中文摘要：

针对顺层瓦斯抽采过程中,因钻孔形变较大、封孔长度不足及封孔方法不合理等因素造成抽采钻孔及其周围煤体漏风严重、抽采瓦斯浓度偏低、流量衰减速度较快及稳定性差等技术难题,基于多孔介质渗流理论、流体平衡理论、“固封液-液封气”钻孔密封技术原理,研究了承压密封液在煤层钻孔内的径向渗流规律,建立了不可压缩流体径向驱气稳定渗流物理模型、密封液径向渗流运动数学方程及相关参数计算公式,进而提出了固液耦合壁式密封顺层瓦斯抽采技术。结果表明,采用固液耦合壁式密封技术可对抽采钻孔及周围煤体裂隙实施动态密封,使得瓦斯抽采过程浓度稳定,单孔平均浓度提高4~5倍,平均抽采瓦斯体积分数达到89%以上,显著提高了本煤层瓦斯的抽采效率。

英文摘要：

The paper is inclined to bring about a simulated mathematical model for the liquid-type radial current through the boring-holes of the coal seam and its application. As is well known, such problems have often been encountered in the coal-gas mining, as the serious air leakage in the coal boring-hole and its surrounding layers, the low concentrated gas for extraction, dropdown of the current flow rate and poor stability in the gas drainage of the coal seam under mining, due to the serious borehole deformation, the sealing inadequacy and inappropriate sealing methods. To solve the aforementioned problems, we have done lots of on-site investigations on the basis of such theories, as the porous medium flow theory, the fluid balance theory and the theory of borehole sealing technology known as ＂ solid-seals-liquid and/or liquid- seals-gas＂, and in turn established the physical model of the steady flow of the incompressible fluid, as well as the eqilations for the radial flow of the seal liquids and relevant parameters. The analysis over the parameter equations we have done suggests that the speed and the radius of the seepage flow are dependent on the pumping pressure of the liquid injection, coal seam penetration degree and the viscosity of the sealing liquids. What is more, it is also necessary to determine the quantity of liq- uid that can be injected on reliance of the cavity length and radius along with the seam gas pressure. Besides, we have also devel- oped the drainage technology for the solid-liquid coupling wall sealing based on the above illustrated theories. Our study proves that the solid-liquid coupling seal technology of ours can also be used for dynamically sealing boreholes and fractures in the sur- rounding strata and eventually build up the coupled stereoscopic coverage made up of mucus, fractures and coal seam body around the borehole so as to effectively avoid the roadway air penetrating into the borehole through drilling and leaking into the other sur- rounding coal fractures. In so doing, it