ASSEMBLY FOR FULL-SIZE SIDE WINDOW CUTTING IN CASING PIPE IN SINGLE DRILLING STRING TRIP AND DEFLECTING WEDGE SUSPENSION UNIT Russian patent published in 2007 - IPC E21B7/08 E21B29/06 

FIELD: well drilling, particularly equipment to cut windows in casing pipe for secondary well bore drilling.

SUBSTANCE: assembly comprises side-tracking 1, opening 2 and gauging 3 cutting reamers fixedly secured to common shaft 4. The shaft 4 has upper end threadedly connected to drill pipe string 5. Side-tracking cutting reamer 1 is fixedly secured to lower shaft 4 end. Opening 2 and gauging 3 cutting reamers are secured to outer surface of common hollow shaft 1 and spaced apart by designed space. Deflecting wedge suspension unit comprises shear pin bolts 6 and radial threaded orifices for pin bolts 6 receiving made in side surface of cutting part of side-tracking cutting reamer 1. Suspension unit has member for longitudinal direction of deflecting wedge. The member is created as longitudinal slot recessed in side surface of side-tracking cutting reamer 1 in shear pin bolts 6 receiving orifices section. Corresponding extension is made in mating surface of upper deflecting wedge end. The assembly has limiter, which restricts cutting reamers travel in downward direction after pin bolts 6 shearing.

EFFECT: possibility of casing pipe window cutting in single drilling tool trip and simplified deflecting wedge connection to the assembly.

8 cl, 7 dwg