Continuous borehole telemetry system and method

A method for directionally surveying a substantially horizontal borehole being drilled under the earth's surface, wherein such borehole is drilled by means of a bit rotated on the end of a pipe string, comprising:

• positioning a directional survey tool in the pipe string near the drill bit;
• positioning lengths of electrical conductor in each drill pipe section to be added to the pipe string, with such conductor lengths being longer than the pipe sections and having connector portions accessible at the top and bottom of the pipe sections;
• connecting adjacent lengths of conductor in adjoining pipe sections before connecting such adjoining pipe sections;
• positioning such sections of pipe in the pipe string above the survey tool and connecting the connector at the bottom of conductor in the bottom pipe section to the survey tool;
• connecting a side entry pipe at the top of the pipe string;
• passing a side entry conductor through the side entry pipe to provide an electrical conductor path from the exterior to the interior of the pipe string;
• and
• electrically connecting the bottom end of the side entry conductor to the conductor connection portion accessible at the top of the uppermost pipe section.

In a system for controlling a substantially horizontally directionally drilled borehole and utilizing a pipe string having a drill bit at its lower end and motive means for operating the drill bit, together with a directional survey instrument positioned near the drill bit in the pipe string, means for operating the survey instrument continuously and providing directional data to the surface over a conductor cable, which means comprises;

• a hanger positioned in the upper end of each section of pipe;
• and
• a tubular sleeve means in the center of said hanger and sized to receive the conductor cable therethrough;
• said sleeve means being sized to receive a portion of the conductor cable in seating relationship;
• and
• said conductor cable is arranged in sections which are slightly longer than a section of pipe string and including connector portions on each end thereof.

In a system for continuously directing the drilling of a substantially horizontal directional borehole and utilizing a pipe string having a drill bit and associated motive means at the lower end of the pipe string, together with a continuously operable directional survey instrument positioned in the pipe string near the drill bit, means for operating the survey instrument to continuously provide steering data to the surface over an electrical cable, which means comprises;

• a side entry pipe section positioned near the upper end of the pipe string;
• passage means extending through the wall of said side entry pipe section and opening to the interior and the exterior of the side entry pipe section;
• cable conductor means for passage through said side entry pipe and passage means, said cable conductor means having a connection at each end thereof;
• and
• shoulder means arranged in the exterior opening of the passage means, said shoulder means having a threaded portion for threadedly receiving one of said connectors, said conductor cable means is arranged in sections which are slightly longer than a section of said pipe string.