鄂尔多斯盆地富县地区长7油层组致密砂岩成岩作用及孔隙演化

发布时间：2018-03-30 23:38

本文选题：致密砂岩　切入点：致密油　出处：《东北石油大学学报》2017年03期

【摘要】：致密砂岩油是非常规油气勘探的热点领域。以鄂尔多斯盆地东南部富县地区长7油层组为研究对象,利用铸体薄片、扫描电镜、常规物性、X线衍射和稳定同位素等方法,分析致密砂岩的成岩作用,并对孔隙度演化进行半定量恢复。结果表明:长7油层组致密砂岩储层处于中成岩阶段A期,经历机械压实、绿泥石包膜、泥微晶方解石和亮晶方解石胶结、有机酸溶蚀、高岭石及蒙皂石向伊/蒙混层转化、少量微晶石英和石英次生加大等成岩作用。物性演化主要受机械压实、亮晶方解石胶结和有机酸溶蚀等成岩作用影响,但不同成岩作用在不同成岩时期所起作用存在差异。砂岩储层大致经历早成岩阶段A期(T_3—J_1末)、早成岩阶段B期(J_1末—K_1早)、中成岩阶段A期快速埋藏(K_1早—K_2早期)和中成岩阶段A期缓慢抬升等4个孔隙演化阶段,孔隙度从35.0%的原始孔隙度一直演化至现今6.6%。该研究结果对鄂尔多斯盆地东南部富县地区油气勘探有指导意义。
[Abstract]:Tight sandstone oil is a hot field in unconventional oil and gas exploration. Taking Chang7 reservoir formation of Fuxian area in southeastern Ordos Basin as the research object, casting thin slice, scanning electron microscope, conventional physical properties X-ray diffraction and stable isotopes are used. The diagenesis of tight sandstone is analyzed, and the porosity evolution is semi-quantitatively restored. The results show that the tight sandstone reservoir of Chang 7 oil formation is in stage A of middle diagenesis, experiencing mechanical compaction and chlorite coating. Clay microcrystalline calcite and bright crystal calcite cementation, organic acid dissolution, kaolinite and montmorillonite conversion to eosinite / montmorillonite, a small amount of microcrystalline calcite and quartz secondary increasing diagenesis, etc. The physical property evolution is mainly subjected to mechanical compaction, Effects of diagenesis, such as brilliant calcite cementation and organic acid dissolution, But there are differences between diagenesis and diagenesis in different diagenetic periods. Sandstone reservoirs generally experience early diagenesis stage A stage A stage T _ 3-J _ T _ 1 end, early diagenesis stage B stage B stage J _ 1 end -K _ 1 early stage, Middle diagenetic stage A stage A stage rapid burial of K _ 1 early K _ (2)). And 4 pore evolution stages in the middle diagenetic stage A stage A slowly uplift. The porosity has evolved from 35.0% of the original porosity to 6.6%. The results of this study are of guiding significance for oil and gas exploration in Fuxian area of southeastern Ordos Basin.
【作者单位】：中国科学院地质与地球物理研究所;中国科学院大学地球科学学院;陕西延长石油(集团)有限责任公司;
【基金】：国家自然科学基金项目(41372151) 国家科技重大专项(2011ZX08005-004)
【分类号】：P618.13

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