A revolutionary catamaran-hulled drilling vessel concept destined for use in Norway's Aasgard fields development has hit problems in design tests, and design changes could lead to higher costs.
Den norske stats oljeselskap AS (Statoil) hoped its small waterplane area twin-hull (Swath) design would help save $80 million in Aasgard development costs (OGJ, Apr. 22, p. 20).
In June Statoil issued a letter of intent to Smedvig AS, Stavanger, to build and operate a Swath vessel under a $150 million, 5 year contract (OGJ, June 10, p. 29).
A Smedvig official said the catamaran shape cannot be used as it is and a semisubmersible design hull will be used for the Aasgard drilling vessel.
"Test results showed problems that will take time to resolve," he said, "and time is of the essence for Aasgard.
"We cannot afford to spend more time developing the Swath idea at the moment, but it is not a dead concept."
The official said it is too early to say yet whether this problem will affect the cost of developing Aasgard. He said Statoil would need to hire a regular rig to drill the first 15 development wells if the newbuild vessel is delayed.
"If rig fabricators were magicians and could build a semisubmersible type vessel by Statoil's deadline of Apr. 1, 1998," said the official, "this won't apply. As it is, we expect it will be third quarter 1998 before the vessel is ready."
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