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The Kulluk Conundrum

January 06, 2013

The giant drilling platform Kulluk broke free from its tow lines and ended up aground after encountering high seas and strong winds. The conical Arctic drilling barge is stuck in about 25 to 40 feet of water off the uninhabited Sitkalidak Island and a salvage operation is underway. 

The Kulluk is a drill barge constructed in 1983 by Mitsui Engineering & Shipbuilding in Japan and owned by Royal Dutch Shell.  From 1983 to 1993, the rig was operated by Gulf Canada Resources in the Canadian Arctic. She was mothballed in 1993, and in 2005 she was acquired by Royal Dutch Shell and underwent intensive refurbishment. Kulluk is ice-reinforced with 3 in (76 mm) thick, reinforced steel, and a double-sided funnel-shape hull with flared sides enabling her to operate in Arctic waters as moving ice is deflected downwards and is broken into pieces.  The vessel is moored with a twelve-point anchor system.

Kulluk was used for drilling in the Beaufort Sea in 2012 by Shell. The company has already spent close to $5 billion on its Arctic exploration programme in Alaska. Kulluk was one of two drilling platforms operated by Shell in 2012.

On 27 December 2012, while Aiviq was towing the Kulluk platform off the coast of Kodiak Island, Alaska, the towing line between the icebreaker and the drilling rig parted due to a mechanical failure of the towing shackle. Shortly after the tow had been regained, the main engines of Aiviq failed likely due to fuel issues and the vessel lost propulsion power in 20-foot (6 m) seas. In the following morning, power was successfully restored on one of the four main engines and the vessel was able to hold position in the heavy weather.

In the evening of 30-December 2012, Kulluk was again set adrift after the Coast Guard ordered Alert to separate from the rig, now only 4 nautical miles (7.4 km; 4.6 mi) from the nearest point of land, to maintain the safety of the nine crew members on board the tug in nearly 30-foot (9.1 m) seas. The conical Arctic drilling barge is stuck in about 25 to 40 feet of water off the uninhabited Sitkalidak Island,  off the south-east shore of Kodiak Island.

A team of five salvage experts boarded Kulluk on 2 January 2013 to assess the structural integrity of the grounded drilling barge. On 3 January, it was reported that Kulluk had suffered damage since the grounding but its structural integrity had not been compromised and there have been no leaks from the rig’s fuel tanks. At the time of the grounding, Kulluk was carrying 139,000 gallons of diesel fuel and 12,000 gallons of lubricating and hydraulic oil. By 4 January, 14 vessels had been mobilized for the recovery operation and the United States Department of Defense provided two Boeing CH-47 Chinook helicopters to transport heavy salvage gear to the site. The salvage operation has been awarded to the Dutch salvage company Smit International.

The Aiviq, the 360-foot anchor handler that has been cast as the lead vessel on the recovery operation despite hitting an apparently fuel related engine failure just over a week ago that led to the rig’s initial stall. Alviq is an American icebreaking anchor handling tug supply vessel owned by Edison Chouest Offshore (ECO). The $200 million vessel was built in 2012 by North American Shipbuilding.  Aiviq is 110 metres (360 ft 11 in) long overall and 95.5 metres (313 ft 4 in) between perpendiculars and her hull has a beam of 24.4 metres (80 ft) and depth of 10.4 metres (34 ft 1 in). Fully laden, she draws 8.6 metres (28 ft 3 in) of water. Since Aiviq is an anchor handling tug and supply vessel, she is fitted with a large towing winch located amidships as well as chain lockers and storage tanks for both liquid and dry bulk cargo under the main deck. Aiviq is powered by four 12-cylinder Caterpillar C280-12 four stroke medium speed diesel engines, each producing 4,060 kW (5,440 hp) at 1,000 rpm. The engines are coupled to two 4.6-metre (15 ft) Schottel controllable pitch propeller in nozzles via Flender reduction gearboxes.

Alaska’s state department of revenue agency had not made a decision as to whether the rig would be subject to a state oilfield property tax. Some local media reports had speculated Shell’s decision to move the rig could have been influenced by the millage, which charges 2% of the appraised value of applicable property in the state as of 1 January.

Commentary

The failure of the Aiviq anchor handling vessel in heavy weather was the main culprit of the eventual grounding of Kulluk. Suffice to say it is a hazardous and wicked environment to be operating in. Thankfully there was no loss of life. Not sure what the salvage operation means to the disposition of the Kulluk.

Shell has been undertaking the high cost and high risk endeavor of exploring for hydrocarbons in this part of the world. Let us note also that Exxon Mobil announced that they will spend $14 B to move ahead with the Hebron oil platform offshore Newfoundland.

Sources

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See a)Judy Patrick-January 5, 2013.