Comparative Geochemical Characterization of Heavy Oil with Various Genesis

Abstract

Oils from Nizhne-Karmal (Tatarstan, Russia) and Boca de Jaruco (Cuba) reservoirs had been researched by GC-MS. Distributions of alkanes, steranes, hopanes, alkylbenzenes had been used as biomarker characteristics. Initial organic substances of both samples had been formed in sea conditions, what had proved by ratio of pristine to phytane. Lack of steranes in Cuban oil evidence about vertical migration or biodegradation processes. Anaerobic microbiological degradation had caused the absence or partial destruction of saturated hydrocarbons. The maturity of raw materials had been estimated by the ratio Ts/(Ts + Tm). Low value Aryl Isoprenoid Index (AIR) showed stability of photic zone for Nizhne-Karmal oil. Photic zone in Cuban reservoir was subjected to the mixing water column.