Erosion resistent drilling head assembly

Expansible drive core

Floating sub

Foundation drilling apparatus and method with continuously...

Ground-boring device

Hammer device

Hydraulic clamp for rotary drilling head

Hydrocarbon recovery drill string apparatus, subterranean...

Internal wrench for a top head drive assembly

Invertible auger

Kelly bar having hardened flutes

Kelly bushing guard

Kelly driver

Kelly saver drive

Locking swivel device

Method and apparatus for drilling and servicing subterranean...

Method for drilling a wellbore using a bi-center drill bit

Method for drilling with casing

Methods and apparatus for cementing drill strings in place...

Mobile drilling apparatus