The Secondary Porosity Characteristics Research Of Fuyu Reservoir In Daan Oilfield

Dan an oilfield is located in the secondary structural belt of Hong gang terrace in the central depression area of southern Songliao basin. The study area is located in the deep subsags axis on the Hong gang—Da an terraces, in the east of Da an sunken. This paper made research of formation mechanism of lithofacies characteristics, physical property features, special components and secondary porosity in fuyu oil layer of Da an oilfield. Fuyu reservoir is typical of fine, silty sand rock, low permeability tight reservoir, microscopic pore structure of reservoir physical property and oil content has a critical impact. The general characteristics of reservoir property in the study area is poor, mainly special low—ultra low porosity, low permeability tight reservoir. Pore types can be divided into three types: millimeter level, micron level and nanoscale level according to pore diameter. Scanning electron microscope and mercury injection data show that priority of the study area is mainly micron level and nanoscale level.Finallly,according to the mercury injection data reservoir property can be divided into three classes and four subclasses, Namely Ⅰ,Ⅱ and Ⅲ class, and Ⅱcan be divided into Ⅱa and Ⅱb. Finally we set up the classification standard of reservoirs.