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no longer be one complete structure due hotwork repair and demonstrated how mean that operators may have limited to the increased size of the Quad 204 major repair work scopes, traditionally experience with hull structural issues turret. Improved operability and reli- requiring completion in a dry dock, and standard procedures. For example, ability aspects are key design drivers can be carried out while the FPSO is confned space entry procedure may not to improving technology. The mooring producing. adequately address the unique issues

Production force increased due to the larger size of Although, in theory, FPSOs can be presented by working in the enclosed but the vessel and therefore larger safety fac- taken off station, the reality is that this large space FPSO tanks. Clearly defned tors, which contribute largely to a higher has huge cost implications and reservoir procedures are necessary for emergency reliability. issues may also make it technically very responses to incidents, IP rescue, fre and

For the installation of the new mooring diffcult. Even if the FPSO has a detach- muster, isolation standards, boundary system in Q2 2014 and the new FPSO able turret, dry docking is likely to result hotwork management and tank cleaning.

hook-up in 2015, the close interface in a minimum of eight weeks off station. While a great deal of effort is required between SBM Offshore teams optimizes While periodic dry docking can be to put a safe system of work in place both the mooring system and turret ergo- easily scheduled for sailing ships, FPSO and to organize and execute the repairs, nomics. It also facilitates the interfaces operators are increasingly looking for MacLean stressed that the effort required for delivery of mooring equipment and solutions that will enable them to keep to explain to senior management readiness of the installation spread. The their asset on station and in production that often repairing a ship by weld- turret design is tied into to the mooring for more than 20-25 years. This being the ing cannot be avoided, should not be design and to installation requirements: case, it is inevitable that regardless of underestimated.

from the pre-tension of the anchor points advances in integrity management strate- In principle, preparation for on-station up to the hook-up of mooring lines, as gies, structural hot work repairs will be hotwork repair needs to start before the well as requirements for maintenance required on-station. FPSO arrives on station. Operations and/or change-out. The relatively small numbers of FPSOs management teams should account for “This is the most complex in-tank welding in the design, as

Tank cleaned and ready turret SBM has ever supplied that is certain to happen in the for hotwork to the oil and gas industry. The future, but, more importantly in project combines unique skill the development of policies and sets to the industry; turret moor- the safety management system ing supply, feld life extension, for the installation.

technology development and off- According to MacLean, it shore contracting” says Laurent was paradoxical to consider

Agussol, SBM Offshore major that working within the tanks project manager. SBM Offshore involves work at height and says it is the only company in that these very large tank spaces the industry that can complete are categorized as “confned all stages in-house – engineering, spaces.” The key to executing procurement, construction and hotwork repairs, while in ,pro- installation. duction is fully understanding

At the top end of the market, these hazards and developing an the requirements of complex appropriate safe system of work

Tank inspection mooring systems, such as the for entry and working in tanks.

Quad 204 turret mooring system, MacLean concluded that are continually being extended maintaining the hull structure because of deeper water, more of an FPSO while on station is severe weather conditions, larger not impossible if an appropriate vessels to be moored, higher level of planning is carried out. throughputs, increased pres- There are solutions available for sures and longer design lives. many of the issues which may

The industry continues to adapt arise throughout the life of an and tailor solutions for safer ageing installation, however, it and more effcient operations is wise to fully understand the offshore, says SBM. work involved long before it is necessary to implement it.

In particular, agreeing on and

Hotwork repairs

The feasibility of achieving hull establishing the parameters for structural hotwork repairs on a safe system of work within the board an operational FPSO was operating company, partners, explored in a presentation by contractors, crew, and any other

Calum MacLean, projects direc- stakeholder needs careful and tor with Marine Technical Limits. detailed consideration and can

He stressed the importance of take a signifcant amount of forward planning for on-station time.

December 2013 | OE oedigital.com 44 040_OE1213_ProdOps_StrucIntegrity.indd 44 11/22/13 6:31 PM