TELEMETRY SYSTEM FOR BOREHOLE DRILLING

摘要

A telemetry system for borehole drilling comprises an effectively continuous length of hardwire cable which extends along a drill string located in a borehole between electrical signal control, indication equipment situated outside the borehole and probe means situated within the borehole. The effective continuous length of hardwire includes a store of hardwire constituted by a bonded wound hollow coil of hardwire located adjacent the probe means.