Achieving Hull Structural Hotwork Repairs On Board an Operational FPSO

Abstract

Abstract This paper explores the importance of forward planning for on-station hotwork repair and demonstrates how major repair work scopes, traditionally requiring completion in dry dock, can be carried out while the FPSO is producing. Although in theory FPSOs can be taken off station, the reality is that this has huge cost implications and reservoir issues may also make it technically very difficult. Even if the FPSO has a detachable turret, dry docking is likely to result in a minimum of 8 weeks off station. While periodical dry-docking can be easily scheduled for sailing ships, FPSO operators are increasingly looking for solutions that will enable them to keep their asset on-station and in production for upwards of 20–25 years. This being the case, it is inevitable that regardless of advances in integrity management strategies, structural hot work repairs will be required on-station. Given the inevitability of the requirement for hotwork repairs to the hull structure, it is essential that details of how the work will be conducted are fully understood and agreed by all stakeholders long before it is necessary to start hotwork activities. The relatively small numbers of FPSOs mean that operators may have limited experience of hull structural issues and standard procedures, for example, confined space entry procedure, may not adequately address the unique issues presented by working in the enclosed but large space of FPSO tanks. It will be necessary to define and agree procedures for emergency response to incidents, IP rescue, fire and muster, isolation standards, boundary hotwork management and tank cleaning.