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Oil and gas

An oil port and refinery Oil is used as a fuel in power stations, cars, ships and aircraft. It is also essential for many chemical industries. Natural gas is used for domestic heating and cooking, generating electricity and fuel for vehicles. Like coal, oil and gas are fossil fuels: they come from the remains of tiny plants and creatures that lived in the oceans millions of years ago. Their remains accumulated on the seabed and slowly turned into oil and gas. About one fifth of the world’s oil supply is still found under the sea. It is extracted using oil platforms.


Formation of oil

Oil and gas were formed in the seas millions of years ago. When the tiny plants and animals that lived in the sea died, they sank to the bottom (1) and were buried under layers of sand and silt. These were gradually compressed into layers of sedimentary rock (2). The heat action of bacteria changed the remains into crude oil, also known as petroleum, and natural gases. Formation of oil: When the plants and animals that lived in the sea died, they sank to the bottom (1) and were buried under...Read More >>Formation of oil: When the plants and animals that lived in the sea died, they sank to the bottom (1) and were buried under layers of sand and silt. These were compressed into layers of sedimentary rock (2). The heat action of bacteria changed the remains into crude oil. Pressures in the Earth force the oil up through the sedimentary rock, which has tiny holes in it like a sponge. The oil rises until it comes to a dome of hard rock, where it is trapped (3). Wells are drilled into the ground. When the drill reaches oil, the pressure may be enough to send it gushing up to the surface (4).Pressures in the Earth forced the oil up through the sedimentary rock, which has tiny holes in it like a sponge. The oil rose until it came to a layer of hard rock. If the hard rock formed a dome over the soft rock, the oil became trapped under it (3). Geologists looking for oil study the local rock formations and make test drillings. If oil is found, wells are drilled into the ground. When the drill reaches oil, the pressure may be enough to send it gushing up to the surface (4). If not, it is pumped. The crude oil from the well is sent by pipeline or tanker to a refinery.

Thunder Horse oil field is a large offshore deepwater oil field in the Gulf of Mexico, around 150 miles (240 km) southeast of New...Read More >>Thunder Horse oil field is a large offshore deepwater oil field in the Gulf of Mexico, around 150 miles (240 km) southeast of New Orleans, Louisiana. Semi-submersible platforms are supported by columns that are sufficiently buoyant to keep the structure afloat, while at the same heavy enough to keep it upright. They are anchored by chains or ropes during drilling.

Oil platform

The second tallest freestanding structure in the world (after the Burj Khalifa tower in Dubai) is the Petronius oil platform in the Gulf of Mexico. Only 75 m (246 ft) of it shows above the sea surface, but it descends 610 m (2001 ft) to the ocean floor.

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