鄂尔多斯盆地南部延长组重力流致密储层成岩作用及物性演化  

Diagenesis and Physical Property Evolution of Gravity Flow Tight Reservoir of Yanchang Formation in Southern Ordos Basin

作　　者：孙宁亮 钟建华 刘绍光[2] 田东恩[3] 刘闯 曹梦春 杨冠群 郝兵 Sun Ningliang Zhong Jianhua Liu Shaoguang Tian Dongen Liu Chuang Cao Mengchun Yang G uanqun Hao Bing(School of Geosciences, China University of Petroleum, Qingdao 266580, China Exploratioin ＆ Development Technology Research Center, Yanchang Oil Field Co. Ltd., Yan＇an 716000, China Yanchang Oil Field Co. Ltd., Jingbian 718500, China)

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580 [2]陕西延长油田股份有限公司勘探开发技术研究中心,陕西延安716000 [3]陕西延长油田股份有限公司,陕西靖边718500

出　　处：《地球科学（中国地质大学学报）》2017年第10期1802-1816,共15页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.41172093);中央高校基本科研业务费专项资金(No.15CX06002A)

摘　　要：成岩作用及物性演化的研究对致密砂岩储层和致密油开发具有重要意义.综合利用岩石铸体薄片鉴定、扫描电镜、X衍射分析、流体包裹体分析等测试手段,对研究区致密储层进行详细研究.研究表明:深水重力流砂体粒度细,孔喉组合以细孔-微喉型为主,物性差,是一套典型的特低渗透储层;目前正处于中成岩B期,其成岩演化序列为:机械压实作用/方解石胶结→凝灰物质水解蚀变/云母水化/伊利石胶结/绿泥石胶结/石英溶蚀→早期长石溶蚀/石英加大/碳酸盐灰泥重结晶/早期碳酸盐胶结物溶蚀→晚期长石溶蚀→铁方解石胶结,成岩环境主要经历了碱性→酸性→弱碱性的转换过程;距今约99~118Ma的早白垩世,研究区储层发生了连续的2期油气充注;储层物性演化史表明早成岩期储层的成岩作用对储层物性影响大,使储层已经致密化,研究区具有先致密后成藏的特性.The research of diagenesis and physical property evolution is important to tight sandstone reservoir and tight oil exploitation.The tight reservoir was detailedly studied in the study area by the analysis of cast thin section,scanning electron microscopy（SEM）,X-ray diffraction and homogenization temperature analysis of fluid inclusion in this study.The results show that deep-water sand body is a typical ultra-low porosity and permeability reservoir,which has fine granularity,poor reservoir physical properties,with thin pore-micro throat dominated pore-throat combination.The reservoir in the B sub-stage of mesogenetic diagenesis has experienced the following complex diagenesis evolution sequence：compaction/calcite cementation→tuffaceous hydrolyze alteration/mica hydration/illite cementation/chlorite cementation/quartz dissolution→early feldspar dissolution/quartz overgrowth/carbonate plaster recrystallization/early carbonate-cement dissolution→late feldspar dissolution→ferroan calcite cementation.The diagenetic environment underwent an evolution of alkalescence→acid→alkalescence.The test data of fluid inclusions show that Early Cretaceous（99-118 Ma）is the main hydrocarbon accumulation period with two hydrocarbon injections.The reservoir physical properties evolution show that early diagenesis had great influence on the reservoir,and it is inferred that the sandstone had already been compacted very tight before the hydrocarbon accumulation period.

关 键 词：鄂尔多斯盆地 延长组 深水重力流 致密储层 成岩作用 物性演化 石油地质 

分 类 号：P618[天文地球—矿床学]