|Publisher||Offshore Technology Conference||Language||English|
|Content Type||Conference Paper|
|Title||Kulluk-An Arctic Exploratory Drilling Unit|
|Authors||K.P. Gaida, J.R. Barnes, and B.D. Wright, Gulf Canada Resources Inc.|
Offshore Technology Conference, 2-5 May 1983, Houston, Texas
|Copyright||1983. Offshore Technology Conference|
This paper describes the design and construction phase of Beau Drill Limited's Arctic Drilling Unit, Ku11uk (Inuit name for "Thunder"). This floating unit is designed to operate in water depths from 24 to 55 meters and incorporates a 24-faceted conical hull which has been ice strengthened to the American Bureau of Shipping lAA Requirements and the Canadian Arctic Shipping Pollution Prevention Act, Arctic Class IV classification. The double hull has an outer diameter of 81 meters at the main deck and is in the form of a inverted cone which causes the ice to break downward and away from the vessel, protecting its drilling riser system and the mooring lines. The unit is not self- propelled but will be towed to each drill site and is moored on-location by twelve radially deployed anchor lines, each having a diameter of 3 1/2 inches. With this unit, Gulf eventually anticipates operation in the Beaufort Sea to be extended significantly. The Kulluk is presently under construction in Japan with a scheduled delivery date of April 1, 1983.
Gulf Canada Resources Inc. has been active in the search for oil and gas in the Canadian Western Arctic since the 1960's with Gulf Canada1s early activity being mainly in the MacKenzie Delta and, more recently, being in the offshore areas of the Beaufort Sea. Gulf is operator for 1.5 million acres of offshore acreage which lies in the southeastern portion of the Beaufort Sea, between 50 and 100 kilometers offshore in water depths ranging between 20 and 55 meters (Insert, Figure 12). In 1980, Gulf decided to accelerate its northern offshore exploration efforts and after assessing all of the options Gulf decided it should build and operate its own drilling system.
Initial offshore exploration was performed off of artificial sand islands built during the summer months. Their use permitted drilling during the winter months and, with sufficient erosion protection l they can be strengthened for year-round drilling. The deepest water depth an island has been built in is 18 meters. This was the island named Issungnak, which required over 4 million cubic meters of dredged material and required two consecutive summers to build. Since 1981, "caisson retained" artificial islands have been utilized in water depths of 23 and 30 meters. These islands consist of an outer concrete, or steel circumferential barrier surrounding a sand filled core. The outer shell provides protection against fill erosion and thus minimizes the total volume of fill required. However, as with sacrificial islands, its economic use is restricted to shallow water depths.
For exploration in deeper water, a total of four conventional drillships have been brought into the Beaufort Sea. During the past five years these vessels have established that the use of a floating drilling system is feasible, but their shipshape design is highly vulnerable to the ice environment.
|File Size||1,510 KB||10|