不同煤阶煤孔隙特征及其吸附能力响应

我国是煤炭资源大国，煤层气储量规模相当可观，但煤储层又具有低孔、低渗的不足，照搬国外或常规石油天然气的开采程序和方法已被证实是走不通的。应结合实际，根据不同地质条件、不同煤阶的开采程序，进行孔隙特征研究。煤孔隙特征、连通性和吸附能力对煤层气开采影响尤为重要，为研究煤孔隙结构特征随煤变质程度的变化关系及其吸附能力的响应特点，采取不同地区不同变质程度煤样，进行压汞测试和等温吸附实验。实验结果表明，煤孔隙度和平均孔径均随变质程度增加呈现降低—升高—降低的趋势；煤中孔隙连通性随煤变质程度增加逐渐变差；随煤变质程度增加，其最大吸附能力也呈现降低—升高—降低的总体趋势。

Pore characteristics and adsorption capacity response of coals with different ranks

China is a country with large coal resources and the scale of coalbed methane reserves is also considerable.However，coal reservoirs have the disadvantages of low porosity and low permeability.The procedures and methods for copying foreign or conventional oil and natural gas have been proved to be infeasible.The pore characteristics should be studied according to the actual conditions and the mining procedures of different geological conditions and different coal ranks.Coal pore characteristics，connectivity and adsorption capacity are particularly important for coalbed methane mining.In order to study the relationship between coal pore structure characteristics and the degree of coal metamorphism and the response characteristics of adsorption capacity，coal samples of different metamorphic degrees in different regions were used to conduct mercury intrusion.Testing and isothermal adsorption experiments.The experimental results show that the coal porosity and average pore size both show a decreasing-increasing-decreasing trend with the increase of metamorphism；the pore connectivity in coal gradually deteriorates with the increase of coal metamorphism；with the increase of coal metamorphism,its maximum adsorption capacity also shows the general trend of decreasing-increasing-decreasing.