西峰油田长8储层砂岩成岩作用及对孔隙影响

根据砂岩薄片、铸体薄片、扫描电镜、X-衍射等分析，对西峰油田长8油层砂体的岩石学特征、成岩作用进行的研究结果表明,该区长8储层储集砂体成分主要由长石质岩屑砂岩和岩屑质长石砂岩组成，成岩作用处于晚成岩A期。早期的压实作用及多种矿物胶结作用是使原生孔隙遭受破坏的主要成岩类型；溶蚀作用是形成次生孔隙的主要成岩类型。

The Diagenesis of Chang-8 Reservoir Sandstone and Its Effect on Porosity in Xifeng Oilfield

Based on the analysis of thin-section,casting lamella,scanning electron microscope,X-ray diffractions and so on,the characteristic of petrology and the diagenesis of Chang-8 reservoir in Xifeng oilfield in the Ordos Basin was summarized.The result shows that both feldspathic litharenite and lithic arkose are the essential components of Chang-8 sandstone.The diagenesis is in the early A period of the late diagenesis stage.The compaction in the early stage and a number of minerals' cementation lead the loss of primary porosity,the dissolution is the main diagenesis to form second porosity.