Logging Data Interpretation And Comprehensive Reservoir Evaluation Of Gaotaizi Reservior In Yingtuo Region

This paper is targeted at a series of problems to be solved in the Yingtuo area of Jilin oilfield,such as the petrologic features of detrital sandstone reservoir,diagenesis characteristics,logging response characters,and reservoir optimization with better physical conditions of inter-bed development.Resorting to the basic theories in sedimentology,petrology,logging interpretation and petroleum entrapment,it conducts a comprehensive reservoir evaluation of detrital sandstone in Gaotaizi reservior of Yingtuo from the perspective of rock type,mineral component and content,diagenesis type,electrical property and reservoir parameter relativity.It focuses on the establishment of logging interpretation model of reservoir physical property,the impact of diagenesis on reservoir physical property,the analysis of lithogenous phase type,the identification of interbed type and the parameter characterization of interbeds.And finally it explains the influence factors and influence mechanism in the reservoir physical property of Yingtuo,the grade classification of reservoir and the optimization of favorable reservoir.This study shows the detrital sandstone reservoir in Gaotaizi reservior of Yingtuo mainly contain lithic feldspar sandstones and feldspar lithic sandstones with low compositional maturity and middle-poor result maturity.And primary intergranular pores occupy first place and secondary denudation pores come second.Simultaneously,there are a small amount of fracture pores.Generally,the reservoir is at the end of early diagenetic stage and the stage A of mesozone rock.The diagenesis which destroys reservoir is mechanical compaction-pressure solution and cementation;and the diagenesis which helps reservoir is dissolution.In addition,according to the above characteristics,it divides reservoir stratum into silica cement-residual primary pore diagenetic facies,weak carbonate cement-primary pore diagenetic facies,strong carbonate cement-residual primary pore diagenetic facies and carbonate dissolutionprimary-secondary porosity diagenetic facies.As to the logging data interpretation,it firstly carries out data normalization treatment.Next,it sets up models of porosity and permeability in accordance with the high correlation between electrical,physical and lithological property.The result indicates the error is within the standard limits.The interbeds of Yingtuo area mainly belong to argillaceous and calcareous ones.Consequently,it succeeds in identifying different logging.At the same time,it points out the interbed development is restricted by the subfacies distribution of braided river delta.In sum,the physical characteristics are primarily controlled by sedimentation and diagenesis in detrital sandstone reservoir in Gaotaizi reservior of Yingtuo.Besides,the growth of fracture density and fault activity also has local effect.In the end,it divides the reservoir into three physical property levels of ?-? and selects the favorable target area of reservoir accordingly.