Middle Yangzi River Region

located in the middle part of Yangzi paraplatform

un-derwent three sedimentary evolution and development stages:basement formation stage;platform development stage and post-platform reformation stage.Sediments from Upper Sinian to Middle Triassic are mainly marine carbonate rocks of six to ten km thick.The sediments

with multiple source sequences

thick source rocks

type-Ⅰ kerogen as the major parent material

matured or high-matured organic matter

possess good hydrocarbon generating condition.The reservoirs

including mainly porous dolomite reservoir

paleo-weathered crust reservoir

shallow-beach reservoir and fracture-solution pore reservoir

are variety in types and great in thickness.The cap rocks are wide spread in the study area.It is suggested that the area has fine source-ressrvoir-cap rock assemblage

and favourable conditions to form commercial oil and gas fields.According to the preservation condition

the study area can be divided into threetypes:1.Shizhu-Wanxian tectonic stable area;2.paulopost fault-subsided area in Jiang-han Plain and 3.folded-uplift area in West Hunan-West Hubei region.Among them

the Shizhu synclinoriun in Chuandong is most favourable for gas exploration

Dangyang and Chenhu synclinoria located in hinterland of Jianghan Plain have best oil prospects.