COMPOSITION OF RESIN-ASPHALTENE AND OIL COMPONENTS OF HEAVY OILS

Abstract

The relevance of the work is caused by the need to expand the amount of data on resin-asphaltene substances and oil components of heavy oils, which share in the volume of the extracted and processed hydrocarbon raw materials is steadily growing. The refining of oils with high content of asphaltenes, resins, and heteroatomic compounds using existing basic technologies is hard and costly. Hence, information on the composition and structure of the heavy oil components is of great importance for the development of innovative technical solutions of their rational use. This is due, first of all, to the fact that resins and asphaltenes are considered the important reserve for the advanced processing of crude oil, while oil components are considered the basis for the production of commercial petroleum products. The purpose of the work is to study the structural-group composition of asphaltene and resin macromolecules and the molecular composition of oil components of heavy oils sampled in various oil and gas provinces and differing in the age of the enclosing deposits and the content of resin-asphaltene and oil components. Methods: liquid adsorption chromatography, elemental analysis, cryoscopy in benzene, 1H NMR spectroscopy, structural group analysis, combined gas chromatography mass-spectrometry. Results. A comparative description of the composition and structure of macromolecules of resin-asphaltene substances and the molecular composition of oil components of heavy oils from the Ashalchinskoe (I), Usinskoe (II) and Nurlatskoe (III) fields is given. These oils differ in the content of these components and heteroatoms and in the age of the enclosing deposits (Permian, Permian–Carboniferous, and Devonian). It has been found out that the content of asphaltenes and resins increases in the series of heavy oils I–II–III. At the same time, their average molecular weight decreases and the overall sizes of their mean molecules become smaller. This is due to a decrease in the number of structural blocks, which become more compact because of decreasing total number of rings in the naphthenoaromatic system, mainly naphthenic ones. In this case, the number of carbon atoms in the paraffin fragments of the structural blocks of mean molecules increases. The observable changes in the structural parameters of molecules are most pronounced for the resin-asphaltene components of oil from Devonian deposits. It is shown that oil components of heavy oils are characterized by a similar set of saturated hydrocarbons, but differ in the composition of identified aromatic hydrocarbons and heteroorganic compounds. A feature of oil components in the oil III is a wider range of mono- and bicyclic arenes and oxygen-containing structures.

Keywords

• oil
• asphaltenes
• resins
• oils
• structural group composition
• molecular composition