Oil platform
Overview
 
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

, and to temporarily store product until it can be brought to shore for refining and marketing. In many cases, the platform contains facilities to house the workforce as well.

Depending on the circumstances, the platform may be fixed
Fixed Platform
A fixed platform is a type of offshore platform used for the production of oil or gas. These platforms are built on concrete and/or steel legs anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such platforms are, by virtue of...

 to the ocean floor, may consist of an artificial island
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...

, or may float.

Remote subsea
Subsea
Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...

 wells may also be connected to a platform by flow lines and by umbilical
Umbilical cable
An umbilical cable or umbilical is a cable which supplies required consumables to an apparatus. It is named by analogy with an umbilical cord...

 connections; these subsea solutions may consist of single wells or of a manifold centre for multiple wells.
Around 1891 the first submerged oil wells were drilled from platforms built on piles in the fresh waters of the Grand Lake St. Marys
Grand Lake St. Marys
Grand Lake Saint Marys State Park is an Ohio state park, west of St. Marys, and south-east of Celina, south-west of Lima in the north-western part of the U.S. state of Ohio.Grand Lake covers in Mercer and Auglaize counties...

 (a.k.a.
Encyclopedia
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 and natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

, and to temporarily store product until it can be brought to shore for refining and marketing. In many cases, the platform contains facilities to house the workforce as well.

Depending on the circumstances, the platform may be fixed
Fixed Platform
A fixed platform is a type of offshore platform used for the production of oil or gas. These platforms are built on concrete and/or steel legs anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such platforms are, by virtue of...

 to the ocean floor, may consist of an artificial island
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...

, or may float.

Remote subsea
Subsea
Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...

 wells may also be connected to a platform by flow lines and by umbilical
Umbilical cable
An umbilical cable or umbilical is a cable which supplies required consumables to an apparatus. It is named by analogy with an umbilical cord...

 connections; these subsea solutions may consist of single wells or of a manifold centre for multiple wells.

History

Around 1891 the first submerged oil wells were drilled from platforms built on piles in the fresh waters of the Grand Lake St. Marys
Grand Lake St. Marys
Grand Lake Saint Marys State Park is an Ohio state park, west of St. Marys, and south-east of Celina, south-west of Lima in the north-western part of the U.S. state of Ohio.Grand Lake covers in Mercer and Auglaize counties...

 (a.k.a. Mercer County Reservoir) in Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

. The wide but shallow reservoir was built from 1837 to 1845 to provide water to the Miami and Erie Canal
Miami and Erie Canal
The Miami and Erie Canal was a canal that connected the Ohio River in Cincinnati, Ohio with Lake Erie in Toledo, Ohio. Construction on the canal began in 1825 and was completed in 1845. It consisted of 19 aqueducts, three guard locks, and 103 canal locks. Each lock measured by and they...

.

Around 1896 the first submerged oil wells in salt water were drilled in the portion of the Summerland field
Summerland Oil Field
The Summerland Oil Field is an inactive oil field in Santa Barbara County, California, about four miles east of the city of Santa Barbara, within and next to the unincorporated community of Summerland...

 extending under the Santa Barbara Channel
Santa Barbara Channel
The Santa Barbara Channel is a portion of the Pacific Ocean which separates the mainland of California from the northern Channel Islands. It is generally south of the city of Santa Barbara, and west of the city of Ventura....

 in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. The wells were drilled from piers extending from land out into the channel.

Other notable early submerged drilling activities occurred on the Canadian side of Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

 in the 1900s and Caddo Lake
Caddo Lake
Caddo Lake is a lake and wetland located on the border between Texas and Louisiana, in northern Harrison County and southern Marion County in Texas and western Caddo Parish in Louisiana. The lake is named after the Southeastern culture of Native Americans called Caddoans or Caddo, who lived in...

 in Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

 in the 1910s. Shortly thereafter, wells were drilled in tidal zones along the Gulf Coast
Gulf Coast of the United States
The Gulf Coast of the United States, sometimes referred to as the Gulf South, South Coast, or 3rd Coast, comprises the coasts of American states that are on the Gulf of Mexico, which includes Texas, Louisiana, Mississippi, Alabama, and Florida and are known as the Gulf States...

 of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 and Louisiana. The Goose Creek field
Goose Creek Oil Field
The Goose Creek Oil Field is a large oil field in Baytown, Texas, on Galveston Bay. Discovered in 1903, and reaching maximum production in 1918 after a series of spectacular gushers, it was one of the fields which contributed to the Texas Oil Boom of the early 20th century...

