差异性成岩演化过程对储层致密化时序与孔隙演化的影响——以鄂尔多斯盆地西南部长7致密浊积砂岩储层为例  

Impact of Differential Diagenetic Evolution on the Chronological Tightening and Pore Evolution of Tight Sandstone Reservoirs——A Case Study from the Chang-7 Tight Turbidite Sandstone Reservoir in the Southwestern Ordos Basin

作　　者：罗静兰[1] 罗晓容[2] 白玉彬[3] 罗春燕[1] 白雪见 李向军[1] 李弛[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室,陕西西安710069 [2]中国科学院地质与地球物理研究所中国科学院油气资源研究重点实验室,北京100029 [3]西安石油大学地球科学与工程学院,陕西西安710065

出　　处：《地球科学与环境学报》2016年第1期79-92,共14页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41272138);国家科技重大专项项目(2011ZX05008-004-61;2011ZX05001-004-008)

摘　　要：通过岩芯观察、常规薄片与铸体薄片显微镜下鉴定与定量统计,利用电镜扫描、图像孔喉分析、荧光分析、孔隙度与渗透率、毛细管压力测定,以及流体包裹体均一温度、激光拉曼成分测定,结合前期鄂尔多斯盆地西南缘长8—长6砂岩碎屑锆石LA-ICP-MS微区U-Pb定年物源示踪研究成果,分析了鄂尔多斯盆地西南部上三叠统长7致密浊积砂岩类型及其骨架矿物成分对砂岩成岩作用、成岩产物与成岩演化过程的制约,讨论了差异性成岩演化过程对砂岩致密化时序、储层孔隙演化与储集质量的影响。结果表明:受源区母岩性质的影响,长7砂岩类型及骨架矿物成分及其含量存在一定差别,并在纵向上呈现出规律变化;砂岩类型及骨架矿物成分在很大程度上影响成岩演化过程,后者致使储层的致密化过程在时间上有先有后,最终导致长7各砂岩类型的孔隙演化和孔隙结构特征、储层储集质量及其在时空分布上的强非均质性。The diagenesis,authigenic products and diagenetic evolution process restricted by the sandstone detrital components of Upper Triassic Chang-7 turbidite sandstones from the southwester Ordos Basin were studied.Impact of the differential diagenetic evolution process on the chronological tightening,pore evolution and sandstone reservoir quality was also elucidated,based upon observation of cores,observation,identification and quantitative statistics ofconventional,fluorescent and casting thin sections by vacuum impregnated with epoxy resin under microscope equipped by fluorescence system,measurement of sandstone pore and pore throat image,porosity and permeability,capillary pressure,and analysis of homogenization temperature and Laser-Raman chemical composition of fluid inclusions,combined with the previous research result of the LA-ICP-MS in-situ U-Pb dating provenance tracing from the detrital zircons in the Chang-8-Chang-6sandstones.The results show that the Chang-7sandstone types and their petrological components and primary reservoir capacity are controlled by provenance and parent rocks;distribution of the sandstone type and the detrital minerals shows some regulation vertically;the sandstone types and the skeleton minerals influence the diagenetic process and experience certain differential diagenetic evolution process,and finally lead to sandstones tightened chronologically,which result in heterogeneity in the pore evolution,pore structure and reservoir quality heterogeneous distribution temporally and spatially.

关 键 词：岩石学组分 差异化成岩演化 储层致密化时序 孔隙演化 浊积砂岩 长7 鄂尔多斯盆地 

分 类 号：P618.130.2[天文地球—矿床学] TE122[天文地球—地质学]