Chemical Typification and Genetic Criteria for the Composition of Georgian Petroleum

Abstract

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.