Vol 52, No 2 (2016)

The physicochemical properties of substances taking part in processes of diesel fuel cleaning with ammonia water and washing with water are studied. It is shown that ammonia water containing ~2 wt. % of petroleum acids should be used as the reagent. For steady operation of the plate column, the optimal rates of fuel discharge through the plate holes are found to be 0.15 m/sec for cleaning and 0.30 m/sec for washing of the fuel. In this case, the disperse phase layer heights under the plate are 12-16 mm and 75-85 mm, respectively.

The results of study of the structure and properties of high-temperature oleogreases containing thickener components that can be derived from renewable natural materials are presented. The constitution of the primary structures of the oleogreases prepared by using calcium soaps of fatty acids of poultry fat and palm oil as the organic component of the thickener is established. It is proved that the distinctive properties of the oleogreases are ensured by the thickener system based on a dispersion of calcium carbonate and a natural surfactant. In bulk-mechanical, antioxidative, tribological, and protective properties, the obtained oleogreases are not inferior to commercial superalkaline sulfonate lubricant.

The results of modeling of thermal cracking of oil sludge activated by electromagnetic radiation are reported. An experimental-statistical model of dependence of wide gas oil fraction yield on radiation frequency, electromagnetic radiation power, and oil sludge activation time is obtained to optimize the cracking process conditions.

At present, most oilfields are developed by applying water-flooding technology. However, this technology is often accompanied by inorganic scale deposition on water- and oil-pipe and equipment walls due to the incompatibility between the injection fluid and formation water and for other reasons. Barium and strontium sulfates are highly resistant to the acids that are generally used as scale dissolvers. In this work, a new chelating-agent-based alkaline barium- and strontium-sulfate scale dissolver named SA-209 has been developed. Many of its important parameters such as salt concentration, reaction time, pH value, temperature, etc. that affect de-scaling efficiency are evaluated by experiments and analysis. This dissolver has a high de-scaling rate and low equipment and pipe corrosion, is environment-friendly, and so would have a promising application in oilfields.

A study was carried out on combined inhibition by a solution containing 0.5% polymer kinetic inhibitor (KI) + 10.0% methanol as a thermodynamic inhibitor (TI) in the formation of methane hydrate (Class I) and the hydrate of 95.66 mol. % CH₄ + 4.34 mol.% C₃H₈ (methanepropane mixture) (Class II). This combined inhibition was studied by an isothermal method and a method entailing cooling at a constant rate using a GHA350 autoclave. Methane was shown to have an adverse effect on the inhibiting properties of the polymer KI both relative to formation of methane hydrate and hydrates of C₁–C₃ hydrocarbons. The loss of inhibition by the polymer KI in the presence of methanol is expressed as the decrease in the extent of supercooling attainable in the system without adsorption of the hydrate-forming gas (1.5–2.5°C in comparison with the system without TI). The induction time is shown to depend on the extent of supercooling in the system during inhibition of formation of the Class I and Class II hydrates by the solution containing 0.5% KI + 10.0% TI.

In order to study the characteristics of the flow regime, we conducted experiments on filtration of pure water and water/oil through an artificial fractured – vuggy medium. We found that both Darcy and non-Darcy flow can occur in a fractured – vuggy medium. After rewriting the Forchheimer equation, we calculated the inertial coefficient for different fracture widths and vug diameters. Based on the experimental studies, we also propose a new method for determining the flow regime for twophase flow using fractal theory.

The results of studies on the development of the flame atomic absorption method for determining the elemental composition of precipitates formed during use of petroleum products are reported. The feasibility of applying this method to determine the elemental composition of pollutants removed from the fuel and oil feed systems of the equipment and determination of the nature and causes of formation of these pollutants is demonstrated.

We propose a mathematical model describing gas flow from a fractured shale reservoir into a horizontal well. Based on Langmuir adsorption theory and Darcy’s law, we have obtained a basic solution using a combination of a point source function, an integral of a Bessel’s function, and the Poisson summation formula. We plotted typical curves for the dimensionless pressure and its derivative on a log-log scale. We analyze the stages of gas flow from the shale formation to the horizontal well and the factors influencing it.

It is shown that in the mineral transformer oil oxidation process the fluorescence spectrum of the oil shifts to the long-wave region. This phenomenon lies at the foundation of the method of determination of the degree of electroinsulating oil oxidation in real time. The oxidation state is determined by measuring the diagnostic parameter, i.e., the oxidation index that characterizes the magnitude of shift of the fluorescence spectrum of the oil upon its oxidation. The oxidation index is defined as the ratio of the fluorescence intensity measured in the longer-wave spectral range to the intensity measured in the shorter-wave spectral range. The results of measurement of the transformer oil oxidation degree by the fluorescence method vis-à-vis other measurement methods, such as titration and IR spectroscopy, are presented. The proposed method can be used to determine the increase in oil oxidation rate at the earlier stage. The device for implementing the developed method can be a portable one or can be installed in the oil-filled system of the equipment.

In this paper, we present a model for calculating the open-hole extended-reach limit for an extendedreach well which takes into account such factors as annular pressure loss, equivalent density of formation fracture pressure, etc. Studies have shown that the proposed model is the most accurate model available. We also present results of an analysis of the effect of different drilling parameters on the extended-reach limit of the well. Calculations have shown that the extended-reach limit is proportional to the equivalent density of the formation fracture pressure and inversely proportional to the pump rate, the drilling fluid density, and the mechanical rate of penetration (ROP).