The standard metric measurement system does not work in the world of wholesale deliveries of oil and oil products. Traditionally, British units are used here. First of all, such a measure of volume as a barrel is applied. What is a barrel of oil, how to convert this measure into the metric system, and why oil products are measured in this way - you will learn in this article.
What is a barrel?
The British measure existed long before the metric spread. In those distant times, objects that were always at hand served as standards for merchants and merchants. And often the arms and legs of the merchants themselves were also used. For example, units such as feet, inches, and yards correspond to the size of the foot, phalanx, or standard step of an adult. Other measures corresponded to the most common containers - for example, the word "barrel" translates as a barrel. 
Naturally, each merchant had a different barrel. Already several hundred years ago, a list of everything that is measured by barrels did not fit on one page. For merchants engaged in lively trade in different parts of the world, this state of affairs was unacceptable. Therefore, there was an urgent need to create a single measure of volume, convenient for measuring various liquids and bulk solids.
Standardization
The binding of a barrel to liters is established according to the international classification. 1 barrel in liters - 158.9. This rule applies only to liquid substances. The measure “barrel” is also applied to bulk materials, but its volume is somewhat different. 1 barrel in liters for bulk goods (grain, for example) is equal to 163.6 liters. Such an agreement is respected in all international treaties, projects of large mining and agricultural companies. Since the modern market was formed largely due to the active trade of Great Britain and the USA, the British measure of volume measurement was taken as a rule. This tradition has been preserved to this day.
Kilogram and barrel
But the question of what a barrel of oil is and how many kilograms it is, it’s a little more difficult to answer. The fact is that the internal composition and physico-chemical parameters of oil are very different. Therefore, minerals obtained from various sources have different characteristics. The same problem arises when determining how much 1 barrel of oil weighs in tons. In order to clarify the issue, we consider the density of liquid hydrocarbons of common varieties. Trading on these brands is conducted on all international exchanges.
Density
The properties of oil make it possible to determine its density by standard parameters. At the same time, there is a special unit that determines the density and attaches it to the melting temperature. Therefore, it is quite possible to set another parameter - API degrees. It was developed by the American Petroleum Institute and is used for all commercial varieties of petroleum products. An approximate concept of what a barrel of oil is in kilograms can be obtained based on the API parameter.
Top oil brands
The most common is the Brent brand oil mix. Thanks to reliable sources and long-term interest of buyers, this brand is considered a reference. More than 70% of all sold varieties of oil are guided by the cost of Brent. This oil is considered light. On average, a barrel of such oil weighs 132 kg; its density in the metric system is 825-828 kg / m 3 kg or 38.6 ° -39 ° API.
Another reference oil is WTI (West Texas Intermediate). This is the western hemisphere reference oil. Light oil with low sulfur content. Its density is 827 kg / m3 or 39 ° API.
Russian grades of oil
Russia is one of the largest suppliers of oil and oil products. Developed fields produce high sulfur oil. Such oil belongs to the "heavy" grades, its cost is traditionally slightly lower than light. This is because heavy oil refining requires additional refining cycles. Exported varieties of Russian oil - Urals, Siberian Light, Espo and others.
Urals brand oil has the largest share in exports. It is a mixture of hydrocarbons from all fields of the Russian Federation. Its density is 860-871 kg / m3. One barrel of "black gold" of this brand weighs about 137.3 kg.
Siberian Light oil is one of the light export grades. It is mined in the Khanty-Mansi Autonomous Okrug. Its density is 850 kg / m3, according to API standards -36.5 °. One barrel of such oil weighs about 135 kg.
The Espo brand is tied to Arabian varieties. Oil of this brand is supplied through the East Siberian oil pipeline to Asian countries. Its density is 34.8 ° API; one barrel of Espo oil weighs about 135 kg.
As you can see, the question of what a barrel of oil is, it is difficult to give a definite answer. It all depends on the brand of oil and its density. These basic characteristics form the cost of sales of "black gold" in all world markets and predict the level of production of this mineral in the near and medium term.
