Vertical, horizontal and a combination of vertical and horizontal drilling are the traditional methods of drilling for exploration, development and production of methane hydrate, carbon dioxide, natural gas, and oil. The traditional drill pipe string used in these methods is a single-walled pipe which drilling mud or compressed air is pumped as the cutting head is operated. The cuttings produced by the cutting head are displaced or circulated from the borehole up the annulus between the outside of the drill pipe string and the casing and/or the borehole wall. Also non-traditional drill pipe strings consisting of a dual wall rigid outer pipe and a rigid inner pipe have been utilized where the pressure in the production zone is less than that of the pressure being exerted through the annulus by the drilling mud or compressed air. Excessive pressure exerted on the formation may damage the formation and prevent desired flow from the production zone. Dual wall drill pipe relieves the pressure in the bore hole by returning the excess pressure along with the cuttings back to the surface through the inner tube without damage to the formation of the production zone. The benefits of non-traditional rigid dual-wall drill strings have been substantially restricted by their inability to deviate or bend from a vertical to a horizontal or near horizontal plane that would greatly increase production volume by extending the exposure of the pipe through the horizontal length of the production zone.

Key Features

• Designed specifically for use in Reverse Circulation Center Discharge (RCCD) drilling applications.
• Non-metallic flexible inner tube substantially reduces or eliminates erosion of the inner tube wall caused by drilling returns experienced by a steel inner tube.
• Communication wiring enclosed within the flexible inner tube enables real time communication between the drill string downhole and the surface drill machine.
• Non-metallic flexible inner tube allows drill with substantially tighter bend radius than steel inside of steel pipe to permit both vertical and horizontal drilling applications.

Advantages of TNT Horizontal/Vertical Drilling Method

Tube in a Tube – Pin and Box