Apparatus for forming and using a bore hole

Apparatus for guiding and steering an earth boring machine...

Bits for use in drilling with casting and method of making...

Casing hammer assembly for cable tool drilling apparatus

Collapsible spider for use in supporting casing during upward dr

Deep water drilling with casing

Device for drilling, in particular percussion drilling or...

Device for joining threaded rods and tubular casing elements for

Down hole hammer assembly

Downhole filter

Drilling and cementing casing system

Drilling apparatus

Drilling with concentric strings of casing

Environmentally friendly horizontal boring system

Expansible drive core

Internal wrench for a top head drive assembly

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