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
E21B33/00
Sealing or packing boreholes or wells
E21B33/00
Sealing or packing boreholes or wells
E21B33/10
in the borehole
E21B33/10
in the borehole
E21B33/13
Methods or devices for cementing, for plugging holes, crevices or the like
E21B33/13
Methods or devices for cementing, for plugging holes, crevices or the like
E21B33/14
for cementing casings into boreholes
E21B33/14
for cementing casings into boreholes
E21B33/16
using plugs for isolating cement charge; Plugs therefor
E21B33/16
using plugs for isolating cement charge; Plugs therefor