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
33/00
Sealing or packing boreholes or wells
33/00
Sealing or packing boreholes or wells
E21B33/02
Surface sealing or packing
E21B33/02
Surface sealing or packing
E21B33/03
Well heads; Setting-up thereof
E21B33/03
Well heads; Setting-up thereof
E21B33/035
specially adapted for underwater installations
E21B33/035
specially adapted for underwater installations
E21B33/038
Connectors used on well heads, e.g. for connecting blow-out preventer and riser
E21B33/038
Connectors used on well heads, e.g. for connecting blow-out preventer and riser