The Research For Sedimentary Facies Of Shahezi Formation In Northwest Area Of Xujiaweizi Fault Depression

As the favorable exploratory field,northwest area of Xujiaweizi fault depression has multi-layered gas.While in fact,isochronous stratigraphic framework of Shahezi formation hasn't been built,which restricted reservoir exploration of Shahezi formation.Therefore,based on the new exploratory well data,this study focuses on the deep analysis of sedimentary facies of Shahezi formation,and is very significant in summarizing sedimentary discipline of deep layers and defining the favorable exploratory area.Based on the systematic sequence stratigraphy and sedimentary analysis,this study mainly focuses on researches including stratigraphic classification and correlation.Besides,it also concentrates on analyzing sedimentary facies distribution attributes and predicting favorable zones with the feature of reservoir.Through sequence interfaces identification,Shahezi formation in the study area can be divided into four sequences.Therefore,stratigraphic framework of Shahezi formation in study area is built,and sequence boundary's geological implication is analyzed.In conclusion,research such as observation of the sequences' cores,analysis of single well facies,even well facies and seismic facies is accomplished.In addition,evolution model of sedimentation is built.Sedimentary facies plane distribution is analyzed under the sequence framework through well seismic calibration.Eventually,the favorable area of study field is predicted.