What is black gold

oil

How oil came about millions of years ago

Crude oil is a mixture of substances to be found in the earth's crust, which is created by the conversion of organic substances. Petroleum mainly consists of carbon-hydrogen compounds. Dead marine organisms that have been deposited on the ocean floor over the course of several million years are transformed into digested sludge in the absence of oxygen. This was covered by further marine deposits and, under pressure and heat, converted into crude oil and natural gas by anaerobic bacteria.

The search for the black gold

Oil deposits are mostly found in layers of sandstone, limestone and dolomite stone. These rock layers contain pore spaces that are filled with water. When the oil there comes into contact with the water in the pores, it rises - until it hits an impermeable layer. There it accumulates and forms a deposit.

Geologists and geophysicists search for such deposits, mostly using reflection seismics. Small blasts on the ground generate vibrations that spread like waves and are reflected at the layer boundaries. These reflected waves are measured and recorded in a seismogram and then evaluated. Using this data, a profile section of the subsurface can be created, which provides information about the possible existence of oil deposits.

Oil drilling on and in the sea

Ultimately, only a test well can prove whether a crude oil deposit has actually been found. With the help of a derrick, the drill pipe is driven into the ground. At the head of the rod is a chisel that smashes and removes the rock. Flushing pumps press water between the borehole and the rods, which removes the loose rock and in connection with it forms a solid covering for the borehole wall, so that the borehole remains stable and does not collapse.

Crude oil is not only extracted on land, but also in the sea. In the so-called "off-shore extraction", oil deposits that are located under water are tapped. This form of extraction is more costly and labor-intensive: drilling rigs floating on the sea have to be set up.

Oil means wealth - but the deposits are finite

If one finally encounters crude oil, it can shoot out in a high fountain, since the pressure in the deposit is quite high. When the pressure drops, the oil is pumped to the surface. Before the crude oil is finally transported in pipelines, oil tankers or tank wagons from the production sites to the customers, it is prepared in several stages for further processing.

The most important oil producing countries are Saudi Arabia, Russia (Siberia), the USA, Mexico, Iran, China, Venezuela, Norway, Great Britain, Canada, the United Arab Emirates, Iraq, Kuwait and Nigeria. These countries generate most of their income from the production and sale of oil. There are German occurrences in Lower Saxony and Schleswig-Holstein. But they are insignificant in an international comparison. The world's proven oil reserves amounted to around 236 billion tons in 2012. However, this information is fraught with some uncertainties.

Since the oil reserves run out sooner or later, but more and more energy and industrial products are generated with them, the oil price is rising continuously. These price increases are not only evident in the crude oil market, but also in consumer pockets. Heating oil, gasoline and even traveling by plane will therefore tend to be more expensive - even if the price of crude oil can fluctuate sharply in the short term.

The universal oil: processing and use

The crude oil obtained is subjected to fractional distillation in refineries and is broken down into its various components. To do this, the oil is heated to over 350 degrees Celsius. All of its constituents, whose boiling point is below this temperature, change into a gaseous state. The individual components can be separated from one another through gradual condensation and further processing. Gases (methane, ethane, propane and butane), gasoline, kerosene (aviation turbine fuel), diesel fuels and light heating oil are obtained from crude oil. The remaining residues are used to produce lubricating oils, heavy heating oil, heavy oil and bitumen.

The individual components make it clear how diverse the fields of application of crude oil are. It is used to produce fuel for almost all modes of transport and as heating oil for factories and households. Power plants use it to produce electricity, and in the chemical industry, petroleum components are used to make plastics, dyes, detergents, pharmaceuticals and many other chemical compounds.

The oil grades Brent and WTI

There is no single, globally binding oil price. As with apples or automobiles, oil has different varieties from different manufacturers that can fetch different prices in different places. The lighter and the lower the sulfur ("sweeter") the crude oil, the more valuable it is, as it can be processed more easily. More gasoline and diesel can be obtained from these light and low-sulfur oils than from heavy, high-sulfur oils.

Because of the many different grades, three reference grades (benchmarks) have emerged in the oil trade, which simplify the trading business: Brent for Europe, WTI for the USA and Dubai Crude for oil from the Gulf towards Asia.

The North Sea variety Brent

The European lead variety Brent is named after a British oil field in the North Sea. In fact, it is a mixture (blend) of different oils from the North Sea, all of which are of very high quality. Brent is mainly traded on the London commodity exchange ICE, the majority of which is consumed in Europe.

West Texas Intermediate (WTI)

WTI stands for the oil blend West Texas Intermediate (also called Texas light sweet). It's even better than Brent and comes from sources on the US Gulf Coast and the Midwest. WTI almost exclusively supplies the US market. Brent and WTI prices differ. Traditionally, WTI is a bit more expensive because of the better quality. However, since the delivery areas for Brent and WTI are far apart, the price relationship can also be reversed due to the local situation of supply and demand.