Home – Home – Jornals – Russian Geology and Geophysics 2018 number Неопубликованное

The article is devoted to the structure, formation conditions and subsequent development of the Koltogor-Urengoy rift system, which cuts the territory of Western Siberia in the meridional direction and has a length of 1925 km. Based on the interpretation of potential fields, the structure of the main rifts and the system of secondary grabens leading them has been clarified. It is concluded that the Early Triassic riftogenesis significantly predetermined the architecture of the Mesozoic-Cenozoic sedimentary cover of the West Siberian sedimentary basin and had a significant impact on its oil and gas content. Above the main graben rifts of the Koltogor-Urengoy system, in the structural plans of the Mesozoic reference levels, the Koltogor-Urengoy megatrough was formed - a supra-order linear depression extended in the meridional direction, stretching across the entire of Western Siberia. In the southern part of the basin, the more intense Mesozoic-Cenozoic subsidence of the Koltogor-Urengoy and Ust-Tym graben rifts predetermined the formation of large supra-rift depression zones in the sedimentary cover of the Srednepur trough, the Koltogor mega-trough, the Nyurolka and Ust-Tym mega-depressions – the main oil formation zones. Positive structures of the 1st and 2nd order were formed above the projections of the Paleozoic basement: the Northern, Nizhnevartovsk, Aleksandrov, Kaimysov arches; the Yetypurov, Vyngapurov, Srednevasyugan and Pudin megaswells – the main oil accumulation zones. In the north of the basin, anticlinal trap structures were formed above the interrift blocks in the reliefs of the Cretaceous horizons, controlling the Aptian-Albian-Cenomanian gas fields.