School of Resources and Geosciences, China University of Mining and Technology MOE Key Lab of Coalbed
Methane Resources and Formation and Reservoir Formation Process, China University of Mining and Technology

基于构造煤孔隙结构对瓦斯赋存与突出具有重要影响,但在压汞试验中,过大的压力会造成煤基质的压缩,造成较大的试验误差,尤其对吸附瓦斯的纳米级孔隙的影响更为显著,选取宿县矿区典型构造煤样品,采用压汞法与液氮吸附相结合的方法,计算了不同类型构造煤的压缩系数,采用Menger模型表征构造煤的孔隙特征,并对100 nm以下煤样的压汞孔隙体积进行了校正。结果表明:Menger模型适合表征煤中的渗流孔,而对吸附孔的表征较差,说明在压汞试验中,高圧段(>11 MPa)煤基质压缩对分形维数造成了很大的影响;而经校正后,算得的吸附孔分形维数对孔隙特征具有较好的表征作用,在碎裂煤、碎斑煤到鳞片煤阶段,随着煤体变形程度的增加,吸附孔的分形维数D2c呈逐渐增大趋势、孔隙形态逐渐复杂,揉皱煤的D2c略小于鳞片煤。

Based on the pore structure of the structure coal with important influences to the gas occurrence and outburst, but in the mercury test, a too high pressu re would cause a compression of the coal matrix, would cause a big test error and would have more obvious influences to the nanometer-scaled pore of the adsorption gas especially. Coal samples of the typical structure coal from Suxian Mining Area were selected. A method combined with the mercury intrusion method and liquid nitro gen adsorption was applied to calculate the compression coefficient of the different type structure coal. A Menger Model was applied to explain the pore features of the structure coal and to correct the mercury intrusion pore volume of the coal samples with a size below 100 nm. The results showed that the Menger Model would be suita ble to explain the seepage pores in coal and would be poor to explain the adsorption pores. In the mercury intrusion test, the coal matrix compression at the high press ure section (>11 MPa) would cause high influences to the fractal dimension. After the correction, the obtained fractal dimension of adsorption pore would have a good e xplanation role to the pore features. From the fractured coal, mortary coal to the scale coal stage, with the deformation degree of the coal mass increased, the fractal di mension D2 cof the adsorption pore would be steadily increased, the pore configuration would be steadily complicated and the crumpled coal D2 cwould be less than th