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The article provides а retrospective analysis of the emergence of prerequisites for the creation of designs of universal pumping units: from the first patents registered in the 1940s to modern technical solutions used at industrial facilities. The possibility of industrial application in the oil industry of fundamentally new types of vane pumps with а combined design of the impeller and rotor or the electric motor, which received а recent impetus to their spread with the development of electric motor technologies, is considered. The fundamental difference between these types or pump is the transmission of the torque to the impeller not through the shaft. but through the rim or the wheel, which is also the rotor of the eclectic motor. The absence or а shaft provides а number of advantages, in particular, it leads to an increase in suction capacity, an increase in pressure characteristics and an increase in operational properties – all this together increases the scope or industrial application of new types or pumps. One of the potential applications of а compact pump of the horizontal type can be the rocking to а frozen oil pipeline by tapping the coil at special points of the pipeline route. From the point of view to transporting high-velocity oil, the design of this type also looks promising; in addition, the possibly of influencing the transported medium by an electromagnetic field is noted. The possibility or using removable impellers of various types for а hollow pump-electric motor is considered, which can significantly increase the scope or application of new types of pumps.

The results of investigations of the main causes and the most significant factors of intensification of paraffin deposition in main oil pipelines are presented. A comprehensive analysis of the composition and properties of commercial oils and their sediments was carried out, according to which phase diagrams of equilibrium of oil dispersed systems were obtained using the example of commercial oils from Bashkir fields. Based on the phase diagrams, a curve of wax oil saturation was constructed, the analysis of which confirms that the existing thermobaric conditions during the operation of main oil pipelines do not allow transporting oil without the risk of waxing. It was noted a special influence of the value of the temperature gradient in the near-wall zone and the imbalance of the ratio of high-molecular oil components in commercial batches formed in the process of joint pumping on the intensity of waxing of sections of oil pipelines complicated by deposits, which was confirmed by statistical data on the frequency of pigging. The regularities obtained in this way are proposed to be used as an express method for predicting complications associated with intensive waxing of main oil pipelines. In order to quickly assess the risks of waxing of sections of main oil pipelines, an indicator is introduced that characterizes the ratio of the content of solid paraffins to the total content of resins and asphaltenes of oil, called the criterion of instability of a commercial oil batch.

To determine the efficiency of additives Necadd-447, M-FLOWTREAT, FLO-XL, and FLO-MXA, a method for conducting experiments and processing the obtained results is proposed in this paper. The...

The paper presents the results of numerical studies of the effect of the wall-boundary layer of oil deposits formed on the inner surface of oil trunk pipelines. The possibility to reduce the hydraulic drag and to increase the throughput capacity of pipelines due to the thermal insulating and surface-smoothing properties of the asphalt-resin-wax oil deposits layer is mathematically proved. Numerical experiments proved the efficiency of the wall-boundary layer of deposits with various thickness both in isothermal and ‘hot’ oil pipelines. The effect is due to lower roughness of the inner surface of the pipes and higher flow temperature. The latter in non-isothermal sections of hot pumping leads to the lower average viscosity of the pumped oil. In case of isothermal pumping, the deposit layer is efficient only in developed turbulent flow conditions. Moreover, in large diameter pipelines, the effect of the deposit layer is maintained even at its considerable thickness, despite a high reduction in the inner pipeline diameter.

This paper presents results of a comparative analysis of several research methods for oil pipelines waxing process, which are based on the progress made with present-day laboratory equipment and the capabilities of software and hardware computational packages used to simulate properties of multiphase fluids and kinetics of complex multi-factor processes. This paper considers theoretical foundations of proven and substantiated mechanisms of the processes of wax formation and accumulation on the inner surface of oil pipeline walls, including main factors that impact the rate of such processes. The paper also points out disadvantages of the methods of static measurement based only on the diffusion factor of deposition of deposits, predominantly of the paraffin wax type; these static measurement methods preventing from taking into account the impact of other equally significant factors that accelerate and decelerate accumulation of deposits. This work highlights the most accurate methods to determine the chilling point or mass crystallization of paraffin waxes, which are recommended to be used in computerized simulation of the process.

The paper proposes a new approach to assessing the residual resource of the wall of a vertical steel tank by the criterion of low-cycle loading, taking into account its actual deformations. The method is based on the principle of measuring the difference in the power of the luminous flux at the ends of the light tube (light guide) when it is bent. An experiment was carried out using an optical pair (LED and photodiode) and an optical fiber. For this purpose, templates with known radii of curvature were prepared, a prototype of an Arduino-based device was developed and an optical fiber was manufactured, which was subsequently fixed on the wall of a two-hundred-liter metal barrel. As a result of the experiments, a formula was obtained for determining the curvature of the wall depending on the readings of the sensor. The sensitivity of the proposed method is estimated. An algorithm for determining the number of cycles before the formation of fatigue cracks is proposed, taking into account the actual values of the wall deflection.

