DOUBLE WALLED DRILL PIPE ELECTRICAL CONDUCTOR

摘要

The present invention discloses an apparatus for drilling holes in various ground formations using a drill string including an inner flow cavity surrounded by an inner pipe and an outer pipe surrounding the inner pipe to form an outer flow cavity. In order to ensure electrical data transmission in a wear-free manner and to ensure easy installation, the inner and outer pipes are designed as mutually insulated electrical conductors to transfer measurement and control signals between the ground surface and the bottom of the hole during drilling. The pipes are braced against each other by electrically nonconducting spacers and are connectable to electrically operated measurement and control devices.