New data on the formation of oil and gas potential in the Western Urals area of folding

Authors: Karaseva T.V., Anikeenko O.M. (KamNIIKIGS JSC, RF, Perm), V.I. Gorbachev (NPC Nedra JSC, RF, Yaroslavl)

Key words: thrust zone, oil and gas potential, bitumen, source rock.

The main purpose of this paper is to study the processes of formation of oil and gas potential in the Ural thrusts by the example of the Arakaevskaya key 1 well area located in the Sverdlovsk region in the poorly studied Lower-Serginsky perspective oil and gas area of West-Ural folding zone. According to the results of a comprehensive study of core and geophysical investigations have revealed a complex structure of the well section, divided into three parts (autochthon, parautochthon and allochthon), no oil shows and the development of the gas in the allochthon. Throughout the studied sections revealed widespread bitumen, as oil degradation products, and at the bottom of parautochthonous presence destroyed oil deposit, which occur in the generation of the Upper Devonian source rocks. According to the results of 1D basin modeling using palinspastic reconstruction concluded that the identified gas content in the Lower-Middle Carboniferous allochthonous rocks caused by the generation of gases in the source rocks after development processes of thrust dislocations and possibly at the expense of the destruction of the oil deposit. Due to the fact that Arakaevskaya well is drilled in the frontal part of thrust we suggested the possibility of oil deposits conservation in other areas of the Lower-Serginsky perspective oil and gas area. The results can be used to assess the petroleum and gas potential of the zone of folding of the Sverdlovsk region and other regions.