Patent ID: 6082471
Filing Date: 2000-07-04
Classification: E21B

Abstract:
An assembly used to install a pipeline section under a surface barrier and along the path of a pilot bore comprising:(a) a horizontal drilling rig, said drilling rig positioned at one end of the pilot bore,(b) a rotator on said rig,(c) a drill pipe extending into the pilot bore and connected at one end of said drill pipe to the rotator on the drilling rig whereby said drill pipe can be rotated in the pilot bore;(d) an advancer on said drilling rig connected to move said drill pipe whereby said section and drill pipe can be horizontally moved in the pilot bore;(e) a boring head connected to said drill pipe whereby said boring head can be rotated and advanced under the barrier to enlarge the pilot bore, said boring head further comprising:(i) an axial member for connecting the boring head to the drill pipe of the drilling rig;(ii) a plurality of flanges extending radially from said axial member;(iii) a cylindrical body defining a central axis, said plurality of flanges structurally supporting said cylindrical body on said axial member and such that said axial member is positioned along the central axis of said cylindrical body;(iv) a plurality of cutting cones, wherein each of said cutting cones has a cone axis, each of said cutting cones is mounted to one of said flanges such that its cone axis extends at an acute angle up to 45 degrees relative to the central axis of said cylindrical body; each of said cutting cones is mounted for independent rotation about its cone axis; and each of said cutting cones has a plurality of independently rotatable cutting bits mounted thereto;(f) said axial member having a flow conduit therethrough for drilling fluid and having at least one fluid port formed therein for discharging drilling fluid into the region of the boring head, and(g) a drilling fluid pump operatively connected through the pilot bore to said axial member, whereby said drilling fluid pump can supply drilling fluid to said axial member and through said fluid ports to said boring head during boring.