(19)
(11) EP 0 907 820 A1

(12)

(43) Date of publication:
14.04.1999 Bulletin 1999/15

(21) Application number: 97928611.0

(22) Date of filing: 18.06.1997
(51) International Patent Classification (IPC): 
E21B 21/ 10( . )
(86) International application number:
PCT/SE1997/001085
(87) International publication number:
WO 1997/049891 (31.12.1997 Gazette 1998/05)
(84) Designated Contracting States:
AT DE FI FR GB IE SE

(30) Priority: 24.06.1996 SE 19960002472

(71) Applicant: Sandvik Aktiebolag (publ)
811 81 Sandviken (SE)

(72) Inventors:
  • LILJEBRAND, Per-Olof
    S-811 52 Sandviken (SE)
  • OLSSON, Urban
    S-810 41 Forsbacka (SE)
  • BECCU, Rainer
    77069 Houston, Texas (US)

   


(54) DRILL TUBE FOR FORMING DRILL STRINGS