The present disclosure provides downhole tools, methods for three dimensional printing hardfacing on such downhole tools, and systems for implementing such methods.

The present disclosure provides downhole tools, methods for three dimensional printing hardfacing on such downhole tools, and systems for implementing such methods.

A rotary drill bit for use with a horizontal directional drill string. A coupler at a proximal axial end is configured to attach the rotary drill bit to a drill head at a distal end of the drill string. A cutting portion at a distal axial end is provided with a plurality of vanes with respective cutters that operate to cut a hole in earth when the rotary drill bit is rotated about a central axis. The plurality of vanes project radially outwardly from a surface of the cutting portion such that the surface forms respective troughs circumferentially interspersed with the plurality of vanes. A plurality of engagement features is positioned axially within the cutting portion and radially inward of an outer cutting diameter to facilitate attachment of a product pullback device between the plurality of vanes without removing the rotary drill bit, or any portion thereof, from the drill head.

The present invention provides a safety system (1) for protecting against a hazard of a drill rod failure in a drilled rock bore (B) above horizontal, and especially a hazard posed by a broken drill rod section (S) lodged within the bore (B). The safety system (1) comprises: a plug member (2) for insertion into a proximal end region (E) of the bore (B) adjacent a rock-face (F), the plug member (2) being configured to be fixed within the proximal end region (E) of the bore (B); and an impact reduction member (5) for reducing an impact of the broken drill rod section (S) striking the plug member (2) within the proximal end region (E) of the bore (B). The impact reduction member (5) is configured to be located within the proximal end region (E) of the bore (B) and to extend within the bore (B) above the plug member (2).

The present invention provides a safety system (1) for protecting against a hazard of a drill rod failure in a drilled rock bore (B) above horizontal, and especially a hazard posed by a broken drill rod section (S) lodged within the bore (B). The safety system (1) comprises: a plug member (2) for insertion into a proximal end region (E) of the bore (B) adjacent a rock-face (F), the plug member (2) being configured to be fixed within the proximal end region (E) of the bore (B); and an impact reduction member (5) for reducing an impact of the broken drill rod section (S) striking the plug member (2) within the proximal end region (E) of the bore (B). The impact reduction member (5) is configured to be located within the proximal end region (E) of the bore (B) and to extend within the bore (B) above the plug member (2).

A multi-impeller passive-rotating-stirring-type rotary drilling rig for open caissons includes a hollow main drill pipe, a drill bit, four cutting edges, four impeller shafts, four passive impellers and a rotation bracket. Through being uniformly distributed at a peripheral of the drilling rig, four passive impellers contact with a hole wall of a borehole during the drilling process for passively generating relative rotation opposite to the rotation direction of the drill bit, so as to accelerate sufficient mixing of silt and water for forming mud during the drilling process.

A multi-impeller passive-rotating-stirring-type rotary drilling rig for open caissons includes a hollow main drill pipe, a drill bit, four cutting edges, four impeller shafts, four passive impellers and a rotation bracket. Through being uniformly distributed at a peripheral of the drilling rig, four passive impellers contact with a hole wall of a borehole during the drilling process for passively generating relative rotation opposite to the rotation direction of the drill bit, so as to accelerate sufficient mixing of silt and water for forming mud during the drilling process.

Disclosed are small model pit launch horizontal direction drills suitable for drilling a substantially horizontal bore hole and laying pipe underground from within a surface dug pit. The devices comprise a stationary frame and a carriage component competent to move forward and back along the frame and drill and retrieve an attached drill stem through an aperture in the frame. The carriage components are configured to allow an operator to straddle the carriage and operate the device from a seated position within the frame component interior.

Disclosed are small model pit launch horizontal direction drills suitable for drilling a substantially horizontal bore hole and laying pipe underground from within a surface dug pit. The devices comprise a stationary frame and a carriage component competent to move forward and back along the frame and drill and retrieve an attached drill stem through an aperture in the frame. The carriage components are configured to allow an operator to straddle the carriage and operate the device from a seated position within the frame component interior.

A method comprises determining a value of at least one oppositional force for a drillstring at multiple depths in the wellbore, determining a value of hook load for the drillstring at the multiple depths based on the value of the at least one opposition force at the multiple depths, and determining a calibrated drillstring weight based on a change in the value of the hook load over the multiple depths of the wellbore. The change in the value of the hook load can be determined based on a change in a measured hook load and/or a change in an estimated hook load. From the calibrated drillstring weight, an adjusted estimated hook load can be determined.