STRUCTURAL STYLES OF MINJIANG DEPRESSION, EAST CHINA SEA SHELF BASIN AND IT'S BEARING ON PETROLEUM ACCUMULATION

The East China Sea Shelf Basin is a superimposed petroleum bearing basin. Thick Mesozoic deposits are widely distributed in the Minjiang Depression. There are several sets of reservoirs and cap combinations in vertical sequence. The East China Sea Shelf Basin has experienced several episodes of tectonic movements such as the Jilong movement, Yandang movement, Oujiang movement, Yushan movement and Longjing movement. According to the dynamic mechanism, the Minjiang Depression can be divided into three structural types, namely extensional, compressional and complex structural styles. The depression has three major faults i.e. the Yandang fault, Taibei fault and Huyan north fault. Various types of structural reservoirs are strictly controlled by both the structural style and fault distribution pattern in the basin. The Jilong-Xinzhu Depression is the major oil-generation depression, the Minjiang-Xiapeng slope is the path for oil and gas migration, and the local structures on the slope are the favorable traps for oil and gas accumulation.