5ABS. Rules For Mobile Offshore Drilling Units[M]. Houston, USA, 2008.
6AWS. AWS D1.1 Structural Welding Code-Steel[M]. Miami, USA, 2006.
7USGS. U. S. Geological Survey Fact Sheet 2008- 3049 : Circum Arctic Resource Appraisal: Estimates of Undiscovered Oil and Gas North of the Arctic Circle Ehttp://pubs. usgs. gov/Is/ 2008/3049/1.