东濮凹陷上古生界石千峰组致密砂岩储层特征

东濮凹陷上古生界石千峰组发育一套厚度较大且具有勘探潜力的河流-湖泊相致密砂岩。采用岩心观察、薄片鉴定、扫描电镜、阴极发光、X衍射全岩及黏土矿物分析等技术手段,对东濮凹陷上古生界石千峰组致密砂岩储层的岩石学特征、物性特征和成岩作用进行了分析。结果表明:储层岩石类型主要为岩屑长石砂岩和长石岩屑砂岩;孔隙度2%~10%,渗透率(0~1)10^-3m²,整体上表现出特低孔超低渗特点;成岩作用主要为压实、压溶、胶结、溶蚀和交代作用。样品古地温、镜质体反射率(R_o,%)和X衍射黏土矿物分析结果进一步证实研究区石千峰组砂岩储层属于中成岩阶段A期。

Upper Paleozoic Shiqianfeng Formation Tight Sandstone Reservoir Features in Dongpu Depression

The upper Paleozoic Shiqianfeng Formation in the Dongpu depression has developed a set of thicker fluvial-lacustrine facies tight sandstone with exploration potential.Through technical means of core observation,thin section identification,SEM,cathode luminescence,whole rock X-ray diffraction and clay mineral analysis etc have carried out analyses for upper Paleozoic Shiqianfeng Formation tight sandstone reservoir petrologic,physical property features and diagenesis in Dongpu depression.The results have shown that the rock type of the reservoir is mainly lithic arkose,feldspathic litharenite;porosity 2%~10%,permeability(0~1)10^-3 m²,presented extra-low porosity and ultra-low permeability features as a whole;diagenesis is mainly compaction,pressure solution,cementation,corrosion and metasomatism.Sample paleogeotemperature,vitrinite reflectance(R_o,%)and X-ray diffraction clay mineral analyzed results have further verified the study area Shiqianfeng Formation sandstone reservoir belongs to the phase A of middle diagenetic stage.