The Restoration Of Paleo-porosity And Forecast Of Perspective Plays Of Fuyu Reservoir In Sanzhao Area,Songliao Basin

It has been in the stage of tight oil exploration in Fuyu reservoir in Sanzhao area,but it is difficult to develop the remain resource reserve.Currently,the study of detailed and classified evaluation for remain resource reserve in Sanzhao area has been carried out.However,the deficient study on the reservoir characteristics in a crucial period of hydrocarbon accumulation leads to the problem of forecasting sweet points effectively and implementing correct development scheme.This study applies log data,analysis of casting lamella,quantitative scanning of rock,rate-controlled mercury penetration technique and nanometer CT scanning to analyze the current detailed microscopic characteristics of Fuyu reservoir in Sanzhao area.The Fuyu reservoir rocks are mainly well sorted feldspathic litharenite,which have fine particles and belong to fine sand or siltstone.There are mainly 5 pore types.Based on the strong reservoir heterogeneity,the shape and connectivity of pores are divided into 3 types in different level of permeability.The plane distributive characteristics of porosity and permeability in Fuyu reservoir are also analyzed according to the data of the reservoir physical property in study area.Furthermore,the influenced factors of porosity are discussed,and the dependency between them and porosity is also analyzed.And then,sorting coefficient,median grain diameter,the content of cement and the depth,which have good dependency on porosity,are chose as parameters to establish porosity forecast models of Fuyu reservoir in different diagenetic stages.The paleo-porosity in the crucial period of hydrocarbon accumulation is restored by restoring or simulate the value of the above parameters in the same period,which is used to divide the types of reservoir.The correlation between the porosity change in the past and the oil potential of the reservoir is also analyzed based on the oil testing result.Finally,the key controlling factors of tight oil accumulation are analyzed based on the condition of reservoir,source rock,faults and tectonics,and the perspective plays of tight oil accumulation are forecast to help figure sweet points in the exploration and development in this study area.