 near Baytown, Texas
Baytown, Texas
Baytown is a city within Harris County and partially in Chambers County in the Gulf Coast region of the U.S. state of Texas. Located within the Houston–Sugar Land–Baytown metropolitan area, it lies along both State Highway 146 and Interstate 10. As of 2010, Baytown had an population of 71,802...

 is one such example. In the 1920s drilling was done from concrete platforms in Lake Maracaibo
Lake Maracaibo
Lake Maracaibo is a large brackish bay in Venezuela at . It is connected to the Gulf of Venezuela by Tablazo Strait at the northern end, and fed by numerous rivers, the largest being the Catatumbo. It is commonly considered a lake rather than a bay or lagoon, and at 13,210 km² it would be the...

, Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

.

The oldest subsea well recorded in Infield's offshore database is the Bibi Eibat well which came on stream in 1923 in Azerbaijan
Azerbaijan
Azerbaijan , officially the Republic of Azerbaijan is the largest country in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west, and Iran to...

. Landfill was used to raise shallow portions of the Caspian Sea
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

.

In the early 1930s the Texas Company
Texaco
Texaco is the name of an American oil retail brand. Its flagship product is its fuel "Texaco with Techron". It also owns the Havoline motor oil brand....

 developed the first mobile steel barges for drilling in the brackish coastal areas of the gulf.

In 1937 Pure Oil Company (now part of Chevron Corporation
Chevron Corporation
Chevron Corporation is an American multinational energy corporation headquartered in San Ramon, California, United States and active in more than 180 countries. It is engaged in every aspect of the oil, gas, and geothermal energy industries, including exploration and production; refining,...

) and its partner Superior Oil Company
Superior Oil Company
Superior Oil Company was an independent American oil company that is now part of ExxonMobil. Superior Oil was founded in 1921 in Coalinga, California by William Myron Keck, also founder of the W. M. Keck Foundation....

 (now part of ExxonMobil Corporation) used a fixed platform to develop a field in 14 feet (4.3 m) of water, one mile (1.6 km) offshore of Calcasieu Parish, Louisiana
Calcasieu Parish, Louisiana
Calcasieu Parish[p] is a parish located in the U.S. state of Louisiana. The parish seat is Lake Charles. As of 2010, the parish population was 192,768...

.

In 1946, Magnolia Petroleum Company
Magnolia Petroleum Company
The Magnolia Petroleum Company was an early twentieth century petroleum company in Texas and was founded on April 24, 1911 as a consolidation of several earlier companies. Standard Oil of New York exchanged its stock for all of the Magnolia stock in December 1925 though it continued to operate as...

 (now part of ExxonMobil) erected a drilling platform in 18 ft (5.5 m) of water, 18 miles off the coast of St. Mary Parish, Louisiana
St. Mary Parish, Louisiana
St. Mary Parish is a parish located in the U.S. state of Louisiana. The parish seat is Franklin. As of 2000, the population was 53,500.The Morgan City Micropolitan Statistical Area includes all of St. Mary Parish.-Geography:...

.

In early 1947 Superior Oil erected a drilling/production platform in 20 ft (6.1 m) of water some 18 miles off Vermilion Parish, Louisiana
Vermilion Parish, Louisiana
Vermilion Parish is a parish located in the U.S. state of Louisiana. The parish seat is Abbeville. As of the 2010 census, the population was 57,999....

. But it was Kerr-McGee
Kerr-McGee
The Kerr-McGee Corporation, founded in 1929, was an energy company involved in the exploration and production of oil and gas. On June 23, 2006, Houston-based Anadarko Petroleum Corporation agreed to acquire Kerr-McGee in an all-cash transaction totaling $16.5 billion plus the assumption of $2.6...

 Oil Industries (now Anadarko Petroleum Corporation
Anadarko Petroleum Corporation
Anadarko Petroleum Corporation is one of the world’s largest independent oil and gas exploration and production companies, with approximately 2.3 billion barrels of oil equivalent of proved reserves and production of 206 million BOE as of December 31, 2008. Anadarko employs a worldwide...

), as operator for partners Phillips Petroleum
Phillips Petroleum
Phillips Petroleum Company was founded in 1917 by L.E. Phillips and Frank Phillips, of Bartlesville, Oklahoma. Their younger brother Waite Phillips was the benefactor of Philmont Scout Ranch....

