MONACO -- SBM Atlantia (SBMA) and Murphy Exploration & Production Co. today presented an overview of the Thunder Hawk deep draft semisubmersible floating production unit, currently deployed in deepwater in the Gulf of Mexico. The authors of the paper were Steve Leverette and Dwayne Breaux of SBMA, and Paul Fourchy of Murphy.
The Thunder Hawk facility was installed offshore Louisiana in Mississippi Canyon (MC) 736 in 6,060 ft (1,847 m) of water, and is producing from the Thunder Hawk field located in MC 734. Thunder Hawk is the second of SBMA’s DeepDraft Semi Floating Production Units (FPU).
The scope of the project included providing full engineering, procurement, construction, and installation (EPCI) services for the topsides, hull, moorings, riser design, installation, and offshore commissioning. The Thunder Hawk project is the first Production Handling Agreement (PHA) for the SBM Offshore Group. First oil was achieved on July 8, 2009.
The facility is anchored with a polyester spread mooring system and is connected to the subsea manifolds and infrastructure with steel catenary riser (SCR) flowlines, SCR export risers, and multiple control umbilicals. Provisions have been made to accommodate future subsea tie-backs and associated production from other fields/blocks in the area, including processing production from third party producers.
Unique project components include accommodation of increased GoM metocean criteria to an earlier hull design, development of new hydrodynamic modeling techniques for VIM of the hull during the design, fabrication of the hull in a module fabrication yard which included two new panel lines and additional quayside development during the project schedule, and record setting achievement of “quarters habitable” status of the hull only two months after initial deck lift during quayside integration.
SBM Atlantia and SBM GustoMSC previously teamed up to supply the worlds first DeepDraft Semi for Enterprise Products Partners’ Independence Hub project located in a record setting 8,050 ft (2,454 m) water depth in MC 920.
According to the authors, the DeepDraft Semi is establishing itself as a workhorse for oil companies exploring and developing fields in the ultra deepwaters of the GoM. The Thunder Hawk FPU was one of the first deep water projects to address the new GoM environmental criteria which evolved from the ’Ivan’, ‘Katrina’ and ’Rita’ hurricane experiences. SBM worked with the API in developing the new design guidelines, which MMS has now made into regulation, and worked with Murphy in interpreting the regulations and developing site-specific environmental criteria for the Thunder Hawk development. SBM also helped develop the wave slam load methodologies utilized in this project.
A key feature of the facility is its low motion characteristics to accommodate the requirements of SCR flowlines and risers in a cost-effective manner compared to other FPU concepts. The other significant advantage is the system’s ability to mate the topsides deck to the hull at quayside, thereby avoiding costly offshore lifting and system commissioning operations. By integrating the topsides onto the hull at quayside, the FPU can be fully pre-commissioned and USCG ‘Quarters Habitable’ permits can be obtained prior to mobilizing the facility offshore – thus, reducing costly, labor intensive, offshore commissioning activities.
During the concept definition phase for the Thunder Hawk development, it became evident that hull fabrication in the ‘traditional’ hull construction yards was going to be a risk due to the limited spare global construction capacity. The decision was made to develop a new hull fabrication site at the Dyna-Mac yard in Singapore, a topsides module fabricator. This bold move required a ‘green-field’ development of the existing yard facilities to include panel lines, new craneage, transporters, covered fabrication areas, quayside and high load capacity assembly areas. The timing was quite aggressive, and required that the fabrication yard construction be performed during the hull design. The hull fabrication began as soon as the first panel line was complete.
The Thunder Hawk FPU is SBM’s first lease unit in the GOM, but part of its vast worldwide fleet. SBM is working with Murphy on other fields around the world and anticipates additional cooperation in the future.