For the purpose of extraction and identification of cyclic alkane hydrocarbons in oil from the Taribani field, Georgia, concentrates isolated from 200-350oC fractions have been studied. The concentrate preparation included the following steps: (a) distillation of a crude oil, (b) dearomatization of distillates by silica gel, (c) three-stage thermal diffusion separation of isoalkanes and cycloalkanes, and (d) thiourea adduction. Ten thermal diffusion fractions were obtained. A mixture of the IX and X fractions and separately the VIII fraction were studied. The extracts from these fractions with thiourea were studied as well. Composition of concentrates has been determined by the gas chromatography – mass spectrometry (GC-MS) method.The main components of the VIII thermodiffusion fraction were C11- C22 isoprenoid alkanes. Among them the predominant were pristane C19 and the phytane C20, the well-known biomarkers of oil. In the VIII thermodiffusion faction including dimethyl-, trimethyl-, tetramethyl-, ethyl-, methyl-ethyl-, diethyl-, propyl, methyl-propyl adamantanes, were identified.

Manifestations of natural bitumen are recorded in almost all regions of Georgia. The bitumen of Kari Crossing, Natanebi, Chibrevi, Baida, Polpoy-Teibi, Mirzaani and Kila-Kupra were studied. The main aromatic structures contained in organic extracts obtained from bitumen under investigation are identified, and physical and chemical characteristics, elemental composition and distribution of microelements in these organic extracts are determined. The study of microelements distribution showed that bitumen of the Kari Crossing and the Baida 2, in which the ratio V/Ni is less than 1 stratigraphically belong to the third-generation bitumen, and the Chibrevi and Mirzaani bitumen with the ratio V/Ni >1 is of older origin and belongs to Paleozoic period. By content of oils, tars and asphaltes the bitumen under investigation belong to the asphalt type bitumen.

The individual composition of polycyclic aromatic hydrocarbons has been studied in high boiling (340–590°) fractions of Norio oil (wells 200, 201) which are characterized by high content of aromatic hydrocarbons and high intensity fluorescence. The eluates obtained by adsorption fractionation of aromatic hydrocarbons separated by aniline and concentrates of their crystalline components have been studied by GC, MS and GC-MS methods. For analysis of the obtained data an automated system of mass deconvolution and identification (AMDIS) was used. In the eluates under investigation the following structures were identified: indenes, tetralines, dinaphtilbenzenes, naphthalenes, fluorenes, phenantrenes, antracenes, mono- and polyalkyl derivatives ofnaphtofluorene and phenantrene, and terpeniles. In crystal samples of the eluates the banzantracene, chrizene, their methyl-, dimethyl and trymethylanaloges, phenantrene derivatives, antracenes and pyrenes were identified. The heterocyclic analogues of polycyclic aromatic hydrocarbons likemethylbenzoanthracenes, benzonaphthothiophenes, benzocarbazoles and dibenzthiophene were identified in Georgian oils for the first time.

The results of investigation of molecular composition of biological markers of Eastern Georgia crude oils by methods of GLC, MS, GC/MS, genetic and geochemical aspects of their chemical composition, the main geochemical criteria for making various genetic correlations are presented. It was established that though these crude oils belong to different chemical types they all belong to a single genetic type. High concentrations of isoprenoid alkanes, ratio iC19/iC20 > 1, were revealed. In fractions higher than 420°С amongst the main biomarkers — steranes and triterpanes (C27–C33) – prevail hopanes of the 17αH-hopan series (C30H52); steranes (C27–C29) are represented by α-sterans and iso-sterans. Based on the main geochemical criteria the degree of catagenesis of oils and the probability of biodegradation of some of them was determined. In some crude oils polymethylsubstituted decalines, the relict type hydrocarbons (C14-C16) have been identified.