Page 444 - Pipelines and Risers

Design Codes and Criteria for Risers 41 1

allowable and failure) is not being maintained with the codes reviewed. However, the authors
would emphasize that these codes do result in safe designs. The authors would recommend
when designers are approaching the identified limits that they use the Hauch & Bai method
verify the reserve strength of the riser and decide whether a limit state design is justified.

From this review of the local bucklingkollapse limit state it can be concluded that the three
approaches presented are safe for deeper water applications, although some do not maintain a
consistent level of safety for the load combinations.

21.7 References
1. API RP 2RD, (1998) “Recommended Practice for Design of Risers for Floating
Production Systems and TLP’s”, First Edition, 1998.
2. API, Spec. 175, (1996) “Specification for Unbonded Flexible Pipe”, First edition
December 1996.
3. Hauch, S. & Bai, Y. (1999) “Bending Moment Capacity of Pipes”, OMAE’99.
4. IS0 13628-7, (1999) “Petroleum and natural gas industries - Design and operation of
subsea production systems”, Part 7: ”Completiodworkover riser systems“, International
Standardisation Organisation.
5. IS0 13628-7, (1999) “Proposal for a revisiodclarification of the CWO IS0 standard
limit states and criteria”, mail from Finn Kirkemo, Seaflex, Dated 08.10.99.
6. IS0 13628-7, (1999) “Updated Pipe Design criteria_Nov99”, mail from Finn Kirkemo,
Seaflex, Dated 30.1 1.99.
7. Jensen, J.C., (1999) “Ultimate Strength and Fatigue Analysis of Metallic Catenary
Risers”, a M.Sc. thesis at Stavanger University College for J P Kenny AIS.
8. Kirkemo, F., Mldrk, K.J., Spdahl, N., and Leira, B., (1999) “Design of Deepwater Metallic
Risers”, ISOPE’99.
9. Langford, G., Bai, Y., Jensen, J., Damsleth, P. and Grytl, O., (2000) “Strength and
Fatigue of Deepwater Metallic Risers”, DPT’2000.
10. NF’D, (1990) ”Regulations Relating to Pipeline Systems in the Petroleum Activities”,
1990.
11. Silva,R.M.C. et al, “The comprehensive monitoring program for the first steel Catenary
Riser installed in the semi-submersible P-18”. Proceedings of the Deep Offshore
Technology Conference, Stavanger 1999
12. Veritec, (1987) ”Veritec JIP guidelines for flexible pipes”, 1987.