(19)
(11) EP 1 640 556 B8

(12) CORRECTED EUROPEAN PATENT SPECIFICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 B1)

(48) Corrigendum issued on:
15.10.2008 Bulletin 2008/42

(45) Mention of the grant of the patent:
18.06.2008 Bulletin 2008/25

(21) Application number: 04292251.8

(22) Date of filing: 20.09.2004
(51) International Patent Classification (IPC): 
E21B 4/18(2006.01)

(54)

Dual tractor drilling system

Ziehvorrichtung zum Bohren

Tracteur pour un systeme de forage

(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

(43) Date of publication of application:
29.03.2006 Bulletin 2006/13

(73) Proprietors:
  • SERVICES PETROLIERS SCHLUMBERGER
    75007 Paris (FR)
    Designated Contracting States:
    FR 
  • SCHLUMBERGER HOLDINGS LIMITED
    Road Town, Tortola (VG)
    Designated Contracting States:
    GB NL 
  • SCHLUMBERGER TECHNOLOGY B.V.
    2514 JG Den Haag (NL)
    Designated Contracting States:
    AT BE BG CH CY CZ DE DK EE ES FI GR HU IE IT LI LU MC PL PT RO SE SI SK TR 

(72) Inventors:
  • Lavrut, Eric
    92350 Le Plessis Robinson (FR)
  • Kotsonis, Spyro
    92350 Le Plessis Robinson (FR)

(74) Representative: Hyden, Martin Douglas et al
Rouse Patents 1st Floor 228-240 Banbury Road
Oxford Oxfordshire OX2 7BY
Oxford Oxfordshire OX2 7BY (GB)


(56) References cited: : 
GB-A- 2 398 308
US-A1- 2001 045 300
US-B1- 6 467 557
 US-A- 6 082 461
US-A1- 2004 168 828
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).