太原地区中奥陶世上马家沟组岩溶储层成岩作用及孔隙演化  

Diagenesis and porosity evolution of karst reservoir of the middle Ordovician upper Majiagou formation,Taiyuan area

作　　者：黎雪 季汉成[1,2] 王嗣敏[1,2] 房超[1,2] 向鹏飞 李林致[1,2] 郭瑞婧 

机构地区：[1]中国石油大学(北京)油气资源与探测重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249

出　　处：《东北石油大学学报》2017年第6期55-65,共11页Journal of Northeast Petroleum University

摘　　要：通过岩心、野外露头观察,采用薄片、扫描电镜和地球化学分析等方法,研究太原地区中奥陶世上马家沟组岩溶储层岩石类型、储集空间类型、成岩作用类型及特征,以及成岩演化阶段和成岩作用对岩溶储层孔隙的影响及控制作用。结果表明:上马家沟组主要包括含石膏角砾灰岩、砂屑灰岩、细晶灰岩、泥晶含生屑白云质灰岩、粉晶灰质白云岩、灰质角砾白云岩、中晶白云岩、粉晶白云岩等8种岩性,孔隙和溶洞为主要储集空间;储层受到不同期次的压实—压溶、胶结充填、交代、构造破裂、溶蚀和重结晶等6种成岩作用的复合叠加;成岩演化划分为沉积—准同生成孔阶段(中奥陶世)→风化淋滤阶段(晚奥陶世—泥盆纪)→沉积充填阶段(石炭纪—早白垩世)→溶蚀改造阶段(晚白垩世—古近纪)等4个成岩阶段;储层主要受白云石化、构造破裂、溶蚀等3个成岩作用控制,不同成岩作用影响优质储层的分布和发育。该研究结果为太原地区优质储层的勘探提供有利参考。Based on the observation of the cores outcrops,thin sections and molded thin sections,scanning electron microscope,and other geochemical analysis method,the types of the major storage spaces are identified,the diagenesis types and characteristics and digenetic evolution of karst reservoir within the upper Majiagou formation in middle Ordovician,Taiyuan area and the way they have controlled the development of the reservoir are deeply studied. The result revealed that the gypsum-bearing brecciola,calcarenite,fine crystalline limestone,silty crystalline bioclast-bearing dolomitic limestone,fine crystalline limy dolomite,limy breciated dolostone,calcarenite,medium crystalline dolostone,fine crystalline dolostone are the dominant rock types,and the main reservoir spaces are pores and caves. The reservoir had experienced composite superimposed diagenesis which included compaction,pressure-solution,cementation,metasomatism,tectonic disruption,dissolution,de-gypsum,rejuvenation of crystals in varying ages. The diagenetic evolution can be divided into four stages: Penecontemporaneous pore period( middle Ordovician),weathering leaching period( late Ordovician-Devonian),minerals filling period( Carboniferous-early Cretaceous) and pore dissolution reconstruction period( late Cretaceous-Paleogene).The reservoir is mainly controlled by dolomitization,dissolution,and tectonic fracture. Dolomitization was bene-ficial to the preservation of intergranular pores,and also helped to form cracks by strengthening the compactness and brittleness. The structural fracture provided a fluid channel for the dissolution and expand it along the way.The contribution to the reservoir of penecontemporaneous karstification is limited,while the epigenic karstification was significant to the reservoir and the buried karstification plays a important role in reservoir in late dissolution.

关 键 词：岩溶储层 成岩作用 孔隙演化 上马家沟组 中奥陶世 太原地区 

分 类 号：P618[天文地球—矿床学]