37 research outputs found
Experimental Study of the Effect of Composite Solvent and Asphaltenes Contents on Efficiency of Heavy Oil Recovery Processes at Injection of Light Hydrocarbons
The current state of research in the field of solvent injection techniques for increase of heavy oil production efficiency is discussed in the chapter. As a result of a series of experiments on the physical modeling of oil displacement processes in a porous medium in large-sized model, features of asphaltene precipitation and the formation of fixed residual oil upon injection of solvent based on light alkanes are revealed. The oil displacement by n-hexane was studied and the difference in the composition of residual oil in the zones of dispersion and diffusion has been shown. The influence of the composition of asphaltenes peculiarities on the dynamics of oil recovery and on the accumulated oil recovery during the injection of n-hexane, as well as the composition and quantity of asphaltenes precipitated in the porous medium, has been estimated. The effect of toluene and nonylphenol additives on the proportion of asphaltenes in the residual oil and cumulative oil recovery has been evaluated using the Ashalchinskoye field oil as an example of heavy oil in the physical modeling of injection of n-hexane as the base solvent
Heavy Oil Residues: Application as a Low-Cost Filler in Polymeric Materials
Deposits of oil sands, bitumen, extra-heavy oil, and heavy oil appear in more than 70 countries all over the world and the fraction of oil recovered gradually increases. High content of poly-condensed high molecular weight oil components (PHMOCs), which may amount up to 50-60% depending on conditions of oil formation, is the main difference of heavy oil and bitumen from conventional oil. PHMOCs can lay the foundation for the preparation of a large number of valuable materials due to their structural manifold and their potential still not discovered to full extent. This work is devoted to the study of the effect of PHMOCs on properties of the composition materials prepared from polyethylene matrix. An «asphalt» – industrial product of deasphalting of tar, as well as asphaltenes and resins isolated from heavy oil, were used as a source of PHMOCs. HDPE and fillers were characterized using MALDI, FTIR, DSC and TGA. For the new composite materials we evaluated the physicomechanical properties, the thermal decomposition characteristics (by TGA), and the accumulation rate of carbonyl groups in the oxidized polymer (on FTIR). Studies of new composite materials showed that the introduction of filler in an amount of up to 4% in a polyethylene matrix does not lead to a significant change in the physicomechanical properties, but for a number of parameters they are improved. It also figured out that the addition of PHMOCs to polyethylene makes it unnecessary to stabilize the resulting compositions with stabilizers of thermal oxidative degradation. Results of experimental studies indicate that industrial residue - «asphalt» is a promising filler and low cost of this stock renders it perfect source for the industry of polymer materials
Plasma immersion ion implantation for surface treatment of complex branched structures
The paper presents experimental results demonstrating the capabilities of plasma immersion ion implantation of silicon (Si) for surface treatment of complex branched structures such are self-expanding intravascular nickel-titanium (NiTi) stents. Using NiTi stents of diameter 4 and 8 mm, it is shown that plasma immersion ion implantation can provide rather homogeneous doping of their outer and inner surfaces with Si atoms. Also presented are research data on the processes that determine the thickness, composition, and structure of surface layers subjected to this type of treatment
Structural phase states in nickel-titanium surface layers doped with silicon by plasma immersion ion implantation
The paper reports on a study of NiTi-based alloys used for manufacturing self-expanding intravascular stents to elucidate how the technological modes of plasma immersion ion implantation with silicon influence the chemical an
Isolation of Porphyrins from Heavy Oil Objects
The chapter describes the opportunities of extracting porphyrins by polar solvents (acetone, N,N-dimethylformamide (DMF), isopropanol, and acetonitrile) and sulfuric acid from various highly molecular petroleum fractions and residues. It has been found that the predissolution of petroleum objects such as asphaltenes and resins in aromatic solvents allows improving the extraction of porphyrins by means of reducing their association with polycondensed heteroatomic structures. Based on the absorption spectra and mass spectra, primary types of porphyrins in obtained extracts were revealed. The distinctions between porphyrin extractions in resins and asphaltenes were revealed. Sulfuric acid extraction allows producing highly concentrated primary extracts of demetallated porphyrins. The share of porphyrin fractions in obtained extractions was 13.0–24.2 wt%, which depends on the concentration of metal porphyrins in initial asphaltenes and resins
Two-Photon Interferometry for High-Resolution Imaging
We discuss advantages of using non-classical states of light for two aspects
of optical imaging: creating of miniature images on photosensitive substrates,
which constitutes the foundation for optical lithography, and imaging of micro
objects. In both cases, the classical resolution limit given by the Rayleigh
criterion is approximately a half of the optical wavelength. It has been shown,
however, that by using multi-photon quantum states of the light field, and
multi-photon sensitive material or detector, this limit can be surpassed. We
give a rigorous quantum mechanical treatment of this problem, address some
particularly widespread misconceptions and discuss the requirements for turning
the research on quantum imaging into a practical technology.Comment: Presented at PQE 2001. To appear in Special Issue of Journal of
Modern Optic
Formality theorems for Hochschild complexes and their applications
We give a popular introduction to formality theorems for Hochschild complexes
and their applications. We review some of the recent results and prove that the
truncated Hochschild cochain complex of a polynomial algebra is non-formal.Comment: Submitted to proceedings of Poisson 200
ESTIMATING THE ACCURACY OF AUTOCALIBRATION METHODS FOR DETERMINING THE COORDINATES OF RADIO WAVE SOURCES WITH A CONSTANT CONDITIONAL MODEL OF AMPLITUDE AND PHASE ERRORS IN A DIGITAL ANTENNA ARRAY CHANNELS
Particle number fluctuations in a non-ideal pion gas
We consider a non-ideal hot pion gas with the dynamically fixed number of particles in the model with the λφ4 interaction. The effective Lagrangian for the description of such a system is obtained by dropping the terms responsible for the change of the total particle number. Within the self-consistent Hartree approximation, we compute the effective pion mass, thermodynamic characteristics of the system and identify a critical point of the induced Bose-Einstein condensation when the pion chemical potential reaches the value of the effective pion mass. The normalized variance, skewness, and kurtosis of the particle number distributions are calculated. We demonstrate that all these characteristics remain finite at the critical point of the Bose-Einstein condensation. This is due to the non-perturbative account of the interaction and is in contrast to the ideal-gas case