A Study On Micro-pore Structure And Infiltrating Mechanism In Niuquanhu Area Of Santanghu Oilfield

In view of few researches into pore textures and fluid filtration characteristics of Qiguzu-toutunhezu reservoir in Niuquanhu block in Santanghu Basin, in order to enhance the hydrocarbon recovery of the region of interest and improve the reservoir development effect, with the employment of the experiments like cast thin slice, scanning electron microscope, conventional high pressure mercury penetration, constant speed mercury penetration, true sandstone microscopic water/oil displacement and nuclear magnetic resonance, the thesis makes a thorough research into pore texture characteristics and microscopic filtration characteristics of the sandstone reservoir. The research shows that the microscopic pore textures are complicated, the anisotropy is high and waterflood development water/oil displacement efficiency is low, which are mainly caused by the high microscopic anisotropy of the reservoir.Specially, the research shows that Qiguzu-toutunhezu reservoir belongs to braided delta front intrafacies, the intergranular pore is the main type of pores, which take up 65.50 percent of total pores, intergranular dissolved pores, feldspar dissolved pores and lithic dissolved pores are on the second place, and there are few carbonate dissolved pores. The reservoir belongs to mesopore-fine throat and mesopore-medium throat. The pore distribution of the sandstone reservoir is comparatively centralized. The reservoir inhomogeneity is mainly caused by the throat inhomogeneity.Diagenesis mainly includes compaction, cementation, metasomatism and dissolution. Compared with compaction, cementation exerts more direct impact on the decline of the porosity of the sandstone reservoir (pore loss factor is 63.75 percent in the cementing process). Based on the classification of diagenetic stages, the reservoir diagenesis is on the stage of the late period of early diagenetic stage to early period of late diagenetic stage.The water/oil displacement experiment shows that inhomogeneity of pore texture exerts great impact on displacement efficiency.