Crude oil is a liquid mixture of hydrocarbons and various other chemical compounds. This mixture of hydrocarbons is also commonly known as petroleum, and is referred to as sweet when it has a low sulfur content. Petroleum can have a wide variety of different physical makeups, but the lack of sulfur results in it having a somewhat sweet taste. This type of petroleum is typically used to make gasoline and diesel, since it tends to yield high quantities of naptha and fuel oil during refinement. Sweet crude oil originates from many different places around the world, including the United States, the North Sea and North Africa.
There are two main factors typically used to differentiate one type of crude oil from another. The first is whether it is heavy or light, and refers to the specific gravity of the petroleum. Lighter oil is easier to pump out of the ground and transport, so it typically costs more money to bring heavy crude to market. The other descriptor is based on the sulfur content of the crude, and petroleum that has a sulfur content of greater than 0.5% is typically referred to as sour. Sweet crude oil possesses a sulfur content lower than 0.5% and typically also has a pleasant smell and sweet taste.
Sweet crude oil is usually considered to be more desirable than sour crude, largely due to the chemical makeup traditionally associated with this type of oil. Large quantities of the hydrocarbons that are necessary for the production of gasoline and diesel fuel are typically present in sweet crude. This means that the fractional distillation of sweet crude tends to result in larger amounts of naptha, fuel oil and kerosene than are typically recovered from sour crude. Naptha is a feedstock that can be used to make high octane gasoline, while diesel is just one of the many grades of fuel oil.
Many different areas around the world produce sweet crude oil. The United States extracts light, sweet crude from areas such as West Texas, Louisiana and Appalachia, and South America has reserves in the Guyana-Suriname Basin and elsewhere. Some of the largest sweet crude reserves in the world are in northern Africa, particularly Libya. The North Sea between the United Kingdom and continental Europe also contains many wells that draw sweet crude. A number of other areas around the world also have sweet crude oil reserves, including the Indian subcontinent, many other Asian countries, and even areas in Oceania such as Australia and New Zealand.