(19)
(11) EP 2 297 423 A2

(12)

(88) Date of publication A3:
14.01.2010

(43) Date of publication:
23.03.2011 Bulletin 2011/12

(21) Application number: 09735461.7

(22) Date of filing: 21.04.2009
(51) International Patent Classification (IPC): 
E21B 10/16(2006.01)
E21B 10/43(2006.01)
(86) International application number:
PCT/US2009/041193
(87) International publication number:
WO 2009/131969 (29.10.2009 Gazette 2009/44)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA RS

(30) Priority: 21.04.2008 US 46508

(71) Applicant: Baker Hughes Incorporated
Houston, TX 77027 (US)

(72) Inventors:
  • BUSKE, Robert, J.
    The Woodlands TX 77380-3615 (US)
  • OVERSTREET, James, L.
    The Woodlands TX 77380-3615 (US)
  • PESSIER, Rudolf, Carl
    The Woodlands TX 77380-3615 (US)

(74) Representative: Hano, Christian 
v. Füner Ebbinghaus Finck Hano Patentanwälte Mariahilfplatz 3
81541 München
81541 München (DE)

   


(54) ANTI-TRACKING FEATURE FOR ROCK BITS