paraffins, which is consistent with the experimental data described in the literature for non-watered oils, indicating the identity of the nature of intermolecular interactions between non-watered oil and oil with a low degree of water cut. The maximum effect of the thermal method for reducing the viscosity of oil with a low degree of water cut can be achieved when it is heated to the paraffin melting point T m *, determined using the ln(η) = f (1/T) dependence. The peculiarity of the rheological behavior of high-water-cut oil is due to an increase in the energy of intermolecular interaction, which in the entire temperature range is practically comparable to E act1 of low-water cut oil at T <T m *, which is associated with the formationn of invert emulsions stabilized by interphase layers of asphaltene molecules. It is shown that an increase in temperature and shear deformations contribute to a decrease in the values of the effective viscosity of low and high water cut oil; however, the destruction of their colloidal structure does not occur in the entire range investigated. The loss of aggregate and kinetic stability of high-viscosity watered oil is achieved in the presence of a surfactant composition based on Sorbital C-20 and a sodium salt of alkylbenzenesulfonic acid, which causes the desorption of “natural stabilizers” from the oil-water interface and, as a consequence, the coalescence of water droplets.
The influence of polycarboxylate and naphthalene-sulfone superplasticizers, paraffin hydrophobizator and complex hydrophobic-plasticizing additives on the structural characteristics, physical-mechanical, hydrophysical properties, corrosion resistance and frost resistance of fine-grained Portland cement concretes was studied. Structural parameters of concretes (average and true density; density coefficient; total, open, closed porosity) were compared with compressive strength, water absorption, softening coefficients and salt resistance of materials. It is shown that the introduction of superplasticizers increases the density, softening coefficients and salt resistance, reduces the water absorption of Portland cement structures, and the use of paraffin hydrophobization and complex hydrophobic-plasticizing additives increases the closed porosity as a result of the formation of mosaic hydrophobic films on the surface of solid phases, which have a positive effect on the hydrophysical and physical-mechanical properties of concretes.
Isothermal data of superficial tension of solutions of surfactant mixture and low-temperature nitrogen sorption of multidimensional porous silica received by template synthesis prove complementarity of its properties and properties of SAA micelles. The measured isotherms of gas sorption belong to IV Type inherent in mesoporous adsorbents. The BET specific surface area is 600–800 m2/g, and the Gurvich pore volume is 0.7–1.0 cm3/g. With increase in mole fraction of nonionic component these values decrease, the ordered texture of SiO2, characteristic of MCM-48 mesoporous molecular sieve, collapses, d211-spacing becomes < 3.31 nm, and NLDFT distribution is transformed from monomodal to polymodal one.
Physicochemical aspects of the regulation of interfacial processes occurring at the oil-water-rock interface in the presence of ionic surfactants and their compositions are considered with the goal of developing efficient, scientifically grounded innovative technologies ensuring enhanced oil recovery and refining. A complex of studies of surface phenomena in the presence of ionic surfactants made it possible to identify criteria for evaluating the effectiveness of their action at the oil-water-rock interface, which makes it possible to predict the behavior of surfactants in real conditions of oil production and to use them purposefully in various enhanced oil recovery technologies.
The adsorption capacity on the interphase surfaces of solution / air and solution / mineral material of binary mixtures of anionic (alkylbenzenesulfonic acid and its sodium salt (ABSCNa)) and nonionic surfactants (Tween-80) was studied. It has been established that the adsorption interaction of binary mixtures of surfactants with the surface of quartz and dolomite is affected by the presence of potential-determining ions that activate the surface of mineral materials, the charge and hydration of the anionic antagonists, the nature of the intermolecular interactions between the surfactant-components of the mixture. It was shown that the ABSCNa / Tween-80 mixture, characterized by low adsorption capacity to the mineral materials under study and absence of interaction between the surfactant components of the mixture, has a maximum oil displacement capacity from the surface of dolomite and quartz.
