Ocean Rig UDW Inc. is an operator of semi-submersible oil rigs and UDW drillships based in Athens, Greece. The company also maintains offices in Luanda, Angola, Jersey, Rio de Janeiro, Brazil and Stavanger, Norway..
The company has two semi-submersibles, the Leiv Eiriksson and Eirik Raude, and four ultra deepwater drill ships "Ocean Rig Olympia", "Ocean Rig Mykonos", "Ocean Rig Poseidon" and "Ocean Rig Corcovado". Four further ultra deep water drill ships are currently under construction with three due for completion in 2013, and one in 2015.
Areas of operation as of 2012 are Brazil, West Africa, East Africa and the Norwegian sector.
The company was established in 1996 as Ocean Rig ASA. Ocean Rig was listed on the Oslo Stock Exchange in 1997–2008. Since 2011 it is listed in NASDAQ. In 2007–2008, 74% of the company is owned by DryShips Inc, controlled by Greek-American shipping tycoon George Economou.
In 2011 the Leiv Eirikson finished operations the Black Sea on contract to Petrobras and TPAO and went to the Arctic on contract to Cairn Energy. In 2012 Leiv Eirikson is drilling in the East Falklands Basin. The Eirik Raude is in Ghana on contract to Tullow Oil. Both semi-submersible drilling rigs are based on the proprietary Bingo 9000 design. The rigs have a water depth capacity of 10,000 feet (3,000 m) and variable deck load of 7,000 tonnes.