Borehole Drilling Method

hydraulic rotary drilling

http://resource.geosciml.org/classifier/cgi/boreholedrillingmethod/hydraulic_rotary_drilling

notation 3 more like this
definition A drilling method using a drill stem equipped with a bit that is rotated to cut and grind the rock with a fluid pumped down the stem to force cuttings up through the annular space between the stem and the wall of the hole. Oil well drilling of this type utilises tri-cone roller, carbide embedded, fixed-cutter diamond, or diamond-impregnated drill bits. This is preferred because there is no need to return intact samples to surface for assay as the objective is to reach a formation containing oil or natural gas. Sizable machinery is used, enabling depths of several kilometres to be penetrated. Rotating hollow drill pipes carry down bentonite and barite infused drilling muds to lubricate, cool, and clean the drilling bit, control downhole pressures, stabilize the wall of the borehole and remove drill cuttings. more like this
source https://en.wikipedia.org/wiki/Drilling_rig#Hydraulic_rotary_drilling more like this
type
Resource
Concept
in scheme boreholedrillingmethod
has top concept
hydraulic rotary drilling
is primary topic of hydraulic rotary drilling
top concept of boreholedrillingmethod