Hydrocarbon systems in foredeep troughs of ancient platforms

Punanova Svetlana A. Sc.D., chief researcher Institute of Oil and Gas Problems, Russian Academy of Sciences punanova@mail.ru
10.24411/2076-6785-2019-10012

The features of the distribution of hydrocarbon systems in the sedimentary cover in foredeep troughs Pre-Urals and Yenisei-Khatanga deflections on the territory of the Volga-Ural oil and gas and Yenisei-Anabarsky gas-oil-bearing basins are considered. Some common and different features of the basins are described. In both basins, high oil and gas potential can be expected to realize in deeply submerged Paleozoic and pre-Paleozoic (Riphean- Vendian) sediments, presumably in non-structural type traps. 

Materials and methods
Research materials: data on hydrocarbon (HC) systems of the Pre-Ural and Yenisei- Khatanga defl s of ancient platforms - East European and East Siberian. The oil and gas potential of these troughs is associated with the Volga-Ural oil and gas bearing and Yenisei-Anabara gas and oil basins. Research methods: comparison of geochemical data of petroleum parameters of structural units that are close in tectonic terminology (both are marginal (advanced, preorogenic) deflections) in order to identify both their similarities and differences that led to the characteristics of their hydrocarbon systems and types of traps. 

Results
Predorogenic deflections differ in geological structure (more complex in the Yenisei- Khatanga trough), age and number of productive complexes, the type and amount of OM contained in them, the degree of catagenesis, the predicted type of trap. 

Conclusions
For the Pre-Ural downwarp, non-structural traps of the combined type are predicted, associated with abnormal zones of various genesis; possible biotherm constructions in carbonate strata. In the Yenisei-Khatanga trough, nonstructural traps are predicted with a predominance of sub-thrust traps of pinching, lithological replacement and tectonically screened.
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