large diameter drilling meaning in English

大口径钻探

analysis and disposition for an accident of drill bit being buried in large diameter drilling with non-circulation of slurry by hydraulic piling rig
某旋挖钻机大口径无循环钻进埋钻事故的分析处理
the application of slew ring in powered rotary disc of large diameter drill not only solved the support problem of power transmission but also expanded the view of design
回转支承应用于大口径钻机动力转盘，不仅解决了大口径钻机动力传动的支承问题，也开阔了设计思路。