The article is devoted to the need of taking into account the thixotropic properties of oils when oil pipeline starts after a long stop, as well as to calculation of the time of its safe stop. To evaluate the parameters of thixotropy, it is proposed to use the results of laboratory experiments of oil samples on a rotary viscometer. Typical properties of the rheological flow curves of thixotropic oils for the starting flow mode are determined. The use of the wave equation of damped vibrations is proposed to describe the rheological flow curve of the forward course of measurements of a rotational viscometer, characterized by the presence of ascents and descents of shear stresses. This equation, supplemented by a model of nonlinear-visco-plastic liquids, allows accurately finding the areas of appearance of thixotropic properties of oils. The article presents the results of experimental studies of the manifestation of thixotropic properties of two oil samples at a lower temperature. The wave equation of damped vibrations allows describing mathematically the ascents and descents of shear stresses observed at low oil temperatures. Experiments have shown that the wave properties of thixotropic oil do not change with a decrease in temperature except for the amplitude of maximum vibrations and are invariant properties of the studied liquid. The presented explanation of the physical mechanism for the manifestation of wave properties based on the hardening of the supramolecular paraffin crystal lattice characteristic of thixotropic oils explains the invariance of the frequency change function and the attenuation coefficient during starting processes at the beginning of the movement of the movable cylinder of a rotary viscometer. The result of laboratory studies allows determining the nature of changes in the contours of the zones of manifestation of thixotropic oil properties as a dependence on the temperature and shear rate.

The aim of this paper is to explore the organization of oil’s traffic from various oilfields through a system of main pipelines adapted to control the rheological properties of the pumped product due to rational oil blending of various oilfields at the nodal points of the pipeline system – at oil pumping stations with storage facilities. The current trend of increasing high-viscosity and high-pour-point oil production and the urgent need of their main pipeline transport are the main problem of our research. Its solution will provide an oil-transfer system from various oilfields that will minimize the total energy consumption for oil pumping. To determine the blending parameters at the nodal points we suggest to use the standard multidimensional optimization algorithm: the simplex method as the main calculation module. The objective function is presented in the form of total energy consumption for oil pumping, depending on the concentration of oil blending at the nodal points of the main oil pipeline system. We propose a method for calculating the objective function for any branched main oil pipeline system using algorithms for constructing a blending tree and determining its properties using the tree traversal algorithm. The issues of determining the limits of possible blending based on mass balance and quality reserve preservation of oils that delivered to consumers were also considered in our paper work. As an example, we solved this problem for an element of a main oil pipeline system with four oil blending nodes in the case of an oil viscosity increase of one of the suppliers. Carrying out multidimensional optimization of energy consumption for this system made it possible to increase its energy efficiency by more than 2%.

The article proposes a methodology for calculating the factors of rational mixing of oils with various rheological properties that are jointly transported through an extensive system of trunk pipelines to save energy demands for pumping. The calculation is aggravated by the absence of additivity of viscosity of specially formed multicomponent blends of oils that compels the calculation in a simplex place that characterize the possible compositions of oil blends. It is proposed to use the standard polydimensional optimization strategy as the main calculation module. The objective is presented in the form of summarized energy demand for pumping depending on the concentration of oil blend at the nodal points of their blending. There is proposed a method for calculating the objective for any extensive network of oil trunk pipelines using algorithms of constructing a blend tree and determining its properties using traversal tree algorithm.

The paper discusses the problems of cleaning technological pipelines and tanks to restore the capacity and useful volume capacity of oil pumping stations. The world experience of using chemical reagents for cleaning oil pipelines from asphalt-resinous paraffin deposits is considered, the disadvantages and advantages of the method are determined taking into account the restrictions that exist at the facilities of the main oil pipeline transport. The analysis of the results of experimental laboratory studies and pilot tests of the chemical washing technology at the existing facilities of Transneft PJSC is presented. Recommendations are given on improving the technology to reduce the consumption of chemicals and time costs. Particular attention is paid to the shortcomings and features of the use of hydrocarbon solvents for cleaning technological lines from pipes of small diameter and large tanks. The expediency of an additional physical effect is substantiated to increase the efficiency and rate of destruction and removal of hard-to-remove deposits, for which the use of ultrasonic resonators providing flow homogenization and dispersion is proposed.

The paper considers a new approach to identifying the possibility of saving pumping energy for in the oil trunk pipeline system by optimization the mixing ratio of the oils pumped to different directions in complicate branched network. To get the effect of energy consumption reduction, optimal mixing concentrations are calculated on the simplex space characterizing the composition of the oil blend. The problems of calculating the flow rate and required energy by a more explicit function type without iterative methods are considered. Attention is paid to determining the boundaries of possible ratios of blending taking into account the condition of mass balance. An example to solving the task aimed to optimization of oil flows distribution in condition of differences of their rheological properties in the case of the simplest configuration type of the pipeline network is also shown. The considered method presents the local nodal solution of a more complete transportation optimization task – The Maximum flow of the Minimum cost.