PD材料保压式封孔工艺

Pressure Retaining Sealing Holes Technique of PD Material

钻孔密封一直是制约瓦斯抽采的难题,封孔材料方面经历了水泥砂浆,常规聚氨酯到无机材料的过程。封孔工艺也从常压封孔演变到保压封孔。PD材料是在现有材料的基础上,开发的新型密封材料,既有水泥砂浆的可渗透性、致密性,又具备聚氨酯材料的膨胀性。保压式封孔工艺可以帮助材料在钻孔里向周围裂隙渗透,提高对周围裂隙的封堵效果。现场实验发现,PD材料相对聚氨酯材料,具有较好的抗衰减性,尤其在封孔15 d后,效果较好;同样保压封孔工艺相对常规工艺,抽采效果更佳理想,浓度提高近70%。

Borehole sealing is the problem of restricting gas extraction. The sealing materials have experienced the process from cement mortar, conventional polyurethane to inorganic materials, and the sealing process has evolved from the atmospheric sealing to pressure retaining sealing. PD material is the new development sealing material on the basis of existing materials, which not only has the perme- ability, density of cement mortar, but also has the expansion of the polyurethane material. The pressure retaining sealing holes tech- nique can help the material permeate to the around cracks in the borehole, and improve the sealing effect on the surrounding cracks. The field experiment found that the PD material had good anti -decay relative to polyurethane material, particularly in the sealing of 15 d after application. The pressure sealing technique relative to conventional technology had ideal extraction effect, and the concentration increased by nearly 70%.