(19)
(11) EP 0 931 202 A1

(12)

(43) Date of publication:
28.07.1999 Bulletin 1999/30

(21) Application number: 97931974.0

(22) Date of filing: 28.07.1997
(51) International Patent Classification (IPC): 
E21B 17/ 00( . )
 F16L 13/ 02( . )
(86) International application number:
PCT/IB1997/000949
(87) International publication number:
WO 1998/013574 (02.04.1998 Gazette 1998/13)
(84) Designated Contracting States:
AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

(30) Priority: 26.09.1996 IT 1996BA00041

(71) Applicants:
  • Colli Drill S.R.L.
    00060 Capena (IT)
  • Chirulli, Renzo
    70124 Bari (IT)

(72) Inventors:
  • CHIRULLI, Renzo
    I-70124 Bari (IT)
  • COLLI, Elio
    I-70124 Bari (IT)

   


(54) WELDED DRILL PIPES IN WHICH THE INTERNAL FLASH IS REMOVED AND RELATIVE PROCEDURE OF MANUFACTURING