method and apparatus for establishing and maintaining electrical continuity with a column of drilling

摘要

An insulated electric conductor employed in a tubular drill string to transmit electric energy between subsurface and surface locations is arranged within the drill string in a wound, helical, coiled, looped, folded, overlapped or other convoluted configuration. Preferably, the convoluted conductor, or a portion thereof, is maintained in tension. The convoluted configuration provides an excess length of conductor stored within the drill string which enables the conductor to be extended as the drill string is lengthened.