Drill string rotation encoding

Drill string telemetry

Drill string telemetry system

Drill string telemetry system and method

Drilling assembly with reduced stick-slip tendency

Drilling system with downhole apparatus for determining paramete

Dual spectra well logging system

Duct mapping device using sonde

Dynamometric measuring assembly for a drill pipe equipped with m

Electric and electro-hydraulic control systems for subsea and re

Electrical connector for borehole telemetry apparatus

Electrical submersible pump cable

Electro optic high temperature well bore modulator

Electromagnetic and acoustic repeater and method for use of same

Electromagnetic borehole telemetry system incorporating a...

Electromagnetic borehole telemetry system incorporating a...

Electromagnetic MWD telemetry system incorporating a current...

Electromagnetic power and communication link particularly...

Electromagnetic resistivity tool and method for use of same

Electromagnetic signal pickup apparatus and method for use...