Northstar Island is a

artificial island An artificial island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those tha ...

in the

Beaufort Sea The Beaufort Sea (; french: Mer de Beaufort, Iñupiaq: ''Taġiuq'') is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, and west of Canada's Arctic islands. The sea is named after Sir Fr ...

, northwest of

Prudhoe Bay, Alaska Prudhoe Bay is a census-designated place (CDP) located in North Slope Borough in the U.S. state of Alaska. As of the 2010 census, the population of the CDP was 2,174 people, up from just five residents in the 2000 census; however, at any give ...

and north of the

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

coast.Alaska Oil and Gas Conservation Commission
"Northstar Unit, Northstar Oil Pool"
State of Alaska. July 25, 2005. Accessed July 29, 2009. The island was created to develop the Northstar Oil Pool, which is located approximately below the seabed. The oil pool was discovered on January 30, 1984 by Royal Dutch Shell. A small artificial island was built at the site to house an exploration oil well. After additional exploration, Alaska International Construction began construction of the island in the winter of 1999–2000. A standard oil-drilling platform, such as those used in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

, was not feasible because of the annual formation of pack ice close to the northern Alaska coast. A stable, year-round artificial island was the only way to provide the permanent structures needed for a production oil well. To protect against the erosive force of masses of ice, the island's shores were covered in concrete mats that extend above the average waterline and below it. Because of its distance from shore, no

causeway A causeway is a track, road or railway on the upper point of an embankment across "a low, or wet place, or piece of water". It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden causeways is the Sweet Tra ...

could be built to the island, unlike with previous projects such as the creation of

Endicott Island Endicott Island is a artificial island located in the U.S. state of Alaska, 2.5 miles (4 km) offshore and from Prudhoe Bay of the Beaufort Sea. Endicott Island was built in 1987 by Alaska Interstate Construction and is used by BP and Hilc ...

. Northstar Island thus became the first drilling operation in the Beaufort Sea to use a subsea pipeline to transport oil to shore and then into the

Trans-Alaska Pipeline System The Trans-Alaska Pipeline System (TAPS) is an oil transportation system spanning Alaska, including the trans-Alaska crude-oil pipeline, 11 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one of ...

. Through 2000 and 2001, construction continued. In the winter, an

ice road An ice road or ice bridge is a human-made structure that runs on a frozen water surface (a river, a lake or a sea water expanse).Masterson, D. and Løset, S., 2011, ISO 19906: Bearing capacity of ice and ice roads, Proceedings of the 21st Inte ...

was built across the frozen Beaufort Sea. In the summer, barges brought supplies.Murphy, Kim
"Arctic oil pipeline brings out activists, supporters"
''Los Angeles Times''. April 29, 2000. Accessed July 30, 2009. During the first winter of construction, more than of gravel was brought in from the Alaska mainland over ice roads to bring the island above sea level. To reach the seabed, workers had to cut blocks of frozen Beaufort Sea ice and remove them with cranes.Nelson, Kristen
"BP spending three-quarters of a million dollars a day at Northstar"
''Petroleum News''. March 28, 2000. Accessed July 30, 2009. Similar techniques had to be used as workers trenched the seafloor for the three pipelines connecting the island to the shore. The pipes were welded and placed in the trenches more than below the seabed. The trenches were then filled by the special floating backhoes that dug them. Because the Northstar Oil Pool is under high pressure, two pipelines were required: one to take oil away from Northstar, and the other to take natural gas to it to provide pressurization as oil is extracted.Nelson, Kristen
"BP spending three-quarters of a million dollars a day at Northstar"
''Petroleum News''. May 28, 2000. Accessed July 30, 2009. By the time the winter ice melted, the island was above sea level, and both pipelines were in place and tested. In the summer of 2000, an equipment barge arrived at the island with the first modular buildings for the site, but not until a short delay was caused by

Greenpeace Greenpeace is an independent global campaigning network, founded in Canada in 1971 by Irving Stowe and Dorothy Stowe, immigrant environmental activists from the United States. Greenpeace states its goal is to "ensure the ability of the Earth t ...

activists who occupied the barge for 39 hours in Barrow. In October 2000, the first natural gas began to flow to the island to power equipment brought on the barge. The winter of 2000–2001 brought a new ice road and new construction, including the beginning of drilling on the island. The final two barges of modular equipment arrived in summer 2001. When construction was completed, the entire Northstar Island project—including pipelines—cost $686 million. It immediately began to pay off, however. Production began on October 31, 2001, and it exceeded per day by June 2002 and per day by June 2003. By mid-2006, Northstar had pumped more than of oil. By mid-2007, that figure was more than 120 million.Ragsdale, Rose
"30 Strong: Meeting Northstar's challenges"
''Petroleum News''. October 14, 2007. Accessed July 30, 2009. Today, the project is 98.08 percent owned by Hilcorp Alaska, LLC. The remaining 1.92 percent is controlled by

Murphy Oil Murphy Oil Corporation is a company engaged in hydrocarbon exploration headquartered in Houston, Texas. The company is ranked 625th on the Fortune 500 and 1860th on the Forbes Global 2000. As of December 31, 2020, the company had of estimate ...

Co. Production at Northstar has not always been smooth. In 2003, a

transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...

failed and shut down operations for more than a month until a heavy-duty helicopter flew in a new one.Nelson, Kristen
"Both Northstar and Alpine back on line"
''Petroleum News''. December 14, 2003. Accessed July 30, 2009. Specialized leak-detection equipment and sensors had to be developed to prevent problems with the unique undersea pipeline employed by the project in the Beaufort Sea.

References

{{authority control Energy infrastructure completed in 1999 Artificial islands of Alaska Islands of North Slope Borough, Alaska Oil platforms Islands of Alaska BP buildings and structures Petroleum in Alaska 1999 establishments in Alaska