(19)
(11) EP 2 689 094 A2

(12)

(88) Date of publication A3:
05.12.2013

(43) Date of publication:
29.01.2014 Bulletin 2014/05

(21) Application number: 12716529.8

(22) Date of filing: 26.03.2012
(51) International Patent Classification (IPC): 
E21B 17/01(2006.01)
(86) International application number:
PCT/GB2012/050672
(87) International publication number:
WO 2012/131354 (04.10.2012 Gazette 2012/40)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30) Priority: 25.03.2011 US 201161467799 P
27.05.2011 US 201161490846 P

(71) Applicant: National Oilwell Varco, L.P.
Houston, Texas 77036 (US)

(72) Inventors:
  • SKAUGEN, Geir
    N-Stavanger 4027 (NO)
  • AUSTEFJORD, Arne
    N-4307 Sandnes (NO)

(74) Representative: Lucas, Brian Ronald 
Lucas & Co. 135 Westhall Road
Warlingham, Surrey CR6 9HJ
Warlingham, Surrey CR6 9HJ (GB)

   


(54) A RISER