HISTORICAL-GEOLOGICAL MODELING OF HYDROCARBON GENERATION IN THE MESOZOIC–CENOZOIC SEDIMENTARY BASIN OF THE KARA SEA (
basin modeling)
A.E. Kontorovich, L.M. Burshtein, N.A. Malyshev, P.I. Safronov, S.A. Gus’kov, S.V. Ershov, V.A. Kazanenkov, N.S. Kim, V.A. Kontorovich, E.A. Kostyreva, V.N. Melenevsky, V.R. Livshits, A.A. Polyakov, M.B. Skvortsov
Keywords: Generation, migration, accumulation, dissipation of hydrocarbons, basin modeling, source rock, Arctic petrolife-rousareas, Kara Sea, West Siberian Basin
Abstract
Numerical models are developed to predict the generation, accumulation, and escape of hydrocarbons at the time of sediment accumulation (basin modeling) in the West Siberian geosyneclise during the Jurassic, Cretaceous, and Cenozoic. A theoretical framework for such computer models is presented with a special emphasis on modeling of gas generation during early catagenesis. The study provides a description of the algorithm used for interpretation of simulation results and considers the stages of formation of a shale cap rock during lithogenesis. Peak oil generation began in the Aptian and continued for about 80 Myr till Eocene–Miocene time; gas generation in the late catagenetic window took place from Valanginian to Maastrichtian. Numerical simulations show that the major oil-prone source rocks in the South Kara kitchen area were, in the decreasing order of potential, the Bazhenovo (Yanov Stan), Kiterbyut, and Malyshevka Formations. The Upper Jurassic regional rock unit generated over 60% of liquid hydrocarbons and heterocyclic compounds (oils). The major gas-prone source rocks in the area were, in the decreasing order of potential, the Kiterbyut, Malyshevka, Alym, and Bazhenovo (Yanov Stan) Formations. The Lower and Middle Jurassic regional rock units generated about 65% of hydrocarbon gases. Results are presented to quantify the amount of hydrocarbons dissipated due to either the absence or poor effectiveness of confining seals and to explore the role of Cenozoic tectonic processes in the formation of petroleum accumulations in the basin.
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