Noble Corporation  Noble Corporation plc is an offshore drilling contractor organized in London, United Kingdom. Its affiliate, Noble Corporation, is organized in the Cayman Islands. It is the corporate successor of Noble Drilling Corporation. The company operates 25 drilling rigs including 8 drillships, 4 semi-submersible platforms, and 13 jackup rigs. In 2019, the company's revenues were primarily from Royal Dutch Shell (36.5% of revenues), Exxon Mobil (13.7% of revenues), Equinor (13.1% of revenues), and Saudi Aramco (11.9% of revenues). In 1985, Noble Affiliates, Inc. (now Noble Energy), distributed its shares in Noble Drilling Corporation to its shareholders via a corporate spin-off and Noble Affiliates began publicly trading on the NASDAQ. In 2002, the company underwent a restructuring whereby it moved its domicile to the Cayman Islands and established Noble Corporation as the parent holding company. In early 2009, the company moved its domicile from the Cayman Islands to Switzerland due to the potential for more U.S. taxes on Caribbean tax havens. In 2013, the company moved to the United Kingdom. In 2010, the company acquired Frontier Drilling in a $2.16 billion cash transaction. The company was added to the S&P 500 Index in 2011 but was removed from the index in 2015. In 2014, the company distributed its interests in Paragon Offshore plc to its shareholders. In 2012, the Noble Discoverer drillship, operating under contract for Royal Dutch Shell lost its mooring and drifted close to shore. There were no injuries or environmental damage reported as a result of the accident. In 2017, an employee went missing on the Noble Lloyd Noble drilling rig.