Northstar Island
Encyclopedia
Northstar Island is a 5 acres (20,234.3 m²) artificial island
in the Beaufort Sea
, 12 miles (19.3 km) northwest of Prudhoe Bay, Alaska
and 6 miles (9.7 km) north of the Alaska
coast. The island was created to develop the Northstar Oil Pool, which is located approximately 12500 feet (3,810 m) 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, construction of the production island began in the winter of 1999–2000. A standard oil-drilling platform, such as those used in the Gulf of Mexico
, 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 4 feet (1.2 m) above the average waterline and 18 feet (5.5 m) below it.
Because of its distance from shore, no causeway
could be built to the island, unlike with previous projects such as the creation of Endicott Island
. 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
. Through 2000 and 2001, construction continued. In the winter, an ice road
was built across the frozen Beaufort Sea. In the summer, barges brought supplies.
During the first winter of construction, more than 700000 cubic yards (535,188.4 m³) 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. 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 7 feet (2.1 m) 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. 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
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 50000 bbl (7,949.4 m³) per day by June 2002 and 70000 bbl (11,129.1 m³) per day by June 2003. By mid-2006, Northstar had pumped more than 100 Moilbbl of oil. By mid-2007, that figure was more than 120 million. Today, the project is 98.08 percent owned by BP. The remaining 1.92 percent is controlled by Murphy Oil
Co.
Production at Northstar has not always been smooth. In 2003, a transformer
failed and shut down operations for more than a month until a heavy-duty helicopter flew in a new one. 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.
Artificial island
An artificial island or man-made island is an island or archipelago that has been constructed by people rather than formed by natural means...
in the Beaufort Sea
Beaufort Sea
The Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canada's Arctic islands. The sea is named after hydrographer Sir Francis Beaufort...
, 12 miles (19.3 km) northwest of Prudhoe Bay, Alaska
Prudhoe Bay, Alaska
Prudhoe Bay or Sagavanirktok is a census-designated place 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; however, at any given time several thousand transient workers support the Prudhoe Bay oil field...
and 6 miles (9.7 km) north of the Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
coast. The island was created to develop the Northstar Oil Pool, which is located approximately 12500 feet (3,810 m) 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, construction of the production island began in the winter of 1999–2000. A standard oil-drilling platform, such as those used in the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
, 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 4 feet (1.2 m) above the average waterline and 18 feet (5.5 m) below it.
Because of its distance from shore, no causeway
Causeway
In modern usage, a causeway is a road or railway elevated, usually across a broad body of water or wetland.- Etymology :When first used, the word appeared in a form such as “causey way” making clear its derivation from the earlier form “causey”. This word seems to have come from the same source by...
could be built to the island, unlike with previous projects such as the creation of Endicott Island
Endicott Island
Endicott Island is a 45-acre artificial island located in the U.S. state of Alaska, 2.5 miles offshore and 15 miles from Prudhoe Bay of the Beaufort Sea...
. 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
Trans-Alaska Pipeline System
The Trans Alaska Pipeline System , includes the Trans Alaska Pipeline, 11 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one of the world's largest pipeline systems...
. Through 2000 and 2001, construction continued. In the winter, an ice road
Ice road
Ice roads are frozen, human-made structures on the surface of bays, rivers, lakes, or seas in the far north. They link dry land, frozen waterways, portages and winter roads, and are usually remade each winter. Ice roads allow temporary transport to areas with no permanent road access...
was built across the frozen Beaufort Sea. In the summer, barges brought supplies.
During the first winter of construction, more than 700000 cubic yards (535,188.4 m³) 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. 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 7 feet (2.1 m) 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. 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
Greenpeace is a non-governmental environmental organization with offices in over forty countries and with an international coordinating body in Amsterdam, The Netherlands...
activists who occupied the barge for 39 hours in Barrow
Barrow, Alaska
Barrow is the largest city of the North Slope Borough in the U.S. state of Alaska. It is one of the northernmost cities in the world and is the northernmost city in the United States of America, with nearby Point Barrow being the nation's northernmost point. Barrow's population was 4,212 at the...
. 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 50000 bbl (7,949.4 m³) per day by June 2002 and 70000 bbl (11,129.1 m³) per day by June 2003. By mid-2006, Northstar had pumped more than 100 Moilbbl of oil. By mid-2007, that figure was more than 120 million. Today, the project is 98.08 percent owned by BP. The remaining 1.92 percent is controlled by Murphy Oil
Murphy Oil
Murphy Oil Corporation is an international oil and gas company, founded in 1944 as C.H. Murphy & Co by Charle H Murphy Sr., that conducts business through various operating subsidiaries. Murphy produces oil and/or natural gas in the United States, Canada, Malaysia, the United Kingdom and Republic...
Co.
Production at Northstar has not always been smooth. In 2003, a transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
failed and shut down operations for more than a month until a heavy-duty helicopter flew in a new one. 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.