After a long-distance tow, the topsides for the Leviathan platform were installed by LNG-fuelled semi-submersible crane Sleipnir
Heerema Marine Contractors’ semi-submersible crane vessel Sleipnir completed a record-setting 15,300-tonnes lift in September, when it installed the topsides for Noble Energy’s Leviathan, Israel’s largest gas field development.
Located in the eastern Mediterranean and scheduled for production this year, the Leviathan field is estimated to hold 22Trn ft3 of recoverable gas. Some US$3.75Bn is being spent to develop Leviathan by US-based Noble Energy, the field operator, with a 39.66% stake, and partners Delek Drilling (22.67%), Avner Oil Exploration (22.67%), and Ratio Oil Exploration (15%).
To transport the various platform components and launch the 15,000-tonne jacket, Heerema used several of its own barges, including its heavy deck barge H-591, exemplifying the benefit of its distinctive asset base and ability to offer complete platform transportation and installation solutions. With a deadweight of 52,034 t, H-591 has a length of 180 m, beam of 46 m, depth of 11.7 m and maximum launch capacity of 24,000 t.
Fabricated in Corpus Christi, Texas, the Leviathan topsides were towed out by the Boskalis oceangoing tug Boka Sherpa. Sources indicate that the trip of approximately 11,500 km across the Atlantic to Israel onboard H-591 lasted a month. Boka Sherpa, with a length overall of 75.05 m, beam of 18 m and depth of 8 m, has a maximum bollard pull of 205 tonnes. Propulsion for the oceangoing tug is supplied by four 3,000 kW Wärtsilä 6L32 engines that drive two controllable-pitch propellers in nozzles.
Lifting the topsides of the Leviathan platform was left to Sleipnir. As the world’s first dual-fuel crane vessel and outfitted with two revolving cranes that can lift up to 20,000 tonnes in tandem, Sleipnir is a “unique Vessel” noted Heerema chief executive Koos-Jan van Brouwershaven.
He said the vessel’s LNG power makes it environmentally friendly and its powerful revolving cranes make it budget friendly. “And our client enjoys the benefits,” said Mr van Brouwershaven, “because lifting larger modules means less time involved and therefore a smaller budget will suffice for a job.”
Sleipnir installed the two main topsides, with a total weight of 24,500 tonnes, for the Leviathan platform in less than 20 hours, reported Heerema.
Leviathan’s initial development has four subsea wells, each capable of flowing more than 300M cubic feet per day (MMcf/d) of natural gas. Noble Energy completed umbilical installation, tie-in of onshore pipelines to offshore pipelines, and tie-in to the Israel Natural Gas Lines grid in Q2 2019. First gas from Leviathan is targeted for Q4 of 2019; the field is expected to have twice as much recoverable gas as Israel’s Tamar gas field.
In 2013, Heerema used its launch and cargo barge H-851 to transport the jacket for Israel’s deepwater Tamar gas field from Corpus Christi. Oceangoing tugs Fairmount Summit and Fairmount Alpine, then owned by Fairmount Marine, part of the Louis Dreyfus Group, were contracted by Heerema and mobilised for the effort. Both 205-tonne bollard pull oceangoing tugs are now owned by Boskalis and have been renamed Boka Summit and Boka Alpine, respectively. Boskalis acquired Fairmount Marine BV and Fairmount Ocean Towage Company BV from the French group Louis Dreyfus Armateurs in 2014. Acquiring five 205-tonne bollard pull ocean anchor-handling tugs allowed Boskalis to expand its services in both offshore energy and salvage. The use of oceangoing tugs for long distance wet towage complements Boskalis’ dry heavy marine transport offering.