钻孔底部  borehole bottom; foot of hole

多底井钻井  multibranched drilling

海底钻井井口装置  seabed drilling gear

钻井井底深度  bottom driller

表土顿钻钻孔  spudding bit

大孔钻孔  big-diameter hole drilling

底孔钻  under-ream

顿钻井孔  cable tool drilling

多孔钻井  multiple completion

弓钻钻孔器  brace bit

精密深孔钻孔工具  precision deep hole drilling tool

井孔钻进  Hole boring; hole drilling

孔井钻探剖面  caliper log

矿井钻孔器  mine borer

扩底钻孔灌注桩  bell-out bored pile

扩底钻孔桩  under-reamed bored pile

扩孔钻井工具  expanding drilling tool

螺纹底孔钻  tap drill

盲钻井孔  blind flange