 (ConocoPhillips
ConocoPhillips
ConocoPhillips Company is an American multinational energy corporation with its headquarters located in the Energy Corridor district of Houston, Texas in the United States...

) and Stanolind Oil & Gas (BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...

), that completed its historic Ship Shoal Block 32 well in October 1947, months before Superior actually drilled a discovery from their Vermilion platform farther offshore. In any case, that made Kerr-McGee's well the first oil discovery drilled out of sight of land.

The Thames Sea Forts
Maunsell Forts
The Maunsell Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom. They were named after their designer, Guy Maunsell. The forts were decommissioned in the late 1950s and later used for other activities...

 of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 are considered the direct predecessors of modern offshore platforms. Having been pre-constructed in a very short time, they were then floated to their location and placed on the shallow bottom of the Thames estuary.

Types

Larger lake- and sea-based offshore platforms and drilling rig
Drilling rig
A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...

s are some of the largest moveable man-made structures in the world. There are several types of oil platforms and rigs:

Fixed platforms

These platforms are built on concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

 or steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 legs, or both, anchored directly onto the seabed, supporting a deck with space for drilling rigs, production facilities and crew quarters. Such platforms are, by virtue of their immobility, designed for very long term use (for instance the Hibernia platform
Hibernia (oil field)
Hibernia is an oil field in the North Atlantic Ocean, approximately east-southeast of St. John's, Newfoundland, Canada.The production platform Hibernia is the world's largest oil platform and consists of a 37,000-tonne integrated topsides facility mounted on a 600,000-tonne gravity base structure...

). Various types of structure are used, steel jacket, concrete caisson
Caisson (engineering)
In geotechnical engineering, a caisson is a retaining, watertight structure used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, or for the repair of ships. These are constructed such that the water can be pumped out, keeping the working...

, floating steel and even floating concrete
Offshore concrete structure
Offshore concrete structures have been in use successfully for about 30 years. They serve the same purpose as their steel counterparts in the oil and gas production and storage. The first concrete oil platform has been installed in the North Sea in the Ekofisk field in 1973 by Phillips Petroleum...

. Steel jackets are vertical sections made of tubular steel members, and are usually piled into the seabed. Concrete caisson structures
Offshore concrete structure
Offshore concrete structures have been in use successfully for about 30 years. They serve the same purpose as their steel counterparts in the oil and gas production and storage. The first concrete oil platform has been installed in the North Sea in the Ekofisk field in 1973 by Phillips Petroleum...

, pioneered by the Condeep
Condeep
Condeep refers to a make of gravity base structure for oil platforms developed and fabricated by Norwegian Contractors in Stavanger, Norway. A Condeep usually consists of a base of concrete oil storage tanks from which one, three or four concrete shafts rise...

 concept, often have in-built oil storage in tanks below the sea surface and these tanks were often used as a flotation capability, allowing them to be built close to shore (Norwegian
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 fjord
Fjord
Geologically, a fjord is a long, narrow inlet with steep sides or cliffs, created in a valley carved by glacial activity.-Formation:A fjord is formed when a glacier cuts a U-shaped valley by abrasion of the surrounding bedrock. Glacial melting is accompanied by rebound of Earth's crust as the ice...

s and Scottish
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 firth
Firth
Firth is the word in the Lowland Scots language and in English used to denote various coastal waters in Scotland and England. In mainland Scotland it is used to describe a large sea bay, or even a strait. In the Northern Isles it more usually refers to a smaller inlet...

s are popular because they are sheltered and deep enough) and then floated to their final position where they are sunk to the seabed. Fixed platforms are economically feasible for installation in water depths up to about 1700 ft (518.2 m).

Compliant towers

These platforms consist of slender flexible towers and a pile foundation supporting a conventional deck for drilling and production operations. Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1500 to 3000 ft (457.2 to 914.4 ).

Semi-submersible platform

These platforms have hulls (columns and pontoons) of sufficient buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 to cause the structure to float, but of weight sufficient to keep the structure upright. Semi-submersible platforms can be moved from place to place; can be ballasted up or down by altering the amount of flooding in buoyancy tanks; they are generally anchored by combinations of chain, wire rope or polyester rope, or both, during drilling or production operations, or both, though they can also be kept in place by the use of dynamic positioning
Dynamic positioning
Dynamic positioning is a computer controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters...

. Semi-submersibles can be used in water depths from 200 foot.

