There are good reservoir-seal assemblages in Palaeogene system, and this system has become favourable locations for both Cenozoic primary hydrocarbon accumulations and Mesozoic secondary accumulations.

• 古近系内部发育良好的储盖组合，该层系不仅是新生代原生油气藏的主要聚集场所，也是中生界次生油气藏的有利聚集层位。