轻型钻机在西部山区深厚覆盖层水电勘探中的应用

Application of Light Rig for Drilling in Deep Overburden Layer of the Western Mountains

在西部山区水利水电勘探中,采用轻型钻机钻进深厚覆盖层,并成功采集岩心是一项技术难题。钻进深度越大,越易产生坍塌、埋钻等事故,因而成孔极其困难。根据目前西部水利水电勘探的常用设备,采用轻型钻机,合理设计钻孔,并对泥浆护壁方法进行改进,使钻孔成功达到预定深度。应用结果表明:轻型钻机钻进深厚覆盖层时,孔身设计分为4级变径;深度70 m以浅采用硬质合金钻头,深度70 m以深采用孕镶金刚石钻头,钻进稳定;SM-KHm超低固相泥浆护壁,不仅环保而且节水,可有效保护孔壁稳定,防止塌孔;岩心采取率达到95%以上,钻孔最大钻进深度达到223.54 m,有效突破了轻型钻机的最大钻进深度,为轻型钻机钻进西部山区深厚覆盖层及取心提供重要的技术参考依据。

It is a difficult technical problem for drilling in deep overburden layer with light rig and collecting core in the western mountains.Pore-formation became more difficult with collapsing and drill burying in deeper drilling.By the reasonable design and improvement on mud protection,the borehole reached the depth.The application results show that the drilling hole design was divided into 4-stages variable diameter,drilling with bits of different materials;SM-KHm ultra-low solid-phase slurry-supported was adopted in the alluvial medium-fine sand layer and diluvia gravel soil layer for borehole stability;the maximum drilling depth reached 223.54m with more than 95% collecting rate of drill core.