Abstract: After years of exploration, the buried hill in Raoyang sag now is characterized by high degree of exploration and great difficulty in exploration. But the buried-hill exploration is inhomogeneous, so the buried hill has great exploration potential. Since 2006, based on secondary acquisition and merging processing of three-dimensional seismic data, in the light of the buried-hill exploration area in Raoyang sag, the buried-hill reservoir-formation conditions have been reconsidered by new ideas and new perspectives, the controlling mountain fault structure has been summarized again, the buriedhill reservoir-forming modes have been reestablished, the original data of old wells have been reviewed, the existing conclusions and cognitions have been reexamined. Buried-hill reservoirs including Chang-3, Ninggu-8, and Hu-8 buried-hill reservoirs have been discovered one after another in Changyangdian, Suning, and Sunhu buried-hill structural belts. New breakthroughs have been achieved in buried-hill exploration

Key words: buried-hill reservoir, reservoir-forming mode, Raoyang sag, exploration breakthrough, exploration enlightenment