Exhibit 8.1 - Significant subsidiaries

Name of company	Country of incorporation	Principal activities	Percent owned
Drilling unit owning companies
North Atlantic Alpha Ltd	Bermuda	Owner of West Alpha		75
North Atlantic Elara Ltd	Bermuda	Owner of Wesy Elara		75
North Atlantic Epsilon Ltd	Bermuda	Owner of West Epsilon		75
North Atlantic Linus Ltd	Bermuda	Owner of West Linus		75
North Atlantic Navigator Ltd	Bermuda	Owner of West Navigator		75
North Atlantic Pheonix Ltd	Bermuda	Owner of West Pheonix		75
North Atlantic Venture Ltd	Bermuda	Owner of West Venture		75
Scorpion Courageous Ltd.	Bermuda	Owner of Offshore Courageous		100
Scorpion Defender Ltd.	Bermuda	Owner of Offshore Defender		100
Scorpion Freedom Ltd.	Bermuda	Owner of Offshore Freedom		100
Scorpion Intrepid Ltd.	Bermuda	Owner of Offshore Intrepid		100
Scorpion Resolute Ltd.	Bermuda	Owner of Offshore Resolute		100
Scorpion Rigs Ltd.	Bermuda	Owner of Offshore Mischief		100
Scorpion Vigilant Ltd.	Bermuda	Owner of Offshore Vigilant		100
Seadrill Auriga Ltd.	Bermuda	Owner of West Auriga		100
Seadrill Capricorn Ltd.	Bermuda	Owner of West Capricorn		100
Seadrill Castor Ltd.	Bermuda	Owner of West Castor		100
Seadrill China Operations Ltd.	Bermuda	Owner of West Aquarius		100
Seadrill Cressida Ltd.	Bermuda	Owner of West Cressida		100
Seadrill Eminence Ltd	Bermuda	Owner of West Eminence		100
Seadrill Gemini Ltd	Bermuda	Owner of West Gemini		100
Seadrill Indonesia Ltd	Bermuda	Owner of West Callisto and West Leda		100
Seadrill Janus Ltd.	Bermuda	Owner of West Janus		100
Seadrill Jaya Ltd.	Bermuda	Owner of West Jaya		100
Seadrill Juno Ltd.	Bermuda	Owner of West Juno		100
Seadrill Oberon Ltd.	Bermuda	Owner of West Oberon		100
Seadrill Orion Ltd.	Bermuda	Owner of West Orion		100
Seadrill Telesto Ltd.	Bermuda	Owner of West Telesto		100
Seadrill Tender Rig Ltd.	Bermuda	Holding company and owner of West Alliance, West Berani,  West Menang, West Pelaut, T-4, T-7, T-8, T-11 and  T-12		100
Seadrill Triton Ltd.	Bermuda	Owner of West Triton		100
Seadrill Tucana Ltd.	Bermuda	Owner of West Tucana		100
Seadrill T15 Ltd.	Bermuda	Owner of T15		100
Seadrill T16 Ltd.	Bermuda	Owner of T16		100
Seadrill Vela Ltd.	Bermuda	Owner of West Vela		100
Seadrill Vencedor Ltd.	Bermuda	Owner of West Vencedor		100
SeaDragon II Ltd.	Cayman Islands	Owner of SeaDragon II		100
Seadrill Deepwater Drillship Ltd.	Cayman Islands	Owner of West Capella		100
Seadrill Hungary Kft.	Hungary	Owner of West Sirius		100
Seadrill Ariel Ltd.	Liberia	Owner of West Ariel		100
Seadrill Pegasus Pte Ltd.	Singapore	Owner of West Pegasus		100
Seadrill Tender Rigs Pte. Ltd.	Singapore	Owner of West Setia		100
					.
Drilling units under sale leaseback
Rig Finance II Ltd. *	Bermuda	Owner of West Prospero		0	*
SFL Polaris Ltd. *	Bermuda	Owner of West Polaris		0	*
SFL Deepwater Ltd. *	Bermuda	Owner of West Hercules and West Taurus		0	*
Contracting and management companies
North Atalntic Norway Ltd	Bermuda	Drilling services contracter		75
Seadrill Deepwater Crewing Ltd.	Bermuda	Crewing company		100
Seadrill Servicos de Petroleo Ltda.	Brazil	Drilling services contractor		100
Seadrill Management Services Ltd.	British Virgin Islands	Management company		100
Seadrill Asia Ltd.	Hong Kong	Drilling services contractor, holding company		100
North Atlantic Crew AS	Norway	Crewing Company		75
North Atlantic Managemnet AS	Norway	Management company		75
Seadrill Offshore AS	Norway	Drilling services contractor		100
Seadrill Management AS	Norway	Management company		100
Seadrill Management (S) Pte Ltd	Singapore	Management company		100
Seadrill Offshore Singapore Ltd.	Singapore	Management company		100
Seadrill Americas Inc.	USA	Drilling services contractor and technical services company		100
Holding Companies
North Atlantic Drilling Ltd	Bermuda	Holding Company of North Atlantic vessel owning entities		75
Scorpion Offshore Ltd	Bermuda	Holding Company of Scorpion vessel owning entities		100
Seadrill UK Ltd	United Kingdom	Holding Company		100

*  Fully consolidated Variable interest entities