从长壁工作面围岩抽放瓦斯,已成为现代采煤技术极为重要的部分。常用的顶板斜交钻孔抽放法取得了重大成就,现正以类似的方法抽放有喷出危险的底板。 有人认为,如果向抽放钻孔周围地层,特别是向有喷出倾向煤层的邻近层注水,可以增加底板钻孔的瓦斯排出量。在理论上,用高压泵把水注入钻孔的密封段,使钻孔四周压裂或扩大现存裂缝,从而增加地层的透气性是可能的。此外,考虑到煤中水分对沼气的吸附性,使煤炭润湿,可能会影响瓦斯从顶板或底板煤层泄出。 Drainage of methane from the longwall face has become an extremely important part of modern coal mining technology. A significant achievement has been achieved by the commonly used roof bias drilling method, which is now draining a dangerous floor in a similar way. It has been suggested that gas drainage from the floor drilling can be increased by draining the formation surrounding the borehole, in particular by injecting water into the adjacent layers of the coal seam with a jetting tendency. In theory, it is possible to inject water into the sealing section of a borehole using a high-pressure pump, to fracture around the borehole or to expand existing fractures, thereby increasing the permeability of the formation. In addition, taking into account the water adsorption of methane on biogas, making coal wet, may affect the gas from the roof or floor coal seam leak.