Qaidam Basin In Yellowstone - East Chaishan Tertiary Strata, Sedimentary Facies And Reservoir Characteristics Of Study

The paper studys the characters of the Tertiary stratigraphy, depositional facies and reservoir in the Huangshi-Dongqaishan area of Qaidam besin. The stratigraphy includies biostratigraphy, lithostratigraphy and sequence stratigraphy. Three Charophytes assemblages were recognized and three sequenceal stratigraphic interfaces were classified. Four supersequences and seven sequences were divided. The study was focused on the typical facies and single well facies in the depositional facies. On this basis, four depositional facies, ten subfacies and thirteen microfacies were recogniced in the area. The study on the reservoir includes the lithological characters, diagenesis, pore structure and the factors affecting the physical properties. The auther believes that the reservoir is vertically made up of E3 , E1+2 and secondarily of Nl and N21 .Laterally, the distribution of reservoir is oviousely controlled by facies zones. The reservoir pore types are maily of secondary pores and secondarily of primary pores and mixed pores. The diagenesis phase is divided into early B phase and late A phase. The major factors affecting reservoir physical properties are :the compaction, cementation and solution of the diagenesis and the depositional evironment.