摘要：The Sulige Gas Field is the main natural gas development area in the Ordos Basin,and the Permian Shihezi Formation is the main natural gas producing zone.It is a typical tight sandstone gas reservoir with low porosity and permeability which requires artificial fracturing.In order to analyze the reservoir characteristics of the Shihezi Formation and provide reference for the development of natural gas in this section,the petrological characteristics of the reservoir are analyzed through core casting thin sections,scanning electron microscopes,gas permeability testers,mercury intrusion testers,etc.Diagenesis,physical properties,pore structure and seepage characteristics have been studied in detail.The results show that the Shihezi Formation reservoir is mainly composed of quartz sandstone with a high content of quartz,followed by lithic debris,and the sandstone is mostly medium-coarse and coarse-grained.After sorting well to sub-prismatic shape,it is regenerative-porous cementing.The average porosity of the Shihezi Formation sandstone reservoir is 7.2% and the average permeability is 0.42x10-3pm2.The porosity is mainly distributed between 6~9% (Accounted for 63.1%),and the permeability is mainly distributed between 0.12~0.4 (Accounted for 58.2%),indicating that the reservoir is a low porosity and low permeability reservoir.The characteristic parameters of mercury intrusion reflect the poor reservoir physical properties in the study area.The large changes in pore throat size and distribution parameters,indicating that the distribution of pore throats in sandstone has strong heterogeneity.
关键词：Ordos Basin;Sulige Gas Field;Shihezi Formation;petrological characteristics;reservoir physical properties.
