E
FIXED CONSTRUCTIONS
E
FIXED CONSTRUCTIONS
E21
EARTH OR ROCK DRILLING; MINING
E21
EARTH OR ROCK DRILLING; MINING
E21B
EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B
EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B17/00
Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables;; Casings; Tubings
E21B17/00
Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables;; Casings; Tubings
E21B17/02
Couplings; joints
E21B17/02
Couplings; joints
E21B17/04
between rod; or the like; and bit or between rod and rod; or the like
E21B17/04
between rod; or the like; and bit or between rod and rod; or the like