Key words: Yuryuzano-Sylvenskaya Depression, flysch deposits, gas-prone play, petroleum potential
Previously due to the active exploration of the primary Middle Carboniferous and Devonian target formations the flysch deposits of Yuryuzano-Sylvenskaya Depression remained frontier and underexplored. They were viewed only as a thick seal for the underlying oil reservoirs. However high gas readings while drilling in this flyschoid sequence (from 0.12 to 90 %), noncommercial flow of petroleum gas while testing (up to 2000 m3/day), as well as the presence of relatively large cut-through superimposed anticlines in the internal zone of Yuryuzano-Sylvenskaya Depression provide evidence to the potential commercial gas discoveries.
