Main Genetic Types of Oil & Gas and Characteristics of Their Accumulation and Distribution in North Marginal Basins,South China Sea

The north marginal basins of South China Sea are located at the junction of the Eurasian,the Pacific Ocean and the Indian-Australian plates.The geological setting is complex,the Tertiary sediment developed well,and petroleum geological phenomena are rich and colorful.Based on the previous research and exploration,the discovered oil and gas can be divided into three types,biogenic and sub-biogenic gas,normal mature oil gas,highly and over-mature oil gas.And there are also three types of non-hydrocarbon gas.The normal mature continental paraffin oil gas are mainly distributed in the Beibuwan Basin and the Pearl River Mouth Basin.The highly and over-mature coal-related condensate gas oil gas are mainly found in the Qiongdongnan Basin and some areas of the Pearl River Mouth Basin.Coal-related gas and non-hydrocarbon gas are mainly formed in mud diapiric zones of the Yinggehai Basin,the Eastern Qiongdongnan Basin and some areas of the Pearl River Mouth Basin.