An exploratory well was drilled by Union Oil Company of California from a grounded ice island constructed in the Beaufort Sea. The ice island was 60 km west of Prudhoe Bay, Alaska, 3 km offshore, in 3 m of water.

Operations commenced in November, 1976, and terminated in April 1977.Project cost was $8 000 000. The ice island melted by mid July, 1977.

Grounded ice islands can be used in arctic areas of shallow water and little pack ice movement. They are environmentally acceptable and economically feasible.


During the winter of 1976–77, an exploratory well was drilled from agrounded ice island. The purpose of the island was to form a base for the purpose of the island was to form a base for the drilling rig. The well, East Harrison Bay State No. 1, was 60 km west of Prudhoe Bay, Alaska, 3 km offshore in 3 m of water. It was 16 km from the mouth of the Colville River and in Harrison Bay.

The island consisted of a grounded rectangular drill pad enclosed by agrounded ring. The camp was supported by the natural ice between the pad and ring. Outside of the ring was an ice free moat (Fig. 2).


The north slope of Alaska is an arctic desert receiving only 15 cm/year of precipitation. It is bounded on the north by the Beaufort Sea. The sea in this area freezes over in October and breakup is in July. Coastal currents are 0.9km/h and the 0.2 m tides are small. Seawater temperature varies from -2 degrees C to 5 degrees C. Walrus, seals, whales, fish, seabirds, polar bears, whitefoxes and caribou abide in the area.

In the winter, the sun never rises for fifty days and in the summer it neversets for fifty days. The temperature extremes are -50 degrees C to 20 degrees C. Winds occur up to 150 km/h. Blowing snow is a winter problem and in summerfog occurs frequently. Intense problem and in summer fog occurs frequently. Intense storms are sudden and last two to five days. The prevailing winds at the location are from the prevailing winds at the location are from the northeast.

The Colville River, which is 600 km long, is the largest and longest river on the north slope of Alaska. In winter it has little flow but during breakup and in the summer months it has significant discharge into Harrison Bay (Fig. 4- Picture taken July, 1977).


Personnel, equipment, supplies, and fuel were brought to the project by air using seventeen different types of planes.

An 1800 m × 60 m airfield was constructed on the natural sea ice 1.6 km east of the ice island. The island and airfield were connected by an ice road (Fig.5). The ice road and airfield were built by scraping away the snow, then smoothing the surface by spraying it with water and allowing the water to freeze. By mid January, the weather had been cold enough to make ice 1.4 m thick in 3 m of water. This minimum ice thickness was necessary to support the big 4-engine Hercules aircraft which carry 20 000 kg. These aircraft flew 338trips to and from the ice island (Fig. 6). Trips were from Anchorage, Fairbanks and Prudhoe Bay, Alaska.


Loads that were too heavy for airlift (crane and D-8 dozer) were trucked from land over an ice road to the island. Some roads crossed a pressure ridgein the sea ice and an ice bridge was constructed to span the gap across the 2 m high ridge.

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