A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to...http://www.google.es/patents/US7256707?utm_source=gb-gplus-sharePatente US7256707 - RF transmission line and drill/pipe string switching technology for down-hole telemetry
RF transmission line and drill/pipe string switching technology for down ...
