Crude oil otherwise known as petroleum is a composition of hydrocarbons and other compounds which is usually yellow or black in color. It is extracted from the earth, formed naturally from the fossil of animals and plants. The viscosity and relative weight of crude oil varies and it can exist in either liquid or solid state. It can be light or heavy, sticky or non-sticky and for some types of crude oil, heavy flushing is required to remove it from the surfaces. Saudi Arabia, Kuwait, Qatar are major crude oil producing countries. The physical properties play a significant role in simplifying the refinement process for the conversion of crude oil into various end products.
The different Types of Crude oil have variations in viscosity and appearance from one oil field to another. The variations range in odour, color and in the basic properties and qualities. While all Types of crude oil are basically hydrocarbons, there are differences in their properties, especially in the variations in the molecular structure. The many variations may also influence the suitability of the different types of crude oil for particular products and the resulting quality of the products.
The different Types of crude oil are classified based on the American Petroleum Gravity (API) gravity and viscosity. The properties may vary in terms of proportion of hydrocarbon elements, sulfur content etc as it is extracted from different geographical locations all over the world. If the API gravity of the crude oil is of 20 degrees or less, it is graded as 'heavy', those with an API gravity of 40.1 degrees or greater than that is known as 'light' and if the oil ranges between 20 and 40.1 degrees, it is graded as 'intermediate'. Classifications are made based on the sulfur content as well. Crude oil with low content of sulfur means 'sweet' and the presence of high content sulfur is known as 'sour'. The purity of crude oil increases or decreases based on the sulfur content as sulfur is an acidic material.
One of the largest and major Classifications of Crude oil is Brent Blend, which is found in the North Sea. With an API gravity of 38.3 degrees and 0.37% of sulfur, this blend of crude oil comes from 15 various oil fields in the North Sea. Brent Blend is refined in the United States and Gulf coasts during the times of export. West Texas Intermediate (WTI) otherwise known as Texas Light Sweet, OPEC Reference Basket (ORB) and Dubai Crude are other major benchmarks or references. The deposits for West Texas Intermediate are found in Texas and Mexico whereas for OPEC Reference Basket oil is sourced from Bonny light (Nigeria), Arab light (Saudi Arabia), Basra light (Iraq), Saharan blend (Algeria) and Minas (Indonesia). Although, Brent blend is graded as a light crude oil, it is not as light as WTI.
Brent crude and Brent Sweet Light Crude are the other Classifications of Brent Blend. Again, Brent sweet Light Crude is not as light as WTI. Due to the presence of low sulfur content in Brent Blend, this can be easily refined and it is best suitable for the production of gasoline and oil products. This light grade of crude oil is also ideal for the conversion of gasoline as it contains an API gravity of 39.6 degrees and 0.24% of sulfur usually lighter than Bent crude. When compared to Brent Blend and West Texas Intermediate, the OPEC Reference Basket benchmark is a heavier blend. The lighter version of the crude oils is priced high in comparison to the crude oils that are classified as heavy.