中文摘要：

目的：研究长庆油田延9低渗透油藏微生物群落,为实施微生物提高原油采收率提供指导和依据。方法：长庆油田延9油藏三口不同油井（柳28-46、柳28-47和柳27-45）的油水样品建立16S rDNA克隆文库进行研究。结果：构建了柳28-46、柳28-47和柳27-45油井样品的微生物基因克隆文库,其分类操作单元（OUT）数分别为21、20和20个;序列分析比对表明,3口井的共同的优势微生物菌群为铜绿假单胞菌（Pseudomonas aeruginos）,分别占各文库的32.8%、32%和42.9%,它是最常见最主要的采油功能菌之一。此外硫酸盐还原菌（SRB）和铁细菌也处于优势地位,它们是原油开采中的有害菌。结论：延9低渗透油藏微生物群落和其潜在功能的分析为开展微生物提高石油采收率应用提供了良好的基础资料。

英文摘要：

Objective：To study the microbial communities relevant to microbial enhanced oil recovery（MEOR） in low permeability of Yan 9 reservoir in Changqing Oilfield.Method：16S rDNA gene clone library construction methods were used to analyze the microbial communities of water-oil samples from above Yan 9 reservoir.Result：Three 16S rDNA gene clone libraries were constructed,and a total of 21,20 and 20 operational taxanomic units（OTUs） were found in the liu 28-46,liu 28-47 and liu 27-45 libraries respectively.Sequential analysis of a representative clone of each OTU shows that the predominant sequences in the three clone libraries were Pseudomonas aeruginos occupied a percentage of 32.8%,32% and 42.9%,respectively,which is one of the most popular function bacteria for MEOR.In addition,sulfide-reducing bacteria（SRB） and iron bacteria,which are harmful in petroleum industry,were also dominant bacteria in the three clone libraries.Conclusion：Molecular analysis of the microbial diversity and the potential function in low permeability of Yan 9 reservoir provides the basic knowledge for better applications in MEOR.