The Hibernia Gravity Base Structure is an offshore

oil platform An oil platform (also called an oil rig, offshore platform, oil production platform, etc.) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms w ...

on the Hibernia oilfield southeast of St. John's, Newfoundland, Canada. A 600-kilotonne gravity base structure (GBS) built after the '' Ocean Ranger'' disaster, it sits in of water directly on the floor of the

North Atlantic Ocean The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

off St. John's, Newfoundland at . This GBS is designed to resist

iceberg An iceberg is a piece of fresh water ice more than long that has broken off a glacier or an ice shelf and is floating freely in open water. Smaller chunks of floating glacially derived ice are called "growlers" or "bergy bits". Much of an i ...

forces and supports a topsides weighing 39,000

tonnes The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...

at towout, increasing to 58,000 tonnes in operation. There were significant challenges faced by the engineering firms Doris Development Canada, Morrison Hershfield and

Mobil Mobil Oil Corporation, now known as just Mobil, is a petroleum brand owned and operated by American oil and gas corporation ExxonMobil, formerly known as Exxon, which took its current name after history of ExxonMobil#merger, it and Mobil merge ...

Technology in developing a structural solution with adequate strength which was also constructible. In addition, unusual design situations resulted from the construction methods and the structural components used.

Construction

The majority of the construction was performed at a site in Bull Arm, Trinity Bay, Newfoundland and Labrador. A new community housing 3,500 workers was constructed, with its own cafeteria, gym and entertainment facilities. Many of the topsides modules were constructed locally, with some sourced internationally. The 550,000-ton slipform concrete GBS was built inside a

drydock A dry dock (sometimes drydock or dry-dock) is a narrow basin or vessel that can be flooded to allow a load to be floated in, then drained to allow that load to come to rest on a dry platform. Dry docks are used for the construction, maintenance, ...

and mated with the topsides in the nearby deepwater construction site. Kiewit performed outfitting of equipment inside utility shafts and provided construction management services for the gravity base structure. The assembled GBS was towed out on May 23, 1997, and installed in position on June 5. First oil was produced on November 17, 1997, four weeks ahead of schedule.

References

External links

Hibernia Gravity Base Structure
Oil platforms off Canada Buildings and structures in Newfoundland and Labrador {{petroleum-stub Petroleum industry in Newfoundland and Labrador