By the method of mathematical planning of the experiment, the influence of the liquid-solid ratio and the content of waste of salt deposits in magnesia hardening backfill mixtures on their technological properties have been studied. The plan of the experiment has been chosen, the regression equations describing the influence of anhydrite wastes and halite wastes content on the density, spreadability and early setting time of backfillingsolutions, volumetric mass, and 28-day uniaxial compression strength of hardened materials have been obtained. As a result of the statistical analysis of mathematical models, the significance of their coefficients, adequacy, efficiency and the ability to calculate technological characteristics of backfilling mixtures by type and content of man-made raw materials have been estimated.
Interfacial interactions of cationic surfactants of various chemical structures at the solution / finely dispersed mineral material (quartz and dolomite) interface were studied. It is established that the modification of the surfaces of quartz and dolomite with cationic surfactants leads to a change in the structure and radius of the capillaries due to the formation of adsorption-solvate shells. The hydrophobic ability of cationic surfactants is determined by the structure of the hydrophilic part of their molecules – the balance of amino groups in the alkyl chains and the absence of steric hindrances during adsorption interaction with the surface of mineral materials. The mixture of surfactants containing six amino groups and a polyhydric alcohol glycerin has an effective hydrophobic ability from both aqueous and highly mineralized solutions.
The influence of the preparation method, gypsum content and liquid-solid ratio on the process of hardening and properties of mixed gypsum-magnesia binders intended for laying in the developed space of salt areas has been studied. With the introduction of fillers – waste from the development of salt deposits and plasticizers – in them, filling mixtures, which are non-linear viscoplastic thixotropic systems with a certain period of stress and strain relaxation, have been obtained. The phase composition of hardening products, electrokinetic, rheological and physico-mechanical properties of the obtained plasticized filling mixtures depending on the method of injection, the type and content of plasticizers have been investigated. At optimum liquid-solid ratio and the plasticizer content of the mixture with low static and dynamic yield stress and effective viscosity and extended setting time have been obtained.
The influence of amorphous silica, plasticizer, water-repelling agent and integrated hydrophobic plasticizing additives on structural characteristics, physico-mechanical, hydrophysical characteristics and salt resistance of magnesia binders was studied. Some of the structural parameters (average and true density; density coefficient; total, open and closed porosity) were matched to compressive strength, water and salt absorption, water and salt resistance of the materials. It is shown that the introduction of the amorphous silica contributes to the forming of water resistant magnesium-siliceous structures, clogging of the pore space of silicic acid and small increase of closed porosity, and the use of a plasticizer, water-repelling agent and integrated hydrophobic plasticizers - to increase of the density of magnesia structures, a substantial increase in closed porosity as the result of the forming of the solid mosaic hydrophobic films on the surface, which has a positive effect on many of the technological characteristics of magnesia materials.
There is a trend in the world for production growth of hardly recoverable heavy oils and bitumen with high content of resin-asphaltene substances that precipitate when aggregated, causing stability loss of oil dispersies. The goal of this work is to establish regularities for the effect of oil soluble surfactant additives containing the polar functional groups of different chemical nature on the processes of flocculation and sedimentation of model oil dispersions. Methods emplоyed are infrared spectroscopy, turbidimetric titration and dispersion analysis. It has been found that the domestically produced surfactant additive containing both amino and phosphate groups in the chain causes synergistic effect, due to simultaneous action of these functional groups, that slows down flocculation processes (efficiency is 108%) and sedimentation of model oil dispersions, which is confirmed by 13 times reduction of rates and sedimentation constants and 1.6–3.2 times decrease of associate size for resin-asphaltene substances. This results in the increase of aggregative and kinetic stability of the colloidal system. It has been shown that the additive is an effective flocculation inhibitor and dispersing agent for oil dispersion systems, that can be recommended for practical application as a substitute for expensive imported analogues.
