Two-pipe on-grade directional boring tool and method

• Main Authors: KNECHT PAUL W, DIMITROFF TED
• Format: Patent
• Language: English
• Published: 07.12.2004
• Edition: 7
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

A method and apparatus for boring a close tolerance on-grade subsurface borehole. A downhole tool assembly for use with a dual member drill string comprises a directional boring tool. The dual member drill string comprises an outer member and an inner member disposed within the outer member and rota...