(19)

(11)

EP 0 240 490 A1

(12)

(43) Date of publication: 14.10.1987 Bulletin 1987/42 (21) Application number: 85905263.0 (22) Date of filing: 08.10.1985

(51) International Patent Classification (IPC):  E21B 17/ 10( . ) E21B 33/ 14( . ) E21B 17/ 22( . ) (86) International application number: PCT/US1985/001937 (87) International publication number: WO 1987/002409 (23.04.1987 Gazette 1987/09)

(84) Designated Contracting States: BE FR IT (71) Applicant: SHELL OFFSHORE INC. New Orleans, LA 70458 (US)	(72) Inventor: NATIONS, Joe, Frank Slidell, LA 70458 (US)