Search

The products of catalytic cracking of heavy crude oil from the Ashalchinskoye oil field (the Almetyevsk district of the Republic of Tatarstan, Russia) were characterized. The effects of a Fe2O3 nanopowder catalyst and the presence of supercritical water (SCW) on the composition and structure of these cracking products were investigated. Cracking over 0.01 wt % Fe2O3 nanopowder in a SCW environment was found to enhance the yield of distillates by more than 34 wt % and to reduce the content of resinous asphaltene materials by a factor of 2.1 compared to the initial crude oil. It was further shown that Fe2O3-nanopowder-catalyzed cracking produces coke-like asphaltenes with a low H/C atomic ratio (no higher than 0.75). Reaction rate constants were evaluated for the thermal and catalytic cracking of the heavy oil from the Ashalchinskoye field. [ABSTRACT FROM AUTHOR]

The paper describes an investigation of the composition of purified vanadyl porphyrins recovered from heavy oil asphaltenes. For this purpose, high-vanadium crude oils from the Smorodinskoye field, Russia, were compared with low-vanadium crude oils from the Varadero field, Cuba. Based on the comparison of the FT-IR spectra of the asphaltenes, the distinctive features of their structural-group composition were identified. The vanadium content in the Smorodinskoye heavy oil asphaltenes was demonstrated to be 19-fold higher than that in the Varadero heavy oil asphaltenes. To recover and purify vanadyl porphyrins from the asphaltenes, extraction with N,N-dimethylformamide (DMF) followed by two-step column chromatography on silica gel and sulfocationite was employed. The compositions of the vanadyl porphyrin concentrates extracted from the heavy oil asphaltenes differing in vanadium content were identified using MALDI mass spectrometry, FT-IR spectroscopy, and UV-Visible spectroscopy. [ABSTRACT FROM AUTHOR]

An approach to crude oil assay based on the consistent application of two heterogeneous classifications of oils is proposed: according to the quality index and physicochemical parameters. The methodological issues of the classification approach to oil analysis, implemented in the form of a two-stage procedure, are described. The approach is illustrated by an example of analysis of the characteristics features of different types of tight oils in Russia. The analysis used data from 25.190 oil samples with abnormal properties and 10 500 oil samples with complex modes of occurrence. At the first stage, the analysis has been carried out using the classification of tight oils according to the quality index; as a result, the oils were divided into three homogeneous classes: low, medium, and high quality oils. At the second stage of the analysis, the classification of oils by physicochemical characteristics has been used, taking into account the density; viscosity; sulfur, resin, asphaltene, wax, vanadium, nickel, and light end contents; gas saturation of oil; etc. The analysis made it possible to establish the characteristic features of the physicochemical properties of tight oils belonging to different quality classes. [ABSTRACT FROM AUTHOR]

The current status and development of petroleum residue upgrading via coking in Russia and over the world have been surveyed with an emphasis on the role of the process in salving the problem of increasing the refining depth. Theoretical concepts of thermal conversion of heavy petroleum feedstock and the structure of asphaltenes as principal coke-forming compounds have been discussed, the results of studies on the formation of coke as either a byproduct or (to a greater extent) the desired product have been considered, and models of the coke structure have been proposed. The characteristic features of the coking process for petroleum residues of various chemical compositions have been addressed, as well as means for controlling the feedstock thermal stability and the yield and quality of coke with the use of external factors. [ABSTRACT FROM AUTHOR]

Resin and asphaltene fractions of crude oil from the Usa field (Timan-Pechora oil-and-gas province, Russia) obtained by fractional precipitation of asphaltenes and chromatographic separation of resins have been analyzed using Rock-Eval pyrolysis and flash pyrolysis (650°C, 20 s) with on-line chromatographic/mass spectral detection of volatile products. It has been shown that the samples under study contain organic compounds with a relatively low molecular mass in an amount of 2.3 to 15.3 wt % as either impurities or moieties bound in resin and asphaltene molecules by labile chemical bonds. The products of flash pyrolysis of the samples under study differ in the relative amount of the 'unresolvable complex mixture' of unidentified compounds; the chemical group and molecular composition; and the relative amount of identified types of compounds, such as normal and isoprenoid alkanes, α-olefins, cyclohexanes, cheilanthanes and hopanes, hopenes, pregnanes and steranes, alkylbenzenes, naphthalenes, phenanthrenes and anthracenes, and benzo- and dibenzothiophenes. [ABSTRACT FROM AUTHOR]

