产甲烷微生物群落对水力压裂和压裂液添加产甲烷菌可用底物的响应特征研究

加速微生物作用增加生物成因煤层气的资源量逐渐受到关注。对产甲烷微生物群落及利用微生物增产煤层气的实验室研究虽取得一定进展，但现场增产效果差强人意，原位改造储层环境加速生物产甲烷进程尚缺乏系统研究。沁水盆地南部柿庄南区块为近南北向展布并西倾的单斜构造，可看作相对封闭的水文地质单元，是研究储层微生物作用的天然实验室。本项目拟在前期工作的积累上，依靠地球化学测试、16Sr DNA和宏基因组生物测序等手段，结合煤层气地质学、生物学、地球化学和水文地质学等理论，厘清柿庄南区块微生物群落的区域分布和代谢功能，揭示产甲烷作用相关微生物在水力压裂改造原位储层过程中的动态响应特征，查明压裂液添加产甲烷菌可用底物对区域差异分布微生物群落的丰度、多样性和代谢活性的影响，进而阐明原位条件生物甲烷的产出机理，为生物成因煤层气的增产实践提供科学指导和理论依据。

Accelerating microbial action to increase the resources of biogenic coalbed methane has attracted increasing attention. Although some progress has been made in the laboratory research on methanogenic microbial communities and the use of microbes to increase coalbed methane production, the effect of field stimulation is not satisfactory, and there is still a lack of direct evidence for in situ modification of reservoir environment to accelerate the process of biogenic methane production. Shizhuangnan block in the south of Qinshui Basin is a monoclinal structure spreading in a nearly north-south direction and diping westward, which can be regarded as a relatively closed hydrogeological unit and a natural laboratory for the microbial action in the reservoir. Based on the accumulation of previous work, this project intends to clarify the regional distribution and metabolic function of microbial communities in Shizhuangnan block by means of geochemical testing, 16S rDNA and metagenomic sequencing, combined with the theories of coalbed methane geology, biology, geochemistry and hydrogeology, and to reveal the dynamic response characteristics of methanogenic microbes during the process of hydraulic fracture in situ reservoir, and to identify the effects of methanogens available substrates in fracture fluid on the abundance, diversity and metabolic activity of regionally diverse microbial communities. The project further elucidates biogenic methane production mechanism in situ condition, so as to provide scientific guidance and theoretical basis for biogenic coalbed methane production practice.