Abstract:As one of the main oil-bearing strata in Chengdao area, the Lower Paleozoic has experienced a round of exploration climax and fallen into silence. On the basis of systematic analysis of the faults in the Lower Paleozoic buried hills in Chengdao area, this paper analyses the differences of fault sealing ability through the analysis of drilled wells, the active and mechanical properties of faults, explores the sealing mechanism of faults, innovatively puts forward the knowledge that the ancient faults and compressive-torsional faults have better sealing ability, and puts forward the sealing mode of Chengdao buried hills. It is pointed out that the slope and negative structure of the buried hill are the favorable exploration direction for the next step. This knowledge has been further proved in exploration practice, which has realized a new breakthrough in buried hill exploration, enhanced the confidence of buried hill exploration and opened up the prospecting situation.