Sometimes referred to as offshore platforms or oil rigs (which is incorrect), oil platforms are usually large structures equipped with facilities needed to extract oil out of the ground below the sea floor. They also extract natural gas and can either process it on site or temporarily store it before shipping it to another facility (usually a refinery) for further processing. Of course, oil platforms also contain workers’ quarters too.
There are many types of oil platforms in use today. Maybe the easiest way to differentiate them is to divide them into three categories: platforms fixed to the ocean bed, platforms built on artificial islands and floating platforms.
History of offshore platforms
The first drilling from submerged oil wells took place at the end of the 19th century, it was in 1891, to be exact. The Grand Lake St. Marys reservoir in Ohio, built as a way to supply water to the Miami and Erie Canal, was the place. Salt water platforms were raised in California in 1896, the Summerland field. The workers used the existing piers which extended into the channel to drill the wells.
By the early 20th century, offshore drilling became a common practice around Lake Erie, Caddo Lake in Louisiana and all along the coast of the Gulf of Mexico, in Texas and Louisiana. At first, these drilling operations were set up in shallow waters, only a few meters deep. We had to wait until the 1940s to see the first offshore platform which could not be seen from the shore. This was the Magnolia company platform set up around 18 miles away from the coast, but still in shallow water.
Types in use
There are several types of oil platforms which engineers use all around the world. The typical, traditional design are the fixed platforms. They sit on concrete or steel legs anchored straight into the sea floor. These platforms are immobile and they are meant to be used for long periods of time. One more type whose design feature is also sea floor anchoring are the compliant towers oil platforms.
A whole range of floating platforms exists, such as the semi-submersibles, jack-up rigs, drillships, tension-leg platforms and other floating production systems.
Largest oil platforms in the world
The largest oil platform in the world, regarding weight, is the Hibernia platform set up off the coast of Newfoundland. It is a gravity-based structure, meaning it is anchored to the ocean bed. It has enormous storage capacities: up to 1.3 million barrels of oil. It is, basically, a small island made of concrete and steel.One more example is the Petronius Platform built in the Gulf of Mexico. A compliant tower structure, it stands at about 600 meters above the sea, making it one of the world’s tallest structures.
Finally, Royal Dutch Shell company is building the first oil platform of its kind about 200km off the coast of Australia, and it should be finished around 2017. This will be the largest floating platform in the world, almost 500 meters long and 75 meters wide.