There are diverse ways to bring oil to the surface .In some cases, the water that may surround the oil, pushes the floating oil layer into the well. In other cases, the surrounding gas pushes the oil to the surface. In early days the gas that arrives with the oil was flared, but more recently it is recovered and utilized or pumped back into the oil bearing strata. In rare cases water is pumped down to assist in oil recovery.
As mentioned under Exploratory Drilling, when the well is completed regulators are attached to the well head to assist in normalized oil flow. The drilling rig is dismantled and the well may be equipped with a pump. The oil obtained at this stage is called crude oil. From the well the oil is transported by several different means, pipelines, railcars tank trucks, etc. to the storage facilities and subsequently to the oil refinery.
Production from Seafloor
When oil is found on the seafloor, a floating or anchored drilling platform is built. These “island” platforms can be found in many locations above continental shields. Due to the complexity of the drilling, these platforms are more expensive to build and add to the cost of the oil production. Often, large drilling and service crews are also housed on these platforms with all the amenities of life, including medical care.
Originally sub-sea wells were drilled from specially equipped ships, but this method was overtaken by special floating or anchored platforms which can withstand significant wave action. However the time form planning to execution of an island structure can be up to one year.
In shallow water, up to about 30 meters of depth, the structures are typically are fixed to the ocean floor, while at depths to about 90 m platforms built on stilts are used. These are generally built on land and rowed to the site, where the stilts are fixed to the ocean floor.
More complicated are the most recent deep water platforms, which are adjusted by undersea radio stations which indicate the wave direction and action to be anticipated by the platforms. Technology developed for oil drilling platforms is anticipated to be applied in the future for other application also.
Due to the distance between oil production and oil use areas, large quantities or crude oil is transported. Transport is common by pipelines both above land and underwater, the current length of oil pipelines is above 1 million km and several lines of 50 000 km lengths are in planning. Between continents, oil transport is by large tanker vessels which can carry up to 600 000 tons of crude in double shelled hulls. These large tankers require complex land facilities also for loading and unloading. These tankers are used both for shipping crude oil and other processed petroleum products.
The refining of oil
Crude oil is a mixture of many substances. In the oil refinery during processing, oil is divided into various ingredient groups used for different practical aims. In the course of the oil's preparation, dissolved gases are removed, is dehydrated and desalinated, and then the volatile substances are distilled from the dehydrated oil. After the oil has been stabilized, division starts with a method called fractionized distillation. This happens in a high tower. Crude oil is heated so that most of its ingredients boil and become steam. The steams in the tower rise upward, whilst they gradually cool down until they condense. Different substances condense at different temperatures, thus pouring out of the tower at different altitudes. The end products of oil refining among others are benzene, kerosene, diesel oil, and lubricants.
According to their boiling points the benzene separates first, then the petroleum, diesel oil, and lube oil. The remaining part is the pakura. In the course of distillation a gas similar to natural gas arises. A part of the fluids created as the end product of distillation are too dense and heavy to directly make use of. With a method called cracking however, the large molecules are sliced to smaller pieces thus gaining more benzene and oil from crude oil.
In the first decades of modern oil distillation (1810-1885) they aspired solely to gain petroleum from crude oil. Later lube oil, then from the 1890s benzene and shortly diesel oil was harnessed. From the 1920s the oil processing consisted not only of the aforementioned refining, but with large-scale industrial processes meaning chemical changes, desired composition carbohydrate mixtures are produced from crude oil.
In 1996 Saudi Arabia stood at the top of the world list with 3039 billion barrels of oil, with USA on second place. Russia lagged behind by little, followed by Iran, China, Norway, Venezuela, Mexico, Great-Britain, the United Arab Emirates and Kuwait. The rate of exploitation is also defined by the demand. The world-scale economical depression in the beginning of the 1990s caused a drastic fall in oil mining.
Whereas crude oil is such a useful and sought substance, its production increased by leaps and bounds amidst 1950-1990, from 10 million barrels a day to 65 million barrels. During these four decades world economy became totally dependent on oil, both as a raw material and energy source. In some countries oil was so cheap that nothing prevented its wasteful usage.
The utilization of oil
Economically oil is also important because it is cheaper and cleaner than coal and easier transportable than gas. It's no coincidence that it's called the Black Gold. By burning it, 40% of the world's energy usage is produced. Without oil, transport would be paralyzed, the factories' machinery wouldn't work and neither the central heating system of many buildings.
Several types of fuel are made by distillation, cracking the oil's periodical or higher carbon valence carbohydrates, thus the different octane number benzenes, the diesel oil or the kerosene used on airplanes. From it they also produce lube oils and lubricants, which are indispensable for the operation of mechanical engines. Asphalt is also made from oil, just as many petrochemical products that are later used by the chemical industry. From these compounds vast types of cosmetics, medicine, coloring matter and paint, several types of fertilizers, pesticide, explosives, fibers (nylon), plastic and the artificial rubber used in tires are made.