模拟油藏条件下内源微生物群落空间分布规律

【背景】油藏内源微生物群落是开展内源微生物驱油技术的物质基础,由于油藏多孔介质取样技术难度大、成本高,实施内源微生物驱油后从注入端到产出端多孔介质中的内源微生物空间分布规律尚不明确。【目的】通过室内长岩心连续驱替实验模拟油藏内源微生物驱油过程,分析实施后不同空间位点油砂上吸附的内源微生物群落结构,揭示从注入端到产出端内源微生物群落的空间分布规律。【方法】借助高通量测序技术及荧光定量PCR技术解析不同空间位点油砂原位微生物群落信息。【结果】注入端到产出端不同空间位点生态环境的差异及菌属间的相互作用造成油藏内源微生物群落空间分布差异,存在明显的好氧、厌氧空间演替变化规律。岩心前端主要存在一些好氧类的产生物表面活性剂类微生物如假单胞菌属,岩心中部主要存在兼性和厌氧类的微生物如地芽孢杆菌、厌氧杆菌属,岩心末端主要分布严格厌氧类细菌和产甲烷古菌,厌氧类微生物代谢产生的H2、CO2和乙酸分子可以为产甲烷古菌提供代谢底物。【结论】通过室内物模油砂研究,首次明确了内源微生物群落在多孔介质中从注入端到产出端的空间分布规律,证实油藏内源微生物的好氧、厌氧空间接替分布规律,深化了对油藏内源微生物的认识。

Spatial distribution of indigenous microbial communities under simulated reservoir conditions

[Background] The indigenous microbial community in the porous medium of the reservoir is the basis for the indigenous microorganism enhanced oil recovery. Because of the difficulty and high cost of the sampling technique from porous media in the reservoir, the spatial distribution of indigenous microbes from the injected into the output of porous media after the indigenous microorganism flooding has not been clarified. [Objective] simulation of indigenous microbial enhanced oil recovery process was done via long core dynamic continuous displacement experiment. The spatial distribution of the indigenous microbial communities from injection to output end was revealed by analysis the internal microbial community structure adsorbed on the oil sand of different spatial loci after implementation. [Methods] The microbial community structure adsorbed on the oil sand of different space sites of core was analyzed by the high-throughput sequencing and fluorescent quantitative PCR. [Results] from injection to output end, the difference in the ecological environment of porous media and microbiological interaction lead to the spatial difference of the microbial community. There has been a clear law of aerobic to anaerobic succession. Aerobic microbes are mainly distributed in the front of the core, such as Pseudomonas, which can drive the crude oil in the front of the core by producing the biological surfactants. Facultative and anaerobic microorganisms such as Geobacillus and Anaerobaculum are mainly in the middle of the core, while anaerobic bacteria and methanogens are mainly at the end of core. Anaerobic bacteria produce H2, CO2 and small molecular acids through the anaerobic metabolism of organic nutrition, which provides a metabolic substrate for the methanogens at the end of the core. [Conclusion] aerobic and anaerobic succession spatial distribution of indigenous microorganisms in the porous media was clarified for the first time, and the understanding of the indigenous microorganisms in the reservoir was further deepened.