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In article possibilities of predicting the viscosity of stable multicomponent water-oil systems in practice, when it is impossible, for a number of reasons, to obtain their experimental values, are considered. A predictive model is proposed to describe the change in the viscosity properties of various oil-water emulsions depending on the degree of water saturation. It is shown that the proposed formula allows to determine the effective viscosity of water-oil systems in the entire range of variation of the velocity gradient in the absence of experimental data and is acceptable for engineering practice. Keywords: viscosity; water-oil emulsions; matematical description; water saturation degree; heterogeneous systems.

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The experience of operating gas separation process units shows that it is not always possible to achieve effective separation of liquid particles. Traditional calculation formulas for determining the settling rate of particles in separators are based on the thermodynamic equilibrium of the main parameters of the incoming gas flow (pressure, density). At the same time, well production, in particular condensing gases, is a nonequilibrium system, which is characterized by a certain delay (relaxation times) in changing parameters. As a result of this delay, the settling rate of particles in the separator does not have time to reach the steady state Stokes regime corresponding to effective separation. The paper proposes a nonequilibrium model for the sedimentation rate of particles and developed an algorithm for its numerical implementation. Using this algorithm, multivariate computational experiments were carried out to study the dynamics of particle settling. It was found that for the effective separation of liquid particles in a gravity separator, the relaxation time for the settling velocity of the particles should not exceed 10 sec. Keywords: gas separation; gravity separator; particle settling rate; relaxation time.

MATERIALS AND METHODSIt's known from oilfield practice that, transportation process of not mono-componential, homogeneous but multi-componential, multiphase heterogeneous systems occurs in mining technological pipelines from exploitation wells to oil producing terminals. However, depending on the time, well product constantly changes its commodity quality in addition to its physical-chemical and rheological properties. Namely for this reason, the number of technical-technological problems and complications occuring in technological pipeline system is more but their solution is hard.Currently, the number and scope of the scientific researches, being carried out connected with the dependence of qualitative indicators on oils for oil mixtures and their mixing and specific problems occurring in this case, is being expanded. The problems created by "undesirableness" of some mixtures, during extraction, production and transportation of oils, inadmissibility of applying the additivity rule to them indicates the urgency of the problem and importance of solving the problem.In addition to a number of difficulties occuring during pipeline transportation of different types, rheological oils by being mixed with one another or light oils, as well as solvents, disbalance cases are observed in their storage as well as delivery and reception processes. In this regard, a number of oil and oil products can even be considered "undesirable" couple.The analysis related with oil losses during the transportation shows that, volume loss can occur in the mixing of the components sharply differing from each other due to their properties. The first normative document on the volume loss occuring in their mixing during the transportation of oils and oil products was published in 1996 by American Oil Institute. Such cases are possible to occur while heavy oils (oil products) are being mixed with light oil products. For instance, the volume obtained by mixing bitumen with light oil can be less than the total volume of the components. It should be noted that, such volume loss is not related to the physical loss of the substance and the total mass of the load remains unchanged during the mixing.

It is known that the multi-phase flows are widespread in the oil-gas production, as well as in the collection and transportation of hydrocarbons from offshore fields. These gravitational upward and downward flows are characteristic for the rising pipes of gaslift and flow wells, as well as for the risers of subsea multi-phase pipelines. A new approach for the estimation of the real parameters of multi-phase flows considering the phase displacement is offered in the paper and the perspectives of their definition based on the microscopic parameters of well operation shown as well. A possibility of the specification of the real density, real gas content and phase displacement of gas-fluid flows in the rising pipes of gas-lift wells based on the actual operation data in the context of the wells of Guneshli (OFP-15) offshore field is shown.

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