Hibernia Canadian Project Still Has Many Contracts To Award
Despite recent reports regarding delays and cost overruns, the $3.8 billion (preproduction costs) Hibernia Project will still achieve its goal of oil production in 1997, according to Bob Kimberlin, president, Hibernia Managment and Development Co. Ltd. Hibernia, which is projected to produce 125,000 barrels per day (150,000 barrels per day at peak capacity) for 19 years, has created much interest and activity in the marine sector recently with contract award and bid announcements. While Mr. Kimberlin conceded that there is a $223 million overrun in the construction costs of the Gravity Base Structure (GBS) (versus original forecasts), he maintains that costs are below forecasts in other areas, and combined with ongoing savings measures, the project will come in within budget.
Recently a team of experts—including Hibernia, NODECO and Norwegian Contractors personnel— was assembled to improve GBS construction techniques.
"The Norwegian Contractors team has many years of experience in building GBSs in Norway," said Henk van Zante, construction general manager.
RECENT PROGRESS In the Topsides area at Bull Arm, the Wellhead module fabrication is 40 percent complete, and final fabrication is expected by December. In mid-February, the first steel plates were cut for the Topsides Mounted Structures (helideck, life boat station, auxiliary life boat station and flare boom). Construction of the Topsides Mounted Structures is expected to be complete in March 1995.
In the overseas fabrication yard, work is also progressing. The Process Module and Living Quarters and Services Module, which are being built in South Korea, are 35 percent complete. The Mud Module and Utility Module, which are being built in Italy, are 25 percent complete. These modules will be completed in early 1995 and transported to the Bull Arm construction site for assembly and hook-up.
Neptune Heavy Lift of Norway was awarded the contract for loadout, transportation and mating with the GBS. The scope of the contract includes the design, engineering and execution of the mating operation of the topsides drilling and production facility with the GBS at the deep water site at Bull Arm.
Once the five Topsides supermodules have been assembled on the assembly pier, barges will be aligned under the completed facility. The drilling and production facility weighing 37,000 tons will be transferred from the pier to barges, which will then be towed in a catamaran fashion to the GBS at THE GRAVITY BASE STRUCTURE The GBS design was selected for the Hibernia project in 1985. Affiliate companies of two of the Hibernia owners, Mobil and Chevron, have gained considerable experience from developing and operating GBS projects in the North Sea. The GBS will consist of three components: a concrete base slab, a concrete caisson (ice wall) reaching from the seabed to about 16.4 feet (5 m) above mean low water level, and four concrete shafts starting at the base slab and extending above the caisson. The four shafts—two drill shafts, a riser shaft and a utility shaft—will support the topside facility. When completed, the GBS will have a total height of 364.2 feet (111 m). The topsides facilities will be mated to the GBS and the completed platform towed to the field site. During tow-out, the completed platform will weigh about 600,000 tons. At the field site, the platform will be grouted and solid ballast will be added to secure it to the ocean floor.
THE TOPSIDES The most significant changes in the Hibernia project since its original design is the approach to the Topsides. The original Topsides design used the steel Main Support Frame (MSF) as its principal structural member. Developments in integrated structure technology suggested that weight, and costs, could be saved by assembling the Topsides with fewer, larger modules, and by using skidding techniques instead of heavy lift vessels to bring the modules together.
The Hibernia consortium studied the feasibility of applying this new technology to the project. The new design has eliminated the MSF and accommodated the Topsides in five large modules and seven smaller topside-mounted structures.
These design improvements have not only resulted in significant cost savings, but have also enhanced the operation safety of the platform. LOADING & TRANSPORTATION The loading and transportation system will include pipelines connecting the platform to the two offshore loading systems (OLS). They transfer oil from the pipelines to t a n k e r s which will transport Hibernia oil to the market. Each OLS will be capable of loading 55,000 barrels of oil per hour, and of being flushed and filled with water in the event of potential impact by a large iceberg. The size and number of tankers to be used has not yet been finalized. As set out in the development plans, three 120,000-dwt double-hull tankers with a cargo capacity of approximately 900,000 barrels of oil each will be used. Contracts for the tankers and submerged Offshore Loading System are separate from other contracts for the project, and will be directly managed by the Hibernia company.
For additional information on the Hibernia project,will have a deadweight of 5,215 tons. Each propeller will be driven by a MaK engine of 4,500 kW at 500 rpm through a Schelde Gears designed and built propulsion gear. Each gear has an 800 mm horizontal offset between input and output shafts and a built-in quillshaft-mounted, hydraulically operated multi-plate friction clutch. All gear elements, which have single helical teeth and are hobbed, carburized, hardened and ground, run in journal bearings.