Petroleum-bearing complexes in the Lower-Middle Jurassic and Lower Cretaceous clinoforms of the West Siberian basin

The West Siberian basin formed as a result of the Early Triassic rifting and downwarping of the Earth's crust during the Mesozoic and Cenozoic. Three stages are recognized in this process: early (postrift, Middle Triassic-Middle Jurassic), middle (platform, late Middle Jurassic-Eocene), and late (neotectonic, late Eocene-Quaternary). In this paper, the regularities and conditions of sedimentation are described concisely, and the potential of Lower-Middle Jurassic petroleum-beating complexes (Zimnii, Sharapov, Nadoyakh, Vym', and Malyshev) and Neocomian cllinoforms is estimated. The conclusion is made that the further increase in reserves of hydrocarbons in the West Siberian petroliferous province in a sufficient volume is possible at the cost of these two petroleum-bearing stories. A program of their further study on a regional scale is proposed. This program will be a base for a more complete estimation of resources of the complexes under study, for determination of areas for detailed seismic prospecting and parametric drilling, and for their geological and economical estimation aimed at a necessary licence.