Challenges with Ice-related Design and Operating Philosophy of the Shtokman Floating Production Unit

The Shtokman Gas Condensate Field (SGCF) is located 610 km from Murmansk in the Barents Sea. The water depth at location is around 340 m. The offshore facilities of the SGCF Phase 1 development will include ice-resistant disconnectable moored floating production unit (FPU). Significant sea ice invasions occur at Shtokman in approximately 3 out of 10 years and ice stays at location for an average of about 5 weeks. It consists mainly of first year ice, but a few second year ice floes have also been observed in the region. Sea ice thickness and keel depth of ice ridges may reach 2 m and 21 m, respectively. Design will ensure that the FPU can safely withstand actions from nearly all sea ice situations without physical ice management assistance. Ice management will be carried out to detect and manage rare but potentially hazardous situations, and thereby increase reliability. Icebergs may also occur in the SCGF area. Probability of iceberg impact on the FPU is estimated to be less than once in the 50 years life of the project, and it can be further reduced by ice management. 70% of icebergs observed in the Barents Sea are bergy bits. Almost half of the icebergs observed were surrounded by pack ice. This is important for design and operations since icebergs in pack ice are difficult to detect and manage. In general, iceberg probabilities at Shtokman are around 50 times less than in Canada’s Grand Banks, but sea ice is around 30 times more likely at Shtokman than in the Grand Banks. The present paper describes sea ice and iceberg related challenges connected to design and operating philosophy of the Shtokman FPU. Some of the actions performed by SDAG to address the challenges and to ensure sound design and safe operations with acceptable downtime are also presented.

• Record URL:
  • http://www.poac.com/Papers/POAC09_72-152.zip
• Summary URL:
  • http://www.poac.com/PapersOnline.html
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03766756
• Supplemental Notes:
  • Abstract reprinted with permission of the International Conference on Port and Ocean Engineering Under Arctic Conditions (POAC).
• Corporate Authors:

  Port and Ocean Engineering under Arctic Conditions (POAC)

  ,    
• Authors:
  • Liferov, Pavel
  • Metge, Michel
• Conference:
  • 20th International Conference on Port and Ocean Engineering under Arctic Conditions (POAC'09)
  • Location: Luleå , Sweden
  • Date: 2009-6-9 to 2009-6-12
• Publication Date: 2009

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 1133-1142
• Monograph Title: POAC '09: Proceedings of the 20th International Conference on Port and Ocean Engineering under Arctic Conditions
• Serial:
  • Proceedings of the International Conference on Port and Ocean Engineering Under Arctic Conditions
  • Publisher: Port and Ocean Engineering under Arctic Conditions (POAC)
  • ISSN: 0376-6756
  • EISSN: 2077-7841
  • Serial URL: http://www.poac.com/PapersOnline.html

Subject/Index Terms

• TRT Terms: Design; Floating structures; Ice floes; Icebergs; Offshore moorings; Offshore structures; Sea ice; Thickness
• Geographic Terms: Barents Sea
• Subject Areas: Bridges and other structures; Design; Environment; Marine Transportation; Terminals and Facilities; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 01554624
• Record Type: Publication
• Report/Paper Numbers: POAC09-139
• Files: TRIS
• Created Date: Feb 26 2015 9:53AM