Abstract:

Lishu area in southern Songliao Basin is a multi-overlapped fault-depressed basin de-veloped upon the Premesozoic metalmorphic basement during Late Jurassic-Middle Creta-ceous.The total thickness of Mesozoic strata in Shiwu fault-depression is about 10000m.The Wujiazi Formation is an important oil-gas source rock.The Quanto sandstone reser-voir developed in depression stage is the main deep-generated low-reserved reservoir. The distribution and thermal evolution of the source rock and two structural move-ments(late Denglouku and Nenjiang stages)controlled hydrocarbon distribution.The steep slope belt in the north of Shiwu faulted-depression is the principal area for hydro-carbon accumulation.From deep depression area to upwelling area,the present area could be divided into three semi-circle hydrocarbon accumulating belts such as Houwujia-hu gas belt,Xiaowujiazi oil-gas belt,Yangdachengzi thick oil belt.