1. Hydrocarbon migration and accumulation in the northwestern Bozhong subbasin, Bohai Bay Basin, China.
- Author
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Xu, Shang, Hao, Fang, Xu, Changgui, Zou, Huayao, Zhang, Xintao, Zong, Yi, Zhang, Yuanyin, and Cong, Fuyun
- Subjects
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HYDROCARBONS , *GEOLOGICAL basins , *STRUCTURAL geology , *PETROLEUM reservoirs , *GEOLOGIC faults - Abstract
Abstract An important exploration breakthrough has been achieved in the western subsag of the Bozhong subbasin, but the hydrocarbon accumulation mechanism was not clear. The hydrocarbon migration and accumulation mechanism of the western subsag of the Bozhong subbasin is discussed based on the modeling of hydrocarbon migration pathways and the study of late-stage reactivation of neotectonic faults. Three processes for lateral petroleum migration and accumulation can be recognized in the studied area: 1) migration and accumulation along the T8 unconformity; 2) migration and accumulation within the Guantao Formaiton (N 1 g); and 3) interaction of migration and accumulation along the T8 unconformity and Guantao Formation (N 1 g). The reactivation of faults in the studied area began 5.1 Ma. Following hydrocarbon lateral migration, late-stage reactivated neotectonic faults serve as effective vertical conduits for hydrocarbon migration and accumulation into the shallow Minghuazhen Formation (N 1 m) reservoirs. The modeling results of preferential petroleum migration pathways (PPMPs) and favorable accumulation areas are consistent with the actual exploration results. Two kinds of potential exploration targets can be predicted in the northwestern Bozhong subbasin: the first kind is hydrocarbon accumulation areas near or within generative kitchens (e.g. Target 1); the other kind is hydrocarbon accumulation areas removed from the generative kitchens, but with hydrocarbon sourcing from multiple generative kitchen and numerous PPMPs (e.g. Target 2). Studying preferential petroleum migration pathways will help reduce exploration risk. Highlights • The T8 unconformity and Guantao Formation (N 1 g) carrier beds are favorable hydrocarbon lateral migration conduits. • Late-stage reactivated faults during neotectonism serve as favorable conduits for vertical hydrocarbon migration. • Proven oil fields usually have multiple generative kitchens and numerous preferential petroleum migration pathways. • Potential exploration targets can be predicted based on preferential petroleum migration pathways. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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