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.