Diagenesis and pore evolution of shan 2 reservoir of Shenmu-Shuangshan gas field

In order to reveal the relationship between different diagenesis and pore evolution, the characteristics of diagenesis and pore evolution of Shan 2 reservoir in Shenmu-shuangshan gas field were studied based on the laboratory results of physical property,cast section, X-ray diffraction and inclusions.The result shows that the lithology of Shanxi reservoir is mainly coarse sandstone,middle to coarse quartz sandstone and lithic sandstone,a small circle and angular.Relatively fine granularity,in addition to the bottom and partial containing granular in sandstone orgrit,is usually fine,granule or powder,granule and powder sand.high compositional maturity and low textural maturity.Compaction, pressure solution,cementation and dissolution are the main diagenesis.The diagenesis in this area has entered into the B period of late diagenetic stage.The analysis of pore evolution model shows that the initial porosity is 35.37 %,13.92 % porosity is lost due to the early stage compaction, the cementation at early and late stage causes 18.75 % porosity to loss,but the dissolution at late stage adds 4.82 % porosity.The different diagenesis has common effect on porosity,which leads to the characteristics of low porosity and low permeability in studied area.