Oil platform


An oil platform, also called an oil rig, offshore platform, or oil production platform, is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms will also have facilities to accommodate the workers, although it is also common to have a separate accommodation platform linked by bridge to the production platform. Most commonly, oil platforms engage in activities on the continental shelf, though they can also be used in lakes, inshore waters, and inland seas. Depending on the circumstances, the platform may be fixed to the ocean floor, consist of an artificial island, or float. In some arrangements the main facility may have storage facilities for the processed oil. Remote subsea wells may also be connected to a platform by flow lines and by umbilical connections. These sub-sea facilities may include one or more subsea wells or manifold centres for multiple wells.
Offshore drilling presents environmental challenges, both from the produced hydrocarbons and the materials used during the drilling operation. Controversies include the ongoing US offshore drilling debate.
There are many different types of facilities from which offshore drilling operations take place. These include bottom-founded drilling rigs, combined drilling and production facilities, either bottom-founded or floating platforms, and deepwater mobile offshore drilling units, including semi-submersibles and drillships. They are operated in a depth of 280 ft since they are in shallow waters due to being built and anchored to this depth.

History

Jan Józef Ignacy Łukasiewicz was a Polish pharmacist, engineer, businessman, inventor, and philanthropist. He was one of the most prominent philanthropists in the Kingdom of Galicia and Lodomeria, crown land of Austria-Hungary. He was a pioneer who in 1856 built the world's first modern oil refinery.
Around 1891, the first submerged oil wells were drilled from platforms built on piles in the fresh waters of the Grand Lake St. Marys in Ohio. The wide but shallow reservoir was built from 1837 to 1845 to provide water to the Miami and Erie Canal.
Around 1896, the first submerged oil wells in salt water were drilled in the portion of the Summerland field extending under the Santa Barbara Channel in California. 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 since 1913 and Caddo Lake in Louisiana in the 1910s. Shortly thereafter, wells were drilled in tidal zones along the Gulf Coast of Texas and Louisiana. The Goose Creek field near Baytown, Texas, is one such example. In the 1920s, drilling was done from concrete platforms in Lake Maracaibo, Venezuela.
The oldest offshore well recorded in Infield's offshore database is the Bibi Eibat well which came on stream in 1923 in Azerbaijan. Landfill was used to raise shallow portions of the Caspian Sea.
In the early 1930s, the Texas Company developed the first mobile steel barges for drilling in the brackish coastal areas of the gulf.
In 1937, Pure Oil Company and its partner Superior Oil Company used a fixed platform to develop a field in of water, one mile offshore of Calcasieu Parish, Louisiana.
In 1938, Humble Oil built a mile-long wooden trestle with railway tracks into the sea at McFadden Beach on the Gulf of Mexico, placing a derrick at its end – this was later destroyed by a hurricane.
In 1945, concern for American control of its offshore oil reserves caused President Harry Truman to issue an Executive Order unilaterally extending American territory to the edge of its continental shelf, an act that effectively ended the 3-mile limit "freedom of the seas" regime.
In 1946, Magnolia Petroleum drilled at a site off the coast, erecting a platform in of water off St. Mary Parish, Louisiana.
In early 1947, Superior Oil erected a drilling/production platform in of water some 18 miles off Vermilion Parish, Louisiana. But it was Kerr-McGee Oil Industries, as operator for partners Phillips Petroleum and Stanolind Oil & Gas, 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 British Maunsell Forts constructed during World War II 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 and the Mersey estuary.
In 1954, the first jackup oil rig was ordered by Zapata Oil. It was designed by R. G. LeTourneau and featured three electro-mechanically operated lattice-type legs. Built on the shores of the Mississippi River by the LeTourneau Company, it was launched in December 1955, and christened "Scorpion". The Scorpion was put into operation in May 1956 off Port Aransas, Texas. It was lost in 1969.
When offshore drilling moved into deeper waters of up to, fixed platform rigs were built, until demands for drilling equipment was needed in the to depth of the Gulf of Mexico, the first jack-up rigs began appearing from specialized offshore drilling contractors such as forerunners of ENSCO International.
The first semi-submersible resulted from an unexpected observation in 1961. Blue Water Drilling Company owned and operated the four-column submersible Blue Water Rig No.1 in the Gulf of Mexico for Shell Oil Company. As the pontoons were not sufficiently buoyant to support the weight of the rig and its consumables, it was towed between locations at a draught midway between the top of the pontoons and the underside of the deck. It was noticed that the motions at this draught were very small, and Blue Water Drilling and Shell jointly decided to try operating the rig in its floating mode. The concept of an anchored, stable floating deep-sea platform had been designed and tested back in the 1920s by Edward Robert Armstrong for the purpose of operating aircraft with an invention known as the "seadrome". The first purpose-built drilling semi-submersible Ocean Driller was launched in 1963. Since then, many semi-submersibles have been purpose-designed for the drilling industry mobile offshore fleet.
The first offshore drillship was the CUSS 1 developed for the Mohole project to drill into the Earth's crust.
As of June, 2010, there were over 620 mobile offshore drilling rigs available for service in the competitive rig fleet.
One of the world's deepest hubs is currently the Perdido in the Gulf of Mexico, floating in 2,438 meters of water. It is operated by Shell plc and was built at a cost of $3 billion. The deepest operational platform is the Petrobras America Cascade FPSO in the Walker Ridge 249 field in 2,600 meters of water.

Main offshore basins

Notable offshore basins include:
Larger lake- and sea-based offshore platforms and drilling rig for oil.
  • 1) & 2) Conventional fixed platforms
  • 3) Compliant tower
  • 4) & 5) Vertically moored tension leg and mini-tension leg platform
  • 6) Spar
  • 7) & 8) Semi-submersibles
  • 9) Floating production, storage, and offloading facility
  • 10) Sub-sea completion and tie-back to host facility
Note that jack-up drilling rigs, drillships, and gravity-based structures are not pictured here.

Fixed platforms

These platforms are built on concrete or steel legs, or both, anchored directly onto the seabed, supporting the 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. Various types of structures are used: steel jacket, concrete caisson, floating steel, and even floating concrete. Steel jackets are structural sections made of tubular steel members, and are usually piled into the seabed. To see more details regarding design, construction and installation of such platforms refer to: and.
Concrete caisson structures, pioneered by the Condeep concept, often have in-built oil storage in tanks below the sea surface. These tanks were often used as a flotation capability, allowing them to be built close to shore 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.

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.

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. The "conventional" TLP is a 4-column design that looks similar to a semisubmersible. Proprietary versions include the Seastar and MOSES mini TLPs; they are relatively low cost, used in water depths between. Mini TLPs can also be used as utility, satellite or early production platforms for larger deepwater discoveries.