Source and accumulation process of Jurassic biodegraded oil in the Eastern Junggar Basin, NW China

Petroleum in the Jurassic Reservoirs within the Eastern Fukang Sub‐depression, Junggar Basin, NW China: Correlation and Source Rock

“…Our results indicate that Jurassic reservoirs within the eastern Fukang sub-depression have received oils generated from the Permian, Triassic and Jurassic source rocks. Previous studies have proposed that the Permian source rocks in the Fukang sub-depression started generating and expelling hydrocarbons during the Early Jurassic (Xiao et al, 2010;Hou et al, 2021). Oils generated from depocenters of the depression migrated northeast to the Baijiahai sub-uplift and east to the eastern uplift during the middle to late Jurassic, as demonstrated by the results of basin modeling (Xiao et al, 2010).…”

“…This is supported by the fact that, to date, no Permian-sourced oil pools have been discovered and very low amounts of extract yields with a Permian origin were obtained from the oil-stained reservoir cores. The tectonic uplift in the late Jurassic caused erosion of the upper Jurassic sediments and resulted in heavy biodegradation of the Permian-sourced oils in the Jurassic reservoirs (Xiao et al, 2010;Hou et al, 2021). The Triassic source rocks in the depression entered the oil window during the middle Cretaceous (Hou et al, 2021) and oils generated from these source rocks seem to have charged very limited reservoirs within the study area.…”

“…The tectonic uplift in the late Jurassic caused erosion of the upper Jurassic sediments and resulted in heavy biodegradation of the Permian-sourced oils in the Jurassic reservoirs (Xiao et al, 2010;Hou et al, 2021). The Triassic source rocks in the depression entered the oil window during the middle Cretaceous (Hou et al, 2021) and oils generated from these source rocks seem to have charged very limited reservoirs within the study area. During the early Paleogene, the Jurassic source rocks in the Fukang sub-depression started generating and expelling hydrocarbons (Hou et al, 2021).…”

“…The Triassic source rocks in the depression entered the oil window during the middle Cretaceous (Hou et al, 2021) and oils generated from these source rocks seem to have charged very limited reservoirs within the study area. During the early Paleogene, the Jurassic source rocks in the Fukang sub-depression started generating and expelling hydrocarbons (Hou et al, 2021). The Jurassicsourced oils migrated through faults and sandstone bodies and accumulated in a complex series of structural and stratigraphic traps within the Jurassic succession, with oil mixing with early-charged Permian or Triassic origin hydrocarbons in several wells.…”

The characteristics and genetic mechanisms of the Upper Permian Shangwuerhe clastic reservoir in the eastern Junggar Basin, Northwest China

“…Due to the rise in oil and gas exploration in the basin uplift areas and shallow layers, and the rapid advancement of drilling and development technologies, the petroleum exploration field shifted from tectonic reservoirs in uplift areas to lithologic reservoirs in the depression areas. Moreover, it moved from conventional petroleum systems to unconventional systems (i.e., tight and shale petroleum systems) and from shallow to deep petroleum reservoirs (Jia et al, 2007(Jia et al, , 2016He and Li, 2014;Du et al, 2016;Hou et al, 2021;Liu et al, 2021;Zhang et al, 2021;Li et al, 2022).…”