Colloid-chemical properties of water solutions of compositions of surfactants of different nature are studied. The synergetic effects for the compositions of cationic/anionic surfactants and cationic/non-ionized surfactants at micellization and adsorption are found. It has been found that the maximal synergism of action, showing up in a decrease of surface tension, is offered by the composition of cationic/anionic surfactants in the component 4 : 1. This fact stipulates the efficiency of its dispersive action and its capacity of forming on the surface of particles the dispersible phase of oil slime of the structured layer, possessing maximum elasticity and mechanical strength, as compared to the molecules of cationic and non-ionized surfactants. Water dispersions of oil slime obtained with the use of the composition of cationic and anionic surfactants are the aggregative and kinetically stabilized dispersions of direct type.
It has been established that introduction of adhesives, containing groups reactive towards asphaltens, into the bitumen causes its colloid structure change. This in turn affects the irreversible change processes caused by air oxygen and elevated temperature. Maximal deceleration of thermo-oxidative destruction processes is effected by additives containing phosphate groups, either individually or together with amino groups, as the result of their interaction with bitumen asphaltens.
As a result of the investigations carried out by Fourier-transform infrared spectroscopy and thin-layer chromatography with flame-ionization detection methods it has been established that the studied surfactants of cationic and nonionic nature are bound up with the surface of dispersed phase in oil dispersion by means of the Vandervaals forces and chemisorptive interaction forces. The surfactant adsorption on nucleophilic parts of low-polarity particles of dispersed phase proceeds due to acid-base interaction of polar functional (amine-, carbonyl, hydroxyl, sulfoxy, ethoxylated and propoxylated) groups that enables to screen dispersible particles in oil dispersion and to increase stability.
The composition of complex hydrophobic plasticizer for portland cement concretes has been developed on the basis of wax-bearing emulsion and the hardening accelerator, and its behavior in portland cement mixtures has been studied.
The effect of different surfactants on rheological properties and stability of model oil dispersions has been studied by the rotary rheometry method. It has been determined that the ethylene - propylene oxide block copolymer based on ethylenediamine sugnificantly increases the solvation degree and the thickness of adsorptive-solvate layers on the dispersed particles surface, as compared with other studied surfactants. It improves structural-rheological parameters, thereby causing better screening of the asphaltene particles, to prevent their coagulation and provide stability for oil dispersions.
The possibility of modifying oxidized asphalt by performing polycondensation of maleic anhydride with aliphatic amines of various chemical structures in the dispersion medium was considered. The influence of the reactant structures and reaction conditions on the physicomechanical and structural-rheological properties of the polymer-modified asphalt was examined.
The effect of a blend of styrene-butadiene-styrene and ethylene-vinyl acetate copolymers on the heat resistance of oxidized bitumen was examined. The structural and rheological properties of the modified bitumen were analyzed.
Mechanical and structural-rheological properties of oxidized bitumen modified with styrene butadiene-styrene copolymers side vinyl groups in their butadiene fragment were studied. A comparative analysis of the modified and unmodified bitumen composites was performed.
Colloid chemical properties of surface-active substances of different classes and bitumen are investigated, their interaction with the mineral material is studied. New materials and emulsion technologies for road coatings are proposed, which allow one to improve the quality and performance characteristics of roadway.
Multiplicity of technological and constructive requirements to bitumen binders used in construction and reconstruction of roads makes it necessary to develop composite materials based on bitumen with various polymer additives. This work presents the results of a study of structural and rheological properties of oxidized bitumen modified with block copolymers of polyethylene and vinyl acetate or butyl acrylate, as compared to styrene butadiene styrene thermoplastic elastomer. It was shown that oxidized bitumen based on West Siberian oils, as compared with the residual bitumen, is characterized by a smaller degree of aromaticity, which makes it difficult to use them together with SBS block copolymers. EVA, as opposed to SBS, have polar groups actively interacting with bitumen elements (asphaltenes, naphtene paraffin, and aromatic compounds), which ensures their better compatibility after modification. Besides, paraffin contained in great amounts in oxidized bitumen and adversely affecting its properties is blocked inside the polymer net of the modifier, which slows down ageing processes and increases service life of materials. For the covering abstract see ITRD E121480.