超短半径水平孔钻具及导向器的应用研究

Application Research on Ultra-short Radius Horizontal Drilling Head and Whipstock

高压水射流径向水平孔钻进技术是水平孔施工技术之一,它是在垂直瓦斯抽放或煤层气勘探钻孔布置机械或水力扩孔装置,对准选定的煤层部位进行扩孔。扩孔后下入特制的转向工具在300 mm的曲率半径内实现由垂直转向水平。该技术可以使用同一垂直钻孔,在不同煤层内完成多个水平钻孔。这些径向水平钻孔的形成,沟通了新的瓦斯流动通道,从而大幅度提高瓦斯抽放效率。

As one of radial horizontal drilling techniques,high pressure water jet drilling technology is capable of using mechanical or water jet apparatus to make a cavity at the selected coal seam.A specially made whip-stock is then to be installed in the cavity to drill in seam horizontal holes from the vertical hole.Using this technology can bore a number of radial holes at different coal seams from the single vertical gas drainage well.The space of vertical wells can be significantly reduced by drilling these radial boreholes thus dramatically increase the gas drainage efficiency.