Gulf gas boost

Flatrock is a multiple reservoir deep-gas discovery below the Chevron-operated Tiger Shoal Field in the Gulf of Mexico, 19 km southwest of Vermilion Bay, USA.

Gas produced at Flatrock is processed at the South Marsh Island (SMI) Block 217 platform, which, before its expansion earlier this year, was already producing double the Gulf of Mexico average for a single platform. Since the expansion capacity has doubled.

"This one platform alone could increase US natural gas production by 13%," said J.P. Quackenbos Jr., president of Cajun Maritime LLC, Chevron's main contractor on the project.

To carry out the work, Cajun purchased a 300 tonne capacity Liebherr LR 1300 lattice boom crawler crane. "This crane has a number of features that are attractive to us. The sealed bearings, stainless steel, zinc plated surfaces and special coatings make it particularly suitable for the maritime market, and there are a number of safety mechanisms that we like. We also like the big engine, high line pull and the load chart - it holds its capacity well as the radius increases," Quackenbos explained.

The model was used in a range of installations, including 32, 42 and 76 inch (81, 106 and 193 cm) diameter pipe piles, a new service crane and a water treatment deck platform. The lifts included a 60 tonne separator package, placed at a 20.1 m radius and a 71.2 tonne well deck set at a radius of 18.3 m.

With the crane being set on a barge, Cajun Maritime engineers had to ensure it maintained a zero degree list at all times, allowing the crane to lift to its full load chart with no reductions.

Since completing its work on Flatrock in July, the LR 1300 spent about two months working on a project in Galveston Bay, Houston, before returning to Flatrock in October to carry out further expansion activities.