Oil & Gas Geology ›› 2022, Vol. 43 ›› Issue (6): 1334-1346.doi: 10.11743/ogg20220605

• Petroleum Geology • Previous Articles    

Characteristics of the Meso-Cenozoic tectonic transformation and its control on the formation of large-scale reservoirs in the Archean buried hills in Bozhong 19-6 area, Bohai Bay Basin

Deying Wang1(), Xiaojian Liu1, Hui Deng1, Yongjiang Liu2, Deyu Li1   

  1. 1.Tianjin Branch,CNOOC Ltd. ,Tianjin 300459,China
    2.Ocean University of China,Qingdao,Shandong 266100,China
  • Received:2022-03-04 Revised:2022-09-11 Online:2022-12-01 Published:2022-11-21

Abstract:

There are few studies on the relationship between tectonic transformation in North China since the Meso-Cenozoic and the origin of traps and reservoirs in buried hills in the Bohai Bay Basin. The data of core, seismic and thin section observation, coupled with understanding on the regional tectonic background, are applied to clarify the characteristics of the Meso-Cenozoic tectonic transformation in Bozhong 19-6 area and its influence on buried-hill strata, traps and the Archaean reservoirs. It is shown that the buried-hill structure in Bozhong 19-6 area underwent tectonic transformations from the pre-Indosinian to Indosinian, from the Indosinian to Yanshanian and from the Yanshanian to Himalayan under the interaction of North China, South China and paleo-Pacific plates, resulting in four fault systems trending NW, NE, near NS and EW. The NW-trending faults formed in the period of Indosinian tectonism controlled the overall trap and stratigraphic distribution of the Archean and Paleozoic; The NW- and near NS-striking faults developed in the period of Yanshanian movement made the buried-hill traps more complex, and overall structure of the buried hills was finalized with the fault depression in the Himalayan period. Multi-episode tectonic movements are of great significance to the formation of large-scale fractures in the Archean buried hills, and the Indosinian overthrusting was critical to the formation of large-scale fractures in Archean. The Yanshanian tectonic activities further expand the scale of the Archean fractured reservoirs developed, and the Himalayan tectonic transformation has a significant impact on the "reactivation" of early fractures. Multi-stage spatiotemporal tectonic transformation is the key to the development of large-scale reservoirs in the Archean. The correlation mechanism between the Meso-Cenozoic tectonism and origins of buried-hill trap and reservoir in eastern China proposed in this study, provides a more effective method for mapping of buried-hill reservoirs in eastern China, and is of great significance to guiding buried-hill petroleum exploration in similar basins.

Key words: multi-stratigraphic structure, trap genesis, Archean burried hill, structural transformation, Meso-Cenozoic, Bozhong 19-6 area, Bohai Bay Basin

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