Analysis on Lithofacies Paleogeography of Zhangxia Age in North China

摘要

On the basis of sequence stratigraphy,we analyzed numerous data of outcrops and wells,and established the sequence stratigraphic framework during Zhangxia Age in the North China,then studied its sedimentary facies and lithofacies paleogeographic characters.The research indicates that Zhangxia strata are dominated by clear water carbonate deposition,and especially developed oolitic limestone.The primary sedimentary facies of Zhangxia Age is oolitic beach facies,between which occur open marine facies.The main reservoir rocks of Zhangxia Age are oolitic limestone and dolomitized oolitic limestone,and the former is poorer than the latter in porosity and permeability.According to the distribution of sedimentary facies and regional properties of Dolomitization,we predict that the favorable reservoirs of Zhangxia Age in North China may develop in the north of Shijiazhuang – Linfen Line and the south of Datong – Beijing Line.