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Volume 14 - Summer and Fall 2020                   ijmt 2020, 14 - Summer and Fall 2020: 41-50 | Back to browse issues page

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Sharifi S M H, Pirali N, Najafi B. Investigation of Available Configurations for Flexible Risers in Shallow Water. ijmt. 2020; 14 :41-50
URL: http://ijmt.ir/article-1-686-en.html
1- Faculty of Mechanical Engineering, Petroleum University of Technology
2- Petroleum University of Technology, Abadan, Iran
3- Iranian offshore oil co. (I.O.O.C.)
Abstract:   (373 Views)
Flexible risers have been used widely in recent years for floating structure in shallow and deep water. Flexible risers have various configurations and each configuration has its specific charectresitics that helps the riser to solve the problems that exist in shallow and deep water. Selecting and designing the best configuration for flexible risers in shallow water, like deep water, present many challenges, some of these challenges can be addressed: high vessel displacement compared to the water depth, minimum riser clearance with the seabed or sea surface or the vessel keel, bending radius limitation and etc. The aim of this paper is to investigate the traditional configurations like lazy wave and pliant wave and to compare them with a new configuration like weight added wave for the riser with 15 inches internal diameter in 45m water depth connected to a turret moored floating storage unit. It is concluded that the traditional configuration can not solve the sea surface clearance problem when the riser is empty condition, in this condition the weight of riser is decreased and the buoyancy force is become higher than riser weight and lift the riser up and the riser become flooded on the sea surface. To preventing the riser from flooding on the sea surface it’s needed to use configuration with added mass. Also concluded that using added mass in touch down zone (TDZ) reduces the tension in PLEM connection point about 89% . Also concluded that the minimum bending radius for weight added wave configuration is increased about 29% in compared with traditional configurations. 
Full-Text [PDF 827 kb]   (131 Downloads)    
Type of Study: Research Paper | Subject: Offshore Structure
Received: 2020/06/10 | Accepted: 2020/12/23

1. Z. Tan, C. Loper, Y. Hou, and T. Sheldrake, "Application of Flexible Risers in Shallow Water: Weight Added Wave Configuration," ASME 2009 28th Int. Conf. Ocean. Offshore Arct. Eng., pp. 373-380, 2009. [DOI:10.1115/OMAE2009-79476]
2. H. T. Kim and O. M. O'Reilly, "Instability of catenary-type flexible risers conveying fluid in subsea environments," Ocean Eng., vol. 173, pp. 98-115, 2019. [DOI:10.1016/j.oceaneng.2018.12.042]
3. sadjad karegar, "MASTER ' S THESIS Flexible Riser Global Analysis for Very Shallow Water," 2013.
4. F. Gray, "Flexible and Rigid Pipe Solutions in the Development of Ultra-Deepwater Fields," 22nd Int. Conf. Offshore Mech. Arct. Eng., pp. 1-15, 2016.
5. Y. Zhang, "A Study For Worst Periods And Load Cases Selection In Dynamic Analysis Of Flexible Riser," pp. 1-8, 2017.
6. D. H. A. Berton, "Challenges And Soloution For Deepwater Flexible Risers In The Asian Regions," petromin Deep. subsea Technol. Conf, vol. 5, 2007.
7. X. Li, H. Ji, B. Zhang, T. Liu, and W. Ye, "Design of Flexible Riser for FPSO in South China Sea," Isope-2016, pp. 109-116, 2016.
8. N. Ismail, R. Nielsen, M. Kanarellis, and W. Corporation, "Design Considerations for Selection of Flexible Riser Configuration," vol. 42, no. 2, pp. 1-14, 1992.
9. D. Hanonge and A. Luppi, "Challenges of flexible Riser Systems in Shallow Waters," Proc. Annu. Offshore Technol. Conf., vol. 2, no. May, pp. 1101-1114, 2010.
10. Y. Hou, J. Yuan, Z. Tan, and J. Witz, "Application of an Enhanced Lazy Wave Flexible Riser System in Extreme Shallow Water With an External Turret Moored FPSO," Proc. Annu. Offshore Technol. Conf., vol. 2019-May, pp. 1-8, 2019. [DOI:10.4043/29327-MS]
11. A. Gurung, P. Viana, A. O'Brien, and A. Rimmer, "Use of Stabilisation Chains to Optimise Lazy Wave Flexible Risers in Harsh Environments," Soc. Pet. Eng. - SPE Offshore Eur. Conf. Exhib. OE 2015, 2015. [DOI:10.2118/175485-MS]
12. "API Spec 17J Specification for Unbonded Flexible Pipe," 1997.
13. "API Spec 17B Recommended practice for flexible pipe," 1998.
14. Orcina, "OrcaFlex Manual Version 9.7a." .
15. K. Jiang, Y. Lu, and Y. Bai, "A theoretical method to estimate the fatigue life of tensile armors of flexible pipes," Proc. Int. Conf. Offshore Mech. Arct. Eng. - OMAE, vol. 5, pp. 1-11, 2018. [DOI:10.1115/OMAE2018-77175]
16. "ISO 13628-11 Petroleum and natural gas industrie Design and operation of subsea production systems- Flexible pipe systems for subsea and marine applications."
17. Y. Zhang, Z. Tan, and Y. Hou, "Design Analysis OF a Weight Added Wave Configuration OF a Flexible Riser In Shallow Water," OMAE2010-20360, pp. 1-8, 2017.

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