Northstar Island facts for kids
Northstar Island is a small, man-made island in the Beaufort Sea, off the coast of Alaska. It's about 12 miles (19 km) northwest of Prudhoe Bay, Alaska. This island was built to reach a large amount of oil called the Northstar Oil Pool. This oil is found deep under the ocean floor, about 12,500 feet (3,800 meters) down. Royal Dutch Shell first found this oil on January 30, 1984.
Contents
Building Northstar Island
Why an Island?
Building a regular oil platform, like those in the Gulf of Mexico, wouldn't work here. The waters off northern Alaska get very cold, and thick ice forms every year. This ice could damage a normal platform. So, a strong, year-round artificial island was the best way to build the equipment needed to get the oil.
To protect the island from the powerful force of moving ice, its edges were covered with special concrete mats. These mats go about 4 feet (1.2 meters) above the water and 18 feet (5.5 meters) below it. This helps keep the island safe from erosion caused by ice.
Construction Challenges
Because Northstar Island is far from the shore, a bridge or road couldn't be built to it. This was different from earlier projects like Endicott Island. Northstar Island was the first oil operation in the Beaufort Sea to use pipelines under the ocean to move oil to the shore. From there, the oil goes into the Trans-Alaska Pipeline System.
Construction of the island began in the winter of 1999–2000. During winter, workers built an ice road across the frozen Beaufort Sea. In the summer, large boats called barges brought supplies to the island.
Bringing Materials and Laying Pipes
In the first winter, over 700,000 cubic yards (535,000 cubic meters) of gravel were brought from the Alaska mainland using ice roads. This gravel helped raise the island above sea level. To reach the seabed, workers had to cut out huge blocks of frozen ice and lift them with cranes.
Similar methods were used to dig trenches on the seafloor for three pipelines. These pipes connect the island to the shore. They were welded together and placed more than 7 feet (2.1 meters) below the seabed. Special floating machines then filled the trenches. Two pipelines were needed because the Northstar Oil Pool is under high pressure. One pipe carries oil away, and the other brings natural gas to the island. This gas helps keep the pressure right as oil is removed. By the time the winter ice melted, the island was ready, and the pipelines were in place and tested.
Island Operations and Production
Getting Started
In the summer of 2000, a barge arrived with the first buildings for the island. There was a short delay when some Greenpeace activists stayed on the barge for 39 hours in Barrow. In October 2000, natural gas began flowing to the island to power the equipment.
The winter of 2000–2001 brought another ice road and more construction. This included starting the drilling for oil on the island. The last two barges with equipment arrived in the summer of 2001.
Oil Production
The entire Northstar Island project, including the pipelines, cost $686 million. But it quickly started making money. Oil production began on October 31, 2001. By June 2002, it was producing over 50,000 barrels of oil per day. By June 2003, this increased to over 70,000 barrels per day.
By mid-2006, Northstar had pumped more than 100 million barrels of oil. By mid-2007, this number was over 120 million barrels. Today, most of the project (98.08 percent) is owned by Hilcorp Alaska, LLC. The rest (1.92 percent) is controlled by Murphy Oil Co.
Challenges in Production
Oil production at Northstar has faced some challenges. In 2003, a large electrical part called a transformer broke down. This stopped operations for over a month until a new one could be flown in by a heavy-duty helicopter. Special equipment and sensors had to be created to detect leaks in the unique undersea pipeline system used in the Beaufort Sea.
See also
In Spanish: Isla Estrella del Norte para niños
