Oil sources and accumulation processes of the Neoproterozoic Luotuoling Formation (-930 Ma) in the Liaoxi Depression are investigated using integrated fluid inclusion, basin modelling and oil-source rock correlation analyses. In the upper Luotuoling Formation sandstone reservoir in Han-1 well, abundant bitumen inclusions and white fluorescent bitumen-bearing oil inclusions were observed. Combined with microthermometry of aqueous inclusions and burial history analysis, the oil charge time of the upper Luotuoling Formation sandstone reservoir took place at approximately 465-455 Ma. This oil was derived from the Gaoyuzhuang Formation source rock according to biomarkers and isotope compositions. However, oil generation of the Gaoyuzhuang Formation had already ended before 455 Ma, so the oils cannot be generated directly from the Gaoyuzhuang Formation source rocks, but definitely migrated from the destroyed paleo-oil accumulations in the Wumishan or Tieling formations. In addition, the lower Luotuoling Formation sandstone reservoir contains mainly yellowish orange fluorescent oil inclusions. The oil in the lower Luotuoling Formation sandstone reservoir was directly generated from the Hongshuizhuang source rock at 240-230 Ma. The study on oil accumulation history of the Neoproterozoic Luotuoling Formation reservoir is significant for further exploration of Proterozoic petroleum resources in the Liaoxi Depression, North China Craton.
NSTL
Elsevier