摘要
为揭示瓦斯在本煤层抽采时的渗流机理，开展了煤岩体变形与瓦斯渗流相互作用规律研究．根据煤层瓦斯渗流特性，考虑渗透率的动态变化过程，研究裂隙瓦斯渗流、微孔隙吸附瓦斯解吸扩散和煤岩体变形等过程，建立耦合渗流模型．针对特定矿井抽采煤层的瓦斯地质条件，进行了耦合模型的数值模拟研究．结果表明：抽采初期瓦斯压力下降较快，抽采稳定后下降趋缓，距抽采孔越远下降梯度越小，有效抽采半径约为3m．现场实验孔距6m顺层瓦斯抽采，抽采稳定时瓦斯纯量达5～7m^3／min，抽采效果较理想．
In order to reveal the mechanism of gas flow during gas extraction, the correlation between deformation and gas seepage in coal seam was studied. Based on gas seepage character- istics, a coupling model was established. The dynamic processes such as gas seepage in frac- tures, the adsorption gas desorption and diffusion in micro pores and the coal deformation were investigated, as well as the dynamically varied permeability. Numerical simulation study on the model was carried out in specific geological conditions . The results show that the gas pressure drops quickly in the early stage, and after a period of extraction the pressure declines steadily, and the closer to the location of borehole the faster gas pressure drops, and effective extraction radius is about 3 m. In-seam borehole spacing at 6 m reaches a stable pure metahne flow rate up to 5-7 m^3/min in field drainage test.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2014年第2期208-213,共6页
Journal of China University of Mining & Technology
基金
国家重点基础研究发展计划(973)项目(2011CB201206)
大型油气田及煤层气开发国家重大专项(2011ZX05040-2)
关键词
瓦斯抽采
耦合模型
数值模拟
现场实验
瓦斯压力
gas extraction
coupling model
numerical simulation
field test
gas pressure
