(19)
(11)
EP 0 211 925 A1
(12)
(43)
Date of publication:
04.03.1987
Bulletin 1987/10
(21)
Application number:
86901528.0
(22)
Date of filing:
21.02.1986
(51)
International Patent Classification (IPC):
E21B
7/
04
( . )
E21B
17/
00
( . )
(86)
International application number:
PCT/NO1986/000019
(87)
International publication number:
WO 1986/004950
(
28.08.1986
Gazette 1986/19)
(84)
Designated Contracting States:
DE FR GB IT NL SE
(30)
Priority:
21.02.1985
NO 19850000689
(71)
Applicant:
A/S RAUFOSS AMMUNISJONSFABRIKKER
N-2831 Raufoss (NO)
(72)
Inventor:
SANGESLAND, Sigbjorn
N-7000 Trondheim (NO)
(54)
DRILLING PIPE FOR MAKING A DRILL STRING