Light Hydrocarbons and Their Message on Geochemistry of Oils and Condensates from the Bovanenkovskoye Field (West Siberia)

Abstract

Summary The studied Bovanenkovskoye oil-gas-condensate field is located at the Yamal Peninsula – in the north of West Siberia, where a new gas-production centre is being formed. The aim of the study is to conduct geochemical type assignment of oil (5) and condensate (10) samples from the Lower Cretaceous (K₁al – 2, K₁a – 3, K₁g – 3), Middle (J₂bt – 3, J₂b – 3), and Lower Jurassic (J₁p – 1) deposits, using data about their properties and composition (distribution of n-alkanes, i-alkanes, steranes, terpanes, arenes, and, mainly, of light hydrocarbons C₄–C₈). In the presented research, the use is made of GC and GC/MS analyses of crude oils (condensates) and their hydrocarbon fractions. The obtained results suggest the hydrocarbon formation in the Bovanenkovskoye field from a single center of oil and gas generation due to the terrestrial organic matter of the Lower and Middle Jurassic strata (Malyshevka, Layda formations) and a significant contribution of the aquatic organic matter from the Upper Jurassic strata (Bazhenov formation) to the generation of the Aptian condensates.