Impulse non-stationary flooding requires managing the processes influencing reliability and durability of the tubing string. In this case, it is necessary to determine the medium displacement for ...known dimensional parameters and stress fields, while taking into account the dynamic solution for the low-frequency limit. The results obtained from the analysis are compared against the measurements performed by various authors. Assuming there is a certain frequency of injected fluid oscillation or pressure pulses, one could expect that the radial movement is in equilibrium with the pressure existing at any given period of time. As a result, expressions describing the behavior of impulse waves propagating along the pipe wall were obtained. The reflected waves appear in all cases: whether the change in speed is caused by a change in the pipe wall thickness, Young modulus or shear rigidity of the environment. Changes in density or bulk modulus of the injected fluid or in the radius of the wellbore also cause reflected waves; all the waves may be described by a single equation.
In recent years, there is an increased interest in pipes with regularly variable section area (converging-diverging pipes) in the oil chemical industry. At the same time, there is no simple ...engineering technique for calculation of hydrodynamic characteristics of such devices, which significantly impedes computations for mass exchange processes inside them. Attempts to concentrate energy dissipation and their control near the phase boundary were mainly directed at using the fluid flow pulses induced by an external generator, alternating displacement field, pulses caused by fluid flow through the conduit with a variable cross-section. As a result, it has been revealed that the forces determined by action of convective acceleration are capable of causing a significant deformation and breakage of disperse inclusions (drops and bubbles). For rigid particles, the action of the convective acceleration leads to a periodic impulse renewal of liquid near the surface of the rigid particle.
Emergencies and breaks of field pipelines result in both gas, oil, and refined products waste and high costs for maintenance and repair evaluated in billiard rubles annually. The purpose of this work ...is calculate test pressure in field pipelines with the account of pipes ovality and curvature, stress pattern, surface damage areas, plasticity of pipe steels and optimal parameters control. To determine maximum test pressure it is advisable to divide the pipeline into parts for hydraulic tests, denote sources of water feeding and points of water discharge. Minimum elastic bend radius (EBR) and walls thickness (WT) should be found for every part. Unfailing service can be provided by periodical hydraulic tests, e.g. once in three years (in case when the test pressure is σtp = σfp) or by periodic decrease of the operational pressure. The other way to provide unfailing service of the pipeline is decreasing cyclic load.
The international accelerator neutrino experiment T2K (Tokai-to-Kamioka) began accumulating data in 2010 and has since then accomplished 10 runs in the neutrino and antineutrino modes. The present ...article reports on the latest results following from the analysis of these data and including the first ever 3
constraints on the
CP
-violating phase
. Also, the plans for an upgrade of the near detector ND280 are surveyed.
This paper analyzes stress-strain behavior and bearing capacity of a rotor in a self-discharging separator, diameter 500 mm, manufactured from parts that underwent a hardening cycle. Three variants ...of the rotor were studied having the same design but differing in body materials: austenitic steels 06X17H13M3-BД, ALIII-23-43-02 and austenitic-ferritic steel 10X26H5M, ALIII-23-24. Research results allow recommending austenitic-ferritic steel for manufacture of separator rotors, as they provide necessary margin of safety for the design.
Abstract
The total rock pressure on a formation wing is greater than the lateral pressure, and on the fold, on the contrary, the lateral rock pressure is greater than the total pressure. As a result, ...the formation material flows from wing zones to the fold, as a result of which the formation thickness on the fold increases, as noted by the studies of Soviet scientists. The study of the mechanism of hydraulic fracturing during water injection revealed large fracturing pressures in wells located in reduced parts of the structure (fold wings), and smaller pressures – in elevated parts (fold). The study showed that if the rock of the well bore zone is destabilized during field development for well operation, fresh water causes hydration and swelling or dispersion of clays, which act as the rock cementing material. This can both lead to a decrease in permeability and to the destruction of the well bore zone. This effect during well development may be prevented by using mineralized reservoir water or fresh water with hydration inhibitor additives such as NaCl (5-10%), CaCl
2
(1-3%), KC1 (1-3%). Another complication in well completion is the colmatation of the well bore zone. In order to ensure the stability of the fixed part of the formation behind tubing in the bottomhole zone, there is a need to ensure the static equilibrium in the porous medium. Rocks with low rheological properties (low relaxation rate) provide longer resistance of the well bore zone to destruction.
Abstract
The average operating time before structural and technological failures of the submersible part of a typical ESP is 64.5–81.9% of the average operating time of new ESPs. Given that the set ...of typical ESPs includes a significant share of repaired and mixed (equipped with new and refurbished units) installations, this fact can be interpreted as evidence of poor quality of repair. The data obtained from Tatneft and Bashneft companies agree with this conclusion. The data provided by Nizhnevartovskneftegaz company do not contradict this conclusion. The high values of T
tkt
obtained by Rosneft-Samaraneftegaz are a consequence of poor identification of the causes of ESP lifting during control operations, as a result of which some failures are treated as design and technological ones.
Abstract
The transforming mechanism of rocking machines is an articulated four-link mechanism made following the symmetrical and asymmetrical kinematic schemes. On the straight line passing through ...the extreme positions of the base of the bolt and the balancing lever, there is a center of rotation of the crank in symmetrical mechanisms. In different variants they are asymmetrical mechanisms. The dimensions of the converting mechanism of Russian symmetrical rocking machines are smaller than foreign asymmetrical rocking machines. This method can be used to show the contrast between technical and operational indicators of the rocking machines manufactured using various kinematic schemes. A contrast of the data multiplied by
S
0
K
/
K
1
with the real data of rocking machines revealed their compliance, which confirms the correctness of the method.
Abstract
Experimental work showed that as a result of placing screens in a well with a bottomhole, the formation of which is composed of inhomogeneous, weakly cemented or loose sandstones, often with ...reduced permeability due to poor-quality completion, it is necessary to strive for a maximum decrease of
ζ2ϕκ
due to an increase in the wellbore of the screen shell and thereby an increase in the quality of filtration actions for colmatant breach, which contributes to a decrease of
ζ2η.
The following conclusions were drawn when examining sand phenomena from weakly cemented and loose formations with a heterogeneity coefficient of more than 10. The particles that make up the rock structure should not be removed from the formation due to the use of a screen. In practice, this means that the screen must not conduct 85-75% (by weight) of the larger sand fractions. To maintain the overall stability of the reservoir skeleton, it is possible to allow the removal of not more than 15-25% (in weight) of fine particles.
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