Location: Stones field along the Walker Ridge protraction area
Region: Gulf of Mexico
Water depth: Ultra-deep water 9,490 ft. (2,892 m)
Date: Q1 2015
As well competing with other contractors for good weather windows during simultaneous pre-commissioning operations, InterMoor, a brand in Acteon’s Engineering, Moorings and Foundations division, faced several technical challenges typical of ultra-deep water projects, including high loads (over 200mT) and size of chain components.
SCOPE OF WORK
- Chain tensioning/de-tensioning through the in-line mooring connector (ILMC) tensioning system
- Subsequent cut and removal of excess chain
- Riser pull-in rope stretching and transfer to the FPSO
- Provision of Tow Masters on-board the FPSO
- BTM buoy clump weight rigging removal
- Dock and equipment support to Shell contracted heading control tugs
- FPSO heading control steering lines design, procurement and offshore installation
- Dive-Support Vessel mooring design, procurement and offshore support for hook-up and disconnection
InterMoor provided full project management and engineering, including: design, procedures, procurement, dock support, offshore equipment and personnel for all phases.
UTEC provided the positioning survey for the AHV
Mirage custom-designed and fabricated the diamond wire cutting saw and clamping system.
Seacor Keith Cowan anchor-handling vessel (AHV)
HOS Iron Horse in the second part of the operations.
SOLUTIONS AND KEYS TO SUCCESS
- Integrated project team
- Extensive and thorough planning
- High quality engineering
- E.g. design of specific interface adapter between clamp and cutting saw to mitigate heave
- E.g. special use of Orcaflex to model dive vessel movements in relation to FPSO
- Responsiveness to client’s changing needs
- HSE focus
- Flexible/cost-effective spread: cheaper/smaller vessel (AHV)
- Chain removal completed successfully, i.e. no dropped objects
- No LTIs or recordable incidents
- The job was completed without schedule impacts for the FPSO