Abstract:Linnan Sag is the most important oil and gas sag in Huimin Depression. With the development of exploration, the difficulty of exploration is increasingly growing in Linnan Sag. Based on study of the essential characteristics of oil and gas reservoirs and summarization of the distribution features and rules, main controlling factors of reservoirs in Linnan Sag were analyzed for oil and gas exploration in the future. There are various petroleum reservoir types in Linnan Sag, and the sag is dominated by fault-block reservoir and composite reservoir about fault. Reservoirs are mainly distributed in turbidite fan facies, alluvial fan facies, and fluvial facies. According to the study, the distribution and accumulation of petroleum reservoirs is mainly controlled by source rocks, sedimentary facies belts, and faults in Linnan Sag. Petroleum reservoirs are controlled by hydrocarbon source rocks and distributed surrounding the oil-generating sag. Because the favorable of sedimentary facies belts are continuously overlapped, they are well reservoir beds. Faults not only control the hydrocarbon migration pathways, but also control the hydrocarbon accumulation by trapping with formations and structures.