1. College of Earth Sciences, Jilin University, Changchun 130061, China; 

 Shennan oilfield is located in the Shenxian sag in the middle of Jizhong depression in the Bohai Bay Basin. It has a geat development of faults. Therefore, the distribution of oil and gas is affected by faults. It be? longs to a typical structural hydrocarbon accumulation. According to the study of reservoir distribution, the oil source is mainly from the first and third members of Shahejie Formation. The reservoir conditions in this area are good because there is a stable mudstone cap rock in the upper part. The oil and gas in the Dongying Formation and Shahejie Formation migrated laterally along the transport layer from the deep depression to form primary oil and gas reservoirs, while the Minghuazhen Formation and Guantao Formation are secondary oil and gas reservoirs formed by vertical migration of oil and gas along faults. Through the study of reservoir potential, there are oil and gas reser? voirs in the deep Dongying Formation and Shahejie Formation of Tai??4 block. In addition, Ze ??10 and Ze ??70 blocks have good fault diversion systems and have potential for oil and gas accumulation in shallow layers.