with mid-Miocene Series to Quaternary 1. Regional Setting System. Research shows that the East China With an area of 770,000 km2, the East Sea Shelf Basin is the target area for oil/gas China Sea is located between the Chinese exploration. Specially, the Xihu Trough located continental margin and the western Pacific at the East Depression Zone and Oujiang Ocean. Trough located at the West Depression Zone According to the seafloor topography, have good potential. the East China Sea is composed of the East China Sea Shelf and Okinawa Trough. 2. PETROLEUM SYSTEM Tectonically, the East China Sea can be divided The basic features of the petroleum into two basins and three uplifts including the system in the East China Sea Shelf Basin are as East China Sea Shelf Basin, Okinawa Trough follows: Basin, Zhemin upliftd area, Diaoyu Island 2.1. Source Rock folded-uplift belt and the Ryukyu uplifted area. Cenozoic strata are characterized by The East China Sea Shelf Basin is a alternating sandstones and shale with coal Cenozoic depositional basin 267,000 km2 in seams and carbonic shale interbeds. Organic area. Distribution of basin-fill developed in matter is mainly characterized by humics (? - various Cenozoic times is obviously controlled type kerogen). Source rocks mainly consisting by tectonic pattern which is zoned in east- of shale and coal beds can be divided into two westward and blocked in south-northward, and types, i.e. gas-generation and oil/gaseast-westward zonation specially comes into generation. A distinguishable feature of source prominence. rock in the East China Sea Shelf Basin is that NNE-trended raised zones including widely existing coal beds in all strata become Guanyin, Yushan, Haijiao and Hupijiao divide the dominant source rock (oil/gas-generation) the basin into west depression zone and east although no carbonate rocks have been found in depression zone. The west depression zone is the basin up to now. structurally characterized by coop-like troughs including Changjiang, Qiantang, and Oujiang. 2.2. Reservoir from north to south, and deposited mainly Tertiary reservoir in the East China upper Cretaceous System and Paleocene Series. Sea Shelf Basin is mainly sandy beds. Single The east depression zone is structurally beds of blocky sandstone could exceed 50 m in characterized by a series of fault-troughs thickness. Those sandstone beds in the including Fujiang, Xihu and Jilong from north sandstone / shale interbedding interval are to south, and mainly deposited Eocene, commonly less than 10 meters in thickness.
Oligocene and Miocene Series. Reservoir capacity is laterally controlled by The East China Sea Shelf Basin had depositional environment, and vertically experienc