Jack-up drilling rigs

Jack-up Mobile Drilling Units (or jack-ups), as the name suggests, are rigs that can be jacked up above the sea using legs that can be lowered, much like jacks. These MODUs (Mobile Offshore Drilling Units) are typically used in water depths up to 400 feet (121.9 m), although some designs can go to 550 ft (167.6 m) depth. They are designed to move from place to place, and then anchor themselves by deploying the legs to the ocean bottom using a rack and pinion
Rack and pinion
A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. A circular gear called "the pinion" engages teeth on a linear "gear" bar called "the rack"; rotational motion applied to the pinion causes the rack to move, thereby...

 gear system on each leg.

Drillships

A drillship is a maritime vessel that has been fitted with drilling apparatus. It is most often used for exploratory drilling of new oil or gas wells in deep water but can also be used for scientific drilling. Early versions were built on a modified tanker hull, but purpose-built designs are used today. Most drillships are outfitted with a dynamic positioning
Dynamic positioning
Dynamic positioning is a computer controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters...

 system to maintain position over the well. They can drill in water depths up to 12000 ft (3,657.6 m).

Floating production systems

The main types of floating production systems are FPSO (floating production, storage, and offloading system)
Floating Production Storage and Offloading
A floating production, storage and offloading unit is a floating vessel used by the offshore industry for the processing of hydrocarbons and for storage of oil. A FPSO vessel is designed to receive hydrocarbons produced from nearby platforms or subsea template, process them, and store oil until it...

. FPSOs consist of large monohull structures, generally (but not always) shipshaped, equipped with processing facilities. These platforms are moored to a location for extended periods, and do not actually drill for oil or gas. Some variants of these applications, called FSO (floating storage and offloading system) or FSU (floating storage unit), are used exclusively for storage purposes, and host very little process equipment.

The world's first Floating Liquefied Natural Gas (FLNG) facility is currently under development. See the section on Particularly large examples below.

Tension-leg platform

TLPs are floating platforms tethered to the seabed in a manner that eliminates most vertical movement of the structure. TLPs are used in water depths up to about 6,000 feet (2,000 m). The "conventional" TLP is a 4-column design which looks similar to a semisubmersible. Proprietary versions include the Seastar and MOSES mini TLPs; they are relatively low cost, used in water depths between 600 and 4300 ft (182.9 and 1,310.6 ). Mini TLPs can also be used as utility, satellite or early production platforms for larger deepwater discoveries.

Gravity-based structure

A GBS can either be steel or concrete and is usually anchored directly onto the seabed. Steel GBS are predominantly used when there is no or limited availability of crane barges to install a conventional fixed offshore platform, for example in the Caspian Sea. There are several steel GBS in the world today (e.g. offshore Turkmenistan Waters (Caspian Sea) and offshore New Zealand). Steel GBS do not usually provide hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

 storage capability. It is mainly installed by pulling it off the yard, by either wet-tow or/and dry-tow, and self-installing by controlled ballasting of the compartments with sea water. To position the GBS during installation, the GBS may be connected to either a transportation barge or any other barge (provided it is large enough to support the GBS) using strand jacks. The jacks shall be released gradually whilst the GBS is ballasted to ensure that the GBS does not sway too much from target location.

Spar platforms


Spars are moored to the seabed like TLPs, but whereas a TLP has vertical tension tethers, a spar has more conventional mooring lines. Spars have to-date been designed in three configurations: the "conventional" one-piece cylindrical hull, the "truss spar" where the midsection is composed of truss elements connecting the upper buoyant hull (called a hard tank) with the bottom soft tank containing permanent ballast, and the "cell spar" which is built from multiple vertical cylinders. The spar has more inherent stability than a TLP since it has a large counterweight at the bottom and does not depend on the mooring to hold it upright. It also has the ability, by adjusting the mooring line tensions (using chain-jacks attached to the mooring lines), to move horizontally and to position itself over wells at some distance from the main platform location. The first production spar was Kerr-McGee's Neptune, anchored in 1930 ft (588.3 m) in the Gulf of Mexico; however, spars (such as Brent Spar
Brent Spar
Brent Spar or Brent E, was a North Sea oil storage and tanker loading buoy in the Brent oilfield, operated by Shell UK. With the completion of a pipeline connection to the oil terminal at Sullom Voe in Shetland, the storage facility had continued in use but was considered to be of no further value...

) were previously used as FSOs.

Eni
Eni
Eni S.p.A. is an Italian multinational oil and gas company, present in 70 countries, and currently Italy's largest industrial company with a market capitalization of 87.7 billion euros , as of July 24, 2008...

