Crowley Maritime has delivered a huge offshore oil production and drilling platform, Olympus, to the US Gulf of Mexico.
The project provided the first opportunity for all four of the company’s new high-bollard-pull, ocean class tugboats, including the Ocean Wind, Ocean Wave, Ocean Sky and Ocean Sun, to work together.
Owned by Royal Dutch Shell, the rig has been developed for drilling operations in the US Gulf of Mexico region.
In order to relocate the 120,000t, 406ft tall tension-leg platform from Ingleside, Texas, 425 miles to its deepwater location in the Gulf of Mexico, the tugs worked together in both nearshore and offshore waters.
In the initial nearshore phase, Ocean Wind and Ocean Wave assisted in pushing the Olympus away from the Keiwit facility dock in Ingleside, Texas, through the Port of Aransas and out to deeper waters.
Ocean Sky was also available and equipped enough during this phase to provide push assistance if needed.
During the second stage, the offshore phase, Ocean Wave, Ocean Wind and Ocean Sun tugs towed the vessel to its final location in more than 3,000ft of water, while Ocean Sky ensured safety of the towing vessels and platform, by taking on the escort tug role.
The Crowley-contracted offshore tugboat Harvey War Horse II provided additional support during the execution.
In the final positioning phase, Ocean Wind, Ocean Wave and Ocean Sun helped position the platform in its final location and remained on site in a star pattern to provide support, as the platform was attached to tendons and made storm safe. By remaining on site as a stand-by vessel, Ocean Sky is expected to offer additional security.
Crowley solutions vice president, John Ara, said: "The design of the ocean class has allowed us to participate in the full scope of marine transportation, including nearshore, offshore and positioning work."
The twin-screw, steel-hulled Ocean Wave and Ocean Wind tugs are classed as Dynamic Positioning 1 (DP1) tugboats and have an overall length of 146ft beam of 46ft hull depth of 25ft and design draft of 21ft.
Ocean Sky and Ocean Sun tugs are classed as DP2 and are 10ft in length.
Constructed in South Korea, the Olympus features 24-slot drilling units and a deck large, enough to process crude from a six-well subsea development on site.
Outfitted with 15,000 psi-rated trees, the Olympus is expected to produce and process 100,000 barrels of oil equivalent per day when it operates at full capacity.
Image: Crowley Olympus in the initial nearshore phase. Photo courtesy of Crowley Maritime Corporation.