Abstract:

There is close contact between fault features and faulted reservoir accumulation, because fault is the main channel of vertical hydrocarbon migration. Based on the analysis of fault features of Enping Sag, the fault is divided into 2 fault systems and 4 kinds of faults in different active stages, and then its structural styles, activities, sealing and its impacts on hydrcarbon accumulation in Neogene are studied. The results show that 7 structural styles were summarized from kinds of faulted belts, in which developing tilting half anticline and anticline are the most favorable traps in hydrocarbon accumulation; The long active faults and the late active faults are the main migration faults of Enping Sag, which play dual role with channel and sealing in hydrocarbon accumulation: its sealing abilities restricted the hydrocarbon column height, and its activities controlled the hydrocarbon enrichment of drilling traps; So the rules between drilling hydrocarbon enrichment and the migration faults activities of migration period is introduced, that is, 1.09 is the critical value of faults activities growing index in migration period; The higher of the growing index is, the stronger of fault’s vertical migration abilities is, so the better hydrocarbon accumulation probability in Neogene traps is.

Key words: Enping Sag, fault feature, fault activity, fault sealing, structural style, Neogene