梧桐庄矿新增大口径3号排水孔施工技术

Construction Technology of Large Diameter Drainage Hole in Wutongzhuang Coalmine

摘要:

介绍了梧桐庄矿大口径排水孔钻探成井、固井施工技术。该孔设计孔深646 m，终孔直径520 mm，落点坐标水平位移≯5 m，下入重达90余吨的φ426 mm套管646 m，水泥固井。由于钻孔直径大，垂直度要求高，施工难度大，预防钻孔超斜、确保顺利安全下入φ426 mm套管并固井是关键。通过采用小口径先导孔钻进再扩孔成井的施工方法，并采取合理的钻具组合和泥浆，制定有效的防斜技术和下套管措施等，顺利完成了施工任务，施工质量满足设计要求。

Abstract:

The paper introduced the construction technology of well drilling and cementing for large diameter drainage hole in Wutongzhuang coalmine. The designed depth is 646m, the termination diameter is 520mm and the tolerance of hole bottom coordinate should not be more than 5m. 646m case (426mm in diameter and weighted more than 90t) was put down to the borehole with cementing. Because of large borehole diameter and high demand of verticality, construction was difficult. Safely putting down φ426mm case and cementing were the key points to prevent hole deviation. Based on the effective deviation control and casing measures, the construction was fulfilled by small diameter pilot hole drilling and borehole reaming with rational drilling tool assembly and drilling mud.