大口径钻孔下管固管工艺探讨

大口径钻孔的工作管下放和固管工艺直接关系到钻孔的成败。以山西某煤矿瓦斯抽采孔为例,详细阐述了大口径钻孔下工作管和固管的过程,以及保证工程质量和施工安全所采取的防范措施。在施工过程中,钻机根据钻塔的承载力、钻机的提升力实际状况,采用串杠法提吊、水泥浮力塞减轻套管质量、井口密封固管的等施工方法,成功的完成了我国煤炭行业迄今为止下工作管质量、直径最大的大口径钻孔工程,工程质量优良,与采用巨型吊车焊箍直接提吊、井口密封固管的施工方法比较,具有经济效益好,施工场地不受限制等优势。为煤矿瓦斯排放、降温、排水等大口径钻孔工程中的施工提供了一种可靠、经济的施工工艺。

A Discussion on Large Diameter Borehole Casing Lowering and Fixing Technology

The technology of large diameter borehole working casing lowering and fixing is directly related to the borehole drilling success or failure. Taking a gas drainage borehole in a Shanxi coalmine as an example, elaborated the process of large diameter borehole working casing lowering and fixing, countermeasures to ensure project quality and safety in operation in. During the operation, according to the derrick bearing capacity and rig lifting capacity, use operation measures including string bar lifting, cement buoyant plug to reduce casing weight, as well as wellhead sealing fixing. Thus have successfully completed the large diameter borehole drilling engineering with heaviest working casing, largest diameter, and excellent project quality up to now in Chinese coal industry. Comparing with using giant crane welded hoop direct lifting, wellhead sealing fixing operation methods, the method has predominance of good economic returns, unconstrained operation site. It provides a reliable, economic operation technology for coalmine gas drainage, temperature reduction, water drainage large diameter boreholes operation.