Unravelling Hydrocarbon Migration and Entrapment in the Western Siberia Basin using Advanced Petroleum System Modeling

The problem of the maintenance of the production level, entailing the industrial development of new reservoir systems is vital in Western Siberia (Russia). Such targeted systems include the deep Neocomian deposits (Achimov Fm) and Late/Middle Jurassic reservoirs. Hydrocarbon fields occur in Neocomian sandstone lenses, disseminated within silt and marine shale deposits. These reservoirs, stratigraphically associated to a large and complex system of clinoforms, correspond to both deep-water sand facies of the Achimov Fm at the base of the slope, and deltaic and shoreface sandstones interbedded with shales at the top. They contain hydrocarbons originating from the Bazhenov Fm (20-70 meters), considered as the major source rock in this basin. Late Jurassic siliceous layers underneath the Bazhenov black shale constitute another reservoir system of interest. Accumulations were discovered in Late/Middle Jurassic sandy reservoirs, but their oil and gas habitats remain undervalued to date. These reservoirs, affected by fracturing and deformation, are characterized by a series of anticlines and synclines structures separated by sub-vertical faults.