致密砂岩储层埋藏-成岩-油气充注演化过程与孔隙演化定量分析——以鄂尔多斯盆地东部上古生界盒8段天然气储层为例  

Burial,diagenesis,hydrocarbon charging evolution process and quantitative analysis of porosity evolution: A case study from He 8 tight sand gas reservoir of the Upper Paleozoic in Eastern Ordos Basin

作　　者：李杪[1] 侯云东[2] 罗静兰[1] 陈娟萍[2] 罗晓容[3] 贾亚妮[2] 

机构地区：[1]西北大学地质系大陆动力学国家重点实验室,陕西西安710069 [2]中国石油长庆油田分公司勘探开发研究院,陕西西安710021 [3]中国科学院油气资源研究重点实验室/中国科学院地质与地球物理研究所,北京100029

出　　处：《石油与天然气地质》2016年第6期882-892,共11页Oil & Gas Geology

基　　金：国家自然科学基金项目(41272138;41572128);国家科技重大专项(2011ZX05008-004-061;2016ZX05008-004-032)

摘　　要：目前国内对致密砂岩的成岩-孔隙演化过程、埋藏-热演化史、油气充注史基本停留在相对独立和单一的静态研究阶段,因此,对于砂岩的岩石学组分及其差异性成岩演化过程导致的储层致密化过程与油气充注时序关系的研究依然十分薄弱。通过各类薄片显微镜下研究与定量统计,结合扫描电镜、阴极发光、包裹体均一温度与激光拉曼探针成分等多种分析测试手段,开展了鄂尔多斯盆地东部上古生界盒8段不同类型致密砂岩的埋藏-成岩-油气充注-孔隙动态演化历史的精细研究,在此基础上讨论了各砂岩致密化过程与油气充注在时序关系上的差异性。研究结果显示,钙质胶结砂岩和高塑性岩屑砂岩的成岩-油气充注演化过程相对简单,前者经历中成岩阶段A期碳酸盐胶结作用后基本成为致密储层,时序关系为先充注后致密;而后者经历早成岩阶段压实作用后一部分成为致密储层,时序关系为先致密后充注;石英砂岩和岩屑石英砂岩经历了较为复杂的成岩-油气充注演化过程,时序关系为边充注边致密。Current researches about the evolution process of diagenesis-porosity, the burial-thermal history, and the hydro- carbon eharging history of tight sandstone reservoirs are still in a static stage in China. Apparently,less attention has been paid to the relevance between hydrocarbon charging and tightening process caused by the petrological components of sandstones and its differential diagenetic evolution process. In order to better understanding the dynamic evolution history of burial-diagenesis-hydrocarbon charging-porosity of tight sandstone, samples from the 8th Member of Xiashihezi Forma- tion （HeS） of the Upper Paleozoic in eastern Ordos Basin were studied in detail through the identification and quantita- tive statistics of cast sections, together with various analysis methods such as SEM, CL, homogenization temperature and chemical composition of fluid inclusions etc. Furthermore, the differences of the timing of densification process and hydro- carbon charging among different sandstone layers were discussed. The results indicate that the diagenesis-hydrocarbon charging evolution processes of both the calcium-cemented sandstone and high plastic lithic sandstone are relatively simple. The former became tightened after carbonate cementation in the stage A of middle diagenesis phase, which confirms that hydrocarbon charging was early than tightening; while the latter became tightened after compaction in the early diagenetic stage, which confirms that tightening occurred before hydrocarbon charging. In contrast, the quartz sandstone and lithic quartz sandstone are complicated in diagenetic-charging evolution process and their tighenging and hydrocarbon charging synchronous.

关 键 词：砂岩类型 成岩序列 孔隙定量演化 致密砂岩 鄂尔多斯盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]