| Oil Platform |
Article Index for Oil |
Website Links For Oil |
Information AboutOil Platform |
| CATEGORIES ABOUT OIL PLATFORM | |
| oil platforms | |
| coastal construction | |
| marine architecture | |
|
An oil platform is a large structure used to house workers and machinery needed to drill and then produce Oil and Natural Gas wells in the ocean. Depending on the circumstances, the platform may be attached to the ocean floor, consist of an Artificial Island , or be Floating . Generally, oil platforms are located on the Continental Shelf , though as technology improves, drilling and production in deeper waters becomes both feasible and profitable. A typical platform may have around thirty wellheads located on the platform and Directional Drilling allows reservoirs to be accessed at both different depths and at remote positions up to 5 Mile s (8 Kilometre s) from the platform. Many platforms also have remote wellheads attached by Umbilical connections, these may be single wells or a manifold centre for multiple wells. HISTORY The Thames Sea Forts of World War II are considered the direct precedessors of modern offshore oil 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. {Link without Title} The first oil platform in the world is the s) offshore on the Caspian Sea . The most unique feature of the Oil Rocks is that it is actually a functional city with a population of about 5000. The Oil Rocks is a city on the sea, with over 200 km of streets built on piles of dirt and landfill. Most of the inhabitants work on shifts; a week on Oil Rocks followed by a week on the shore. TYPES Larger lake- and sea-based oil platforms and Oil Rig s are some of the largest moveable man-made structures in the world. There are several distinct types of platforms and rigs:.
under construction in Norway . Almost all of the structure will end up submerged.]]
ESPECIALLY LARGE EXAMPLES The Petronius Platform is an oil and gas platform in the Gulf Of Mexico , which stands 2,000 Feet above the ocean floor. This structure is partially supported by buoyancy. Depending on the criteria it may be the World's Tallest Structure . The Hibernia platform is the world's largest oil and gas platform, located on the Jeanne D'Arc basin, in the Atlantic Ocean off the coast of Newfoundland . The ''Gravity Base Structure'' (GBS), which sits on the ocean floor, is 364 feet high and has storage capacity for 1.3 million barrels of crude oil in its 278.8 foot high caisson (Dorel Iosif). The platform acts as a small concrete island with serrated outer edges designed to withstand the impact of an Iceberg . 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 s. The platform stands 734 feet high, which is half the height of New York's Empire State Building (1473) and 108 feet taller than the Calgary Tower (626.6 feet). 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 Storage Unit and/or tanker loading facility. Elements in the oil/gas production process include Wellhead , Production Manifold , Production Separator , Glycol process to dry gas, Gas Compressor s, Water Injection Pump s, Oil/gas Export Metering and Main Oil Line pumps. All production facilities are designed to have minimal environmental impact. Larger platforms are assisted by smaller ESVs (emergency support vessels) like the British Iolair that are summoned when something has gone wrong, ''e.g.'' when a Search And Rescue operation is required. During normal operations, PSVs (platform supply vessels) keep the platforms provisioned and supplied, and AHTS Vessels can also supply them, as well as tow them to location and serve as standby rescue and firefighting vessels. CREW The size and composition of the crew of an offshore installation will vary greatly from platform to platform. Because of the cost intensive nature of operating an offshore platform, it is important to maximise productivity by ensuring work continues 24 hours a day. This means that there will essentially two complete crews onboard at a time, one for day shift and the other for night shift. Crews will also change out at regular intervals, nominally two weeks. Essential personnel
Incidental personnel
DRAWBACKS Risks The nature of their operation — extraction of volatile substances sometimes under extreme pressure in a hostile environment — has risk and frequent accidents and tragedies occur. In July 1988 , 167 people died when Occidental Petroleum 's Alpha offshore production platform, on the Piper field in the North Sea , exploded after a gas leak. The accident greatly accelerated the practice of housing living accommodation on self-contained separate rigs, away from those used for extraction. However, this was, in itself, a hazardous environment. In March 1980 , the ' Flotel ' (floating hotel) platform Alexander Kielland capsized in a storm in the North Sea with the loss of 123 lives. Given the number of grievances and conspiracy theories that involve the oil business, and the importance of gas/oil platforms to the economy, they are in the United States seen as potential terrorist targets. Agencies and military units responsible for maritime counterterror in the US ( Coast Guard , Navy SEALs , etc.) often train for platform raids. Ecological effects In British waters, the cost of removing all platform rig structures entirely was estimated in 1995 at $345 billion, and the cost of removing all structures including pipelines — a so-called "clean sea" approach — at $621 billion. Crewed platforms also generate domestic waste associated with day-to-day living; throwing this waste directly into the sea is usually the most convenient and cost-effective form of disposal for the crew. Garbage bags thrown overboard can pose a threat to local wildlife as well as divers that work in the area. Enormous amounts of waste can accumulate on the sea floor surrounding long-lived platforms. Further effects are the leaching of Heavy Metals that accumulate in buoyancy tanks into water; and risks associated with their disposal. There has been concern expressed at the practice of partially demolishing offshore rigs to the point that ships can traverse across their site; there have been instances of Fishery vessels snagging nets on the remaining structures. Proposals for the disposal at sea of the Brent Spar , a 449 ft tall storage buoy (another true function of that which is termed an oil rig), was for a time in 1996 an environmental '' Cause Célèbre '' in the UK after Greenpeace occupied the floating structure. The event led to a reconsideration of disposal policy in the UK and Europe. In the United States, Marine Biologist Milton Love has proposed that oil platforms off the California coast be retained as Artificial Reef 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. In the Gulf Of Mexico , more than 200 platforms have been similarly converted. TALLEST OIL PLATFORMS
SEE ALSO
REFERENCES EXTERNAL LINKS
|
|
|