Types of Crude Oil

Types of crude oil are commonly determined by location of its origin e.g., "West Texas Intermediate, WTI" or "Brent") and by its relative weight (API gravity) or viscosity ("light", "intermediate" or "heavy"); refiners may also refer to it as "sweet", which means it contains relatively little sulfur, or as "sour", which means it contains substantial amounts of sulfur and requires more refining in order to meet current product specifications.

The fact is; each crude oil has unique molecular characteristics which are understood by the use of crude oil assay analysis in petroleum laboratories. Actually, classification of crude oil types by geographical source generally offer little information about general toxicity, physical state and other changes that occur with weather and time.

Now let’s look at different types of crude oil according to relative weight or viscosity and according to location of its origin:

Crude Oil Types according to relative weight or viscosity

Light crude oil

Type of crude oil known as Light Crude oil is liquid petroleum that has low density and that flows freely at room temperature. It has low viscosity, low specific gravity and high API gravity of about 37 and 42 degrees due to the presence of a high proportion of light hydrocarbon fractions. It generally has low wax content as well.

Medium Crude Oil

The type of crude oil known as Medium Crude is also a liquid petroleum that has low density, low viscosity, low specific gravity but with an API gravity between 22 and 38 degrees.

Heavy Crude Oil

Heavy crude oil type is any type of crude oil which does not flow easily. It is referred to as “heavy” because its density or specific gravity is higher than that of light crude oil. Heavy crude oil has been defined as any liquid petroleum with API gravity less than 20°.

Extra Heavy Crude Oil
Type of crude oil known as Extra heavy oil is defined with API gravity below 10.0 °API (API gravity, is a measure of how heavy or light a petroleum liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks. )

Crude Oil types according to sulfur content

Type of crude oil with less than 0.42% sulfur is designate as sweet crude oil while the types containing higher levels of sulfur is called sour crude oil.

Light, sweet crude is more expensive than heavier, sourer crude because it requires less processing and produces a slate of products with a greater percentage of value-added products, such as gasoline, diesel, and aviation fuel.

Heavier, sourer crude typically sells at a discount to lighter sweeter grades because it produces a greater percentage of lower value-added products with simple distillation and requires additional processing to produce lighter products.

Crude Oil Types according to location of its origin

Brent Blend

Brent Blend is light, sweet North Sea crude with an API gravity of approximately 38 and a sulfur content of approximately 0.4%. Brent Blend is used for pricing around two-thirds of the crude traded internationally. Rolling price assessments are based on physical Brent-Forties-Oseberg crude oil cargoes loading not less than 10 days ahead and loaded free on board at the named port of shipment (‘Brent Dated).

Russian Export Blend

Russian Export Blend is a medium, sour crude oil with an API gravity of approximately 32 and a sulfur content of approximately 1.2%. Its spot price is reported at Augusta, Italy, and Rotterdam, the Netherlands, which act as the two primary delivery points.

West Texas Intermediate

West Texas Intermediate, the US benchmark crude oil, is a light, sweet crude oil with an API gravity of approximately 40 and a sulfur content of approximately 0.3%. The spot price of West Texas Intermediate is reported at Cushing, Oklahoma.

Other crude oil type according to location of its origin includes:

Saharan Blend (Algeria), Minas (Indonesia), Iran Heavy (Islamic Republic of Iran), Basra Light (Iraq), Kuwait Export (Kuwait), Es Sider (Libya), Bonny Light (Nigeria), Qatar Marine (Qatar), Arab Light (Saudi Arabia), Murban (UAE) and BCF 17 (Venezuela).