地面钻井抽放上覆远距离卸压煤层气试验研究

Study on Drainage of Relieved Methane from Overlying Coal Seam Far Away from the Protective Seam by Surface Well

通过模拟及实测，对下保护层开采后其上覆远距离煤层的卸压效果进行了研究，并在淮北桃园矿开展了地面钻井抽放上覆远距离卸压煤层气试验．结果表明，下解放层开采后其上覆远距离煤层能充分卸压，将地面抽放钻井打到采动裂隙“Ｏ”形圈内，可将其卸压煤层气大面积抽放出来，为我国煤层气开采提供了一条新途径，具有推广应用前景．

Based on physical and numerical simulation, it has been proved that the pressure of overlying coal seam far away from the protective seam can be relaxed completely after the protective seam has been mined out. Its relieved methane can not flow down into the working face of the protective seam but can be drained out from the “O shaped” circle of mining induced fractures by surface well. The method has been used sucessfully in Taoyuan Colliery and has provided a new way for many gassy mines in China to exploit coal bed methane resource.