The phase composition of asphaltenes taken from oils of Romashskino field (Russia) was studied with calorimetry. It was found that in asphaltenes there are ordered amorphous phases which break in the temperature ranges 70-130 and 130-170 °C. Polarization microscopy data show that the liquid crystal phase appears at temperatures from 180 to 190 °C. Moreover, it is shown that in asphaltenes the crystal phases of co-precipitated paraffinic hydrocarbons and salts can be present. [ABSTRACT FROM AUTHOR]

Abstract: Based on the experimentally measured parameters of elemental composition, average molecular masses, and PRM spectrometry data, we calculated the average structural parameters of resin and asphaltene molecules in Paleozoic crude oil of some oilfields in the Timan–Pechora petroliferous basin. The values of the structural parameters of cyclic and aliphatic fragments in the molecules of resin–asphaltene components of the crudes studied here are within the ranges established earlier for high-molecular compounds of crudes from other petroliferous basins. The average structural-group characteristics of resins in crudes from carbonate reservoirs vary over narrow ranges of values independently of the age and depth of occurrence of the reservoir. The resinous fractions of crudes from terrigenous horizons show symbatic enrichment with paraffin fragments and depletion with naphthene fragments of molecules with depth. This points to the presence of a paragenesis of petroleum hydrocarbons and heteroatomic compounds in the Earth’s interior. [Copyright &y& Elsevier]

The mineral and organic components of the core material from Vereiskian and Bashkirian deposits of the Akanskoe field in the Republic of Tatarstan have been studied by complex thermal analysis. The occurrence depth intervals with abnormally light oil have been revealed in the Bashkirian deposits. These facts together with the data on the composition of oils (high values of the ratio of light to heavy alkane homologues for heavier and more viscous Bashkirian crude oils, the bimodal MMD character of C-C n-alkanes, and enrichment in high-molecular-mass asphaltenes at the bottom of the reservoir) suggest the influx of a lighter oil to the formed Bashkirian deposit. No facts of this sort have been identified for the Vereiskian oil. [ABSTRACT FROM AUTHOR]

In this article the research in elaboration of non-waste reprocessing technology for oil emulsions, regenerating from oil-slime of Krasnodar oil-reprocessing plant is specified. According to the results of the research some technological solutions for the raw meal preparation for the production of bricks and haydite have been set forward. For the production of bricks and haydite we have used oil-slime, collected during the treatment of sewage and process waste water, which is a trick liquid of density 0.86 - 0.97 g/cm³(Nº 2 and 3 in Chart 1), containing water, mechanical impurities and combustible fractions. Combustible fractions mainly consist of asphaltenes, benzol and alcoholic tars. [ABSTRACT FROM AUTHOR]

Changes in the properties and chemical structure of high-molecular-mass heteroatomic compounds (resins, asphaltenes) as a result of the thermal treatment of heavy oils from the Zuunbayan (Mongolia) and Usinsk (Russia) oil fields have been shown. The structural-group parameters of resins and asphaltenes isolated from crude oils and their thermolysis products have been determined on the basis of elemental analysis, molecular mass, and 1H NMR data. It has been shown that the yield of gaseous, liquid, and solid products varies depending on the thermolysis time and temperature. A model for the thermal conversion of the high-molecular-mass components of petroleum is proposed and the rate constants ( k) and activation energies ( E) of the petroleum thermolysis reactions have been calculated. The competing routes of the conversion of petroleum components at different temperatures have been established. [ABSTRACT FROM AUTHOR]