煤矿采动区地面瓦斯抽采井井管防错断结构设计及应用

Fault Prevention Structure Design and Application of Ground Gas Drainage Well Tube in Coal Mining Area

针对地层受煤矿采动影响后,地面瓦斯抽采井管出现断裂的情况频繁出现,严重影响瓦斯抽采效果,严重时导致井下瓦斯超限,影响矿井安全生产的问题,设计了地面瓦斯抽采井井管防错断可伸缩结构。可伸缩结构在采动后可有效缓冲煤层上部地层的拉伸力,有效避免可伸缩结构以下套管断管或延缓断裂幅度,防止地层碎屑物进入孔内,保证瓦斯抽采效果。现场应用表明,采用常规结构的地面井抽采纯量最大约4 m^(3)/min,采用可伸缩结构的地面井抽采纯量最大达12 m^(3)/min,可伸缩结构的地面井是常规结构地面井的3倍。

In view of the fact that the ground gas drainage well pipe breaks frequently after the formation is affected by coal mining,which seriously affects the gas drainage effect,leads to underground gas overrun and affects the safety production of the mine,the anti-fault telescopic structure of the ground gas drainage well pipe is designed.The telescopic structure effectively buffers the tensile force of the upper strata of the coal seam after mining,effectively avoids the casing pipe breaking below the telescopic structure or delays the fracture amplitude,prevents the formation debris from entering the hole,and ensures the gas drainage effect.Field application shows that the maximum extraction purity of ground wells with conventional structure is about 4 m^(3)/min,and the maximum extraction purity of ground wells with telescopic structure is 12 m^(3)/min,which is 3 times of that of conventional structure.