抽采钻孔“三堵两注”固-液两相封孔技术

Solid-liquid Two-phase Sealing Technology of "Three Plugging and Two Injection" in Pumping Drilling Hole

为了提高抽采钻孔封孔效果,在理论分析液相材料轴向和径向流动特征的基础上构建了“三堵两注”固-液两相封孔方法,并在现场对新方法的封孔效果进行了验证。理论分析表明:为了使液相材料顺利地进入钻孔周围的裂隙,需要及时补液保持液相材料压力;为了避免过多的流体材料漏失,液相材料需保持一定的粘度。试验研究证明,当膨胀土与水的比例为1∶4时,配置成的液相材料具有合适的粘度。最后,现场试验研究表明:抽采200 d后,试验钻孔的平均瓦斯抽采浓度为45.10%,比钻孔的平均瓦斯抽采浓度为25.88%提高了74.28%.“三堵两注”固-液两相封孔方法提高了密封质量,能大幅提升瓦斯抽采浓度。

In order to improve the sealing effect of extraction drilling, the solid-liquid two-phase sealing method of "three plugging and two injection" was constructed based on the theoretical analysis of the axial and radial flow characteristics of liquid material, and the sealing effect of the new method was verified on site.The theoretical analysis shows that in order to make the liquid material enter the fissure around the borehole smoothly, it is necessary to replenish liquid in time to maintain the liquid material pressure.In order to avoid excessive fluid material leakage, liquid material needs to maintain a certain viscosity.The experimental results show that when the ratio of expansive soil to water is 1∶4,the liquid phase material has suitable viscosity.Finally, the field test shows that after 200 days of extraction, the average gas extraction concentration of the test drill hole is 45.10%,which is 74.28% higher than that of the drill hole which is 25.88%.The solid-liquid two-phase sealing method of "three plugging and two injection" can improve the sealing quality and greatly increase the gas extraction concentration.