Abstract:

Paleozoic and Mesozoic sediments of continental margins and platform covers are mostly folded into mountains in China,and the unique marine superimposed-residual basins become a significant feature of China petroleum geology.During the geological evolution,the ancestors of these basins once had excellent source,reservoir and seal rocks,with their conditions of hydrocarbon resources and accumulation as good as those of other basins in world petroleum provinces.However,the marine carbonate sequences in China are older in age,deeper in exploration targets,and complex in hydrocarbon accumulation due to multiple events of tectonic superimposition and reworking,resulting in the peculiarity of petroleum exploration in these marine carbonate sequences.Recent exploration results have shown that large hydrocarbon accumulations are still likely to be formed under suitable conditions in these marine sequences because of their foundations of organic matter.Differential tectonic evolution has make the marine basins be significantly different in hydrocarbon potential and production capacity. Thus,Sichuan and Ordos basins are predominated by gas production,and Tarim basin is able to produce both oil and gas.Therefore,looking for giant and large fields should be focused on Tarim,Sichuan and its periphery and Ordos basins with developed marine sequences.

Key words: differential tectonic evolution, Sichuan Basin, Ordos Basin, Tarim Basin, superimposed basin, marine sequences in China