【摘要】 塔里木盆地下寒武统肖尔布拉克组发育一套百余米厚的白云岩。基于柯坪地区11条野外露头剖面1 000多张岩石薄片的沉积学和古生物学特征观察描述,运用微相分析方法,对下寒武统肖尔布拉克组进行岩石学、古生物学和沉积环境分析。根据显微镜下碳酸盐岩颗粒类型、生物群、沉积组构等显微特征,在肖尔布拉克组识别并划分出11种微相类型和5种成因上相似、纵向上变化具有一定连续性的微相组合。此外,微相分析还表明,肖尔布拉克组储集层发育主要受控于沉积环境,晶间(溶)孔、粒间(溶)孔和微生物格架孔为主要的储集空间类型,弱纹层状粉—细晶自形晶—他形晶白云岩微相(MF2)、内碎屑白云岩微相(MF10)具有最好的储集物性,与微生物相关的微相(MF6,MF7和MF8)次之。更多还原

【Abstract】 A suite of over 100 m thick dolomite was deposited in the Lower Cambrian Xiaoerbulake formation, Tarim basin. Based on the detailed observation and description of the sedimentary and paleontological characteristics of more than 1 000 thin sections obtained from 11 field sections in Keping area, the paper analyzes the petrological and fossil features and sedimentary environment of the Lower Cambrian Xiaoerbulake formation with microfacies analysis method. According to the microscopic characteristics of grain, biogroup and sedimentary fabric of the carbonate rock, 11 microfacies types and 5 microfacies assemblages with similar genesis and certain continuity in vertical variation are identified and classified in the Xiaoerbulake formation. In addition, the results of microfacies analysis also show that the reservoir development of the Xiaoerbulake formation is mainly controlled by sedimentary environment, and the intercrystal(dissolved) pore, intergranular(dissolved) pore and microbial framework pores are the main reservoir spaces. Weak-laminated fine-grained dolomite(MF2) and intraclastic dolomite(MF10) have the best petrophysical properties, and microbial microfacies such as MF6, MF7 and MF8 have relatively good petrophysical properties.更多还原