渤南断阶带沙四上亚段储层成岩演化研究  

Research on the diagenetic evolution of the upper fourth member of Shahejie formation reservoir in Bonan step-fault zone

作　　者：徐宁宁 邱隆伟[1] 杨生超 解超 刘魁元[2] 单宝杰[2] 刘连启[2] 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266555 [2]中石化胜利油田分公司河口采油厂,山东东营257200

出　　处：《中国矿业大学学报》2015年第1期104-115,共12页Journal of China University of Mining & Technology

基　　金："十二五"国家油气重大专项(2011ZX05009-002)

摘　　要：渤南断阶带沙四上亚段发育广泛的低孔低渗碎屑岩储层.综合铸体薄片分析、扫描电镜观察和黏土矿物X衍射分析等手段,总结储层发育的成岩作用类型及特征、所属成岩阶段和成岩演化序列;结合地层埋藏史、热演化史和烃类充注史提出储层阶段性时空演化过程和成岩-成藏耦合关系.结果表明:储层中成岩A1期次生孔隙形成时间与烃源岩主生排烃期、有效圈闭形成时间具较好的耦合关系,构成油气成藏的各项条件;渤南断阶带东部和西部因埋深和原始组成物质差异造成储层成岩特征和成岩-成藏过程的差异.根据储层自生矿物间接触关系判定成岩作用顺序为草莓状黄铁矿胶结→石英次生加大/长石岩屑溶蚀→石英弱溶蚀/方解石胶结/长石弱胶结→方解石溶蚀→铁方解石胶结→晚期黄铁矿胶结.相伴随的黏土矿物演化是由成岩早期的伊蒙混层、伊利石和高岭石矿物组合到成岩中后期的伊利石、高岭石、伊蒙混层和绿泥石矿物组合,对应质量分数变化为伊蒙混层减少约30%、伊利石增加约40%、高岭石减少约20%和绿泥石增加约20%.渤南断阶带东部和西部储层埋深差异约400m同时石英质量分数相差约10%.由此造成两者分别处于中成岩A期和B期的成岩阶段进而造成储层物性、油气储集能力和成藏过程的差异.The reservoir of the upper fourth member of Shahejie formation in the Bonan stepfault zone exhibits low porosity and permeability.By using thin sections,scanning electron microscopy,clay mineral X-ray diffraction,and other technical methods,this study summarizes the diagenetic types and characteristics,diagenetic stages,and diagenetic evolution sequences in order to reveal the space-time evolution process of the reservoir and the coupling relationship between diagenesis and petroleum accumulation considering the burial,thermal,and hydrocarbon generation histories.The results indicate that the formation conditions for petroleum entrapment are in accordance with the main hydrocarbon generation and expulsion stage in addition to the formation time of the secondary pores and the effective trap.Because of differencesin burial depth and composition of the original substances,the reservoir diagenetic features and the processes of diagenesis and petroleum entrapment vary in the eastern and western regions of the Bonan step-fault zone.The following diagenetic sequence of the reservoir was evaluated by the contact relationships of authigenic minerals as evidenced from early framboidal pyrite cementation,quartz overgrowth,and the dissolution of feldspar and lithic fragments to the late quartz dissolution and cementation of calcite and feldspar and then to the late calcite dissolution,ferrocalcite cementation,and late pyrite cementation.The evolution of clay minerals was accompanied by agroup of illite-smectite mixed-layer illite-kaolinite in the early stage to a group of illite-kaolinite-illite-smectite mixed-layer chlorite in the late stage with a 30% reduction in the illite-smectite mixed layer,a 40%increment in illite,a 20%reduction in kaolinite,and a 20%increment in chlorite.Differences of 400 meters in burial depth and 10%in the mass fraction of quartz were noted in the reservoir in the eastern and western regions of the Bonan step-fault zone.Therefore,differences in the diagenetic stages occurred with stage A of the m

关 键 词：渤南断阶带 低孔低渗储层 成岩演化 成岩—成藏耦合 

分 类 号：TE122.23[石油与天然气工程—油气勘探]