78058405
Apr 13, 2001
Mar 25, 2003
Metal downhole communications units comprising annular inductive couplers for connecting linking tubular components, namely, drill pipes, drill collars, drill bits, jars, motors, hammers, turbines and other downhole tools
Metal GoodsNon-metal downhole communications units comprising annular inductive couplers for connecting linking tubular components, namely, drill pipes, drill collars, drill bits, jars, motors, hammers, turbines and other downhole tools
Nonmetallic Building Materials