许昌武庄铁矿深孔绳索取心钻进技术

许昌武庄铁矿ZK3349孔设计孔深1500 m，覆盖层厚度达400多米，基岩中存在多个破碎带，第四系和第三系地层接触带软硬互层，并含有大量卵石、漂石，钻探施工极易出现缩径、孔壁坍塌、孔斜等问题。针对这些问题，采取了相应的钻探技术措施，顺利终孔。总结了该孔覆盖层裸孔钻进和深孔绳索取心钻进技术。

Wire-line Core Drilling Technology for a Deep Hole in Xuchang

The depth of 1500m was designed for ZK3349 in Wuzhuang iron mine of Xuchang, where the thickness of over-burden layer was up to more than 400m,there were several fracture zones, the contact zone of quaternary and tertiary strata with soft and hard interbedded rocks containing large amounts of gravel and boulder.Diameter shrinkage, wall collapse and hole inclination were often encountered.The corresponding measures were taken to smoothly fulfil the drilling.The open hole drilling in overburden layer and wire-line core drilling technology in deep hole are summarized.