Abstract: Based on the analysis of thin section, SEM and the reservoir property data, the digenesis and characteristics of the development of the secondary porosity in the glutenite of northern Dongying Sag are studied. Glutenite
fans such as nearshore subaqueous fan, deep water turbidite fan are developed in the northern part of Dongying Sag. They have a low maturity in composition and structure. Glutenite reservoir has experienced many kinds of
diagenesis, such as compaction, cementation, dissolution and so on. Mechanical compaction is the main compaction. Cementations are mainly carbonate cementation, quartz overgrowth and clay minerals cementation. Dissolution comprises carbonate cementation content dissolution, feldspar particles and limestone debris dissolutions. Accordingt the characteristics of vitrinite reflectance, fluid inclusion thermometry, and clay minerals mixed-layer proportion,it is ascertained that the glutenite has experienced stage A and B of the early diagenesis, and stage A of the middlediagenesis. At the same time, the pores have experienced an evolutionary process from primary to secondary. In this area, secondary pore mainly develops in the range of 1 650～2 450m. Compared with Binnan and Shengtuo area,secondary porosity in Lijin is less developed.

Key words: Dongying Sag, Paleogene department, northern glutenite, diagenesis, secondary pores