The Hibernia Gravity Base Structure is an offshore oil platform on the Hibernia oilfield southeast of St. John's, Newfoundland, Canada. A 600-kilotonne

gravity base structure A gravity-based structure (GBS) is a support structure held in place by gravity, most notably offshore oil platforms. These structures are often constructed in fjords due to their protected area and sufficient depth. Offshore oil platforms Pri ...

(GBS) built after the ''

Ocean Ranger ''Ocean Ranger'' was a semi-submersible mobile offshore drilling unit that sank in Canadian waters on 15 February 1982. It was drilling an exploration well on the Grand Banks of Newfoundland, east of St. John's, Newfoundland, for Mobil Oil o ...

'' 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 oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe an ...

off

St. John's, Newfoundland St. John's is the capital and largest city of the Canadian province of Newfoundland and Labrador, located on the eastern tip of the Avalon Peninsula on the island of Newfoundland. The city spans and is the easternmost city in North America ...

at . This GBS is designed to resist iceberg forces and supports a

topsides The topsides on a boat, ship, watercraft, or floating production storage and offloading (FPSO) vessel, is that part of the hull (watercraft), hull between the waterline and the Deck (ship), deck.Rognaas, G., Xu, J., Lindseth, S., & Rosendahl, F. ( ...

weighing 39,000

tonnes The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States c ...

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

Morrison Hershfield Morrison Hershfield is an employee-owned professional services firm providing engineering and management consulting services in the areas of energy and industrial, buildings, technology and telecom, transportation, environment, water and wastew ...

and Mobil 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 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