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.
Part of the book: Phthalocyanines and Some Current Applications
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.
Part of the book: Recent Insights in Petroleum Science and Engineering