's Devil's Tower
Devil's Tower (oil platform)
Devil's Tower is a deep-water oil and gas production Spar oil platform located in the Gulf of Mexico and named after Devils Tower National Monument.Devil's Tower is located in block 773 of the Mississippi Canyon region of the Gulf of Mexico...

 located in 5610 ft (1,709.9 m) of water, in the Gulf of Mexico, was the world's deepest spar until 2010. The world's deepest platform is currently the Perdido spar in the Gulf of Mexico, floating in 2,438 meters of water. It is operated by Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...

 and was built at a cost of $3 billion.

The first truss spars were Kerr-McGee's Boomvang and Nansen.
The first (and only) cell spar is Kerr-McGee's Red Hawk.

Normally unmanned installations (NUI)

These installations (sometimes called toadstools) are small platforms, consisting of little more than a well bay
Well bay
A well bay is an area of an oil platform where the Christmas trees and wellheads are located. It normally consists of two levels, a lower where the wellheads are accessed and an upper where the Xmas Trees are accessed often along with the various well control panels, which will have pressure...

, helipad
Helipad
Helipad is a common abbreviation for helicopter landing pad, a landing area for helicopters. While helicopters are able to operate on a variety of relatively flat surfaces, a fabricated helipad provides a clearly marked hard surface away from obstacles where a helicopter can safely...

 and emergency shelter. They are designed to be operated remotely under normal conditions, only to be visited occasionally for routine maintenance or well work.

Conductor support systems

These installations, also known as satellite platforms, are small unmanned platforms consisting of little more than a well bay
Well bay
A well bay is an area of an oil platform where the Christmas trees and wellheads are located. It normally consists of two levels, a lower where the wellheads are accessed and an upper where the Xmas Trees are accessed often along with the various well control panels, which will have pressure...

 and a small process plant. They are designed to operate in conjunction with a static production platform which is connected to the platform by flow lines or by umbilical cable
Umbilical cable
An umbilical cable or umbilical is a cable which supplies required consumables to an apparatus. It is named by analogy with an umbilical cord...

, or both.

Particularly large examples

The Petronius Platform
Petronius Platform
Petronius is a deepwater compliant tower oil platform operated by Chevron Corporation and Marathon Oil in the Gulf of Mexico, 210 km southeast of New Orleans, United States....

 is a compliant tower 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...

, which stands 2000 feet (609.6 m) above the ocean floor. It is one of the world's tallest structures.

The Hibernia platform in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 is the world's largest (in terms of weight) offshore platform, located on the Jeanne D'Arc basin, in the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 off the coast of Newfoundland
Newfoundland and Labrador
Newfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400...

. This gravity base structure
Gravity base structure
A gravity-based structure is a support structure held in place by gravity. A common application for a GBS is an offshore oil platform. These structures are often constructed in fjords since their protected area and sufficient depth are very desirable for construction...

(GBS), which sits on the ocean floor, is 364 feet (110.9 m) high and has storage capacity for 1.3 Moilbbl of crude oil in its 278.8 feet (85 m) high caisson. The platform acts as a small concrete island with serrated outer edges designed to withstand the impact of an iceberg
Iceberg
An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice...

. The GBS contains production storage tanks and the remainder of the void space is filled with ballast with the entire structure weighing in at 1.2 million ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...

s.

Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...

 is currently developing the first Floating Liquefied Natural Gas (FLNG) facility, which will be situated approximately 200km off the coast of Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

 and is due for completion around 2017. When finished, it will be the largest floating offshore facility. It is expected to be approximately 488m long and 74m wide with displacement
Displacement (ship)
A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...

 of around 600,000t when fully ballasted.

Maintenance and supply

A typical oil production platform is self-sufficient in energy and water needs, housing electrical generation, water desalinators and all of the equipment necessary to process oil and gas such that it can be either delivered directly onshore by pipeline or to a floating platform
Floating Production Storage and Offloading
A floating production, storage and offloading unit is a floating vessel used by the offshore industry for the processing of hydrocarbons and for storage of oil. A FPSO vessel is designed to receive hydrocarbons produced from nearby platforms or subsea template, process them, and store oil until it...

 or tanker loading facility, or both. Elements in the oil/gas production process include wellhead
Wellhead
A wellhead is a general term used to describe the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment....

, production manifold, production separator, glycol process to dry gas, gas compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...

s, water injection pumps
Water injection (oil production)
Water injection refers to the method in oil industry where water is injected back into the reservoir, usually to increase pressure and thereby stimulate production. Water injection wells can be found both on- and offshore, to increase oil recovery from an existing reservoir...

, oil/gas export metering and main oil line pumps.

Larger platforms assisted by smaller ESVs (emergency support vessels) like the British
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 Iolair
Iolair
Iolair is a specialised semi-submersible offshore platform designed for BP to support and service oil platforms in the North Sea and served as an emergency support vessel in the Forties Oil Field...

 that are summoned when something has gone wrong, e.g. when a search and rescue
Search and rescue
Search and rescue is the search for and provision of aid to people who are in distress or imminent danger.The general field of search and rescue includes many specialty sub-fields, mostly based upon terrain considerations...

 operation is required. During normal operations, PSVs
Platform supply vessel
A Platform supply vessel is a ship specially designed to supply offshore oil platforms. These ships range from 20 to 100 meters in length and accomplish a variety of tasks...

 (platform supply vessels) keep the platforms provisioned and supplied, and AHTS vessels
Anchor handling tug supply vessel
Anchor Handling Tug Supply vessels are mainly built to handle anchors for oil rigs, tow them to location, anchor them up and, in a few cases, serve as an Emergency Rescue and Recovery Vessel ....

 can also supply them, as well as tow them to location and serve as standby rescue and firefighting vessels.

Essential personnel

Not all of the following personnel are present on every platform. On smaller platforms, one worker can perform a number of different jobs. The following also are not names officially recognized in the industry:
  • OIM (offshore installation manager)
    OIM (offshore installation manager)
    The Offshore Installation Manager is the most senior manager of an offshore platform operating on the UKCS.Many offshore operators have adopted this UK offshore management model and title and applied it to their operations in all global regions irrespective of the local regulations in force.In the...

     who is the ultimate authority during his/her shift and makes the essential decisions regarding the operation of the platform;
  • operations team leader (OTL);
  • offshore operations engineer (OOE) who is the senior technical authority on the platform;
  • PSTL or operations coordinator for managing crew changes;
  • dynamic positioning operator, navigation, ship or vessel maneuvering (MODU), station keeping, fire and gas systems operations in the event of incident;
  • automation systems specialist, to configure, maintain and troubleshoot the process control systems (DCS), process safety systems, emergency support systems and vessel management systems;
  • second mate to meet manning requirements of flag state, operates fast rescue craft, cargo operations, fire team leader;
  • third mate to meet manning requirements of flag state, operate fast rescue craft, cargo operations, fire team leader;
  • ballast control operator to operate fire and gas systems;
  • crane operators to operate the cranes for lifting cargo around the platform and between boats;
  • scaffolders to rig up scaffolding for when it is required for workers to work at height;
  • coxswains to maintain the lifeboats and manning them if necessary;
  • control room operators, especially FPSO or production platforms;
  • catering crew, including people tasked with performing essential functions such as cooking, laundry and cleaning the accommodation;
  • production techs to run the production plant;
  • helicopter
    Helicopter
    A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

     pilot
    Aviator
    An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...

    (s) living on some platforms that have a helicopter based offshore and transporting workers to other platforms or to shore on crew changes;
  • maintenance technicians (instrument, electrical or mechanical).

Incidental personnel

Drill crew will be on board if the installation is performing drilling operations. A drill crew will normally comprise:
  • Toolpusher
  • Driller
    Driller (oil)
    The driller is a team leader in charge during the process of well drilling. The term is commonly used in the context of an oil well drilling rig....

  • Roughneck
    Roughneck
    Roughneck is a slang term for a person whose occupation is hard-manual labour, typically in a dangerous working environment. The term applies across a number of industries, but is most commonly associated with oil rigs...

    s
  • Roustabout
    Roustabout
    A roustabout is a labourer typically performing temporary, unskilled work. The term has traditionally been used to refer to traveling-circus workers, natural gas, or oil rig workers....

    s
  • Company man
    Company man
    A company man in the petroleum industry refers to a representative of an operating/exploration company. Other terms that may be used are company representative, foreman, drilling engineer, company consultant, rigsite leader or "well site manager".In a normal scenario, gas/oil-drilling companies...

  • Mud engineer
    Mud engineer
    A mud engineer works on an oil well or gas well drilling rig, and is responsible ensuring the properties of the drilling fluid, also known as drilling mud, are within designed specifications.-Use of mud:Mud is a vital part of drilling operations...

  • Derrickhand
    Derrickhand
    The Derrickhand or Derrickman position varies greatly from one drilling rig to another. He almost always reports directly to the driller. The name derrickman comes from the position that he normally occupies, which is at the top of the derrick...

  • Geologist
    Geologist
    A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...


Well services
Well services
Well services is a department within a petroleum production company through which matters concerning existing wells are handled. Having a shared well services department for all assets operated by a company is seen as advantageous as it allows the pooling of talent, experience and resources for...

 crew will be on board for well work. The crew will normally comprise:
  • Well services supervisor
  • Wireline or coiled tubing operators
  • Pump operator

Risks

The nature of their operation — extraction of volatile substances sometimes under extreme pressure in a hostile environment — means risk; accidents and tragedies occur regularly. The U.S. Minerals Management Service
Minerals Management Service
The Bureau of Ocean Energy Management, Regulation and Enforcement , formerly known as the Minerals Management Service , was an agency of the United States Department of the Interior that managed the nation's natural gas, oil and other mineral resources on the outer continental shelf...

 reported 69 offshore deaths, 1,349 injuries, and 858 fires and explosions on offshore rigs in the Gulf of Mexico from 2001 to 2010. In July 1988, 167 people died when Occidental Petroleum
Occidental Petroleum
Occidental Petroleum Corporation is a California-based oil and gas exploration and production company with operations in the United States, the Middle East, North Africa, and South America...

's Piper Alpha
Piper Alpha
Piper Alpha was a North Sea oil production platform operated by Occidental Petroleum Ltd. The platform began production in 1976, first as an oil platform and then later converted to gas production. An explosion and resulting fire destroyed it on 6 July 1988, killing 167 men, with only 61...

 offshore production platform, on the Piper field in the UK sector of the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

, exploded after a gas leak. The resulting investigation conducted by Lord Cullen and publicized in the first Cullen Report was highly critical of a number of areas, including, but not limited to, management within the company, the design of the structure, and the Permit to Work System. The report was commissioned in 1988, and was delivered November 1990. The accident greatly accelerated the practice of providing living accommodations on separate platforms, away from those used for extraction.

However, this was in itself a hazardous environment. In March 1980, the 'flotel
Flotel
Flotel, a portmanteau of the terms floating hotel, refers to the installation of living quarters on top of rafts or semi-submersible platforms...

' (floating hotel) platform Alexander L. Kielland capsized in a storm in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 with the loss of 123 lives.

In 2001, Petrobras 36 in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

 exploded and sank five days later, killing 11 people.

Given the number of grievances and conspiracy theories that involve the oil business, and the importance of gas/oil platforms to the economy, platforms in the United States are believed to be potential terrorist targets. Agencies and military units responsible for maritime counterterrorism in the US (Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

, Navy SEALs, Marine Recon
United States Marine Corps Force Reconnaissance
The Force Reconnaissance Companies , are one of the United States Marine Corps's special operations "capable" forces that provide essential elements of military intelligence to the command element of the Marine Air-Ground Task Force ; supporting the landing or joint task force commanders, and...

) often train for platform raids.

On April 21, 2010, the Deepwater Horizon
Deepwater Horizon
Deepwater Horizon was an ultra-deepwater, dynamically positioned, semi-submersible offshore oil drilling rig owned by Transocean. Built in 2001 in South Korea by Hyundai Heavy Industries, the rig was commissioned by R&B Falcon, which later became part of Transocean, registered in Majuro, Marshall...

platform, 52 miles
Nautical mile
The nautical mile is a unit of length that is about one minute of arc of latitude along any meridian, but is approximately one minute of arc of longitude only at the equator...

 off-shore of Venice, Louisiana
Venice, Louisiana
Venice is an unincorporated community in Plaquemines Parish, Louisiana, United States. It is 130 km south of New Orleans on the west bank of the Mississippi River at . It is the last community down the Mississippi accessible by automobile, and is the southern terminus of the Great River Road...

, (property of Transocean
Transocean
Transocean Ltd. is one of the world's largest offshore drilling contractors. The company rents floating mobile drill rigs, along with the equipment and personnel for operations, to oil and gas companies at an average daily rate of US$282,700...

 and leased to BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...

) exploded
Deepwater Horizon oil spill
The Deepwater Horizon oil spill is an oil spill in the Gulf of Mexico which flowed unabated for three months in 2010, and continues to leak fresh oil. It is the largest accidental marine oil spill in the history of the petroleum industry...

, killing 11 people, and sank two days later. The resulting undersea gusher, conservatively estimated to exceed 20 million USgals (75,708.2 m³) as of early June, 2010, became the worst oil spill in US history, eclipsing the Exxon Valdez oil spill
Exxon Valdez oil spill
The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24, 1989, when the Exxon Valdez, an oil tanker bound for Long Beach, California, struck Prince William Sound's Bligh Reef and spilled of crude oil. It is considered to be one of the most devastating human-caused...

.

Ecological effects

In British waters, the cost of removing all platform rig structures entirely was estimated in 1995 at £1.5 billion, and the cost of removing all structures including pipelines—called a "clean sea" approach—at £3 billion.

In the United States, Marine Biologist Milton Love has proposed that oil platforms off the California coast be retained as artificial reef
Artificial reef
An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block ship passage, or improve surfing....

s, instead of being dismantled (at great cost), because he has found them to be havens for many of the species of fish which are otherwise declining in the region, in the course of 11 years of research. Love is funded mainly by government agencies, but also in small part by the California Artificial Reef Enhancement Program. NOAA has said it is considering this course of action, but wants money to study the effects of the rigs in detail. Divers have been used to assess the fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 populations surrounding the platforms. 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...

, more than 200 platforms have been similarly converted.

Deepest oil platforms

The world's deepest oil platform is the floating Perdido which is a spar platform in the Gulf of Mexico in a water depth of 2438 metres (7,998.7 ft).

Non-floating compliant towers and fixed platforms, by water depth:
  • Petronius Platform
    Petronius Platform
    Petronius is a deepwater compliant tower oil platform operated by Chevron Corporation and Marathon Oil in the Gulf of Mexico, 210 km southeast of New Orleans, United States....

    , 531 m (1,742.1 ft)
  • Baldpate Platform, 502 m (1,647 ft)
  • Bullwinkle Platform, 413 m (1,355 ft)
  • Pompano Platform, 393 m (1,289.4 ft)
  • Benguela-Belize Lobito-Tomboco Platform, 390 m (1,279.5 ft)
  • Tombua Landana Platform, 366 m (1,200.8 ft)
  • Harmony Platform, 366 m (1,200.8 ft)
  • Troll A Platform, 303 m (994.1 ft)
  • Gulfaks C Platform, 217 m (711.9 ft)

See also

  • North Sea oil
    North Sea oil
    North Sea oil is a mixture of hydrocarbons, comprising liquid oil and natural gas, produced from oil reservoirs beneath the North Sea.In the oil industry, the term "North Sea" often includes areas such as the Norwegian Sea and the area known as "West of Shetland", "the Atlantic Frontier" or "the...

  • Rigs-to-Reefs
    Rigs-to-Reefs
    Rigs-to-Reefs is a nationwide program developed by the Minerals Management Service of the U.S. Department of the Interior to turn decommissioned offshore oil and petroleum rigs into artificial reefs.-Overview:...

  • SAR201
    SAR201
    Saudi Aramco Rig 201 is the only offshore rig owned by Saudi Aramco, the largest oil company in the world in terms of production and proven reserves....

  • TEMPSC
    TEMPSC
    TEMPSC is an acronym for "Totally Enclosed Motor Propelled Survival Craft". It is a form of lifeboat typically installed on seagoing vessels, oil platforms or floating installations related to the oil and gas industry for the evacuation of passengers or personnel on board...

  • Texas Towers
    Texas Towers
    The Texas Towers were a set of off-shore radar facilities used by the United States Air Force during the Cold War that were modeled on the offshore oil drilling platforms first employed off the Texas coast...

  • US offshore drilling debate
  • Offshore concrete structure
    Offshore concrete structure
    Offshore concrete structures have been in use successfully for about 30 years. They serve the same purpose as their steel counterparts in the oil and gas production and storage. The first concrete oil platform has been installed in the North Sea in the Ekofisk field in 1973 by Phillips Petroleum...

  • Offshore drilling
    Offshore drilling
    Offshore drilling refers to a mechanical process where a wellbore is drilled through the seabed. It is typically carried out in order to explore for and subsequently produce hydrocarbons which lie in rock formations beneath the seabed...

  • The Chukchi Cap
    Chukchi Cap
    The Chukchi Cap is a large undersea ridge in the Arctic Ocean.The cap is normally ice-covered, year-round.The United States Coast Guard Cutter Healy has been sent on multiple missions to map the poorly explored ridge....


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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