内源微生物驱油功能菌定量化分析技术

Quantification of bacteria responsible for endogenous microbial enhanced oil recovery

为了解决培养法无法对油藏内驱油功能菌进行定量检测的难题,利用荧光定量PCR技术,通过对功能基因进行定量实现了油藏内产脂肽菌、产曱烷菌的定量化检测,其中产脂肽菌选择w/A基因、产曱烷菌选择mtrA基因.结果发现,该方法具有很好的特异性和重复性,标准曲线的相关系数达到0.99以上,扩增效率达到100%.在检测未知样品时,证实该方法的检测下限可以达到10拷贝/pL.利用该技术监测了胜利油田沾三区块驱油一口油井（Z3X24）在内源微生物驱油过程中2种功能菌的定量化变化,数据表明：内源激活前期,产脂肽菌密度快速升高到104拷贝/μL,内源激活后期,厌氧的产曱烷古菌密度升高到104拷贝/μL,该数据表明微生物驱油过程中存在好、厌氧菌的演替规律,将2种菌的定量检测结果与现场油井的产量进行对比,发现油井日油水平的动态变化与这2种菌的动态变化存在明显对应关系.该研究建立的功能菌定量化检测技术为内源微生物驱油现场实施效果的准确预测及驱油机理分析提供了一个有效的分析手段,可以进一步提高微生物驱油工艺措施的针对性和有效性.

We used the rapid SYBR？ Green fluorescent quantitative real-time PCR technique to detect lipopeptide producing bacteria and methanogenic archaea present in the reservoir. The recombinant plasmid containing srfA and mcrA gene was used as standards to generate a standard curve for lipopeptide producing bacteria and methanogenic archaea. The sensitivity,reproducibility and specificity of the technique were evaluated.The correlation coefficient（R2） of the standard curve was above 0. 99 and the amplification efficiency reached 100%. To detect unknown samples, the detection limit of the method reached 10 copies/ pL.Water samples collected in the oil well Z3-X24 located in Zhan3 block of Shengli oilfield were detected using the technique.The concentration of lipopeptide producing bacteria increased to 104 copies/pL in the early stage of endogenous activation, while the concentration of methanogenic archaea increased to 10 copies/pL in the late stage of endogenous activation.The data confirmed there was a good successive ruler between aerobic and anaerobic bacteria in the process of MEOR.We found a correlatin between these two functional bacteria dynamics and the oil production. These results are essential for understanding oil-displacement mechanism of indigenous MEOR and providing scientific guidance to the performance ol MEOR technology in the future.