Abstract: In order to study the law of hydrocarbon enrichment at the oil-source fault in the petroliferous basin, based on the study on the conditions and evolution stage of oil-source fault transport, the method of determining the evolution stage of oil-source fault transport is established by determining the activity period of oil-source fault and the formation period of the oil-source fault transport in the oil source and the oil source outside the oil transfer station. The method is used to determine the evolution stage of oil and gas transport from Nandagang fault to the Lower Member of the Shahejie Formation in Qikou sag, Bohai Bay basin. The results show that, the oil and gas stage of Nandagang fault to the Lower Member of the Shahejie Formation to the Third Member of the Shahejie internal transfer station starts from the deposition of Guantao Formation to the middle deposition of Minghuazhen Formation; The oil and gas stage of the transfer station of the third stage is from the middle deposition to the end of the Minghuazhen Formation. After two evolutionary stages, the oil and gas transporting period is relatively long, which is conducive to the large-scale accumulation and accumulation of oil and gas from the underlying source rocks of the Third Member of the Shahejie Formation in the Lower Member of the Shahejie Formation. According to the method of this paper, it can reasonably explain the phenomenon of oil and gas enrichment in the lower sub-member of the Nandagang fault. This method is suitable for determining the evolution stage of oil and gas transport by oil-source faults.

Key words: oil-source fault, transporting oil and gas, evolution stage, Qikou sag