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
E21B23/00
Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
E21B23/00
Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells