采用无机酸化增透技术的煤结构损伤及应用

Coal structural damage and application using inorganic acidification anti-reflection technology

为解决低渗透性煤层瓦斯抽采较难的问题,提出无机酸化的方法增加煤层渗透性.运用单轴压缩力学实验探究单一无机酸液(盐酸)与复合无机酸液(盐酸/氢氟酸)处理煤体的力学损伤特征,利用扫描电镜实验分析无机酸化煤体的表面微观形貌,揭示无机酸化增透煤岩微观结构损伤机理,并在陕西黄陵煤矿应用.研究结果表明:复合无机酸液侵入煤体内部的孔裂隙中破坏结构,降低煤体力学强度,同时溶蚀孔隙内矿物质成分,达到扩孔效果,证明酸化对破坏煤体结构具有积极作用,可促进吸附煤层气的解吸行为.经复合无机酸化增透后,压裂孔瓦斯抽采量提高20%以上.研究结论可为无机酸化增透技术提供理论依据.

To solve the problem of harrowing gas extraction in a low permeability coal seam,the method of inorganic acidification was put forward to increase the permeability of the coal seam.Uniaxial compression mechanics experiment investigated the mechanical damage characteristics of coal treated by single inorganic acid(HCl/HF)and compound inorganic acid(HCl/HF).The surface morphology of inorganic acidified coal was analyzed by scanning electron microscopy(SEM)experiment.The damage mechanism of inorganic acidified anti-reflection coal rock microstructure was revealed,which was applied in Huangling Coal Mine,Shaanxi province.The research results show that the inorganic acid intrudes into the pores and cracks inside the coal to destroy the structure,reduce the mechanical strength of the coal,dissolve the mineral components in the pores,and achieve the effect of pore expansion,which proves that acidification has a positive effect on the destruction of the coal structure and promotes the desorption behavior of the adsorption of coalbed methane.After inorganic acidification and reflection improvement,the gas extraction amount of the pressure crack hole is increased by more than 20%.The research results can provide a theoretical basis for applying inorganic acidified anti-reflection coal.