UKOOA publishes FPSO Design Guidelines
The UK Offshore Operators Association has published a set of guidelines for the design of floating production, storage and offloading installations (FPSOs) destined for service on the UK Continental Shelf (UKCS).
"Design Guidance Notes for FPSOs for UKCS Service" are the result of discussions held with FPSO owners and operators over the last 18 months that highlighted the need for a single integrated FPSO-specific guidance document. The guidelines effectively translate hard-earned lessons learned in service and summarize good current design practice and research. They can be downloaded free of charge from the UKOOA website.
The Guidance Notes cover marine, structural and production/utility issues and include provision for UK Safety Case and environmental regulations, other relevant UK and international legislation as well as classification society requirements and industry standards such as MARPOL, NORSOK.
General guidance is given in Part 1 on factors affecting FPSO design for harsh environment service and hull and production/utility systems sizing. Vessel motions, layout issues and weight/space control procedures are discussed and vessel selection is covered for new-build, converted and intercept vessels.
The marine/structural section (Part 2) deals with the following issues:
- Hull configuration and design procedures;
- UKCS environmental loads;
- Hull structure design including bow wave impact, green water and sloshing;
- Possible sources of collision damage and mitigating measures;
- Interface between hull and production facility pre-assembled units including hull deflection patterns, motions and acceleration estimates and a discussion of the issues surrounding optimum packaging and support of production facilities;
- Mooring and marine systems;
- Crude oil export by shuttle tanker;
- Operational issues (inspection, maintenance and repair).
Part 3, (Production Systems), covers:
- Front end engineering;
- The development of design philosophies as the basis for a robust design;
- Detailed layout development, both global and local;
- Major systems design including issues of system integration and segregation;
- Small utility and support systems.
"Several sources of information were used in compiling the document," explains John Methven of PGS Production Services and vice- chairman of UKOOA's FPSO committee which commissioned the work. "Interviews were held with operators of UKCS FPSOs to determine problems encountered during the project development phase as well as in service and how these could be avoided in future. Secondly, reference was made to the extensive research program undertaken by the Health & Safety Executive in this field and to guidance issued by UKOOA, NORSOK and others. Lastly, classification society rules from Lloyd’s Register, American Bureau of Shipping and Det Norske Veritas were examined to determine the most relevant guidance these contained on the above topics.
"The document highlights the importance of designing for robustness from the outset to ensure reliable long-term operation, design for high uptime, flexibility for future expansion with minimal disruption to existing production, and the special in-situ inspection and maintenance needs of an FPSO on long-term deployment. The critical need for effective management is also discussed as well as the importance of talking to Operations teams early on in the design process to learn from actual workplace experiences," he adds.
Stuart Smith of Project Reviews Ltd and Bob Marshall of RM Offshore Ltd carried out the work on behalf of UKOOA.