摘要：The tight sandstone reservoirs in the Linxing- Shenfu block in the east of the Ordos Basin are characterized by compactness, poor petrophysical properties, strong heterogeneity, and complex pore throat connectivity networks. The accuracy of tight sandstone reservoir evaluation needs to be improved urgently, and the current Oil and gas recovery effect is not ideal. The use of petrological and petrophysical property evaluation of tight sandstone gas reservoirs to guide gas reservoir development and determination of favorable reservoirs is a hot spot in geological research. In this paper, through the cores drilled in the field, we used X-ray diffraction, casting thin sections, petrophysical property testing and scanning electron microscopy (SEM) to analyze the microscopic characteristics and pore structures of the reservoir. Experimental analysis shows that the average quartz content of the reservoir is 78.8%, followed by the average of clay minerals at 14.6%. The core has strong speed sensitivity and water sensitivity. The core has a medium-grained sandy structure, mainly composed of fine-medium-grained sand-type debris, with medium sorting and good roundness. The average porosity of the reservoir is 6.14%, the average gas permeability is 0.149 mD, and the microfractures are slightly developed. It is a typical low porosity and low permeability reservoir. The analysis of the mercury intrusion experiment shows that the pore throat radius of the core is distributed from 0.2517 to 4.0312 m. The small pore throat is an important cause of poor permeability.
关键词：Tight sandstone;petrological characteristics;petrophysical property analysis;X-ray diffraction;scanning electron microscope
