Класс Месторождения: Уникальное
Тип Месторождения: Нефтегазоконденсатное
Местоположение: Суша/Море
Местность:
Стадия разработки: Добыча
Год открытия: 1968
Источник информации:
Метод открытия:
Площадь: 630.02 км²
Prudhoe Bay Oilfield
The Prudhoe Bay (PBO) field is the largest field in North America and the 18th largest field ever discovered worldwide. Of the 25 billion barrels of original oil in place, more than 13 billion barrels can be recovered with current technology.
Prudhoe Bay field was discovered on March 12, 1968, by ARCO and Exxon with the drilling of the Prudhoe Bay State #1 well. A confirmation well was drilled by BP Exploration in 1969. The next 8 years saw frenetic activity as ARCO, BP, Exxon, and other companies with lease holdings in the vicinity worked to delineate the reservoir, resolve equity participation, and put together an initial infrastructure. Prudhoe Bay came on stream in June 20, 1977, rapidly increasing production until the field’s maximum rate was reached in 1979 at 1.5 million barrels per day. This rate was maintained until early 1989, and is currently declining by 10% per year. Production totaled approximately 475,000 barrels per day on January 1, 2004. More than 10 billion barrels have already been produced.
Prior to 2000 the Prudhoe Bay field was comprised of the East Operating Area, operated by ARCO, and the West Operating Area, operated by BP Exploration. Upon acquisition of ARCO by BP and sale of ARCO Alaska assets to Phillips Petroleum, the two operating areas were consolidated and BP became the sole operator of Greater Prudhoe Bay. Although BP operates the field, a total of nine companies have an interest in the field leases. The profits and costs are shared amongst the owners, according to their ownership.
The Prudhoe Bay Oilfield in northern Alaska was the first developed oilfield in the Arctic, and is the largest in the United States. It is an extremely important asset to the United States and the state of Alaska, containing 16% of US proven reserves of oil and gas (Alaska Oil & Gas Association, 2012; USEIA, 2012). In 2012, taxes on the oil from the Northern Alaska oilfields accounted for over 90% of the Alaska state budget (Alaska Oil & Gas Association, 2012). The PBO is located on the Beaufort Sea coast, halfway between the Canadian border and Point Barrow, a region that was remote and roadless prior to the discovery of oil in March 1968. An extensive infrastructure network quickly grew following the oil discovery, resulting in development within an approximately 2600 km2 area (Fig. 1).
Fig. 1 Alaska North Slope production units that comprise the Prudhoe Bay Oilfield referred to in this article. Major oil production units (red boundaries) and extent of infrastructure. Gray lines are gravel roads, airstrips, and construction pads. Green lines are major pipelines. Small black squares A, B, and C are locations of the detailed 20-km2 map areas of this study. Note the I~nupiat village of Nuiqsut at left in the National Petroleum Reserve Alaska, the Trans-Alaska Pipeline System and Dalton Highway that link the oilfields to southern Alaska. Inset: Location within Alaska. Map courtesy of Aerometric, Inc. and BP Alaska, Inc.
Oilfield engineering evolved rapidly in response to the IRP conditions encountered (Gilders & Cronin, 2000; Orians et al., 2003). Gravel construction pads over 2-m thick were used to insulate the frozen tundra. Since 1995, new technologies, including much closer spacing of the well heads, directional drilling to reach deposits up to 6.4 km from the drilling sites, and reinjection of drilling fluids into the geological formations to eliminate the need for reserve pits, considerably reduced the size of gravel pads for drill sites in newer oilfields. The use of winter ice-roads and roadless access to drill sites have further reduced the footprint of modern oilfields (Gilders & Cronin, 2000; AMAP, 2010; Streever et al.,2011).
The early phase of PBO development stimulated geoecological and permafrost research in the region by the Tundra Biome investigations of the International Biological Programme (Brown, 1975, 1980; Walker et al., 1980); and the Circumpolar Active-Layer Monitoring Program (Brown et al., 2000). Although the oil industry states that the density and extent of the infrastructure of the PBO will likely not be replicated in new oilfields, we focused our studies here because it has the longest history of development and scientific research, and is the only area with detailed time-series of geoecological and historical-change maps that span the complete history of the field. Many of the types of landscape change seen here, such as those associated with roads and climate change, will occur in other IRP areas.
Location
The Prudhoe Bay field is located 650 miles north of Anchorage and 400 miles north of Fairbanks. It is 1200 miles from the North Pole and 250 miles north of the Arctic Circle. Pump Station 1, the beginning of the Trans Alaska Pipeline, is located with in the perimeter of the Prudhoe Bay field.
Geologic Features
The Prudhoe Bay field, like many oil fields, consists of layers of porous rock that contain gas, oil, and water. The water, being the heaviest, lies in the lower rock layers of the field. The oil lies above the water, and the gas rests atop the oil. The oil, gas, and water are held in the Prudhoe Bay field by changes in the rock type (stratigraphy) and by the tilt and faulting of the rock layers. Sandstones are porous and allow the fields’ fluids to flow through them. Shales, however, act as barriers to fluid flow. Thus, whenever a sandstone layer meets a shale layer, either through faulting or as a factor of how the rock was originally deposited, the shale stops the fluid flow and the fluids are trapped.
The oil at Prudhoe Bay is trapped in the Sadlerochit formation, a sandstone and gravel structure nearly 9,000 feet underground. In some locations the oil-bearing sandstone was 600 feet thick during the field’s early life. Today, average thickness of the oil bearing zone is about 60 feet.
Natural gas
The field contains an estimated 46 trillion cubic feet of natural gas (in place) in an overlying gas cap and in solution with the oil. Of that, about 26 trillion cubic feet are classified as recoverable.
Satellite Fields
Since 1998 five satellite fields have been discovered and developed within the unit boundaries of the Prudhoe Bay oil field. These fields are Midnight Sun, Aurora, Orion, Polaris, and Borealis. One of the key objectives of the field’s development has been to maximize sharing of existing infrastructure, including production and support facilities. The production wells for these satellite fields are located on one of the Prudhoe production pads. The liquids are processed through Prudhoe Bay facilities.
Data source: Cumulative geoecological effects of 62 years of infrastructure and climate change in ice-rich permafrost landscapes, Prudhoe Bay Oilfield, Alaska. MARTHA K. RAYNOLDS , DONALD A. WALKER1 , KENNETH J . AMBROSIUS2, JERRY BROWN, KAYE R. EVERETT, MIKHAIL KANEVSKIY, GARY P. KOFINAS, VLADIMIRE . ROMANOVSKY8, YURI SHUR5 and PATRICK J. WEBBER. Global Change Biology (2014) 20, 1211–1224
Fact Sheet Prudhoe Bay. BP, 2006
Следующее Месторождение: Cape Macmillan