膨润土基封孔材料界面改性及长效封孔功能研究

Research on interface modification and long-term sealing properties ofbentonite-based sealing materials

针对煤矿瓦斯抽采平均浓度低、持续时间短的技术难题和工程实践的现场需求,选择机械改性法、有机活化改性法等界面改性方法,以膨润土为基础材料,提高保水性、稳定性和触变性,研发得到瓦斯抽采钻孔液相封孔材料。采用“液封气”思想实现全周期触变封堵新生裂隙。现场应用结果表明:新材料封堵效果良好,平均抽采浓度41.66%,较传统材料提高15.27%,浓度衰减系数降低48%,补浆提升系数提高22%,可实现废孔利用。

Aiming at the technical problems of low average concentration and short duration of gas extraction in coal mine and the field requirements obtained from engineering practice,interface modification methods such as mechanical modification method and organic activation modification method were selected,and bentonite was used as the base material to improve water retention,stability and thixotropy,and a liquid phase sealing materials for gas drilling were developed.The idea of“liquid sealing gas”is adopted to realize full-cycle thixotropic sealing of nascent cracks.The application results of Renlou Coal Mine show that,the new material has good sealing effect,and the average extraction concentration is 41.66%,which is 15.27 percentage points higher than that of the traditional material;the concentration attenuation coefficient is decreased by 48%,slurry lifting coefficient is increased by 22%,which indicating the material can realize waste hole utilization.