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
E21B47/00
Survey of boreholes or wells
E21B47/00
Survey of boreholes or wells
E21B47/09
Locating or determining the position of objects in boreholes or wells; , e.g. the position of an extending arm; Identifying the free or blocked portions of pipes
E21B47/09
Locating or determining the position of objects in boreholes or wells; , e.g. the position of an extending arm; Identifying the free or blocked portions of pipes