油藏环境与物理模型中的微生物群落比较研究

Comparative study of microbial communities in a reservoir and physical models

为揭示模拟油藏环境的岩心与真实油藏的微生物群落结构之间存在的差异程度,应用高通量分析方法,一方面分析具体油藏沾3区块注入水和6口油井的产出液,另一方面分析模拟沾3区块油藏条件的物模实验岩心产出液,对比分析注入水、油井产出液和物模实验岩心产出液三者细菌及古菌的群落结构.结果显示,同一油藏不同油井之间细菌群落结构差异明显,每口油井在不同时间其优势细菌变化较大,常见的细菌有Desulfacinum、Thermodesulforhabdus、Pseudomonas等属;而古菌群落结构保持相对稳定,常见的古菌有Methanosaeta和Methanomethylovorans等属.将注入水、油藏产出液和岩心产出液三者所有的样品分析结果在属水平上进行相对含量排序,对比三者细菌和古菌排序前15个属,结果表明油藏和岩心中的细菌群落结构差异明显,仅有4个共有属,分别是Pseudomonas、Syntrophomonas、Petrobacter和Acinetobacter,而两者主要古菌群落结构非常相近.本研究说明物理模型还不能完全模拟真实油藏,只能部分接近油藏环境.(图9表1参19)

This study aimed to reveal the difference between the microbial community structure of the reservoir environment and physical model environment of a simulated reservoir. The microbial community structures of the injection water and the produced fluid of the ‘Zhan3’ block in the Shengli Oil Field, and the model output fluid were analyzed by a high-throughput sequencing technology. The results showed that there are apparent differences in bacterial community structure between different wells in the same block. The dominant bacteria also changed considerably in the same well at different sampling times. The common bacterial species in the Zhan3 oil reservoir are, among others, Desulfacinum sp., Thermodesulforhabdus sp., and Pseudomonas sp. Contrarily, the Archaea community structure in this block is relatively stable, mainly containing Methanosaeta sp. and Methanomethylovorans sp. The microbial community structures of the reservoir injection water, the oil well output fluid, and the physical model output fluid were recorded to genera-level. The 15 most abundant microorganisms were selected for comparison. The results showed that the bacterial community structures of the reservoir and the core samples were distinct: they only had four genera in common;Pseudomonas sp., Syntrophomonas sp., Petrobacter sp., and Acinetobacter sp. Their Archaea community structure, however, is similar. The results of this study confirmed that the physical model can approximate the reservoir conditions, but cannot adequately simulate the reservoir environment.