深部多尺度裂隙煤体瓦斯多机制流动理论研究

研究深部多尺度裂隙煤体瓦斯多机制流动理论对我国高效开发煤层瓦斯、确保深部煤层安全开采、调整能源消费结构、解决当前“雾霾”等社会难题具有重要意义。为解决深部煤层瓦斯有效抽采关键科学问题，本项目以深部多尺度裂隙煤体为研究对象，利用微、细、宏观测试手段，观测不同尺度条件下煤体孔隙裂隙发育和分布情况，对煤体孔缝结构特征进行精细表征；开展瓦斯气体薄膜透过性测试和多尺度煤体瓦斯放散试验，结合煤层瓦斯抽采过程中多种流动机制共存和跨尺度运移的客观事实，分析瓦斯多机制流动规律和多尺度流动行为，建立煤体孔隙瓦斯多机制流动方程和深部煤体瓦斯分形统计多机制流动HTM耦合模型，揭示深部裂隙煤体瓦斯多机制流动规律；构建深部裂隙煤体多尺度瓦斯抽采模型，形成多尺度煤层瓦斯流动数值模拟方法，根据开采实际分析传统煤层增透措施的增透本质和有效性，提出适合深部煤层瓦斯抽采的增透技术建议，为深部煤层瓦斯抽采和安全生产提供有力支撑。

It is meaningful to study the multi-mechanism flow theory of deep multi-scale fracture coal for efficiently exploiting coalbed methane, ensuring the mining safety of the deep coal seams, adjusting the structure of energy consumption and solving the social problem of smog in our country. In order to solve the key science problems of methane drainage in deep seams, the distribution of pore and crack in coal at different scales is observed using by the micro, meso and macro experimental testing means. And meanwhile, the internal pore and crack structure of coal is finely characterized with the fractal theory. And then, the tests of methane film permeation and methane elution at different scales are carried out in laboratory. Moreover, the methane flow law of multi mechanisms and multi scale flow behavior are analyzed based on the fact of the coexistence of multi flow mechanisms and the crossing scale migration during the process of coalbed methane drainage. In addition, the methane flow equation of multi mechanism and the HTM coupling model of methane fractal-statistical multi mechanism flow are built up, which can used to uncover the methane flow law of multi mechanisms in deep fractured coal. Furthermore, the multi-scale methane drainage model of deep coal is set up to form the multi-scale numerical simulation method for methane flow law in deep coal seams. Finally, the measures suggest the improving coal permeability for coalbed methane drainage is proposed on the basis of the essence and effectiveness the conventional technology measures of improving coal permeability in deep coal seam mining practice. The research results of this project can be a good support for coalbed methane drainage and safe production of deep coal mining in our country.