Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, P.R. China.
Environ Sci Technol. 2014 May 6;48(9):5336-44. doi: 10.1021/es500239w. Epub 2014 Apr 22.
Enhanced oil recovery using indigenous microorganisms has been successfully applied in the petroleum industry, but the role of microorganisms remains poorly understood. Here, we investigated the relationship between microbial population dynamics and oil production performance during a water flooding process coupled with nutrient injection in a low-temperature petroleum reservoir. Samples were collected monthly over a two-year period. The microbial composition of samples was determined using 16S rRNA gene pyrosequencing and real-time quantitative polymerase chain reaction analyses. Our results indicated that the microbial community structure in each production well microhabitat was dramatically altered during flooding with eutrophic water. As well as an increase in the density of microorganisms, biosurfactant producers, such as Pseudomonas, Alcaligenes, Rhodococcus, and Rhizobium, were detected in abundance. Furthermore, the density of these microorganisms was closely related to the incremental oil production. Oil emulsification and changes in the fluid-production profile were also observed. In addition, we found that microbial community structure was strongly correlated with environmental factors, such as water content and total nitrogen. These results suggest that injected nutrients increase the abundance of microorganisms, particularly biosurfactant producers. These bacteria and their metabolic products subsequently emulsify oil and alter fluid-production profiles to enhance oil recovery.
利用土著微生物提高石油采收率已在石油工业中得到成功应用，但微生物的作用仍知之甚少。在这里，我们研究了在低温油藏注水过程中结合营养物注入时，微生物种群动态与采油性能之间的关系。在两年的时间里，每月采集一次样本。使用 16S rRNA 基因焦磷酸测序和实时定量聚合酶链反应分析来确定样品中的微生物组成。我们的结果表明，在富营养水的驱替过程中，每个生产井微生境中的微生物群落结构发生了剧烈变化。随着微生物密度的增加，生物表面活性剂产生菌如假单胞菌、产碱杆菌、红球菌和根瘤菌大量存在。此外，这些微生物的密度与增产油量密切相关。还观察到了油的乳化和流体生产剖面的变化。此外，我们发现微生物群落结构与含水量和总氮等环境因素密切相关。这些结果表明，注入的营养物增加了微生物，特别是生物表面活性剂产生菌的丰度。这些细菌及其代谢产物随后乳化油并改变流体生产剖面，以提高采油率。
