Abstract:

Based on the study of compaction, overpressure and oil potential at the deepest burial depth in Early Cretaceous were restored for the Yanchang Formation, eastern Gansu Province, Ordos Basin. We carefully examine the relationship between vertical distribution of overpressure and testing production. The results show that the oil flow is relatively higher where it is close to the oil source and has lower overpressure, indicating that a close relationship between overpressure and oil distribution. Distribution of oil potential in the main period of accumulation shows that oil tends to migrate and accumulate at the lower oil potential area which coincides with current oil distribution. From this study, we believe that, under the condition of low permeability of reservoirs, fluid dynamics in the main period of accumulation is the main controlling factor for oil migration and accumulation.