我国次生生物成因煤层气研究进展

Research progress of secondary biogenic coalbed methane in China

为总结我国次生生物成因煤层气理论研究和工程实践发展现状,全面收集了我国煤层次生生物气比较丰富地区的煤层水和产气的地球化学数据,归纳总结前人研究结果,从形成机理、形成环境、产气特征和煤层气生物工程多角度进行探讨。结果表明:次生生物气在我国低煤级、中煤级以及高煤级含煤储层和煤矿区中均有存在,总体富含次生生物气地区中的地下水动力条件不强,普遍处于弱径流的水动力环境中,且水型多为Na-HCO3型和Na-Cl·HCO_(3)型;此外,煤层中次生生物气与热成因气往往混合存在,同时部分存在热成因气的生物再改造迹象,且产气途径多以CO_(2)还原为主,气体组分较干;目前,我国人工煤炭次生生物气数量尚达不到工业规模,煤层气生物工程还处于早期试验阶段,这主要受限于煤炭生物转化效率低和规模性生物气化技术不成熟;发现和培育高效产甲烷菌,将煤层气生物工程与采煤采气一体化技术相结合,实现规模性生物降解产气,是微生物增产煤层气工程可持续发展的必要之路。

To summarize the development status of theoretical research and engineering practice of secondary biogenic coalbed methane in China,the geochemical data of coalbed water and gas production in areas with rich secondary biogas are comprehen-sively collected,the previous research results are summarized,and discussed from the perspectives of formation mechanism,forma-tion environment,gas production characteristics and coalbed methane bioengineering.The results show that secondary biogas exists in coal-bearing reservoirs and coal mining areas with low coal rank,medium coal rank and high coal rank in our country.Gener-ally,the groundwater dynamic conditions in areas rich in secondary biogas are not strong,and they are generally in a hydrodynam-ic environment with weak runoff,and the water types are mostly Na-HCO_(3) and Na-Cl·HCO_(3).In addition,secondary biogas and thermogenic gas are often mixed in coal seams,and some of the thermogenic gas shows signs of biological retransformation,and most of the gas generation pathways are CO 2 reduction,with relatively dry gas components.At present,the amount of artificial secondary biogas has not yet reached the industrial scale,and CBM bioengineering is still in the early stage of testing,which is mainly limited by the low coal biotransformation efficiency and the immature large-scale biogasification technology.Therefore,the discovery and cultivation of efficient methanogens,the combination of CBM bioengineering and coal and gas production integration technology,and the realization of large-scale biodegradation gas production,are necessary for the sustainable development of engineering on microbial stimulation coalbed methane.