Study On The Interpretation Method Of Water-flooded Layer Of Yangdachengzi Reservoir Group In Yushulin Oilfield

The reservoir qualities of Yangdachengzi reservoir in Yushulin Oilfield are typical low porosity and low permeability.The reservoiris deeply buried and isaffected by multiple factors such as structure,faults and lithology.The reservoir is characterized by thin thickness,complex lithology,poor physical properties,and rapid change in plane phasing of the rock stratum and poor connectivity.These characteristics have led to problems such as prominent conflicts between layers and planes in reservoir,and rapid waterflooding of some small layers after water injection.In order to improve the production efficiency of Yangdachengzi reservoir group,it is necessary to carry out the research on fine evaluation technology of water flooding of the reservoir,so as to realize the potential tapping of remaining oil in the block.Taking the block of Fuyang reservoir in Yushulin oilfield as the plane unit,and taking Yangdachengzi reservoir group as the longitudinal unit.Based on the analysis of basic geological characteristics and reservoir characteristics,,the change of logging response before and after water flooding is studied,and the logging sensitivity analysis is presented through the study of the ability of logging response reflecting reservoir parameters in the study area,especially for high or medium water-bearing rocks,.And then,taking the core calibration logging as the main measure,a fine evaluation method for the parameters such as shale content,calcareous content,porosity and permeability of the Yangdachengzi reservoir is formed based on the multidisciplinary analysis of the effects of argillaceous filling,calcitic cementation,compaction and other factors on the pore structure of the reservoir during the sand body deposition and diagenetic stage,.What ' s more,theinterpretation model of reservoir oil saturation is developed by using the data of sealing core drilling and regional water analysis,and the quantitative identification standard of water-flooded layer is established according to the parameters of complex pore structure and displacement efficiency.Finally,a interpretation method of water-flooded layer for Yangdachengzi reservoir is determined according to the qualitative and quantitative identification criteria of water-flooded layer..The identification accuracy of water–flooded layer reached over 80%through verification of sealing core drilling wells,and the evaluations of water-flooded layer of 47 sealing core drilling wells in the studying area were completed,which providing a strong evidence for further adjustment scheme of the oilfield.In this paper,it is the first time to conduct the research on evaluation of water-floodedlayers for deep-buried,low-porosity and low-permeability Yangdachengzi reservoir group,,and the systematic research idea and implementation method are showed,which can be applied to the fine evaluation of water-flooded layers in other similar reservoirs,and has universality and important significance in theory and practice.